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MINUTES OF PKOCEEDINGS

THE INSTITUTION

CIVIL ENGINEERS;

WITH OTHER

SELECTED AND ABSTRACTED PAPERS.

Vol. XCV.

EDITED BY

JAMES FOREEST, Assoc. Inst. C.E., Secretary.

LONDON:
Publtsl)el) bg tfje Snstituttcn,

25, GREAT GEORGE STREET, WESTMINSTER, S.W.

[Telegrams, "Institution, London." Telephone, "3051."]

1889.

[The right of Publication and of Translation is reserved.]

ADVEETISEMENT.

The lastitution as a body is not responsible eitlier for tlie statements
made, or for the opinions expressed, in the following page-s.

LONDOS; PltlNTED BY WILLIAM CLOWES Aim SONS, LmiTED, STAUFOnL SIEBET AND CIIABINC CBOaS.

CONTENTS.

Sect. I.— MINUTES OF PROCEEDINGS.

13 and 20 November, 1888.

PAGE

" Friction-Brake Dynamometers." By "W. W. Beaumont. (18 cuts) . . 1

Discussion on ditto. (14 cuts) 29

Correspondence ou ditto. (4 cuts) 70

27 November, 1888.

" The Witham New Outfall Channel and Improvement Works." By J. E.

Williams. (1 plate) 78

Appendixes to ditto. (1 cut) 87

Discussion on ditto. (1 cut) 92

Correspondence on ditto. (2 cuts) 105

4 and 11 December, 1888.

Transfer of Associate Members to the class of Members 112

Admission of Students 112

Election of Members, Associate Members, and Associates 11^

" On the Influence of Chemical Composition on the Strength of Bessemer-
Steel Tires." By J. 0. Arnold. (11 cuts) 115

Discussion on ditto 131

Correspondence on ditto 160

18 December, 1888.

" The Friction of Locomotive Slide-Valves." J. A. F. Aspinall. (3 plates) 167

Discussion on ditto (11 cuts) 179

Correspondence on ditto 194

IV CONTENTS.

Sect. II.— OTHER SELECTED PAPERS.

PAGE

" Preliminary Survey in New Countries, as exemplified in the Survey of

Windward Hawaii." By T. G. Gribblb 195

Appendixes to ditto. (3 cuts) 202

" Rapid Surveying." By F. D. Topham 209

" The Practice of Survepng in the Australasian Colonies." S. K. Vickehy 211

Appendixes to ditto (1 cut) 215

" The Manufacture of Oil-Gas on the Pintsch System, and its Application
to the Lighting of Railway Carriages." By G. M. Hunter. (1 plate.

Scuts) 218

Appendix to ditto 228

" Hurst's Triangtilar Prismatic Formula for Earthwork compared with the

Prismoidal Formula." By J. W. Smith. (11 cuts) 229

" Alpine Engineering." By L. F. Verxon-Haecourt. (2 plates, 1 cut) . 237

Appendix to ditto 278

" The River Clyde." By D. Macalister 279

" The Failure of the Kali Nadi Aqueduct on the Lower Ganges Canal."

Abstracted by W. H. Thelwall 283

" The Reparation of Betchworth Tunnel, Dorking, on the London, Brighton

and South Coast Railway." By G. Lopes. (5 cuts) 291

" The Permanent-Way of some Railways in Germany and in Austria-
Hungary." Translated and Abstracted by W. B. Woethington . . . 303
" The Speed-Trials of the latest additions to the Admiral Class of British

War- Vessels." By D. S. Capper. (1 plate, 5 cuts) 325

Appendix to ditto 343

♦* On the Use of Heavier Rails for Safety and Economy in Railway TraflBc."

By C. P. Sandberg. (1 plate, 1 cut) 354

Obituary 360

Viscount Eversley, 360 ; John Brown, 361 ; William Armitage Brown,
363 ; Henry Carr, 364 ; Robert Denny, 369 ; James Easton, 370 ; John
Fowler (of Stockton), 371 ; William Francis, 374 ; Frank Alexander
Brown Geneste, 375 ; Charles Markham, 377 ; Julius Pazzani, 379 ;
William Rogers, 380 ; George Hennet Ross, 382 ; Ranson Colecome
Batterbee, 383; James John Alexander Flower, 384; Samuel Harpur,
385; Ernest Frederic Morant, 387; Robert Pinchin, 388 ; Charles Thomas
Spencer, 391 ; John Trickett, 392 ; John Wakeford, 393 ; Herbert Francis
Waring, 394 ; John Ashworth, 394 ; Major Augustus Samuel William
Connor, 396 ; George HawMns, 397 ; Staif Commander Graham Hewctt
Hills, 398.

CONTENTS.

Sect. III.— ABSTRACTS OF PAPEES IX FOREIGN TRANSACTIONS
AND PERIODICALS.

PAGE

New Theory of Friction. N. Peteofp 407

On the Critical Extension of Bodies strained simultaneously in Several

Directions. — Wehage 410

Landslip at Zug, Switzerland, 5 July, 1887 411

A Folding Levelling-Stafif. H. Bentabol 415

The Alignment of a Tunnel at Stuttgart. — Widmann 415

Methods of Testing the Resistance of Stones, Cements, and other Building

Materials. L. Durand-Clate 416

On the Testing of Paper. N. Haselkoos 420

Yield of Hydraulic Mortars. — Bonnami 421

Pulverization of Clay and its Application at the Works of the Societe

Arnaud Etienne & Cie. C. Bidois 422

Stone-cutting and Quarrying by "Wire 424

The Theory of Jointed Bow-Girders. E.A.Werner 426

Experiments on a New Form of Strut. C. L. Strobel 428

Highway Bridges of Iron and Steel 430

Inspection and Maintenance of Railway Structures 432

The Garahit Viaduct. G. Eiffel 434

The Bridge over the Po at Casalmaggiore for the Parma-Brescia Railway . 438
Erection of the Large Girders of the Machinery Hall at the Paris Exhibi-
tion of 1889. E. Henard 440

Reports of the French Delegates on the Proceedings of the Second Inter-
national Inland Navigation Congress, held at Vienna in 1886 .... 441
Measurements of the Flow of the Elbe in Saxony, 1886 and 1887. A.

RiNGEL 444

Regulation of the Isar according to Wolf's Method. R. Iszkowski . . . 445
On the Improvement of the River Moldau at Prague, and the Construction

of a Port there 447

Special Plant for Blasting under Water at the Panama Canal Works. Max

DE Najjsouty 448

The Embankment of the Po at Turin. T. Prinetti 449

Jandin's Compressed-Air Dredger. M. Boulle 450

Renewal of the Water in the Hague Canals. M. R. von Pichlek . . . 450

The Cable Railway on the New York and Brooklyn Bridge. G. Leveeich 453

The New Harbour Works at La Rochelle 454

The Qualities of Potable Waters 457

Water-Supply in the Kingdom of Wurtemberg. J. R 458

Facts in Relation to Friction, Waste and Loss of Water in Mains. C. B.

Brush 459

The East Orange Sewage-Works 4G0

On the Disinfecting Action of a Current of Superheated Steam. Prof M.

Gruber . . 4G1

Elucidation of the Disinfccting-Power of Steam. A. Walz .... 462

Comparative Trials of various Gas-Burners. S. Lamansky 462

Wilmsmann's Smoke-Consuming Furnace. — Seiler 464

Raising the steamer " Forndale," sunk in the Entrance Channel of tlie Port

of St. Nazairc. • — Kerviler and — Preverez 465

VI CONTENTS.

TAGK

Consolidation of Earthworks on the Railway from Gicn to Atixcrre.

— Lethier and — Joyan 466

The Laon Steep-Gradient Railway. A. Braj^cher 468

Cost Prices on Railways. G. Ricovr 469

Signalling-Apparatus on the St. Gothard Railway. — Cox 470

Diminution of Earth Temperature in Deep Mines 471

An Apparatus for Measuring Earth-pressure Underground 471

Differences of Level in the Mines of Austria and Hungary. F. R. M. von

Friese 472

On the Relations between Seismic and Atmospheric Disturbances and the

Disengagement of Fire-Damp. G. Chesnau 473

Shaft-Sinking by Haase's Method 475

Cast-iron Tubbing for Lining Levels 476

A New Modification of the Bessemer Process 477

Electrolytic Reduction of Antimony from Ores. W. Borchees .... 478

Electrolytic Coi^per-Refining in Hungary. A. Soltz 479

The Smelting of Gold and Silver Ores in Eastern Hungary and

Transylvania. Dr. Schnabel 480

A Winding-Engine with Spiral Balance-Drum. K. Habermann and J. von

Hauer 484

On the Beer System of Wire Ropeways. C. Raovlt 485

Desrozier's New Disk-Dynamo. E. Meylan 488

Gadot Accumulators, pattern 1888. J. Laffaegue 489

Account of a Series of Experiments made on Hessner's Cell. W. Chukoloff 489

On the Measurement of the Resistance of Submarine Cables. A. Rovillard 490

Philippart's Electrical Tramcars in Paris 492

On the Telephone-Equation. C. L. Madsen 493

The Teleplione Line between Paris and Marseilles 494

The Regulation of Arc Lamps. E. Hospitalier 495

The Electric Lighting of the City of Geneva. R. Chavannes .... 496

Self-Regulating Electric Search-Light. W. E. Fein 497

Electric-Light Installation on the Armour-clad Cruiser "Admiral

Nakimofi'." Lieut. Kolokoltzoff 498

On Siemens and Halske's Electric Winding-Engine at Neu Stassfurt . . 500
On the Connecting of Lightning-Conductors with Water- and Gas-Pii3es.

L. Weber 501

The Decomposition of Salt by Electrolysis. N. N. Beketoff .... 504

The Wimshurst Machine. E. Dieudonne 504

The Glaser Influence Machine 505

Danger-Indicator for the Prevention of Collisions at Sea. P. Marcillac . 506
Studies on the Gas-Thermometer, and Comparison of the Mercury-Thenno-

meter therewith. P. Chappuis 507

The Poisonous Action of Water-Gas. H. Schiller 508

Heat of Combustion of the Coal of the North of France. — Schevrer-

ELestner 509

Index 510

CONTENTS. Vll

COEEIGENDA.

Vol. Ixxxi., p. 378, line 9 from bottom, for "millimetres " re id " metres."
„ .xciv., p. 299, line 3 from bottom, /or " 1869 " read " 1859 "; and /or " Elizabeth "

read " Eliza."
„ „ p. 381, line 6, for « 72 • 56 " read " 74 -68."
„ „ „ „ 11, /or « 84-94 " rmJ" 87 -06."

„ „ „ „ 12,7or "15-06" r^wi « 12-94."

THE

INSTITUTION

CIVIL ENGINEERS.

SESSION 1888-89.— PART I.

Sect. I.— MINUTES OF PROCEEDINGS.

13 November, 1888.

Sir GEOEGE B. BRUCE, President,
in the Chair.

The Telford and Watt Medals, the George Stephenson Medal, the
Telford Premiums, the Manby Premium, and the Miller Prizes,
awarded for the Session 1887-88 (vol. xciv. pp. 152, 153) were
presented by the President to the various recipients.

{Paper No. 2328.)

"Friction-Brake Dynamometers."

By William Worby Beaumont, M. Inst. C.E.

Although the friction-brake dynamometer can never give a
scientifically accurate measurement of the rate of absorption of
the work done upon it by any motor, it has been much used
for that purpose, with results not sufficiently incorrect to affect
materially the truth of calculations based upon them.

The indications of any apparatus depending on friction must be
as variable as the causes of friction and the conditions affecting
it, and hence the value of the measurements, obtained by means
of a friction-brake dynamometer, must depend on the completeness
with which these causes and conditions are taken into considera-
tion or are eliminated.

In a friction-brake the causes of friction are similar to those
which generally obtain in other applications of materials when
brought into rubbing contact ; but the conditions are more variable,
and are chiefly due to variation in pressure and in lubrication,
both these being affected by variation in the rate of work-absorption
and temperature.

From time to time the accuracy of the measurements of power
obtained with friction-dynamometers has been questioned ; and
this Paper is written with the object of placing such facts and
considerations before the Institution as will elicit the views which
are supported by practice among engineers.

[the INST. C.E. VOL. XCV.] B

2 BEATTMONT ON FEICTION-BEAKE DYNAMOMETERS. [Minutes of

Friction-brakes in nse, and recognized as satisfactory instruments
for the measurement of power, or as the best available, are very-
few; but as the friction-dynamometer is an instrument of great
importance to engineers and to the users of steam and other
motors, some of them will be described, with a view to comment
on those questions of principle of construction and of working,
which are primary to confidence in their indications.

The friction - brake dynamometer in nearly all its forms is
essentially that devised by Prony, an outline diagram of which
is shown in Fig. 1. Here the friction between the surface of a
wheel A, rotated by the motor whose power is to be measured, and

Fig. 1

SS^S^^5SK5^^!^SSSSS

the wood blocks W above and below the wheel, is employed in
maintaining a weight P, suspended at a point on a horizontal line
level with the centre of the wheel. The point is at some distance
above the lever B, by which the load is supported, and, in order
that the distance E from the centre of the wheel to the vertical
centre of the load may remain constant, the load is suspended
from a quadrant whose radius is E. This brake is capable of
sufficiently exact determinations of power, ranging from 5 to
200 HP., for most practical purposes, where more than a mere check
upon calculations is required ; but it presents some of the elements
of inaccuracy which pertain to the friction type of absorption-

Proceedings.] BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. 3

dynamometers, especially when used for the measurements of
variable powers. For measuring the power of a motor, capable of
running at a uniform speed with a constant load, the inaccuracy of
its indications may be very small and often insignificant ; but when
the power varies, the inertia of the lever B, and the work done
in moving it and the load P, count without record against the
motor. Moreover, a small load due to the lever, though balanced
while the lever is horizontal, constitutes a load against the motor
when the lever rises ; and the work done when this load is lifted
is also neither recorded nor measured. With a truly circular wheel
and uniform turning power, this brake gives very nearly acciirate
results, provided the lubrication between the rubbing surfaces be

Fig. 2.

K5S!SS!5^E5!5SSSSSrSSS3H!553Sl

uniformly maintained ; but slight variations in this respect, due
to variation in quantity, quality, and temperature of the lubricant
and rubbing surfaces, make it difficult to keep the tension of the
strap E in strict accord with the total friction necessary to main-
tain the load at a constant level. The frequent change of this
tension by the screws C for the purpose of meeting these variations
introduces further inaccuracy.

A simple form of friction-brake, much used as a dynamometer
in portable engine-building establishments, for testing engines by
running them against a known load before sending them out,
consists simply of a thin iron or steel strap, or a pair of straps, E,
Fig. 2, to which are attached a number of blocks W of wood.
Sometimes a leather strap is used. At H a hook is fastened to the
straps for the suspension of the load P, and at S the ends of the

B 2

4 BEAUMONT ON FRICTION -BRAKE DYNAMOMETERS. [Minutes of

strap are connected by a right- and left-handed screw for the
adjustment of the tension on the strap or pressure of the blocks W
upon the wheel A, so as to obtain the necessary frictional grip to
carry the otherwise unsupported load P. With a truly turned
wheel A, and with uniform lubrication, this brake will run for
hours with a variation of but a few inches in the level of the load
P, if the engine under test is of good design and has a fly-wheel
A of the weight many makers adopt. The variations that do occur
from several causes are, however, sufficient' to make adjustment
by the screw S necessarj^ sometimes frequently. The errors in
estimating the work done by the engine, which result from these
causes, are generally small ; but it is desirable to remove them, if
possible, when very accurate tests are required. It has been with
this object that devices for automatically varying the tension
in the belt E with the variation in the total friction have been
introduced by numerous experimenters ; and at an early date a
brake-wheel with an internal water channel was used to avoid
the mechanical difficulties which resulted from the heating of the
brake-wheel and the variations due to the heating of the lubricant.
With either of the brakes mentioned, the work in HP. done
in supporting the load P in lbs. at the distance E in feet from the
centre of the wheel A, making N revolutions in time T in minutes
will be —

H P = (I^x2)X7rxPxN
33,000 X T

or taking C = circumference of circle of radius E, and V = velocity
in feet per minute of circumference, then V = C N, and

HP= ^^^ ^^

P =

33,000 T ~ 33,000 T

33,000 HP _ 33,000 H P

C"N V

^ 33,000 HP ,-^ 33,000 HP
^=— Np-'^"^^ = — CP--

One form of automatically-adjusting or compensating brake,

suitable for small powers, is due to Mr. Deprez, and is shown at

Fig. 3. In this ^ a brake-wheel A is attached to a disk B, and to

the disk are pivoted levers EE. These levers are connected by a link

F and lever G loaded by a weight Q. The weight of the levers E E

is balanced by the quadrant-shaped counterpoise C, so that the
(

' See " Guide pour I'essai des machiues li vapour," par J. Buehetti.

Proceedings.] BEAUMONT ON PRICTION-BEAKE DYNAMOMETERS. 5

weight P is the representative of the work done by the motor, the
weight Q having no varying effect on the work done by the motor,
or on the position of the load P, so long as the lever G remains
horizontal; but as it is by the influence of Q and the lever G
that the friction-blocks W are brought to bear upon the brake-wheel
A, and as that influence decreases as G leaves the horizontal and
approaches the vertical, the weight which the frictional grip will
support decreases. Hence the brake becomes automatic in its
adjustment of the friction, the descent of the weight P increasing
the frictional grip, and correspondingly the lifting of the weight
causes a decrease in the friction, so that the weight again falls, a

Fig. 3.

position of equilibrium being ultimately taken, in which load and
friction are equal. It will be readily seen, that with any of the
causes enumerated, variation of speed of the motor, or oscillation
of the load P, the latter must be raised through some distance,
or the lever G must pass through a considerable angle before the
frictional grip of the brake-blocks is modified. The work of lifting
the load being lost work is an objection to this brake. The system
of compensation does not, however, contain any element that will
affect the load actually carried by the motor, and the only objec-
tion to the brake as a dynamometer for small powers is that the
compensation takes place so slowly that any of the errors attaching
to the simple brake (Fig. 1) remain, and adjustment must fre-

6 BEAUMONT ON FEICTION-BEAKE DTNAMOMETEKS. [Minutes of

quently be made so that the point of suspension of Q remains truly
at the centre of the brake-wheel.

A simple form of self-adjusting brake-dynamometer, due to
Mr. J. Imray, M. Inst. C.E., is shown by Fig. 4. A quadrant Q,
balanced by a weight w, receives the brake-strap carrying P. A
smaller weight p is attached to the other end of the brake-strap.
The compensating action is due to the increase in total friction
which accompanies increase of circumferential surfaces in contact.
If the motor lifts the weight P, the frictional grip is lessened as
the arc BH is lessened, and P returns or finds a position of
equilibrium.

Fig. 4.

What is spoken of as a modification of this brake consists ^ in
using a spring-balance instead of the small weight p; and in
dispensing with the quadrant Q, the wood blocks being continued
on the P side of the band, and the lower end of the sjjring being
fixed. This arrangement, also shown on Fig. 4, acts much in the
same way as Mr. Imray's brake, but the range of movement
necessary for self-adjustment will be less as the pull of the spring

' Variously attributed to Navier and to Messrs. Easton and Anderson, and to
one of Messrs. Eansomes, Sims and Head's managers ; but due, the Author be-
lieves, to Mr. H. A. Byng of the latter firm, who used it first in Paris in 1867 ;
at Brussels in 1SG8 ; at Santiago, Chile, in ISGii ; and at Cairo in 1874, where it
■sas been by Sir Frederick BramwelL

Proceedings.] BEAUMONT ON FEICTION-BEAKE DYNAMOMETEKS. 7

is lessened or increased with any movement, while the weight p
in the other case remains the same, and considerable movement
must take place so as to make a sensible difference in the total
friction due to difference of arc in contact. The spring arrange-
ment is more accurate, as every rise or fall of the weight P
decreases or increases the tension on the spring, and thus a very
small range of movement of P is sufficient to satisfy small variations
in turning moment or frictional grip.

One of the best known forms of friction-brake dynamometers,
fitted with a compensating device, is that designed by Mr. C. E.
Amos and Mr. Appold, and is the form used for the larger powers
by the Eoyal Agricultural Society. It is similar to that shown
by Fig. 2, but, besides the hand-adjusting screw S, it is provided

Fig. 5.

pj-n

with a compensating lever K as shown in Fig. 5, by means of
which the rise or fall of the load P is supposed to be attended
with a decrease, or increase, in tension on the brake-strap, so that
a position of equilibrium is automatically attained without causing
inaccuracy in the indications. With a given tension in the belt,
and with the load P carried so that its point of suspension H is
opposite the pointer T, the lever K takes a vertical position ; but
as soon as the load P is lifted, as in Fig. 6, the lever pivoted at X
moves with, and virtually increases the length of, the belt, and
thus slackens it, allowing the load again to descend. If, on the
other hand, the total friction decreases and is insufficient to carry
the load in its normal position, the descent of the load carries the
compensating lever to a position such as is shown by Fig. 7, thus

BEAUMONT ON FKICTION-BRAKE DYNAMOMETEBS. [Minutes of

tightening the belt and increasing the frictional grip until the
conditions are again such as will enable the load to reassume the
medial position. If the change in the position of the point of

Fig

Suspension of the load has been duo to a temporary cause, this
automatic action may restore the balance without further adjust-
ment ; butllif the departure from the medial position is not small,

Fig. 7.

then the adjustment by the hand-screw S must be resorted to. It
will be seen that the compensating action cannot come into play
except by the rise or fall of the weight from its proper position,

Proceedings.] BEAUMONT ON FRICTION-BBAKE DYNAMOMETERS.

and hence the value of the device is confined to its power of
limiting that rise and fall. In practice, generally speaking, the
adjustment required by means of the screw S is as necessary with
the compensating lever as without it, and its value may therefore
be questioned for this reason alone. A further reason, however,
for questioning the value of this compensating lever is that it
introduces an element of error, which may be small or consider-
able, but which must be variable almost directly in proportion
to the extent to which the lever comes into play. With a
heavily-loaded brake the error must exist, and with a lubricant

Fig. 8.

Fig. 9

Vi"-^ a

which materially lessens the total friction of the wood blocks upon
the wheel, it must amount to a considerable part of the whole
indicated power, unless adequate allowance is made for it. This
allowance has seldom been made, since it has not been necessary
with the conditions under which these friction-brakes have gener-
ally been used, namely, with the brake-strap slack as shown
exaggerated at N, Fig. 9.

When the lever does act in fulfilling its purpose, the tension in
the brake-strap causes it to press against the pivot X with a
pressure proportionate to that tension. This will be more fully
referred to hereafter.

BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

In a better form of compensating brake designed by Mr. Balk,
and used by Messrs. Eansomes, Sims and Jefferies, Fig. 10, the
compensating lever is outside, instead of ^dthin, the circumference
of the brake-strap. It is connected at B and at C to the ends of
the strap, and a fixed pin F passes through a slot at the outer end
of the lever. To the latter is suspended a scale-pan and a weight
p sufficient to keep the lever floating with the pin F midway
between the two sides of the slot. This weight jp becomes a
measure of the tension upon the belt, at least at the parts to which
it is attached ; but it must be varied with change of condition of
the brake-blocks, the lubricant and the temperature of the blocks
and wheel, and as it must be taken as acting at the radius O F
in favour of the weight P, these variations become troublesome
by virtually making P a variant.

Fig. 10.

Fig. 11 shows the larger friction-brake dynamometer used by
Messrs. Eansomes, Sims and Jefieries, and is precisely similar to the
first one of the kind which Mr. Balk perfected. The Author is in-
debted to Mr. John Jefferies for this drawing, and for the following
tabulated particulars showing the gross load, the weight on the end
of the tension or compensating lever, and the variation of the latter
with different speeds and powers. These particulars have been
taken from the records of numerous experiments made with Messrs.
Eansomes' engines by Mr. H. A. Byng. The wheel is 6 feet in
diameter, and 1 foot in width, the load being suspended from
flat steel springs or tapes, forming a tangent to a circle exactly

Proceedings.] BEAUMONT ON FKICTION-BRAKE DYNAMOMETERS.

20 feet in circumference. A counter is attached to the side of the
frame, and thrown in or out of gear by the clutch handle H. The
great advantage of this brake over all others is that the experi-
menter can always ascertain the actual load, although the tension-
lever acts as a compensating lever. There is considerable variation
in the scale-weights with the same gross load. This, Mr. Byng
explains, is due to the heating of the brake-wheel. When much
heated, more grease has to be used, and in consequence the co-
efficient of friction is reduced, and the weights in the scale have
to be augmented to give more tension in the brake-straps. The
figures appear to show that, the larger the number of revolutions,
the smaller the tension for a given total friction, and this infer-

FlG. 11.

7onciRCumFff£MCc

enco is supported by experience. Mr. Byng has found that with
the higher speeds less weight is required on the scale for a given
load, or, in other words, the higher the speed the less the necessary
tension in the brake-belt. By means of the Balk brake the
tension at the ends of the brake-belt is measured directly, and for
accurate trials a higher speed is preferred with less gross load and
with a scale- weight below 7 lbs.

The wood blocks, beech or plane-tree, of the brake above referred
to, have been in use a long time, and are now semi-charred and
saturated with grease ; the surface next the wheel has been several
times coated with black-lead, and some of the blocks have become

BEAUMONT ON FKICTION -BRAKE DYNAMOMETEKS. [MinutoB of

Table I. — The Balk Friction-Brake Dynamometer.

The folio-wing Table shows the gross load and counterbalance weights used in
trials, at various speeds and HP.

Gross Load.

On
Scale.

Effec-
tive
Load.

Revolu-
tions.

HP.

Gross Load.

Scale.

Effec-
tive
Load.

Eevoln-
tions.

HP.

Cvvt. qrs.lbs.
1 0 1

Lbs.
4

Lbs.
105

130

8-28,

Cwt
2

qrs.lbs.
1 14

Lbs.
17

Lbs.
232

134-42

18-90

0 3 22

104

152

9-40

1 22

252

125-20

19-12

1 1 8

136

128

10-59

2 20

260

123-50

19-46

1 0 24

125

145

11-00

1 16

236

136-75

19-56

1 1 17

142

140

12 -Oo'

1 18

232

139-59

19-62

1 1 10

144

138

12-07

1 16

236

144-00 20-60

1 2 1

156

131

12-40

1 8

246

150-00 21-45

1 2 14

168

136

13-94

1 16

236

160-00 22-93

1 2 4

3§

165

139

13-95

1 16

236

155-00 22-17

1 2 18

182

134

14-86

1 12

236

160-00 23-00

2 0 10

202

127

15-64

3 10

280

135-79 23 04

2 0 10

202

131

16-07

3 14

274

142-45 24-00

2 0 0

202

134

16-40

1 0

314

136-00 25-88

2 0 0

202

137

16-78

1 0

314

140 -40| 26-72

2 0 12

202

135

16-55

0 14

314

146-00 27-78

2 0 0

202

136

16-75

0 14

328

140-89 28-00

2 0 8

202

145

17-84

2 21

385

141-50 33 00

1 3 24

202

148

18-20

3 18

388

151 -22' 35-56

2 0 0

205

146

18-16

almost metallic on the surface. In starting for a set of trials, the
wheel and the blocks are thoroughly cleansed and left free of
adherent grease. As soon as the wheel gets warm, their saturated
condition supplies the necessary lubrication. For loads up to
20 HP. there is no difficulty, the Author is informed, in running
this brake all day with perhaps two alterations of the scale weights,
and by applying a very small quantity of cold tallow to the wheel
and rubbing off the excess immediately with dry waste. Mr. Byng
is of opinion that the blocks should be of metal, say Babbit,
properly ground to fit the wheel and jointed together. With such
a brake-strap he thinks some definite relation between load, tension
and velocity might be obtained.

A water-cooled brake used by Messrs. Eichard Garrett and Sons,

Proceedings.] BEAUMONT ON FEICTION-BRAKE DYNAMOMETERS. 13

Leiston, is shown by Figs. 12, 13 and 14. The wheel is 5 feet in
Fig. 12. Fig. 13.

Fig

diameter, and 11 inches wide between the flanges within which
the wood blocks run. An annular trough
is formed by internally projecting flanges
3 • 5 inches in depth. The straight form of
the Appold compensating lever is employed,
though under conditions which seldom, if
ever, bring it into play sufiiciently to affect
materially the accuracy of the indication
of the brake. The Author is indebted to
Mr. Frank Garrett, M. Inst. C.E., for some
interesting particulars concerning the work-
ing of this dynamometer. No lubricant is
now used; but the blocks, which are of
beech, are probably thoroughly saturated
with years of previous use on a wheel not
cooled by water. It has been ascertained
that the brake-wheel with the water con-
tained in it absorbs about 0*75 indicated
HP. at 180 revolutions per minute. The
circumference of the load circle is 1 7 • 5 feet, and the maximum load

BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

carried 418 lbs. Three experimental runs with this brake were
recently made by Mr. Garrett with a view to obtain figures
as to the quantity of water used, its rise in temperature, and
the relation between the work mechanically done and thermo-
dynamically accounted for by the heat conveyed to the water.
Before starting the engine-water was put into the wheel to the
full depth of the annular trough ; this water was weighed and
called A. As soon as the engine was started water was added,
which was also weighed. This second quantity, occupying a depth
of 2 inches in the internal annular trough, w^as called B. The
supply is kept up under ordinary circumstances by a pipe con-
stantly passing a small stream into the wheel. During the experi-
ments referred to, however, the water was all weighed and added
by hand, the depth of 2 inches being as far as practicable main-
tained. This quantity may be called C. When the engine is
stopped at the end of the run all the water falls out except a
quantity equal to the first quantity mentioned, namely, that which
fills the lower part of the wheel to the full depth of the trough.
During the runs the water was carefully maintained at the depth
of 2 inches, so that the quantity added during the run may be taken
as evaporated. The engine ran at 130 revolutions per minute.

Table II. — ExPERniEXTS avith Garrett's "Watee-Cooled Brake.

Trial No

Time .... minutes

Brake HP.

Water A

„ B

„ C evaporated .
Temperature t at start

T at end . .
Heat-units expended, raising!

A+B-f-CtoT . . . ./
Heat-units expended in eva-l

porating C from T . . . /
Total heat-units ....
Mechanical equivalent "i

foot-lbs./

HP. minutes

Per cent, of brake HP.

1
150
31
24 lbs.
180 „
108 „
54° Fahr.
174° „

37,440

107,244

144,684

111,696,048

3,384-4
22-53
72-6

155

24 IbB.

180 „

90 „

58° Fahr.

162° „

30,576

90,090

120,666

93,054,152

2,819-8
18-29
65-0

154
18
24 Iba.
180 „
64 „
52° Fahr.
148° „

25,728

64,704

90,432

69,813,504

2,115-5
13-73

76-27

When the loss by radiation of the frictionally developed heat is
considered, the heat represented by the water raised in tempera-
ture and evaporated, a mean of 71 • 3 per cent., must be admitted
to be a large proportion even if some deduction be made for slight
loss of water by spray.

Proceedings.] BEAUMONT ON FEICTION-BRAKE DYNAMOMETERS. 15

The Author has since made an experimental run with this brake.
The figures obtained show that the evaporation takes place at a
mean temperature of about 160^, and that of the mechanical work
done a mean of about 72 per cent, is accounted for by the water
heated and evaporated in the wheel-trough.

A form of brake used by Messrs. J. and H. McLaren, of Leeds, as
devised by Mr. Druitt Halpin, M. Inst. C.E., is shown in Figs. 15
and 16. The engine upon which it was used gave off about 20 HP.

Fig. 16.

Fig. 15.

The brake-wheel is 5 feet in diameter, and 7 inches in width.
The radius of the load circle is 32 • 19 inches. Water is constantly
supplied to the trough, and constantly taken away by a scoop pipe.
In 1886 Mr. Halpin proposed to use the Appold compensating
lever, but has since abandoned it, as introducing an error varying
with the coefficient of friction of the brake-blocks on the wheel.

As a brake which within a limited range of power might be
considered automatic, and without the errors introduced by some
of the forms of compensating action, the form shown at Fig. 17

BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

may be suggested. In this the ends of the "brake-strap E E'
instead of being connected are led over the rollers E E, which roll
on a path T T, and are connected by links to a lever L pivoted
and connected to the weight P. In the ordinary working of such
a brake the lower blocks would touch the wheel with small pres-
sure, and the weights p p' would be adapted to the total friction
required. The whole of the parts would be put in balance by
the movable weight w. With variations in the turning moment
or the lubricant P would rise and fall, but the rise and fall would
be of short range as the separation or approach of the rollers E E
would rapidly change the extent of surface in contact.

i^sSMiSM^^Wsrf

Special reference should be made to a very simple form of friction-
brake dynamometer, first proposed by Professor James Thomson,
consisting of a cord or rope passed over the upper half-circumference
once, or taking one complete turn round a smooth wheel, the one
end carrying a weight P, and the other attached to a sj)ring-balance
in a manner similar to that shown in Fig. 15, the rope bearing
directly upon the wheel without the intervention of blocks. This
brake works exceedingly well for small powers, and there seems
to be no reason against its use for large powers if a number of
separate roi:)es be used. All the ropes might be attached to a
cross-head at either end, from which the weight P would hang,
and to which the spring-balance could be attached. The pull on

Proceedings.] BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. 17

the spring-Lalance would be deducted from the weight P for the
actual load carried, as in the case of Figs. 14 or 15. During the
recent trials of gas- and steam-engines under the auspices of the
Society of Arts, Professor Kennedy, M. Inst. C.E., used two hemp
ropes, of about If inch circumference, passed once round the fly-
wheel of the engine under trial, and these were found to be quite
sufficient to absorb 20 HP., a water-trough wheel being employed
and very little unguent.

Proportions and Dimensions of Brakes.

In English practice there has not been much diversity in the
proportions given to brakes of these several forms for the absorp-
tion of a given power or the measurement of a given quantity of
work ; but, in the United States, a Prony brake has been used of
dimensions supi^osed to have been sufficient to enable it to absorb
about 500 HP. It was made with a wheel 5 feet in diameter, having
a rim of trough-shaped section supplied with constantly renewed
cooling water.

A comparison may now be made by an examination of the pro-
portions of the brakes described, and by reference to the results of
their working.

The brake used by several engineering firms is of the type
Fig. 5, and of the size used by the Eoyal Agricultural Society at
Newcastle in 1887, for a maximiim of about 20 HP. at 130 revolu-
tions per minute, and fitted with a compensating device, Figs. 5, 6,
and 7. The wheel is 5 feet in diameter and 7 inches in width,
and the radius E of the point of suspension of the load about 2 feet
9 inches, C being 23-75 lbs. With a load P=270 lbs., and the
number of revolutions per minute N = 150, this brake gives 21 • 17
HP. The lubricant used for the brake-blocks was tallow and water.

The similar brake used by Messrs. McLaren gave HP. = 19-1
with N = 148 • 5 and E = 2 feet 9 • 38 inches ; and another of similar
dimensions. Fig. 12, but with water-cooled wheel, also used by
Messrs. McLaren, gave 20-2 HP. with P = 271 lbs., N = 145-7 and
E = 2 feet 8-19 inches ; but it can be used for much higher powers.
Tallow was the lubricant employed.

The water-cooled brake of Messrs. Garrett, for powers up to a
maximum of 40 HP., has a rim of the section shown in Fig. 14,
capable of taking friction blocks of about 10-5 inches in width, the
width between the exterior flanges of the wheel being 11 inches.
With this brake, E =2*8 feet, maximum load P = 418 lbs., and
C = 17-5 lbs., HP.= 40 with N = 180, Mr. Garrett finds that the

[the INST. C.E. VOL. XCV.] 0

18 BEAUMONT ON FRICTION-BKAKE DYNAMOMETEES. [TMinutes of

brake runs most smoothly at 180 revolutions per minute; but, as
it is connected by universal joints to the engine to be tested, it
must run at the speed of the engine. Taking X = 150 for this
brake with the same load P = 418, the HP. = 33-4.

The Eoval Agricultural Society has a brake with three wheels of
the diameter and width of the single brake already mentioned, and
this with X = 150 is intended to measure a maximum of 100 HP.,
or about 33 • 3 HP. per wheel.

As a convenient means of comparing the relative capacity of these
brakes, iudging by the amount of Avork for which they have been

designed, or to which they have been put, a coefficient K =

may l)e employed, W being the width of the wheel in inches,
and y = the velocity of the periphery of the wheel in feet per
minute. This gives for the

Eoyal Agricultiiral Society's single brake K = 824

„ „ „ treble „ K = 495

Garrett's water-cooled brake . . K = 740

Eansomes', Balk's brake . . . K = 1,020

or a mean of 8G0, omitting the Eoyal Agricultural Society's treble
brake.

Compared in this same manner the Prony brake described by
Professor E. H. Thurston,^ as devised for measuring a maximum of
540 HP., the wheel being 5 feet in diameter and 2 feet wide, and
N = 100, gives K = only 75. This brake is stated to have been
freely luljricated with beef tallow, plumbago and lard oil, and,
although designed for a maximum of 540 HP., it does not appear
to have worked above 200 HP., and at this power K = 188.

The Eoyal Agricultural Society's brake, the similar one of
Messrs. McLaren, and that of Messrs. Garrett, are all fitted with
compensating-levers. Without this arrangement there is no doubt
that, although the brakes are not cooled with water, they would
work with accuracy to higher powers, and would probably give
satisfactory results with a constant K = 850, although, for long-
continued runs, K = 900 to K = 950 would be better.

Even with the high coefficient K = 1,020 obtained from Messrs.
Eansomes', Sims and Jefferies' brake with maximum load, the wheel
heats sufficiently to make much lubrication necessary during long
runs. This is shown by the variation in the scale weights with the
same gross load.

It would appear that the water-cooled brake may be made to

> Journal of the Franklin Institute, April 1886. 3rd Series. Vol. xci. p. 290.

Proceedings.] BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. 19

work with a very much lower coefficient ; probably a coefficient of
450 would be high enough for a water-cooled brake if not fitted
with the compensating-levers.

The water-cooled brake described by Professor Thurston provides
an exceptional case ; but, although this brake was designed for
540 HP. as a maximum, it does not appear to have been employed
for more than 174*5 HP., and it is questionable whether its
performance at the proposed maximum would have been at all
satisfactory, or even at half the maximum, especially when it
is remembered that only two bands 3 inches wide were used to
carry the wood blocks, which though 24 inches in length were only
2 • 5 inches in thickness. The flexure of the blocks, under the maxi-
mum tension of the belts, would have been sufficient to have made
the pressure immediately under the belts excessive ; while the
pressure between the belts and at the ends of the blocks would
be very small, and the effect of this on the wood and lubricant
coTild not have conduced to good running. Even with the load
carried. Professor Thurston remarks that : " the friction between
the brake-blocks and the face of the pulley was reduced to a mini-
mum by effective lubrication." This seems to show that the brake
was not strong enough for the power measured, for it is hardly a
desirable thing to have to reduce the friction to a minimum.
Taking 180 HP. as the greatest for which this brake was used,
then the coefficient K = 209.

The determination of the diameter and width of a brake-wheel
for a given power is often affected by prior fixed circumstances and
conditions, but an appeal to experience leads to the conclusion that
a somewhat greater width of wheel than has commonly been
used for the higher powers is advisable. Taking the Eoyal Agri-
cultural Society's single-wheel brake, for width, W = -7^^ =

824 X 20
— — —- = 7 inches, C being the circumference of the wheel ; but

if the compensating-levers were not used, a rather larger power
might be measured on this brake, and using the proposed constant
for long runs, K = 900, then with a diameter of wheel remaining
the same, i.e., 5 feet, W would according to the above = 7 • 6 inches.
For such powers, however, it may be questioned whether a wheel
of lesser diameter and greater width would not be preferable,
although the pressure upon the wood blocks would have to be
greater. For 20 HP. a wheel 3 feet G inches in diameter would
require a width of 10*9 inches.

For a water-cooled brake the proportions adopted in this respect

c 2

20 BEAUMONT ON FRICTION-BEAKE DYNAMOMETERS. [Minutes of

by Messrs. Eansomes', Sims and JefFeries for their brake of Balk's
design, or by Messrs. Garrett and Sons for their brake as described,
would seem to be satisfactory.

For several purposes in connection with these brakes, it is
necessary to consider the tension in the brake-strap or straps, or
belt, and the pressure upon the wood-blocks.

For a given power the total frictional resistance F at the face of
the wheel must be proportional to the velocity V of the periphery

of the wheel of diameter D in feet, or F = =- — =-^ — =

HP. X 33,000 w T rp ,a . , . • X. 1 1
^, , and taking 1, the maximum tension m the brake

strap,

t = the minimum tension.

a = the fraction of the circumference of the wheel embraced

by the brake-blocks,
/ = the coefficient of friction, then following Rankine,^
F = T — / and the ratio T : i is the number whose common

logarithm is 2-729/«,

or - = i0-"'25/« = n.

This may be put

T
Log - = 2-729/rt = n,

and T = F^l + --^\ or T = F

T - t/ n-1

In these brakes a = 1, and by way of illustration/ may be taken
as 0-2. Then, in the case of the large Prony brake already
mentioned as described by Professor Thurston —

T
Log - = 2-729/a = 0-5458,

and n = 3*5.

For the maximum HP. for which the lirake was calculated

540 X 33,000 ,.„,.„
^ = - 1,570-8 = 1''^^^ ^^^•
T = 11,345 X 1-4 = 15,833 lbs.

^ = ^-^'^^ = 3,241 lbs.;
6' o

but taking the maximum HP. at which the brake was worked
= 200 HP., T = 5,902 lbs. and t = 1,204 lbs.

* " Machinery and Millwork," p. 403.

Proceedings.] BEAUMONT ON FRICTION-BKAKE DYNAMOMETERS. 21

If in the same way the tensions on the Eoyal Agricultural
Society's single brake are taken as used at Newcastle last year
with about 20 HP., F =^ 270 lbs., T = 378 lbs., and t = 77 lbs. If
/is taken as 0'3, then with the same brake-load T = 333 "7 lbs.,
and t = 51-6 lbs.

For a comparative approximation to the maximum pressure p
per square foot of wood block upon the wheel surface, W being
the width of the wheel in feet, p may be taken

T + T = Dp W, or T = - ^^^

and p = -^^.

If this be allowed as giving figures which will permit the
pressures on the wood blocks of the several brakes to be compared,
or as an approximation to the pressure, then the greatest pressure
per square foot of surface of Professor Thurston's Prony brake, if it
had been used as proposed for 540 HP., would have been, assuming
the coefficient / = 0*2,

15,883 X 2
i> = -5-;^^- 3,176 lbs.

Assuming the blocks to be only four-fifths of the total area of
wheel-face, then p - 3,811 lbs. At 200 HP., which is more than
the actual power exerted, p = 1,180 lbs.

In the same way, and with the same coefficient, the greatest
pressure per square foot on the blocks of the Eoyal Agricultural
Society's brake at Newcastle would hep = 260 lbs. with the blocks
close, or 312 lbs. with the blocks covering 0*8 of the surface of the
wheel.

With the brake used by Messrs. McLaren, it would be the same
if the same coefficient obtained.

With Messrs. Garretts' brake, p = 269 lbs., or with the blocks
covering 0*8 of the surface p = 323 lbs.

With Messrs. Eansomes', Sims and Jefferies' brake, the wheel of
which is 6 feet in diameter and 1 foot wide, and where the wood
blocks are close together. Fig. 11, p = 110 lbs.

This is only intended as a rough approximation to the greatest
pressure per square foot of rubbing-surface of wood, biit it affords
a means of comparison of the pressi;re with the different brakes.
The mean pressures are probably somewhat less than half those
given. From these figures the advantages of width of wheel will
be seen. The pressure for a given load will, of course, be less for

22 BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

a given power absorption with increase in the diameter of the
wheeL The limit of velocity has, however, here to be considered,
especially with the wheels not cooled with water by the aid of
an internal trough. What that limit is cannot now be said, but
it is noteworthy that Messrs. Garrett find their brake runs more
smoothly at 180 revolutions per minute than at any lower speed,
presumably for the same power.

The Appold Friction-Brake Dynamometer.

It is necessary now to consider the eifect of the introduction of
the Appold compensating-lever, at least to do so sufficiently to find
whether it is a desirable feature or not.

In illustration of this point, it may be conceded that, if the
friction on the one hand be conceived to be almost infijiitely small,
the load P would have to be infinitely great, and the reaction at X
would also be infinite. If, on the other hand, the frictional grip be
increased so as to approach adhesion, then with any load P that could
be put upon the brake, while it still acted as a dynamometer, the
reaction at the pivot at the end X of the compensating lever may
be infinitely small, supposing the lever to come into play. It may
therefore be seen that the reaction at X for any given brake and
given power, may vary with the frictional grip, as affected by lubri-
cation, from zero to any maximum. The greater the difference
between what may be called the capacity of the brake, and the power
of the motor, the less will a given reduction in the friction affect
the compensating-lever, because, with the belt ends working almost
slack in their connections, the greater may be the increase in the
tension in the belt, before it becomes sufficient to make the reaction
at X a quantity sufficiently appreciable to affect the indications.

It may, however, be easily seen that under the ordinary working
conditions, that is to say, with the size of engine usually tested on
the brakes, such as those used by the Eoyal Agricultural Society,
the effect of the lever on the accuracy of the registration may be
very small.

If, for instance, the lever be of the proportions shown in Fig. 8
(p. 9), and the tension on the two ends A of the strap be assumed
to be 100, then the reaction at X will be equal to the difference
of the reactions at A and B, or about 11.

This will act in helping to lift the weight, its effective help in
this direction being proportional to the relation between the
distance from the centre of the wheel to the point X, and the
distance from the centre of the wheel to the point of suspension

Proceedings.] BEAUMONT ON FKICTION-BRAKE DYNAMOMETERS. 23

of the weight, and, if this relation be as 1 to 2, then the reaction
tending to raise the weight will be 5-5, and may be, with the
ordinary relations between the weight P and the tensions in the
ends of the brake-strap, an entirely negligible quantity, and of
practically no numerical effect on the HP. indicated by the brake.
If, however, a brake is used in such a way that the coefficient of
friction is very small, and anything like the al)ove assumed tension
in the strap-ends be allowed to arise, then the error may become
an important quantity.

With the brake, for instance, of the type shown by Fig. 5, as
used by the Eoyal Agricultural Society at Newcastle, with an engine
exerting 20 HP., and a weight P of about 270 lbs., if the tension
at the ends of the brake-strap were as much as 100 lbs., and the re-
action as much as 1 1 lbs., reducing the effective weight to 204 • 5 lbs.,
the difference, 5 • 5, is 2 i^er cent, of the whole. Neglecting the effect
of the compensating lever, and taking the gross load on the brake
as 270 lbs., the circumference of the load-circle being 17-25 feet,
and the revolutions 135 per minute, the engine would apparently
exert 19-05 HP. If, however, the tensions at the ends of the
strap, where connected to the lever, be, to take an extreme example,
as much as 100 lbs., and assuming the reaction to be as above,
11 lbs., and the gross load thus reduced by 5-5 lbs., or to 264-5 lbs.,
then the engine would have exerted only 18 -GG HP., the difierence
being 0-39 HP. This with an engine using 30 lbs. of steam per
brake HP. per hour is equal to 11-7 lbs. of feed- water per hour, or,
with a boiler evaporating 10 lbs. of water per 1 lb. of coal, it
represents 1-17 lb. of coal per hour, or 3-8 lbs. in a run of four
hours of an engine exerting 19 brake IIP.

Under the same circumstances and assumptions, but with the
engine running at 150 revolutions, the HP. would be 21 -IG,
neglecting the effect of the lever, and 20-73 when correction is
made for it, making a difference of 0 - 43 HP.

If, however, the tension of the brake-strai) be taken, as calculated
by the expression given on p. 22, and an assumed coefficient
/ = 0-2, there is obtained by approximation an error of 0-34 HP.
instead of 0-43 HP. In the same way, for / = 0-3 the result
is an error of 0-23 HP., i.e., 20-83 HP. instead of 21-16 HP.

It is, however, an objection that these calculations proceed on
the assumption that the relation between the gross load P, and the
tension T in the belt, remains the same for the velocity concerned,
i.e., 2,355 feet per minute at the periphery of the wheel, as for the
low velocity at which the l>rukc would just slip, when tightened
up on the fixed wheel.

24 BEAUMONT ON FRICTION-BBAKE DYNAMOMETERS. [Minutes of

If the belt of blocks is set so that it will move at a low velocity
under the influence of a weight suspended, as in Fig. 2, when the
wheel is fixed, the tension in the belt and the load that will over-
come the friction of rest being thus ascertained, a coeificient of
friction for that speed may be at once deduced. It would, however,
be useless to apply this coefficient to any calculations regarding
the brake when at work under ordinary conditions, inasmuch as
the coefficient so found will not apply at the high velocity of
wheel-periphery commonly to be dealt with. This is shown by the
facts given on p. 11. The tension in the belt, as controlled by the
adjusting-screw S, miist be miich greater to support a given weight
when the wheel is running than when the wheel is at rest. The
velocity very materially affects the friction, and no demonstration
of the dynamics of the compensating-lever of the Appold brake is
possible without taking these facts into consideration. To be able
to do this, however, experimental inquiry is necessary.

Some useful information on this point was, however, obtained
by Messrs. J. and H. McLaren, who attached a spring-balance
to the upper end X of the compensating-lever of the brake,
which they made of the same dimensions as that of the Eoyal
Agricultural Society. By this means they ascertained the varia-
tion of the reaction at X with variation of velocity of wheel-
periphery, and of lubrication of the wood-blocks. They found
that the pull on the spring-balance increased as the speed of the
engine fell, when the steam-pressure decreased during the clinkering
of the grate. This is precisely what would be expected, from
what has already been said as to the greater tension in the brake-
strap with a very low velocity, and it is clear that with the falling
speed of the engine the weight P descended a little and increased
the tension in the brake-strap, and therefore the reaction at X.
Their experiments conclusively show the direct relation between
tension in the brake-strap and the lubrication. In some cases, when
using tallow, they got 24 lbs. pull on the spring-balance at X, and
when using water the pull was 258 lbs. When they got the
24 lbs. pull there was a considerable quantity of water getting in
between the brake-blocks and the wheel, but in some of the tests
when, to use their own words, they " fairly smothered the brake
in tallow," so that the water could not get in between the blocks
and the wheel-face, they measured 20 HP. with only 4 to 5 lbs.
pull on the spring-balance. Their experiments lead them to con-
clude that, with an internally cooled brake-wheel of the size
employed, compensating-levers could be used without error up to
20 HP.

Proceedings.] BEAUMONT ON FRICTION-BKAKE DYNAMOMETERS.

So long as the Appold brake, like that of the Eoyal Agricul-
tural Society, is not used for more than 15 HP., and is sufficiently,
but still sparingly, lubricated with tallow or suet, the friction
between the wood and iron is such that the weight of the brake-
strap and blocks with the suspended load is sufficient, at the
ordinary speeds of the engines tested, to carry the load without
screwing up the belt so that there is more than a few lbs.
tension at the compensating-lever. Under such conditions the
lever does not affect results, and adjustment of the frictional grip
and position at which the load is carried has to be made by the
hand-screw S. The conditions are the same as, or very similar to,

Fig. 18.

those which would obtain if the brake were as shown by Fig. 2,
that is to say, without compensating-lever, but with a belt so
slack that the bottom blocks barely touch the wheel.

The following investigation on this subject,^ which has been
kindly placed at the Author's disposal by the Consulting Engineers
of the Eoyal Agricultural Society of England, supports the views
herein expressed : —

Let W = load on brake-strap (Fig. 18) ;

T^ T4 = tensions just above and below the points of suspen-
sion of W ;

' The Journal of the Royal Agricultural Society of England,
pp. G72-78.

October 1888.

26 BEAUMONT ON FRICTION-BEAKE DYNAMOMETERS. [Minutes of

To T3 = tensions at two ends, C and D, of strap connected

to lower ends of compensating levers ;
P = pull on upper ends of these levers ;

a, a' — radii of brake-strap and wheel respectively ;
0 D = c?, C D = 6, and 0 E = c ;
Fj = friction of A B C,
F2 = friction of A D, and F = total friction of brake-strap.

The portion A B C of the brake-strap is kept in equilibrium by
the tensions Tj and T2 at its ends, the friction exerted on it by the
wheel and by its own weight. This gives, taking moments
about 0 : —

Ti a = T2 0 M 4- Fi a' + moment of weight of A B C.
Considering the portion A D in the same way —

T3 0 N = T4 a -f F2 a' — moment of weight of A D.

Adding these two equations, then : —

Ti a + T3 0 N = T2 0 M + T4 a -h (Fi -f F^) a' -f- difference
of moments of weight of A B C and A D.

But the moment of weight of A B C = moment of weight of
A D because the strap is accurately balanced.
Therefore (T^ - TJ a = T2 0 M - T3 0 N + F a.
Now 0 M = 0 C sine 0 C M = (cZ-6) sine 0 C M,

and ON = 0D sine ODN = cZ sine ODN,

and Ti - T4 = W.

Substituting these values in the above equation : — ■
W a = T2 {d-l) sine 0 C M - T3 d sine 0 D N + Fa' ;

= d {T2 sine 0 C M - T3 sine 0 D N} - fcT., sine O C M -|- Fa'.
But because the lever is in equilibriiim, considering the forces
at right-angles to it : —

T2sineOCM = P + T3sineODN,
or P = T2 sine 0 C M - T3 sine 0 D N ;

and by taking moments about D of all the forces acting on the
levers,

D E X P = C D sine 0 C M T2

or ((Z-c) P = 6 T2 sine 0 C M.

Substituting these two relations in the above equation, then : —

Wa = d P - (f? - c) P + F a' ;

W« = c P 4- F a ;

or W-'^P=-F.

a a

Proceedings.] BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS.

that is to say, in order to get the effective value of W, the pull at
E, diminished in the ratio of c to a, must be deducted.

This result agrees with the principle that the external forces
acting on the system should balance. Since it is at rest, and the
tensions are internal forces, the load, the pull at E, and the friction
are the only external forces that have to be considered, as the point
of support is in the centre of gravity of the strap. This gives at
once, by taking moments about 0 : —

a W = c P + F a' ;

as before. Also because

P =

h T, sine 0 C M
d — c

it follows that P depends upon the tension of the strap, and upon
the proportion which C D bears to the whole length of the lever.
Now the tension of the strap depends upon the lubrication ; hence,
the more efficient that is, the greater will be the inaccuracy of the
brake.

It is evideut that, in order to determine the probable amount of
error in the Cardiif and Newcastle trials, the pull upon the upper
ends of the levers must be ascertained when the brakes are running
under exactly the same conditions as to power, speed, temperature
of air and lubrication. When the lubrication is constant, the pull
on the upper ends of the levers always bears a constant ratio to
the load on the brake.

The following Table gives the results obtained by Messrs.
McLaren, by means of the water-cooled brake, and by the
Engineers to the Eoyal Agricultural Society with the same engine
at Newcastle.

Table III

Messrs. McLaren's Trial.

K. A. S.

Halpin'a
Brake.

Brake made
like R. A. S.

Newcastle.

Indicated HP

23-70

22-20

24-020

Brake HP

20-20

19-10

20-770

Coal per brake HP. jicr hour ....

2-11

2-14

2-267

Feed-water per brake HP. per hour

22-10

22-00

21-530

Mechanical efficiency

0-85

0-86

0-860

It will be seen that the figures agree very closely.

28 BEAUMONT ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

The Axithor has not here described more of the many forms of
friction-brake dynamometers than are necessary to comprise most
of those of a typical character. Eeference may be made to an
essay,^ by Professor E. Brauer, on various other forms, includ-
ing numerous devices for arriving at a compensating action,
none of which, however, appear to be free from the objections
herein referred to.

It may be suggested that a very useful dynamometer might be
obtained by a combination of absorption and transmission dynamo-
meters.

The Paper is accompanied by three sheets of drawings, from
which the Figs, in the text have been reproduced.

' Zeitsclirift cles Vereincs deutsclier Ingenieure. Baud xxxii. Seite 5G
1888 ; aud Miuutes of Proceediugs lust. C.E., vol. Ixss. p. 266.

[Discussion.

Proceedings.] DISCUSSION ON FRICTION -BRAKE DYNAMOMETERS. 29

Discussion.

Mr. W. WoRBY Beaumont wislied to direct attention to a friction- Mr. Beaumont.
brake dynamometer that had not been mentioned in the Paper.
It had been designed, he believed, by Messrs. Ayrton and Perry.
The wheel was grooved, and over it was placed a rope, of small
diameter, which ran freely in the groove, bearing well upon the
bottom of the groove. The small rope passed round the upper part
of the wheel. At one end it carried a heavy load, and at the other
end it was fastened to a piece of rope of much larger diameter.
That rope did not fit in the groove so as to touch the bottom ;
but the point of suspension of a smaller weight hung from it,
when the rope was lifted sufficiently, would be at a greater
distance from the centre of the wheel than the heavy load hung
from the small part of the rope ; so that a difference in the value
of the balancing weight was brought about by the rise and
fall of the weight. Another point was that the rope of larger
diameter gripped, or was gripped, more strongly than the smaller
rope, as it did not touch the bottom of the groove ; it tended to jam
between the two sides of the groove. He had not seen that brake
in use, and if his descrijition of it were inaccurate perhaps Pro-
fessors Ayrton and Perry would set him right. He wished further
to state that the Paper had been written some time ago. If it had
been written lately it would have been extended in various ways ;
and, instead of the brief reference to rope dynamometers, a fuller
description would have been given of them. When the Paper was
written, early in the year, brakes with compensating levers were
the subject of a great deal of controversy ; they were, in fact, a
burning question, but since then the question had dropped, and
therefore a great deal of what might have been of considerable
interest then was much less so now.

Professor Archibald Barr said that the subject of friction- Professor Barr.
brakes was an exceedingly important one for engineers, and was
becoming more important every day, because the value of correct
experiments on the economy of the steam-engine was now more
appreciated than it had ever previously been. He would allude to
the statement in the Paper, first, that the friction-brake could not
give a scientifically accurate measurement of the amount of work
being done by a motor. No doubt it was perfectly true that no
instrument could give an absolutely correct record ; but he wished

30 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

ofessor Barr. to express strongly his belief that the friction-brake dynamometer,
properly constructed and used, would give a much more accurate
determination of the amount of work being done by an engine than
the steam-engine indicator would give of the work done by the
steam in the cylinder; and, as between the two, he thought the
dynamometer was the most important instrument that engineers
possessed for the determination of what engines were capable of
doing. In the second paragraph of the Paper the Author went on
to speak of the variations of friction and the influence they had
upon the accuracy of the brake results. In a properly designed
brake the variations in friction should have no influence whatever
upon the accuracy of the results. If the construction of the brake
and the method of taking its indications were correct, the variations
of friction were a matter of secondary importance, and need not be
taken into account in any results deduced from the readings.

With regard to the different forms of dynamometer described in the
Paper, the first principle to be observed in constructing a brake was
to haA^e it as accurate as possible, and the second was to have it as
simple as possible ; and he believed that, of all the arrangements
shown in the figures, the simplest, and the one best calculated to give
good results in most cases was that shown by Fig. 15. The still
simpler brake on the same principle to which he would afterwards
refer, in which the strap and blocks were replaced by a rope
or ropes, could be used in many cases with advantage (Pig. 19).
The Author had stated (p. 3) that the inertia of the lever of the
Prony brake, and the work done in moving it and the load, counted
without record against the motor. He would not enter into the
question of the influence of the inertia of the load and that of other
parts of the apparatus ; that would require a somewhat lengthy
treatment ; but he might say that the eff'ect would, on the whole,
be in favour of, or against, the motor, according to circumstances.
If the weight moved up and down (as it did in all friction-brake
dynamometers), the eff'ect upon the motor of such motion was not
measured, in any case, by the work done in raising the weight. If
the engine were made simply to wind a weight out of a mine, the
whole of the work Avould be spent in raising the weight. In raising
the weight in the friction-brake dynamometer, a certain amount of
work was done, but neglecting inertia just that amount less was
done against friction. If the engine were running at a uniform
speed, and the weight went up and down slowly (or under other
circumstances into which he need not then enter), the brake would
give a correct result, independently of the distance the weight was
lifted ; therefore that criticism which, if sound, would apply very

Proceedings.] DISCUSSION ON FKICTION-BRAKE DYNAMOMETERS. 31

strongly against some brakes, such as Thomson's (Fig. 21), did Professor Barr.
not, he thought, hold.

The internal water-channel was an exceedingly valuable pro-
vision ; but it was impossible to have a trough-brake constructed in
many cases. He had recently had occasion to test a gas-engine, and
had used the simple rope-brake. There was some trouble from the
pulley overheating, and, when water was allowed to fall on the
inner surface of the brake-pulley, some got on to the ropes, which

Fig. 19.

so reduced the friction, that the pull at the spring-balance altered
suddenly from say 10 lbs. to 100 lljs., and thus prevented any
trustworthy results being obtained. He overcame the difficulty
completely by tying to the arms of the pulley a number of pieces of
cloth, so that they lay inside the rim of the pulley, and keeping
these soaked with water. In that way a trough-brake could virtually
be improvised in a few minutes. At p. 7 the Author spoke of the
arrangement with the spring-balance shown in Fig. 4, as being
better than that with the weierht. Professor Barr did not think

DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. pHinutes of

rofessor Barr. that was the case as far as accuracy was concerned, because it was
necessary in the one case to take constant readings of the spring-
balance, and, as he had already pointed out, the rise and fall of the
weights in the other case did not necessarily cause any error. If
it were possible to get a simple, self-regulating brake, with a steady
load at the tail end, he thought it would be better, and it would
certainly be much more convenient to use, than a brake with a
variable pull at that point. At p. 11 the Author stated that the
brake shown by Fig. 11 had the great advantage over all others
that the experimenter could always ascertain the actual load,
although the tension lever acted as a compensating-lever. He did
not think that that superiority could be claimed for the arrange-
ment. It was a good brake, no doubt, but there were other brakes

Fig. 20.

which allowed the experimenter quite as well to determine the
amount of pull at the adjusting point. He thought that the brake
would be much improved if, instead of putting the lever half way
round the wheel from the point of suspension of the load, the load
were suspended by means of steel tapes, and the lever applied to
the slackest part of the belt, just under the load. There would
then be a much smaller force at the end of the lever, and, therefore,
a much smaller variation of force than in the other arrangement.
He was now constructing a brake on this principle, as shown by
Fig. 20. With regard to some of the brakes described, such as those
shown by Figs. 10 and 15 for example, he thought there was one
point to which attention had not been sufficiently paid, namely,
the thickness, or rather the thinness of the strap. In the case of
such brakes, the strap used should be exceedingly thin ; it should.

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 33

in fact, be sometliing of the nature of a steel ribbon rather than Professor Barr.

a piece of stiff iron. With reference to the rope-brake mentioned

on p. 16, which the Author attributed to Professor James

Thomson, if it was due to one of the Thomsons, it was to Sir

William, who had used it before any one else, so far as he knew,

though not in quite the same form as that illustrated by Fig. 19.

The brake invented by Professor James Thomson was an entirely

different one (Fig. 21). If the friction was too great the loose pulley

was drawn round, unwinding a portion of the rolling cord from the

running pulley, and thus automatically adjusting the resistance.

Fig. 21.

There was no mention in the Paper of that brake, nor was there
any mention of a brake which he thought was, though not the
simplest, one of the best ever introduced. He referred to the modi-
fication of Mr. Froude's brake, which had recently been adopted at
the Owens College by Professor Reynolds. It worked with great
nicety, with perfect regulation, and with no trouble or mess; it
was a water-brake in which the work was absorbed by fluid friction
instead of by solid friction. Another point, not mentioned in the
Paper, was of much more importance than usually supj^osed, namely,
the dashpot often introduced into brakes. The dashpot might

[the INST. C.E. VOL. XCV.] h

34 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

rofessor Barr. effect a great deal of harm. It was sometimes said that the work
done in it ought to be added to the work done against friction
as calculated from the brake-load and speed. That, however,
was a serious mistake, because the amount of work done in the
dashpot was the force acting upon the dashpot piston, multiplied
by the distance through which the dashpot piston moved ; but the
effect upon the engine was the amount of force upon the dashpot
piston multiplied by the distance through which the circuniference
of the wheel, considered as having a radius equal to the arm at
which the load acted, moved in the time, and that might be many
thousand times as great as the amount of work done in the dash-
pot itself. If the force on the dashpot piston were to vary in a
certain way, and the engine to run at a uniform speed, the up and
down motions of the dashpot would exactly counteract each other,
so far as work done bj^ the engine was concerned ; but that would
be best secured, not by the dashpot commonly used with water
and a loose piston, but with one filled with a very viscid fluid,
so arranged that the resistance would be proportional to the
velocity : then, if the engine were running at a uniform speed,
the resistance of the dashpot would be very great, and would give
a great deal of regulation ; but still it would correct itself, and
no error would be introduced. But the right place to introduce
the dashpot, if one was to be used, was not always, or usually,
at the load. In the case of the brake shown by Fig. 15, for instance,
Professor Barr used a dashpot about Ij inch in diameter filled with
oil, and attached to the spring-balance. If a dash-pot was applied
to the loaded end of the strap, when the load was being lifted
the dash-jjot resisted the lifting, virtually increased the load,
and therefore tightened the strap and increased the tendency of
the brake to lift the load. If, on the other hand, it was applied
to the slack end, any lifting of the load slackened the strap on
account of the dashpot resistance, independently of the reduction
of the pull of the spring-balance, and therefore acted in the
right direction. Besides this, a force of 1 lb. at the slack end
would do as much in regulating the brake as a force of perhaps
20 lbs. at the tight end. For these two reasons the dashpot should
be applied to the slack end. Professor James Thomson had jiro-
posed to regulate the action of his brake (Fig. 21) by passing a cord
from the light weight round a spindle carrying a small fly-wheel,
so that, as the weight rose and fell, the fly-wheel would require to
be rotated. This " inertia regulator " would introduce no error if
the engine ran at a constant speed, or varied in speed only slowly.
He had used such a regulator with success. He could not see the

Piwoedings.] DISCUSSION ON FPJCTION-ERAKE DYNAMOMETERS. 35

w v

use of the coefficient K = -,:r-^ given on p. 18. The formula might Professor Barr.

be simplilied to K = 33,000 -p where P was the load on the brake.

That was, K was a coefficient which expressed the width of wheel
allowed for a certain amount of load. He did not think that the
width of the wheel should be proportioned to the load upon the
brake, giving a certain width of wheel per lb. load; but rather
that a certain surface of wheel should be provided per HP., because
similar brakes might be expected, roughly speaking, to absorb or
dissipate a certain amount of heat per square inch of surface per
minute. It would be a coefficient of that kind for each style of
brake-wheel (water-trough wheel, &c.) which would be useful. It
would be noticed that what was called a constant in the Paper was
exceedingly variable. He should be glad if the Author would
explain the observation (p. 19), "But if the compensating-levers
were not Tised, a rather larger power might be measured on this
brake." The difference between the amounts of work which could
l^e recorded by a certain brake, with or without comjiensating
levers, must simply be the amount of error which the compensating
levers introduced. He thought that, p. 20, the Author had made
a slip in speaking of frictional resistance being proportional to the
velocity ; he probably meant inversely proportional to the velocity.
The calculation, p. 20, appeared to him to be rather an abuse
of mathematical processes. It was given as following Professor
Rankine. Professor Eankine undoubtedly said that the formula
was approximately true for a chain of blocks, and it would be so in
the case of a large numljer of blocks, attached to the flexible strap,
and running dry on the wheel ; but he felt certain that Professor
Eankine would not have applied that formula to a brake with a
small number of blocks such as that shown in Fig. 15 of the Paper,
or the brake used by the Royal Agricultural Society. The formula
was only applicable strictly in the case of an infinite number of
blocks and a perfectly flexible strap. Further, it was inapplicable
to most friction-brake dynamometers, because the friction in almost
all brakes with which they had to do — and certainly those to which
the Author of the Paper applied the formula — was not purely
solid friction ; and did not follow the laws of solid friction uj^on
which the formula was founded. He thought that the coefficients
of friction assumed (0 • 2 and 0 • 3) were in no way near to what they
generally were in brakes. He should wish to protest against such
analytical methods being used to deduce quantitive results without
the constants involved being obtained from experiments made

D 2

36 DISCUSSION ox FKICTION-BKAKE DYNAMOMETEKS. [Miuutcs of

i-ofessor Barr. under like conditions to those to which they were applied. With
regard to the Appold compensa ting-levers, if they did not intro-
duce any error, they did not introduce any compensation. That
was the simple principle which should be borne in mind. Brakes
could be made perfectly well without those levers, and he there-
fore thought that a simpler brake should be used in jDlace of the
" compensating-lever " one, which introduced errors. The Author
had calculated what the error might be, and he had given as an
extreme case a force of 11 lbs. at the end of the comi^ensating-
lever ; but, where Messrs. McLarens' brake was referred to, it
would be seen that the smallest force they got was 24 lbs.,
and the greatest 258 lbs.; therefore the force of 11 lbs. at
the end of the compensating-lever could hardly be called an
extreme case. He presumed that the value, 11 lbs., was what was
too often falsely called a " theoretical result," being founded on some
such erroneous assumption as those he had referred to. There was
also, on pp. 25 and 26, a mathematical investigation which he
thought was not by any means necessary. The jDrincijile was
given in a few lines following the mathematics, and the result
could be got at directly from the principle itself. The Paper
stated, " Since it is at rest, and the tensions are internal forces, the
load, the pull at E, and the friction, are the only external forces
that have to be considered ; " therefore the force at the end of the
compensating-lever, diminished in the ratio of the distances of the
load and the end of the lever from the centre of the wheel, must be
deducted from the load W to get the net load. A great deal had
been said about the results obtained by Mr. Halpin and himself
in testing Messrs. JMcLarens' engine, and they were referred to in
the Paper as corroborating the results obtained by the Eoyal
Agricultural Society. It was true that the engine tested by
Mr. Halpin and himself was the engine tested by the Eoyal
AgTicultural Society. He was not himself present at the Society's
trial, but he had been informed that the engine was working as
diiferently as possible on the occasion when they tested it from
what it was doing on the occasion of the Society's trial ; he there-
fore did not think that their results, corrected for the error intro-
duced by the lever, could fairty be taken as showing that the Eoyal
Agricultural Society's resiilts, uncorrected, were perfectly trust-
worthy. Further, the most striking coincidence was in the
mechanical efficiencies ; but he understood that the indicator- and
brake-trials of the engine by the Eoyal Agricultural Society were
made at different times, and therefore he did not think that the
coincidence of the values got by the Eoyal Agricultural Society and

Procccdiugs.] DISCUSSION ON FUICTION-BRAKE DYNAMOMETEIiS. 37

liy Mr. Halpin and himself could beheld as proving that there was Professor Barr

no important error in the Eoyal Agricultural Society's trials. He

thought that in future the so-called " compensating-levers " should

be dispensed with, and he had no doubt that they would be. He

was glad that the Author had not entered into a subject on

which there had been a considerable amount of controversy, as to

the difference between the crooked and the straight lever. That

was only a very small matter of detail, and did not affect the

accuracy of any of the statements made with regard to the error

introduced by the Appold brake. He might be permitted to

express the conviction, and the hope, that the last had been heard

in this Paper of the Appold brake, except as a matter of historical

interest ; and if so he would rejoice at such a result.

Dr. Edward Hopkinson observed that Professor Barr had alluded ^'*^'- ^- Hniikin-
to a type of brake not mentioned in the Paper, and had asked to
have some description of it ; he referred to the hydraulic-brake
originally introduced by Mr. Froude. Having had something to
do with the more recent modifications of that brake, he might,
]ierhaps, be permitted to describe it. He believed that Mr. Froude
introduced the brake about twelve years ago, and since its intro-
duction it had been occasionally used, chiefly, he thought, by the
Admiralty in connection with testing marine engines. Though
exceedingly powerfiil it was very difficult to regulate its resistance,
and it was not until it had been reconstructed by Professor Osborne
Eeynolds that the brake had become a practical piece of mechanism.
Mr. Froude's original apparatus consisted essentially of a wheel
keyed on to the shaft, the torsional power of which it was desired to
measure, surrounded by a casing supported by the shaft, but free to
move round it. The wheel was formed of two bowls or hemispheres
with their convex surfaces placed together and the flat surfaces
outwards. In the two concave portions of the bowl there were a
number of inclined vanes which divided the hollow space, raking
forward in the direction of rotation. Corresponding with the
vanes in the bowls, there was a similar series of vanes in the
outer casing which raked in the opposite direction. If water was
introduced into the wheel rotating with the shaft, it would be
caught by the vanes of the casing, and rotational motion would be
set up, absorbing the power of the shaft, and increasing imtil
balanced by friction. The pressures parallel to the shaft on the
two halves of the wheel would be balanced. The tangential force
on the casing, tending to turn it round the shaft in the direction
of rotation, could be balanced and measured by a weight at the
end of a lever rigidly attached to the casing, as in the case of the

38 DISCUSSION ON FEICTION-BRAKE DYNAMOMETERS. [Minutes of

Hopkiu- Prony brake. In the original form of Mr. Froixcle's brake there
were great difficulties in keeping the couple or tiirning moment
on the casing constant, although there would be no difficulty
in constructing a brake of that form which would absorb many
thousand HP. The improvements originated by Professor Reynolds
were in respect of the way in which water was introduced into
the brake, and allowed to flow out of it. According to his method
the water entered along the shaft into the wheel between the two
convex surfaces. It was there forced outwards by centrifugal
force to the peripherj^ of the wheel ; it then passed through
passages or ducts cut through the metal of the vanes, and emerged
with rotational motion on the faces of the wheel ; it was caught
by the vanes of the casing, and finally it passed outwards between
the wheel and the casing into an outer chamber formed in the
latter, from which it escaped by a drain-pipe. There were also
air passages in the vanes of the casing, which, as the water entered
the brake, allowed the air to escape in front of it. Supposing
a brake to be applied to an engine, and the water allowed to flow
into it, it would gradually fill the brake, and the couple which the
shaft of the engine exerted on the brake would increase, the air
would be driven out through the air passages, and finally the
water itself would emerge by the exit prepared for it. If the
exit were closed, or partially closed, the pressure would increase,
and more power would be absorbed by the brake. By regulating
the exit of the water in proportion to the sxipply, the resistance
of the brake could soon be adjusted to any desired amount, and
so long as a constant current of water was flowing through,
and the speed with which the shaft was rotated was kej^t
constant, the turning moment on the brake would be precisely
constant. That was a very great advantage over the Prony
form of brake. Any one who had had anj^thing to do with the
Prony brake knew that it was a difficult instniment to deal with ;
it was very difficult to keep the friction constant, it needed con-
tinual care and watching, and there were many sources of error
which, however carefully guarded against, might creep in. The
brake of Professor Eeynolds could be put on the engine-shaft, and,
if the engine was properly governed so that the speed was constant,
it might be left upon the shaft for hours without the least atten-
tion, because, the flow of the water being constant, the work done
in the brake would also be constant. The essential condition was
that the engine should be properly governed, and the speed kept
constant ; but Professor Eej-nolds had introduced a modification by
which the resistance or the couple could be kept constant, even

riuccedingb.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 39

although the speed of the engine varied. This was effected hj Dr. E. Hnpkin-
a simple arrangement connected with the lever which measured ^""'
the tiirning moment on the casing, by which a subsidiary system of
levers actuated and controlled the valve, allowing the water to flow
into the brake. When the engine ran at a greater speed than the
normal, and the resistance consequently increased, the weight lever
wotild tilt up, the valve would be j^artially closed, diminishing the
How of water through the brake, and consequently the resistance
would be diminished down to its normal value ; and vice versa
when the speed of the engine fell and the resistance diminished.
Another advantage was that the brake required no lubrication
whatever. The water passing through the brake sufficiently
lubricated it. He had seen one of those brakes working for six or
eight hours at the Owens College, Manchester, without any atten-
tion whatever. All that it was required to know at the end of six
hours' run was, what weight had been on the lever of the brake, and
what was the number of revolutions through which the engine had
turned during the time ; it could then be told accurately what
work the engine had done in the interval. The work done in the
brake in overcoming the resistance of the water apjieared in
heating the water. The heat thus generated might be carried
away by the steady stream of water through the brake without
causing any great rise of temperature, or by restricting the stream
the temperature might be raised until the water boiled, when the
vapour or steam would pass away through the air passages without
causing any considerable increase of pressure. A brake, 18 inches
in diameter, Avould measure from 1 to 30 HP. at lOO revolutions
jier minute, and for other speeds the power would vary as the cube
of the speed. He might mention that his firm, Messrs. Mather
and Piatt, had constructed for Professor Eeynolds three 18-inch
brakes which had been working in connection with the triple-
expansion experimental engines in the Whitworth Laboratory at
the Owens College, and that the results had been very satisfactory.

Mr. R. E. Froude said he proposed to confine his remarks to two Mr. Fromle.
of the subjects suggested by the Paper, and in the course of the
discussion. The first was the question to what extent and in what
way variations in the frictional resistance of a frictional dynamo-
meter-brake might prejudice the accuracy of the record. Using
general terms, he would treat a friction-brake dynamometer as
consisting essentially of two parts, the rotating wheel driven by
the motor, and the comparatively stationary resisting lever. The
frictional couple between the wheel and the lever he should call
the reaction, and the counterbalancing couple resident in the lever

40 DISCUSSION ox FMCTION-BRAKE DYNAMOMETERS. [Miuutes of]

Froude. he should call the preponderance of the lever. Thus by reaction
he meant to describe equally the couple impressed by the lever
upon the wheel, or by the wheel upon the lever, and by the pre-
ponderance he meant the tendency of the lever to resist that
couple, which might or might not be equal to it ; for there was no
law in nature which compelled an equality between those forces,
except that any difference between them must be satisfied by an
angular acceleration of the lever, and consequently any prolonged
difference would lead to an accumulation of angular velocity on
the part of the lever which would be practically inadmissible.
Therefore, although those two quantities were not naturally equal,
they liad to be made equal. Hence it was found that in most of the
instruments described in the Paper, there was a provision made for
automatically varj'ing the preponderance of the lever to suit varia-
tions in reaction, and it would be found, on a close examination, that
that provision had in all cases the character which it conspicuously
possessed in the instrument shown by Fig. 1, the original Prony
brake — a character which he would term "statical stability" of
the lever about the axis ; in other words, the preponderance of the
lever must vary with the angular position of the lever much as did
the preponderance of a pendiilum. The cause of the property
which he termed stability was various in the different examples.
In some, for instance, it was given hj the attachment of a spring-
balance to some point of the lever or its appurtenances ; but,
whatever the cause, it had that character of "stability" in so far
as that the variation in the preponderance was essentially accom-
panied by some variation, great or small, in the angular position
of the lever. Since the preponderance of the lever was the only
measure they had of the reaction, it was clearlj- necessary for real
accuracy that the variations in the preponderance should be
measured, and various provisions had been made for measuring it
in some of the examples. His main purpose was to treat of the
considerations which had to be kejit in view in devising such
refinements in that mode of measurement as might be required by
the circumstances of the case, and the degree of accuracy needed. It
■would be readily recognized that the ne plus ultra of refinement —
the ideal result to which the refinements should tend — would be a
continuous representation of the momentary reaction as the ordinate
of a diagram, in which the scale of abscissas represented waits of
circumferential travel of the motor. In such a case the area of the
diagram would represent the total work delivered by the motor to
the lever, on the same principle as the area of an ordinary indicator
diagram measured the total work delivered by the steam upon the

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 41

piston. In the attempt to translate that ideal dia^am into practice, Mr. Froude.
they were confronted with the circumstance that, whereas the
ordinate of the ideal diagram represented momentary reaction, the
only force of which they had a measure was the momentary pre-
ponderance of the lever, which might differ from the momentary
reaction by whatever force was used in the momentary acceleration
of the lever ; because, as he had said, any variations in the prepon-
derance must be accompanied by some angular motion on the part of
the lever. Therefore, what they had to consider was how far, in sub-
stituting what might be called a practicable diagram for the ideal
diagram — substituting a diagram of which the ordinates represented
preponderance instead of reaction — how far they were introducing
error in virtue of the inertia of the lever. That was a question which
at first sight seemed complicated, but there was one very simple cri-
terion to which it might be submitted, in virtue of the circumstance,
that the lever, in consequence of its stability about the axis, was
capable of a free oscillation, which would be accomplished in a
certain definite period of time depending upon the inertia of the
lever, and upon the scale of its stability. If, by making the inertia
small enough, or the scale of stability great enough, that period
could be made much more rapid than the most rapid fluctuations in
the reaction, then the difference between the momentary reaction
and the momentary preponderance would practically be nil, and the
difference between the ideal and the practicable diagram would
he nil. If, on the other hand, that condition as to the period of
the lever was not secured, then the difference between the ideal
ordinate and the practicable ordinate would amount to some
important quantity, and then there might be a condition of
affairs something like that represented by Fig. 22. There was the
ideal diagram of which the ordinates represented momentar}- re-
action, and the actual diagram, of which the ordinates rejiresented
momentary preponderance, the difference between the two being
the forces momentarily emjiloyed in angular acceleration of the
lever. This was an error in the diagram, a local ordinate error, but
not necessarily an error in the area of the diagram, which was
the measurement of the total work done. Whether there would, or
would not, be an error in the area of the diagram depended
upon the nature of the fluctuations of the speed of the motor.
That could be best followed by first supposing that the speed of
the motor was perfectly uniform. In that case the scale of
abscissas of the diagram, which primarily represented units of
circumferential travel of the motor, might be equally taken to
represent units of time, and then it would be easily seen that in

DISCUSSIOX ox FEICTIOX-BEAKE DYNAMOMETERS. [Miuutes of

Mr. Froude. the long run the areas of the positive error must balance the areas
of negative error, because, if not, the balance would represent a
certain amount of momentum which had been imimrted to the
lever, and which would have had to be satisfied by an accumulation
of angular velocity, which they knew had not taken place. Let
it be next supposed that the speed of the motor, instead of being
uniform, was varj^ing in such a way as he had represented by the
line AA on the diagram, of which the ordinates represented
momentary speed, what would happen? The excess of speed
would exjjand the longitudinal scale in the regions of positive
error, and the defect of speed would contract the longitudinal scale
in the regions of negative error ; consequently there would be an
excess of the sum of the positive errors over that of the negative

Fig. 22.

IDEAL DIAGRAM

,' MCTUAl DlAGRAlA

OF DIAGRAM

ORDINATES SHEW
MOMENTARY SPEED

CBDAC BDA

AA, Overloading Phjxee,
B-B. CnxLcrlogqmn do,
C. C cr D D, Neutrnl do.

errors, and an excess in the total area of the diagram, which would
therefore over-log the power. Or if the fluctuation of the speed
possessed the precisely opposite character, as B B, then for the
same reasons the diagTam would under-log the power. That kind
of conjunction of variation of speed and error of diagTam might be
described in the technical language of harmonics by saying that
the fluctuations of speed synchronized with the fluctuations of
error, with such a j^base relation, as it was tenned, that the
moments of maximum and minimum speed coincided respectively
with the moments of maximum positive and negative error, or the
precise reverse. If, on the other hand, the phase relation of the
fluctuations of speed to the fluctuations of error was precisely
midway between these' two, as C C or D D, then the error would
be nil. Of course it was not to be exi)ected that the actual

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 43

fluctuations of speed should have precisely any one of these Mr. Fromle.
characters ; they would jorobably be a compound of fluctuations
of various kinds. What might be said in such a case was that
the extent to which the initial ordinate error of diagram would
be converted into error of area, and therefore into total error of
record, depended upon the magnitude of such element in the total
fluctuation of speed as bore precisely the character he had specified.
He did not wish to be understood as implying that under all
circiimstances perfect practical accuracy required the use of such a
.diagram as he had supposed. Whether it did, or did not, depended
entirely upon the nature and the degree of the variations in the
reaction and in the momentary speed of the motor. The purposes
of a continuous record by diagram might, in any case, be very
conveniently fulfilled by the well-known expedient of an in-
tegrating wheel working on the face of a disk rotated by the
motor. This was a theoretically perfect substitute for such a
diagram, and if carefully constructed and used would give ad-
mirable results. He had hitherto confined himself to the as-
sumption that for want of, or in spite of, apparatus for regulating
the reaction to a fixed amount, there were sufficiently prolonged
variations in reaction to necessitate the provision for counterpart
variations in preponderance of lever which he termed " stability,"
an assumption which applied to most of the instruments described
in the Paper, in which indeed the stability was generally fur-
nished by forces brought into play by the very apparatus
which approximately regulated the reaction. The instruments.
Figs. 3 and 4, however, were theoretically exempt from this
condition, and no doubt in these or other ways instruments
might be made to so far exclude prolonged variations in reac-
tion as to practically dispense with the property of stability
of lever, without danger of excessive acciamulation of angular
velocity, or, in other words, of the instrument being " thrown
over." In such a case, the stability being nil, the " period " of
lever would be infinite, and the preponderance constant instead of
varying; but, taking due account of these conditions, the prin-
ciples he had indicated would apf)ly, and the treatment would be
somewhat simplified by the circumstance that the differences
between the momentary reaction and the preponderance, which he
had termed the " errors of the diagram," would be simply the
variations in the reaction. And, although a continuous diagram to
record the constant preponderance became unnecessary, it was
useful to keep in mind the " ideal diagram," of which the ordinates
represented momentary reaction, as a gra})hic expression of the

44 DISCUSSION ON FRICTION-BKAKE DYN.UIOMETEKS. [Mimites of

:\lr. Fronde, fact that the total work delivered by the wheel was the sum of
the products of the momentary reactions into the corresponding
successive units of travel. The treatment, as applied to this case,

might be instructively paraphrased thiis : —

Let P = the constant preponderance.

K = the momentary reaction throughout an infinitesimal

element of travel dc, occupying an infinitesimal

element of time dt.
C = total travel during the experiment.
T = total time occupied liy the experiment.

Then the total work delivered = f K d c ; and let 'Li — = 1{ ^
which may be termed the " travel-mean " of the reaction. And,
in the same way, let —7^ — — E/, which may be termed the " time-
mean " of the reaction.

Then, the true work delivered being C He, the indicated work
was C P, and the error consisted in the difierence between E^. and
P. Xow (and here lay the important pointj, the only condition
which determined the relation between reaction and preponderance
was this. T P = the total amount of angular momentum that
would have been imparted to the lever by its preponderance, if
this were unresisted ; T B.t = the amount that would have been
imparted to it in an opposite direction by the reaction. And, since
these two values must in the long run be equal, P = E;, and the
error consisted in the difierence between Ej and He, namely,
between the time-mean and the travel-mean of the reaction. The
difierence between these two means depended, as he had indicated,
on how the fluctuations in speed chimed with the fluctuations in
reaction. Thus, if in a friction-brake of constant preponderance
(as Figs. 3 or 4) the lever was oscillating, and the weight rising and
falling, the consequent error would depend on how far the moments
of excess of reaction, denoted by upward acceleration of the weight,
coincided persistently ■with the moments of excess or defect of
speed, and vice versa. In an ordinary friction-brake, since friction
was practically independent of speed, there was no reason why such
alternations of speed as were due purely to alternating action of the
steam-governor, for example, should persistently coincide in any
particular v^aj with alternations in reaction ; hence errors due to
this cause might be expected in the long run to balance one another.
On the other hand, alternations in the reaction would themselves
tend to originate speed alternations, which, as modified by the

Proccediugs.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 45

action of the governor and other causes, might conceivably chime Mi'- Froude.

with the reaction alternations in such a way as to introduce

error.

He would now refer briefly to his second subject, namely,
the turbine dynamometer invented by his father, the late Mr.
W. Froude, M. Inst. C.E., to which reference had been made by
Professor Barr and Dr. E. Plopkinson. It was devised specially
to meet the case of dynamometric trials of large marine-engines,
and his father's thoughts were turned in the direction of an
instrument of that type, mainly by the difficulty of devising an
instrument of the ordinary type sufficiently compact to be applied
to a ship, and yet capable of absorbing such an amount of power
with safety. He could not say that Dr. Hopkinson's description
of the instrument conveyed an entirely correct impression of it.
He could not then give an intelligible description of the instru-
ment, but he would refer to the Paper on the subject read by his
father before the Institution of Mechanical Engineers in 1877.^
The only feature on which he would comment was one which had
a direct bearing on Dr. Hopkinson's remarks, namely, the method
of regulating the reaction. That was accomplished by the use of
sliding shutters, which covered the faces of the cells through
which the water circulated, and so by more or less impeding the
circulation of the water diminished the reaction of the instrument.
That expedient answered simply to perfection. At will, the
reaction of the instrument could be regulated from the maximum
of which it was capable, to an amount of about one-fifteenth of
that maximum, with the same revolutions of the engine. The
instrument devised for marine-engine trials was made by Messrs.
Easton and Anderson in 1878, and was tried in H.M.S. " Conquest,"
at Devouport, in 1880, after his father's death. A much smaller
instrument was subsequently made by his brother, Mr. Hurrell
Froude, for testing small rapidly-running engines, chiefly for
driving electric-light dynamos, and it was sold by him to the
Admiralty for tise at Portsmouth Dockyard. It had remained
there in use ever since, and he had been informed that it had
given the highest satisfaction. He therefore could not admit the
correctness of Dr. Hopkinson's remarks that, " though exceed-
ingly powerful, it was very difficult to regulate its resistance,"
and that " it was not imtil it had been reconstructed by
Professor Osborne Keynolds that the brake had become a prac-
tical piece of mechanism," also that "there were great difficulties

lustitutiou of Mechanical Engineers. Proceedings 1877, p. 237.

46 DISCUSSION ON FKICTION-BRAKE DYNAMOMETERS. [Minutes of

Mr. Froude. in keeping the couple or turning moment on the casing con-
stant." He was curious to learn on what authority Dr. Hop-
kinson had made those statements, which, to his mind, were
entirely incorrect. He admitted that the instrument was " exceed-
ingly powerful," in the sense that in an incredibly small compass
it was capable of absorbing an enormous amount of power ; but
he regarded that as a merit rather than a drawback. But the
juxtaposition of the words, " exceedingly powerful " and " difficult
to regulate," appeared to him to be intended to convej^ the im-
pression that the instrument exercised its power in some capricious
and irregular manner, which it certainly did not do. He ad-
mitted, that before the trials he had some apprehensions that
there might be difficulties at the moment of starting the engine,
but those apprehensions were illusory. There was nothing to be
done but to turn on the steam, and the engine steadied itself
immediately and quietly to the speed at which the amount of re-
action balanced the steam-pressure. The contrast between his
apprehensions (which he thought were excusable in dealing with
an instrument capable of absorbing 2,000 or 3,000 HP., har-
nessed to a large marine engine Avithout an intervening fly-
wheel), and the gentleness of the phenomena resulting, was
almost grotesque.

Although this instrument might perhaps be legitimately termed
a " friction-brake dynamometer," it was important to notice that
the part played in its action by fluid friction diftered essentially
from that played by mechanical friction in an ordinary brake.
True, in both cases the friction was the iiltimate absorbent of the
power; but, whereas in the ordinary brake the friction was the
direct agent of the reaction, in the turbine this agent was the
centrifugal force of the circulating water ; and the speed of this
circulation, and consequently the reaction, was diminished, not
increased, by increase of friction. Hence, in order to develop the
maximum absorbing-power of this instrument, it was necessary to
have the surfaces as smooth, and the flow of the water as little
obstructed, as possible. In this brake, unlike the friction-brake
proper, the reaction naturally varied with speed, and it would be
impossible by any self-acting regulating arrangement to equalize
the reaction for such rajiid alternations of speed as might arise, in
default of sufficient fly-wheel, from want of balance in the engine,
and the variation in the turning moment due to the steam-jjressure
in different parts of the stroke. In such cases the turbine would
manifest a pulsation of reaction chiming with, and slightly sub-
sequent to, the primary- pulsation of speed; and hence, in the use

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 47

of this instrximent nnder such conditions, as compared with an Mr. Frmule.
ordinary friction-brake, it was perhaps specially requisite for ac-
curacy that careful attention should be paid to the principles
which he had attempted to indicate in the first portion of his
remarks.

Mr. P. W. WiLLANS desired to say a few words on one or two Mr. Willans.
trials which he made with brakes twelve years ago. He made one
of the A})pold brakes. He did not say that he had designed it in
the best possible way, but his experience with it satisfied him that
there was something wrong about it. He found that on being
lubricated freely with soap and water the engine ran away, and it
did not seem to him that, as the brake was there to measure the
work, the engine ought to run away in consequence merely of a
difference in lubrication. The engine was ungoverned, and this of
course showed the defect at once. About four years ago he made
another of the Appold brakes, and in his first or second trial the
power which he measured on the brake was rather greater than the
indicated power measured on the brake, and that did not seem to
him to be right. The fact was that these brakes were only very
rough measurers of power, and he thought that the best way of
realizing the difficulty was to imagine that, instead of the wooden
blocks, rollers perfectly frictionless were placed between the brake
and the strap. It would then be seen that the weight could be
lifted, by simply using the tightening-screw, the point X, Fig. 5,
bearing the whole strain. The amount of the error was simply a
question of the coefficient of friction. The Author had summed it
up by saying (p. 25 ) that " under such conditions " (that was, when
there was very little pull on the lever) " the lever does not affect
results, and adjustment of the frictional grip and position at which
the load is carried has to be made by the hand-screw S." In other
words, the brake was a compensating one, which might be a good
one when it did not compensate, but which it was not safe to use,
and which he would venture to predict would never again be used
by observers who desired accurate and reliable indications. He had
made up his mind to use one of Mr. Froude's brakes, the one of
which Dr. E. Hopkinson had spoken, and he still intended to use
it for large powers ; but a few months ago Mr. Coope, of Grantham,
had brought him drawings of a brake which seemed to be free from
the errors to which he had referred (Fig. 23). In this brake
it woiild be seen that there were two weights W and W^. The
weight W was lifted and the weight Wj lowered if the brake
blocks began to rotate with the wheel. In the brake actually
made Wj was suspended by four cords c passing over a part of the

DISCUSSION OX FRICTIOX-BRAKE DYNAMOMETERS. [Minutes of

Mr. Willans. circumference of the brake-wheel, and the brake-strap proper was
di\dded into two parts, one on each side of these cords. The
weight W was suspended by a flexible band, which was wound
or unwound if the strap showed any tendency to rotate with the
wheel. The cords c carrjang the weight W^ were connected at
a point p with the brake-straps h h. The brake compensated per-
fectly, because if the weight W was raised, owing to an increase in

Fig. 23.

the friction of the brake-blocks, the arc of contact of the cords c
was reduced and the upward motion of W was at once checked.
Ko readings were necessary during the trial, and little or no
adjustment of the hand-screw, as the load was solely dependent on
the weights W and Wj and their respective distances from the centre,
the only error being the one due to a variation in the position at
the beginning and end of the run of the two weights, a very minute
one, and one which could be measured if necessary. There was a
slight inaccuracy in the balancing due to the length of rope
unwound, but this could be obviated. The rope (Fig. 23) ought

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 49

to he carried roiincl to the other side, as shown by the dotted Mr. Willans.
lines, because of the slight difference in the length of cord over-
hanging; but with that exception, he thought the brake was
quite right in every way. It was designed by Mr. Coope, and it
was on the same principle as Mr. Imray's, Fig. 4; but it was an
improvement on it, because in Mr. Imray's the frictional resistance
was only that due to the two weights resting on the wheel. In
Mr. Coope's brake any required strain could be put on the main
strap, the variation in friction being compensated by varying the
arc of contact of an auxiliary strap only. The only part of the
design for which Mr. Willans was responsible was the spring 8
instead of the rigid screw often employed ; he had found this a
great help in obtaining a smooth working brake, but very likely it
might have been often used by others also.

Professor Alexander B. W. Kennedy said, that recently, in Professor
connection with Dr. Hopkinson and Mr. Tower, he had condticted '^"'^^^y*
certain motor-trials for the Society of Arts, and these trials included
a number of brake-experiments. Their results had not yet been
published, but he believed it would not be improper for him to say
a few words about the brakes used on that occasion. After some
of the beautiful apparatus mentioned in the Paper and in the
discussion, he was afraid that the ropes which he had exhibited
would appear very shabby. But after consideration they had
thought it best to revert to that simplest form of brake, a rope or
couple of ropes, making one turn round the wheel, with a spring-
balance pulling against the weight, as in Fig. 15. He would give
a few figures to show how the method worked. The largest power
that they took up from one wheel with a pair of such ropes, the
wheel running perfectly dry without lubrication, with an engine
having a fly-wheel weighing about 1,650 lbs., and a diameter of
5 feet 5 J inches, the rim 9 inches wide, and running at 60 revo-
lutions per minute, was just under 15 brake HP. Under these
conditions the brake worked perfectly steadily, but the wheel
became heated. In another case they had to take up 19 or 20 HP.,
and they thought it best to have a wheel made with a rim of
trough-section. The wheel was 5 feet in diameter and 7 inches
wide, weighing 910 lbs., running at 140 revolutions per minute,
and it took up 19^ brake HP. without the slightest trouble. They
continually let water drip into the trough and evaporate out, so
that there was perhaps ^^ inch of water in the trough during the
whole time. Working it out roughly, he found that the heat
taken up by the water evaporated amounted to from 80 to 90 per
cent, of the whole brake-power. There was, however, an uncertain

[the INST. C.E. VOL. XCV.] K

50 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

Professor small amount of water lost by splashing, which would affect this
Kemie y. pgypg^tage. In the case of a brake carried once round the wheel '
in that waj', of course the absolute value of the spring-balance
reading was a matter of importance. It was found that the ,
average pull on the spring-balance was about yL of the large |
weight, and never varied rapidly, but only slowly, and to an
extent of only a small percentage of its own value. They had it
noted every five minutes during a trial of many hours, and they
imagined that they had a better average value of the spring-
balance pull in that way than they had of the indicated HP. by
taking the indicator cards every quarter of an hour, instead of
registering the power continuously. In order to get the rope-brake
to work thoroiaghly well, it was advisable that the pulley should
be flat and not rounded, also that the little wooden clips, which it
was safe to put on so as to keep the ropes from slipping off, should
have the rope laced to them, and not fastened by a nail or screAv,
or by any metallic substance which could heat and burn the rope.
Mr. Kapp. Mr. GiSBERT Kapp some time ago had occasion to test electro-
motors, and he wanted a very delicate brake for the purpose,
which would not be liable to any disturbing error such as was
introduced by the compensating-lever. He had found the brake,
which he was about to describe (Fig. 24) very useful for small
powers. In his tests the motor was placed on the floor, and was
provided with a rope pulley which revolved in the direction shown
by the arrow. On the table above was placed an ordinary pair of
scales. Two holes were bored in the table through which the
ropes were brought up. It was important that 4he height of
attachment of the two ropes should be different. The attachment
E was on the same level with the centre of rotation of the beam,
and the attachment D was somewhat lower. When the pulley
pulled down the cord on the right and allowed the cord on the left
to rise, the leverage on the right was slightly decreased and on
the left slightly increased. At the same time the rope got a little
slacker. That, therefore, was a compensating action ; it allowed
the weight to be lifted a little higher, and the rope to slacken
until the weight on the scale would just balance the turning
moment transmitted from the motor pulley through the ropes to
the beam of the balance. The latter was then out of level, and, to
bring it into the horizontal position, additional weight must be
put upon the pan, and the thTimb-nut above the suspending spring
S must be simultaneously tightened so as to put a little more
strain on the rope. Two adjustments had therefore to be made
before an observation could be taken, one the adjustment of the

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 51

weight on tlie scale, and tlie other that of the initial tension in the Mr. Kapp.
rope; but he would here remark that the necessity of making
two adjustments was common to all brakes. The brake he had
described did not require more attention or labour in setting it
than any other ; but it had the advantage that the compensating

Fig. 24.

action did not introdiice an error when the brake was in equi-
librium. Of course, a reading was only taken when the beam was
floating horizontally. In that case the leverage on both sides was
equal, and therefore the reading was correct.

Professor W. E. Ayrton said his experience had been with small Professor
transmission- and absorption-dynamometers ; but, in view of the ■'^y**"^*
great use of electromotors in connection with the vast system
of electric distribution promised next year, some remarks on
dynamometers of this description might not be out of place.
There was no doubt that of the two kinds of dynamometers
the transmission-dynamometer was the less satisfactory; for,
whereas it was quite easy to apply an absorption-dynamometer in
place of a tool driven by a motor, it was not nearly as easy to
apply a transmission-dynamometer, for example, in the case of a

K 2

52 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes oi

Professor dynamo-machine which was driven by a belt. It was a reflection
Ayrton. ^^ electrical engineers that they had no means of doing that. His
colleague, Professor Perry, and he had tried various methods. He
could not give any details of them, as they were far from being in
a practical state yet, but he would endeavour to give an idea of
what they were aiming at. Taking an ordinary belt driving a
dynamo-machine, to estimate the difference in the tightness of
the two parts, they had tried sending waves along them, setting
the two sides of the belt in vibration, and seeing how many nodes
were found in the one and in the other. Another plan they had
thought of was having a wire fastened to the belt and running
with it, and getting the electrical resistance of the two parts, thus
ascertaining the difference of tension. At present, however, there
was no mode available for at once applying something to a belt
driving a dj-namo-machine, and estimating the power given to the
machine. The nearest approach to it was the well-known belt
dynamometer of Hefner-Alteneck, which measured the difference
of tension in the two belts. It was not a very satisfactory appa-
ratus that could be always left in place measuring the power given
to the dynamo-machine. It was extremely noisy; there was no
method of lubricating its many pulleys ; and it was not particu-
larly accurate near the zero. For that reason they thought five or
six years ago that it would be a good plan to make a sort of
dynamometer-coupling, which should always remain in position in
a shaft, and would, therefore, tell the power the shaft was trans-
mitting ; not a laboratory or testing-apparatus, to be only employed
when an investigation was to be made, but something w^hich
shoiild always be indicating the power that the shaft was
transmitting. He exhibited such a coupling, which had been
running for the last five years in the main shaft of the Fins-
bury Technical College. It was made in two parts, joined
together by spiral springs. One-half was keyed to one end
of the shaft ; and the face was keyed to the other. The torque
transmitted was, of course, evidenced by the slight stretching of
the springs. So far. Professor Perry and he had merely followed
a great number of people who had preceded them, and who had
measured a transmitted couple by the extension or bending of
springs. The question was how to measure that slight stretching ;
and it was in the method they employed for measuring the exten-
sion of the rotating springs that the novelty existed. The plan
which they had found best was to attach the arrangement by a
simple link-motion to a light pointer, which carried at the end a
bright bead. When the apjiaratus was rotating, the bead described

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 53

a bright circle, the diameter of which became less as the power Professor
transmitted was greater. In the instrument, the motion was ^^ °"'
exactly, as given by a curve of the calibration which he held in
his hand, 3 HP. per inch. The diameter of the circle measured
the power that the shaft was transmitting at a given speed of
revolution. At a speed of 1 62 revolutions per minute, the diameter of
the circle described by the bright bead diminishing by 1 inch meant
3 HP. The apparatus was very sharp in its action, arising from
the springs being very strong and the pointer light, the sensibility
being obtained by considerable magnification being effected by the
way in which the pointer was fastened. If the load on the engine
were changed, the bead moved instantly to a new place. For a
given load, at a given speed, there was an oscillation of about
^ inch of the bead, so that the diameter of the circle described
by the bead could be read accurately. The slight oscillation
showed that the friction was not resisting motion. They used a
gas-burner over the right shoiilder of the observer, which illumin-
ated the rotating bright bead more conveniently. The idea of
applying a dynamometer directly to the pulley of a dynamo-
machine had been a long-cherished idea with them ; and he was
delighted to find that Professor Smith had carried it out. He had
replaced the ordinary pulley of the dynamo-machine by what
looked like an ordinary pulley, biit which also measured the power
transmitted by the belt to the machine.

The idea of a dynamometer-coupling had also some five years
ago been employed by Professor Perry and himself, with the
co-operation of Mr. Tomlinson, who was assisting them at that
time, in order to get an automatic governing of the speed of an
electromotor. The ordinary method was to have some sort of
centrifugal governor which cut off the current when the speed
was too fast. They, on the other hand, wanted to devise a
dynamometer for governing, so that the motor should be regulated
by the work it had to do, and not by the sj)eed it ought to
go at, but was not going at. In their motor, instead of having
stationary field-magnets, stationary brushes, and a rotating arma-
ture and commutator, they had a stationary armature, rotating
field-magnets, and rotating brushes. Under ordinary circumstances
in one of their ungoverned motors, the brushes were keyed rigidly
to the field-magnet; but, instead of that, in their " dynamo-
metrically governed " motor the brushes were keyed to the tool
driven by the motor, the briishholder being connected with
the field-magnet by a spiral spring. If, further, matters were so
arranged that when the spring was stretched, when there was

54 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

Professor much torque transmitted by the motor to the tool, the brashes
Ayrton. -^gj-g j^ their best position, whereas when the torque transmitted
was small, and the springs were much less stretched, the brushes
were in a less favourable position, there had been an extremely]
simple dynamometrical governing of the motor; the motor went]
at a constant speed, because the greater the pull it had to give, ot\
the greater the couple it had to exert on any tool, the more were
the springs stretched, and the more was the brushholder left
behind, and the better was the position of the brushes electrically.
Dynamometrical governing had been subsequently devised by
Professor Silvanus Thompson in England, and by Professor Elihu |
Thomson in America.

In all compensating absorption dynamometers, there was a certain
object to be carried out. The coefficient of friction varied. People
had tried in a variety of ways to make up for this. Something must
be varied if they did not want the weights to be thrown over. One
plan was to let one of the forces vary by means of the spring-
balance ; but he did not think it was a good plan, as it was likely
to alter the load on the dynamometer. Another plan was to vary
the arc of contact. It was curious that every person who had
arrived at that idea seemed to regard it as his own. It had been
invented over and over again, and he now heard, for the first time,
that Mr. Coope had invented it. He believed it was due initially
to Professor James Thomson. It was afterwards re-invented by
Mr. Carpentier, and modified by Mr. Eaffard, who made compen-
sating-dynamometers on that principle several years ago. The late
Professor Fleeming Jenkin, M. Inst. C.E., while working with
them in telpherage, hit on the same idea and thought it was his
own. He and his colleague had tried several dynamometers
utilizing the same princijDle, and, as far as he had seen, the auto-
matic variation of the arc of contact was the best method of
compensating for alteration in the coefficient of friction.

It had occurred to them, however, four or five years ago, whether
there might not be another way of compensating for variations in
the coefficient of friction when the difference of weights was kept
constant. The idea was to use two cords, not two different cords,
but a cord in two parts, with different coefficients of friction,
joined together, and their arrangements had been referred to
by the Author in his introductory remarks. The plan had
become much simplified after several years of trial. It was
found that a small knot tied on the cord answered all purposes.
It was so simple that he hardly liked to show it ; but its sim-
plicity was its great charm. There was a cord running in a

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 55

grooved pulley and a string was tied ronnd the cord to make a Professor
softish knot or protuberance in the cord. It was not at all a ^y''*°"-
bad compensating-dynamometer. The load might be altered
considerably without getting the weights thrown over. Such
an absorption-dynamometer with a knotted cord had been used
on an electromotor for several hours at a time without either
of the weights falling, and without any adjustment being made
by hand. Every now and then, when the coefficient of friction
diminished and the heavier weight fell, the knot came up against
the pulley and prevented it going over ; then it went back
again and oscillated slightly. He might mention that a form
of knotted-cord absorption-dynamometer had been employed
by them in experimentally calibrating the transmission-dyna-
mometer with rotating bright bead which he had been describing.
The absorption dynamometer in this case consisted of a cotton belt
some 4 inches wide, hanging over an ordinary flat-rim pulley,
carrying weight at each end, and the knot was formed of a
leather lace that was passed two or three times backwards and
forwards through the cotton belt. They had found that the
automatic compensation was very good, and that, by having a
stream of soapy water running over the belt, this form of dyna-
mometer could be used to measure up to 27 HP. The transmission-
dynamometer was calibrated by transmitting through it the power
from the engine which was temporarily all wasted, and at the same
time measured with this knotted-belt absorption-dynamometer.

Mr. John Imray said that, in the Paper, reference had been made Mr. Imray.
to a brake which he had invented many years ago (Fig. 4), and it
might be interesting to the members to know something of the
circumstances under which it was brought out. It was many years
since the late Mr. William Fronde and he investigated, at consider-
able length, the conditions of the frictional hold of belts upon
pulleys, and the result was communicated in the Paper by Mr.
Froude to the Institution of Mechanical Engineers.^ The first
thing they had to look at was this. At that time amongst
engineers there was a fallacy prevalent that, the larger the pulley,
the greater was the frictional hold of the strap upon it. They
disposed of that by trying pulleys of all sizes from 5 inches to
5 feet, with straps on them loaded with weights, and there was not
a shadow of difference between them. The diameter of the pulley
had nothing to do with the frictional hold. They then investigated
the question, and they thought that they were the first who had

' lustitutiuu of Mechanical Eugiucers. Proceedings. 1858, p. 02.

56 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

Mr. luiray. come to a formula for frictional hold, which was very much like
the one given by Professor Ayrton. It appeared from that formula
that a change in the number of degrees of the arc of contact made
a great change in the frictional hold. For instance, they found
that if the one weight was 1 lb., and the other weight was 3 lbs.,
when half the circumference was embraced, then the latter would
be 9 lbs. when the whole circumference was embraced, when three
halves 27 lbs., and so on according to the formula. It there-
fore appeared to him that the best way of making a brake auto-
matically adjustable was to make it vary for itself the amount of
the circumference which was embraced by the strap. For that
reason he schemed the brake shown in Fig. 4. There were two
arms, one on each side of the wheel. Those arms carried metal
straps, by which the large weight was hung; and to the top of
those arms at B the brake-strap was attached. Whenever the
weight rose it took a less part of the circumference ; when it
descended it took a greater part of the circumference, so that it
always cured itself, and it kept very steady. He believed that
Mr. Froude used it, and to a large extent had foimd it suc-
cessful. About the same time Mr. Froude produced a brake for
measuring the power transmitted to a machine. He had two
pulleys, and he passed the strap round one of them, back round the
driving-pulley and then round the other. Those two pulleys were
mounted on a lever with a spring-balance, that measured the
difference between the tight strap and the loose, and recorded
that upon a card which gave a good indication of the power
transmitted.
Professor Professor E. H. Smith stated that he had been asked to explain
the construction of his transmission-dynamometer, which he had
brought for the purpose. One of its chief advantages was that it
tested the machine to be indicated exactly under its ordinary
working conditions. The ordinary driving-pulley was taken from
its shaft, and the dynamometer-pulley was clamped in its place.
The machine exhibited could be clamped upon any shaft, from
1 inch to 2 inches in diameter. It consisted of a central body,
which was bored right through to 2 inches diameter, and in which
were cut three taper slots, up which were driven three wedge keys,
all advanced together hj a ring and a single nut, the nut being
2y\^ inches inside diameter and having its thread on the outside.
Thus the instniment was clamped upon the shaft so that, if the
shaft itself ran true, the dynamometer-pulley invariably ran true,
if it was clamped Avith sufficient tightness. If it was allowed to
get slack it began to vibrate. At the end of the inner body ran

Proceecliugs.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 57

loosely an outer collar or flange to which was bolted the pulley Professor
upon which the driving-belt ran. The pulley was made separate ™' *
from the flange for the sake of changing it, so that difierent sizes
of pulley might be readily put on. Between the flange which ran
loosely upon the inner body and another flange which was keyed
to it at its other end, lay a couple of spiral springs. The belt,
therefore, of the pulley could only drive the shaft through the
intermediation of the sj^ring; and, having calibrated the strength
of the spring, the twist of the spring measured the moment being
transmitted. It only remained to render that twist of the sj)ring
visible upon a scale, which was done by an indicating nut. Upon
the end of the inner body was cut a sharp-pitched, double-threaded
screw, a nut running upon it. Along with the outer j^art of the
instrument, namely, the driving-pulley, ran a steel tube in which
were cut two longitudinal or axial slots, opposite each other, and
the indicating nut had two corresponding wings which could slide
along the slots. Thus, since the rotation of the nut equalled the
twist of the spring, and therefore indicated the driving moment
that was being exerted, and, since the nut must move axially
along the screw a distance proportional to its rotation, the axial
movement of the nut indicated the moment being transmitted.
That was magnified by means of a long light lever. Two little
steel blocks mounted on the pins in the ends of the short double or
forked lever rested continually against the flange of the indicating
nut ; they were always kept pressing one side by a weight on a
small lever. The end of the long lever indicated the driving
moment upon the scale. Two sets of springs were supplied ; one
a right-handed spiral spring, and the other a left-handed spiral,
suitable for machines which rotated in opposite directions.

The transmission-dynamometer of Messrs. Ayrton and Perry
had, no doubt, been greatly improved since its introduction. The
first of these was made in his own works from his own drawings.
Professor Perry supplied a sketch of what he wanted ; but in this
sketch the arrangement of the springs was identical with that of
General Morin's original dynamometer, and quite different from
that actually adopted in this machine.

With reference to friction-absorption dynamometers, he thought
that the moral to be drawn from the first part of Mr. Fronde's
remarks, illustrated by the diagrams, was simply that the whole
dynamometer should be made as light as possible ; and a corollary
from that moral was that, instead of using weight forces, spring
forces should be employed, because spring-balances were less
massive than the weights for the same forces exerted. Professor

58 DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [IMinutes of

Professor Kennedy had referred to the good action of the rope-dynamometer.

Smith, jjg might mention that during the present year he had used a
similar dynamometer made of an ordinary leather belt, running
upon a 5-foot cast-iron fly-wheel, with a spring-balance at the
slack end, and a weight at the other, and it ran very steadily. He
now wished to make two classifications of friction-dynamometers.
In the first place they might be practically divided into friction-
brake dynamometers for small and for large powers. The dyna-
mometers for small powers were easy to construct, but it was
difficult to construct one that would work well to indicate large
powers. The reason of that, he thought, was because the coefficient
of friction must be kept small in order to get smooth, easy work ;
and the necessary consequence was that very large surfaces must
be employed, wide brake-pulleys, and large diameters. The whole
thing became clumsy and awkward for large powers. He had
sketched a diagTam to show why, in order to get smooth working,
the coefficient of friction must be kept down. The reason, in
mathematical language, was that the second differential coefficient
of the ratio of the large tension to the slack tension at the two
ends of the belt, taken with respect to the coefficient of friction,
was very rapid. Taking, for instance, an arc of contact equal to
a whole circle, and the coefficient of friction O'lO, 0*20, 0*30,
0-40, and 0"50, successively, the ratios of the tension at the
tight to that at the slack end woiild be 1*87, 3 '51, 6*59, 12-30,
and 23 "10. If that was indicated graphically by a curve, it
would be noticed that the curve turned up very sharply. Thxis,
at high coefficients of friction a small variation of friction-
coefficient created a gTcat disturbance in the mechanical working
of the machine, while with small coefficients there was a com-
paratively small disturbance. The variation with regard to the
arc of contact was of exactly the same kind. Thus, to avoid
irregularity of working, it had been frequently found necessary to
use unguent in order to keep down the coefficient of friction.
At first sight, the use of unguent might seem most irrational
in a machine of that kind, which was a machine for creating
friction. The second classification which he would like to make
was one with regard to the compensating attachments. Careful
distinction should be made between two kinds of compensation,
firstly, momentary compensation, compensation for variations of
coefficient of friction that lasted only for a moment or two ; and,
secondly, compensation for gradual and permanent variation of the
coefficient of friction.

The first kind might depend on the inertia of the mass of

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS.

one part of the instrument. This was the principle of the designs Professor
shown in the three diagi'ammatic sketches, Figs. 25, 26, and 27.
The first two of these he had used successfully, the second. Fig. 26,
being what was ordinarily used at Mason College. In this,

Fig. 25.

however, the compensation-joint came near the tight end of the
strap. If it was inserted at the slack end, as in Fig. 27, it should
act more delicately and promptly. In each case the strap was
tightened at the compensation-joint by an auxiliary lever a c,
which was bound to the main lever by a spring c d (usually an

DISCUSSION ON FKICTION-BEAKE DYNAMOMETERS. [Minutes of

Professor india-riibber band).

Smith.

The tension of this spring was conveniently,
but not necessarily, made adjustable; but this tension did not
need to be measured. On gripping of the blocks on the drum
occurring, the main lever was carried round, but the inertia of the
auxiliary lever caused its end c to lag behind the main lever in its
motion, and thus to slacken the strap at the joint a h. There was
one minor fault inherent in these brakes, namely, that the mo-
mentary compensation took place in spite of the tightening of the
spring c d. The auxiliary lever should be made massive at the
end c, in proportion to the average tension put on the spring c d ;
but, since the whole weight of the apparatus was accurately
balanced over the centre of the brake-wheel by the adjustable
weight G, no force measurement except that of the indicating
spring came into the calculation of the brake-power. In each

Fig. 28.

ScoJecL

SvrLng

case the centre of mass g of the aiixiliary lever, and the joints
a and h, should all be on one radial line. It would be an improve-
ment to bell-crank the auxiliary lever, and place the spring
binding it to the main lever radially as in Fig. 28. In this
arrangement the weight of the auxiliary lever being left mo-
mentarily behind to the left of the vertical through the joint on
which it rested, exerted a txarning moment tending towards an
extra slackening ; that was, a moment partially counteracting the
tightening effect of the spring, which moment increased the further
the brake was drawn round by the gripping of the blocks.

Deprez's brake (Fig. 3), was an example of compensation for
gradual and permanent change of coefficient of friction. The rope
or leather strap with weight and spring-balance at the slack end
also belonged to this class. Fig. 29 showed another form which it
would be interesting to try. In this the tension t at the slack end

'Proceedings.] DISCUSSION ON FEICTION-BRAKE DYNAMOMETERS.

was produced by a spring acting throngli a bell-crank, shaped and Professor
supported so that, when the brake gripped and was carried round, ^""*^"'
compensation took place in three different ways ; first, the spring
shortened and exerted less pull ; second, its leverage round the
fulcrum decreased while that of the end of the strap increased, so
that the ratio of slack-end tension to the pull of spring diminished ;
third, the strap was lifted off the brake-drum through a small
increasing arc, so that the arc of contact was diminished. The
objection that the ratio of t to the pull of the spring was variable,
and entered into the calculation of the HP., might be met by
inserting a second scaled spring between the end of the strap and
the bell-crank, in which case the tension of the lower spring would

FiCx. 29.

not need to be measured. The apparatus then became, however,
more complicated and expensive. It might be interesting to note
the correct formula that took the place of the well-known logar-
ithmic or exponential formula (which was only ajjplicable to a
continuously-covered arc of contact), when the friction was pro-
duced by blocks at finite angles apart. If there were n blocks
from the slack pull t to the tight pull T spaced equally at the

2 TT

angle -:j^ apart ; and if </> was the " angle of repose " (tan 0 =

coefficient of friction) ; then the correct ratio between the pulls at

the two ends was

~ 1

sin|.(i-

-ky^\

sinj.Q-

~k)-

-*!

DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

Professor on the Supposition that the blocks were connected by links with

Smith, frictionless pin and eye-joints.

r. Halpin. Mr. Druitt Halpin could not agree with the statement in the
Paper, that the dynamometer could never give scientifically accu-
rate measurements of the rate of the absorption of the work done.
He thought, if proper precautions were taken in using the instru-
ment, and in registering its indications, one of the most accurate ,
results might be obtained with which engineers were acquainted. He
would endeavour to show how such results had been secured in the
trials carried out at Leeds by Professor Barr and himself ; and it
mis:ht be of interest to describe the means taken to arrive at the
truth in those trials. He had interpolated a column in itabcs
in Table III (p. 27) in the Paper, and some remarks which he
would explain.

Messrs. McLaren's Trial.

Halpin's
Brake.

Brake made
like R.A.S.
" corrected."

Brake made

like R. A. S.

but calculated

by R.A.S.

Rule.

Indicated HP 23

Brake HP 20

Coal per brake HP. per hour . j 2

Feed-water per brake HP. per\ „„

hour /; ^-^

Mechanical efficiency ... 0

22-20

19-10

2-14

22-00

0-86

R.A.S. Trial

at
Newcastle.

22-20

29-95

1-39

14-26

1-54

24-020

22-770

2-267

21-530

0-860

All tests to which he referred were made with the same com-
pound-engine, indicating approximately 20 HP., which had been
tested at Newcastle in 1887 by the Eoyal Agricultural Society
of England. The first tests mentioned in the Paper were on a
brake similar to that sho\\Ti by Fig. 15. That brake carried the
load directly at P, and at the top, at the tail-end of the brake-
strap, there was a spring-balance, which had been accurately
tested with dead-weights. The rim of the brake was as shown in
Pigs. 14 and 15, and water was run into the rim on one side, and
-continuously removed at the other. Passing a constant quantity of
water through the rim of a brake-wheel was a very different thing
from getting water in, and letting it boil off at any varying tempera-
ture ; as the power of maintaining the temperature constant made it
possible to keep the coefficient of friction constant, and thus to
ensure the uniformity of the brake resistance. A further precau-
tion to obtain accuracy was that the spring-balance was connected

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 63

to the recording-paper of a Moscrop recorder, which he certainly Mr. Halpin.

thought was a most delicate instrument, both in connection with

the indicator and with the brakes. In that way, an absolutely

autographic record was secured of the variations in the pulls in

the tail-strap of the brake. Those variations occurred from one

reason : the brake had run only a day or a day and a half before

use, and he had found from experience that, if a brake was running

in proper order, having the temperature completely under control,

the blocks having been at work a reasonable time, it could be

treated absolutely in the same manner as a counter ; it must not

be toiiched fi'om the beginning to the end of the run. If a brake

Fk;s. 30.

381 lbs

was not running in that condition, to his mind it was not running
correctly. That was the first test made of which the figures were
given in the first column, the indicated HP., and the brake HP.,
and the result was that a mechanical efficiency of 85 per cent, was
obtained. The second column referred to a test conducted with
the same engine. It was made on a brake as nearly as possible
like the brakes used at Newcastle by the Eoyal Agricultural
Society, except that the precaution was taken of measuring the
whole of the forces acting on the brake, it not being assumed that
any negligible forces were passing through certain fixed points.
The brake was shown (not to scale as far as the lever was con-
cerned) in Figs. 30, and the data in connection with the test
were given in the second column of the Table, abstracted from

64 DISCUSSION ON FRICTION-BEAKE DYNAMOMETERS. [Minutes of

Jlr. Halpin. the Paper, with the addition in inverted commas of a single word,
" corrected." The results were given as foxmd ; but with the
addition that the whole of the forces, and not merely some of them,
as at Newcastle, were measured. The inner end of the compensating-
lever was left free, and two powerful spring-balances, carefully
calibrated, were attached to it ; the effect was that, when carrying
a load of 381 lbs. vertically at the end of the lever, the pull was
313 lbs. This altered the result ; for had the brake-power been
calculated, as was done by the Eoyal Agricultural Society, and
the number of revolutions taken multiplied by the load lifted and
multiplied by the radius, the brake HP. would have been 29 • 95,
with an indicated HP. of 22 • 2, giving a mechanical efficiency of
the brake of 1 • 54. Under the circumstances, he thought that error
w^as worth noticing. A fourth column showed the results as
obtained by the Eoyal Agricultural Society at Newcastle ; and
the Author stated, quoting from a Table published by one of the con-
sulting engineers of the Society : " It will be seen that the figures
agree very closely." The Author stopped there, but Mr. Anderson
went on to say : " Hence we are bound to assume that the experi-
ments at Newcastle were substantially accurate, or that Messrs.
Halpin and Barr have erred to the same extent we are supposed
to have done." He thought the accidental closeness of the
figures was arrived at by introducing a necessary correcting
coefficient of 56 per cent. In making the test referred to in
the second trial, a most interesting fact had been graphically
recorded. The brake was similar to that shown by Fig. 5, with
a compensating-lever, and water was run on to it, as at New-
castle. The pull at the end of the lever was graphically registered
by the Moscrop recorder. Everything was measured — the water,
coal, and all else used by the engine in the experiment —
and the boiler was fed from a large tank, containing a weighed
quantity of water. In the middle of the run it became necessary
to refill the tank ; and as only one water-service of pijjes was
available, both for replenishing the tank and for cooling the rim of
the brake-wheel, the tank was filled from that service ; therefore
the Moscrop recorder showed immediately the variation of the pull
at the inner ends of the compensating-lever ; so soon as the water
began to enter the tank, and the available supj^ly of water on the
brake-wheel was limited, the coefficient of friction changed enor-
mously. The brake HP. went down from 29 • 95 to 23 or 24. The
speed remained constant, and the indicated HP. decreased, owing
to the action of the automatic expansion-gear, on the steam admis-
sion in the high-pressure cylinder. When the cock was shut again.

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 65

after the tank was filled so as to feed tlie boiler from, it, and the Mr. Halpiu.
water was again txirned on to the rim. of the brake-wheel, there
was the same evenness in the pull on the inner end of the com-
pensating-lever. To obtain accuracy, the curves were plotted and
treated with a planimeter. Autographic registrations had been
made, during both trials at Leeds, by means of the Moscrop recorder ^
(Fig. 31), where the top line in each case showed the variations in
the boiler-pressure ; the centre line the percentage of variations in
the revolutions of the engine, an increase or decrease of speed of
2 J per cent, being measured by the vertical distance between the
lines ; and the bottom line the variations in pull on the tail of the
brake-strap during the first trial, and on the inner end of the com-
pensating-lever during the second trial. A great decrease in this
pull was noticed about the middle of the run, owing to the shortness
of the water-supply to the rim of the brake-wheel, as explained
above. If those curves were treated by a planimeter, as indicator-
diagrams were, very accurate results could be obtained. A year
before the trials were made, he had suggested to the Eoyal Agri-
cultural Society, at a meeting of the Institution of Mechanical
Engineers, the desirability of not working with the usual form of
brake, but working with a water-cooled brake, which would be
under complete control ; and also, instead of introducing a further
unknown error, by using the present form of brake separate from
the engine, and having two universal couplings with an inter-
mediate length of loose shaft, plus another shaft with two additional
bearings carrying the brake-wheel, to obviate the existence of all
such sources of error by putting the brake directly on the crank-
shaft of the engine to be tested. What the value of that error
might be he was unable to say ; but when the brake was running
directly on the engine-shaft, the consumption of coal was 2 • 1 1 lbs.
per indicated HP. per hour (Table III, line 3) ; and when it was
running, having the power absorbed by means of the indirect
transmission, and using the necessary correction, it rose to 2 "14 lbs.
Trustworthy results, however, could not be expected from the
indicator-diagrams at the Newcastle trials, as they were not taken
at the same time as the brake-tests were made, and an inspection
of some of the sample ones, published by the Consulting Engineers,
bore an error on their face of 27 per cent. When a comparison of
the indicated and the brake HP. produced a mechanical efficiency
of 1-082 per cent., the Consulting Engineers gave a foot-note,^ to

' The Engineer, vol. Ixv., 1888, p. 23.

' Institution of Mechanical Engineers. Proceedings, 1886, p. 370; and
Journal of the Royal Agricultural Society, 1887, p. 725.

[the INST. O.K. VOL. XCV.] ¥

DISCUSSION ON FEICTION-BKAKE DYNAMOMETERS. [Minutes of

Mr. Halpin. the effect that " there was an error in the observations, due pro-
bably to defective indicator-pijjes," but when they had to record

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an efficiency of merely 0-943, they did so without comment,
evidently crediting this result as a physical possibility. He
asserted that, unless the wliole of the external forces acting on a

•ProceediugB.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS.

dynamometer were accurately measured, the results were worthless, Mr. Halpin.
and did not give the proportional efficiencies of various motors
tested on the same brake. He could confirm one statement in
regard to the Leeds trials. Professor Barr stated that he was
informed that the engine when in their hands ran much better
than it did at Newcastle. Mr. Halpin was close to the engines
during all the trials, and observed their work, and he could fully bear
out that statement. When the engine was brought to Newcastle,
it was new; it came into the hands of Professor Barr and Mr,
Halpin after it had been running two or three weeks, and the
difference in working was very marked.

Mr. John Goodman said that none of the speakers had referred to Mr. Goodmaiu

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a method, in use in America, for making dynamometer-brakes run
more smoothly than with the ordinary wooden blocks, namely, by
covering each block with a piece of leather. Some time ago when
he was making a brake trial, the brake vibrated a great deal ; and
instead of putting a dashpot on in the usual way, he covered each
of the blocks with a piece of old leather belting, and immediately
the brake ran as steadily as possible. During the past week he
had made several experiments with leather, wood and rope on a
friction-machine, the results of which were shown by Fig. 32.

F 2

68 DISCUSSION ON FRICTION-BEAKE DYNAMOMETERS. [Minutes of

lan. The lubricants were plumbago and tallow, which showed that by-
using rope, or by lubricating the surfaces, the friction was much
more regular than with dry leather and dry wood. The machine
was driven by a gas-engine. At each ignition of the gas there
was a distinct vibration due to a momentary change of speed and
friction. With dry wood, at every ignition of the gas, there was
a diiference in the coefficient of 0-030; with dry leather, 0-014;
with dry rope, 0 • 002 ; with wood lubricated with tallow and
plumbago, 0 • 007 ; with lubricated leather, 0 • 004 ; thus showing
that with a variation in speed, due to each ignition of the gas, the
vibration due to dry wood and dry leather was more than ten
times as great as with rope and lubricated wood. That might
throw some light upon the circumstance that the rope-brake used
by Professor Kennedy ran so very smoothly, even under the most
trying circumstances.

ont. Mr. W. WoRBY Beaumont, in reply, said, with reference to the
Table exhibited by Mr. Halpin, the conditions under which the
brake was used when those figures were obtained were certainly
not the conditions that existed when the Eoyal Agricultural
Society's brake was tried at Newcastle. At Newcastle the lubricant
gave a much higher coefficient of friction than water ; and, as stated
in the Paper, Messrs. McLaren found that with tallow the pull ui")on
the small lever was as low as 4 lbs., and in that case the error was
insignificant. Of course, one person could manipulate an instrument
so as to make very different indications from those obtained by
another person using it under different conditions. He therefore
did not think it was right that the figiires quoted should be taken
as final, because the conditions were diiferent. Accordingly, the
64 per cent, of correction need not be made. That, he thought,
was proved by the fact that the figures, when corrected, came to
the same within about ^i^, as ascertained by the Eoyal Agri-
cultural Society's brake, showing that it was only the ditFerence
of conditions that rendered the correction necessary. He had
not mentioned the steam-engine indicator referred to by Professor
Barr, and had no intention of siaggesting the possibility of com-
paring either the relative values or importance of indicators
and friction djmamometers. Concerning the rise and fall of the
load P, and the work done by the engine but not recorded in its
favour, the statement in the Paper was substantially correct, in
view of the action which took place in ordinary cases. With
brakes such as those shown by Figs. 5 and 12, the difference
between the velocity at which the load was lifted or fell was not,
he believed, sufficient to' allow the engine to obtain any note-

Proceedings.] DISCUSSION ON FRICTION-BRAKE DYNAMOMETERS. 69

worthy relief during the fall ; and, if this were the case, the raising Mr. Beaumom
of the load was work done but not acknowledged. If the load
were raised slowly, and dropped quickly, the engine might be the
gainer by relief during the fall. On the other hand, it was sup-
posed, as by Professor Barr, that when the load was lifted less
work was done against friction. This would be true if the load
could be caused to rise without change in the friction ; but inas-
much as the lifting of the load was a result of increase of friction,
the supposition was not allowable, except under conditions which
did not seem to occur in practice. But, the falling of the load
was assumed to be attended by the performance of more work
against friction ; as the fall was the result of decrease of
friction, this also was not a permissible assumption. Hence, the
work of raising the load was uncompensated work, and not recorded
in favour of the engine. The spring mentioned at p. 7, as pre-
ferable to a weight jj, was intended to be understood as prefex'able
in practice ; and with brakes that did not work " with a steady
load at the tail end," as stipulated by Professor Barr. If the very
simple and good brake, which would work with such a steady tail
load, coiild be had, it would be easy to work with accuracy without
any tail load. The rise and fall of the load P would, however, if
considerable, without doubt be attended with less inaccuracy with
a dead-weight tail load than with a spring. A brake, as Fig. 2, but
with a spring at S similar in effect to the springs shown in Coope's
brake, could probably be thus worked. Fig. 23. The reference
by Professor Barr to the use of the dashpot was a most important
one, as it showed how inaccurate the indications of a brake might
be if a dashpot were used. The coefficients mentioned on p. 18
were simply numbers proportional to the surface passed over by
the brake-blocks per HP. per minute in a number of cases ; and
from these were deduced constants, which might form a guide for
the determination of the minimum surface for such brakes. Or
two brakes equal in every respect, except that one was fitted with
compensating-levers, that brake which was not so fitted might be
employed to deal with more power, because the necessary increase
in the tension upon the brake-strap would not, after a certain maxi-
mum was reached, be attended by the inaccuracy which the levers
would introduce. There was no abuse of the mathematical method
in the calculation of the maximum tension on the brake- straps, for
the blocks, though not many in most cases, were sufficiently
numerous to permit the method of calculation adopted with almost
inappreciable error. With the small range of flexure demanded,
the brake-strap might be considered flexible without inaccuracy.

70 DISCUSSION ON FRICTION-BKAKE DYNAMOMETERS. [Minutes of

[r. Beaumont. The low coefficients of friction, assumed for the calciilation, were
purposely taken, so that a maximum pull upon the compensating-
levers would be arrived at ; and hence, if a larger coefficient were
more nearly that actually occurring, then there would be a still
smaller pull, with the loads taken, on the upper end of the com-
pensa ting-lever, and the error due to it would be less than that
given on pp. 20 and 23. He therefore considered a pull of 11 lbs.
at the upper end of the compensating-lever, and under the circum-
stances mentioned at p. 24, less than half what had been found by
Messrs. McLaren. If the engine referred to by Professor Barr did
work better at Leeds than at Newcastle, it was not shown by the
figures given on p. 27 ; but the boiler did appear to have done so.
The friction-brake described by Mr. Willans seemed likely to
give excellent results. The introduction of the springs at the
adjusting screws was a good feature, and would probably materially
reduce the necessity for other compensation. The information given
by Mr. Goodman would be \erj useful to engineers dealing with
friction-brakes and similar mechanism.

Correspondence.

'rofessor Professor T. Alexander and Mr. A. W. Thomson considered that

Hr. Thomson. *^® Appold brake gave quite accurate results when it was used

properly. There was a verj^ simple method of arriving at the

result (p. 26)—

a W = c P + F «'.

Suppose the compensating-lever to be as shown in Fig. 8 ; but for
simplicity, with the points of attachment A and B in a straight
line from X ; the cranking of the lever was of no consequence, so
far as the calculations were concerned. Let the lever take some
definite fixed position, say that of Fig. 6, when the engine was
working smoothly ; in this position the lever might be supposed to
be fixed to the gi'ound. Let the tensions of the lever on the brake-
blocks, towards the left at B, and right at A, be represented by
Tj and T3; then, since there was equilibrium, the sum of the
moments round 0 the centre, of (a) friction of brake-blocks, (h)
weight W, and (c) the tensions T2 and T3, was zero. Taking the
lever now, not as fixed to the gi-ound, but as pivoted at X ; then
E, the resultant of To and T3, must pass through X. T2 and T3
might now be replaced by R ; and the sum of the moments round
0 the centre, of (a) friction of brake-blocks, (b) weight W, and (c)

Proceedings.] CORRESPONDENCE ON FRICTION-BRAKE DYNAMOMETERS. 71

the force R, was zero. Eesolving E into vertical and horizontal Professor

Alexande
Mr. Thomson.

components, V and P acting at the point X; then, since X was exan er an

vertically under 0, the line of action of V passed through 0, and
its moment was zero ; and therefore the sum of the moments round
0 the centre, of (a) friction of brake-blocks, (b) weight W, and (c)
the horizontal force P acting towards the left at X, was zero ; that

was —

aW = cP -f Fa'.

The amount of this horizontal force P could be easily measured by a
sjiring-balance. With a low coefficient of friction, the tension on
the brake-strap had to be increased ; and since the ratio existing
between T2 and T3 was constant, depending on the proportions of
the lever, it followed that P might be of considerable amount ; and
any quantitative results calculated without taking it into account
would be erroneous. With a high coefficient of friction the force
P might be small, and the results might probably be not far
wrong, even if P was left out of account. In every case, however,
where accuracy was desired, the moment of P must be considered.

Mr. B. DoNKiN, Jun., submitted the results of some experiments Mr. Donkin.
with an Appold brake made in 1876, to determine the pull on the
compensating-levers. Por this purpose the fulcrum pins of the levers
were removed, and the levers retained in jjosition by strings, of which
one pair ran horizontally over jiulleys at d (Fig. 33) ; another pair
was made fast at e, and a third was threaded round the shaft and
carried vertically up to the handrail/. In working, the pairs e and
/were put on as safeguards, those marked ad g being the only ones
used. Before making an experiment the engine was run for about
half an hour, till the wheel was well warm, the strings over the
pulley at d being made fast at g, and the weights on the brake
lifted by means of the adjusting screw k. The strings were then
unfastened and weighted sufficiently to bring the load to the proper
position, the centre a being vertically below the centre of the
wheel. To effect this, it was necessary to adjust slightly the screw
h and the weight at g ; and, by disregarding the position of the
centre a, and screwing up or slacking out the adjusting screw /r, a
greater or less weight at g would keej^ the brake central. The
distance of the string a d below the centre of the shaft was 6| inches
full in all the following experiments. With 10 HP. (200 lbs. at
2 feet 7.V inches radius) on the brake, the weight at g was from 10
to 12 lbs., 11 lbs. being apparently the best. With 7 HP. (140 lbs.)
on the brake, the weight at g was from 6j to 7^ lbs., 6j lbs. being
apparently correct. With .5 IIP. (100 lbs.) on the brake, the weight

72 COKKESPONDENCE ON FRICTION-BRAKE DYNAMOMETERS. [Minutes of

Mr. Donkiu. at g was from 4^ to 5^ lbs., 5 lbs. being correct. With the strings
a' shown by the dotted line a' d' g', a being 1 foot 6| inches below
the centre of the shaft, with 5 HP. (100 lbs.) on the brake, the
weight required at g' was from 8.V to 9 lbs. Another experiment
was made by fixing strings to the tops of the levers at a, 6^ inches
below the centre of the shaft, and also another pair to the levers
4 inches above point 5, or 2 feet 2| inches below the centre of the
shaft, the strings being led over pulleys as before, and either or
both pairs could be used to keep the levers in position. At first the
top strings were used and the bottom ones left slack. With 7 HP.
(140 lbs.) on the brake, 3 to 4 lbs. on the string were sufficient

Fig. 33.

Experiments on Appold Brake with Ajios AcjrsTiNG Leters.

when the wheel was cool and the tallow stiff; after a time,
however, 6 lbs. were required, and this was enough during the
whole run of three hours. The top string was next slacked out and
the bottom one brought into use, and the necessary weight hung
upon it to keep the brake on its centre was 21 lbs. ; when the
requisite load on each string was found, the strings were used
alternately, the one not in use being looped up. The engine was
afterwards run with the governor disconnected at 92 revolutions
per minute, the top string being in use, and when the steam
I)ressure was steady the lower string was brought into use instead
of the top. The revolutions of the engine increased to 130 and
dropped down to 120 per minute, and, to adjust the engine, 16 lbs.

Proceediugs.] COERESPONDENCE ON FRICTION-BRAKE DYNAMOMETERS. 73

were added to the load of 140 lbs. on the brake, while to bring the Mr. Doukin.

brake to the centre 1 lb. was added to the 21 lbs. on the lower

string, when the speed of 92 revolutions per minute was again

obtained. This was repeated several times ; also, when the weights

from the lower were taken on to the upper string, the speed was

much reduced. The point of attachment of the lower string was

next altered and brought 18^ inches below thg centre of the shaft,

when it was found that, although the speed of the engine varied

as the strings were reversed, the difference was not enough to be

measured by putting more weight on the brake, as the engine was

not running j^erfectly uniformly. Lubrication of the brake by

tallow made the weights rise a little, oil caused them to fall.

When an attempt was made to run the brake without the com-

pensating-levers, the addition of oil sent the weight down with a

force of 8 or 10 lbs., but tallow alone instead of oil sent them up

with a force of 2 or 3 lbs. An experiment by running the brake

without the levers was not successful, as the weight could not be

kept properly balanced for more than a minute or so.

Mr. Frank Garrett remarked that he did not attach the para- Mr. Garrett,
mount importance to the subject of the construction of friction-
brake dynamometers generally, which had been accorded to it by
those who were possessed by the mania for engine-racing, and to
whom the capacity of a dynamometer to register the last foot-
pound appeared to be vital. He nevertheless esteemed the water-
cooled brake (Figs. 12 to 14) very highly, as a most trustworthy,
steady-going instrument, upon which he could rely for comparative
results, whether with regard to the duty of steam-engines or to the
steam-making capacity of coal. He had found it a most invahaable
assistant when experimenting with the governor of a steam-engine,
the compensating-lever acting admirably under the trying con-
dition of removing the weights suddenly from the scale, sometimes
one by one at intervals, and sometimes as quickly as possible,
until the engine had been relieved of all its load. The experiment
communicated by him to the Author had interested him greatly.
He might perhaps claim to have established the fact that, with a
water-cooled brake, a check, more or less approximate and reliable,
upon the duty of the engine might be recorded by means of the
heat-units transmitted to the water. In his experiments he had
disregarded the heat-units absorbed by the increased temperatures
of the brake-wheel, and these would probably go far to account for
the difference existing between the foot-pounds recorded by the
brake-wheel and the mechanical equivalent of the heat-ixnits trans-
mitted to the cooling water as given in Table II (p. 14).

74 COKEESPOXDEXCE ON FRICTION-BRAKE DYNAMOMETERS. [Miuutes of

Professor Professor A. Jamiesox stated that about a year ago he had
Jamieson. occasion to make a series of tests on a Griffin gas-engine. The
brake proposed by the makers of this engine was the same as
that used by the Eoyal AgricuUiiral Society described and com-
mented upon in the Paper. Owing to the evident defects of the
Agricultural Society's brake, one of the following form, Fig. 34,
was adopted instead, which gave fairly good results with the gas-
engine, developing 13 "6 brake HP. Thechief objections, however,
to it were :— 1. That even for that small jDower, it was necessary
to have two brakes, one brake upon each fly-wheel. 2. That the
lubrication of the brakes required considerable attention. 3. That
the back pull, indicated by the Salter's balances, varied considerably,
and hunted up and do^vn within limits which necessitated some
guessing and frequent observations. 4. That the oil or grease for
lubricating the fly-wheels bespattered the floor, the wall opposite,
and the observer's clothes, when reading the Salter's balances.

He had again, December 14th, 1888, had an opportunity of
testing an identically similar gas-engine at Kilmarnock. This
time he employed only one brake fixed on one of the fly-"R"heels.
Fig. 35 illustrated this form of brake, which he understood was the
same as that which had been used by the judges at the late gas-
engine trials under the auspices of the Society of Arts. The
following Table showed the more important results : —

Mean revolutions of brake fly-wheel per minute . . 205
Maximum deviation from mean speed, per cent. . . 5|

Dead load, W, in lbs 157

Mean back pull on balance, in lbs 4

Radius of dead load, W, from centre of brake wheel = r\ o . c:;9

1 2

in feet }

Size of each of the two small ropes, diameter in inches 0

Mean brake HP. during two hours' run 15

Gas-consumption per brake HP. in cubic feet per hour 21

indicated HP. „ „ 18

He considered this form of brake preferable to any one of the
numerous forms that he had tried, and believed it could be adopted
for large powers, and for long continuous runs for the reasons : —

1. It could be constructed on very short notice from materials
always at hand in every factory or worksho]), and at very little
expense. 2. It was so self-adjusting that no very accurate fitting
was required. 3. It could be put on and taken oif in about one
minute ; being very light and of small bulk it could be hung up
or laid by in a cupboard. 4. It needed little if any attention for
lubrication. 5. The back' pull registered by the spring-balance

Proceedings.] CORRESPONDENCE ON FRICTION-BRAKE DYNAMOMETERS. 75

was steady, and might be made a minimtim by properly adjusting Professor
the load W before commencing the trial run. 6. The brake-wheel •^''"■"'i^^oii'
soon attained such a maximum temperature that the radiating heat
balanced the heat being generated by friction. 7. It might be

Fig. 34.

Pointer

^^\\\\\\\p\\\\\\^\^

used for small as well as for large powers, without any special
attendant apparatus except a weight and a spring-balance. 8. For
larger powers only more, or larger, or flatter ropes, or a larger
brake-wheel, were required.

76 COEKESPONDENCE ON FKICTIOX-BrtAKE DYNAMOMETERS. [Minutes of

Mr. Schon- Mr. W. ScHONHEYDER wished to state that, having conducted a
heyder. considerable number of brake-tests of engines, steam, gas and
caloric, he preferred a brake similar to that illustrated by Fig. 16,
with the strap clipping one-half, three-foiarths, or the whole cir-
cumference of the wheel ; for smaller powers without any cooling
arrangements, but for larger powers with the mode of cooling
described, whereby water was continuously being run into the
trough-shaped rim and continuously withdrawn therefrom. With
such a brake the load P could be weighed with any desired degree
of accuracy ; the horizontal distance of the load from the centre of
the shaft could be measured to the greatest nicety, and the counter-
pull of the spring-balance could be read as frequently as desired,
or a diagram could be traced indicating all the variations of pull
during the whole test. Not a single factor need remain un-
determined, and therefore the amount of brake-power obtained
must be undisputable. He could not agree with the Author that
" In practice, generally speaking, the adjustment required by
means of the screw S is as necessary with the compensating-lever
as without it, and its value may therefore be questioned for
this reason alone ;" for he had made several tests with brakes
fitted with compensating-levers, and had run the engines for six
hours and more withoiit once having to touch the adjusting screw ;
but he did not consider this could have been accomplished without
the continuous cooling arrangement, which permitted complete
control over the temperature of the wheel, and therefore insured a
uniformity of friction otherwise unattainable; the wood blocks
M^ere slightly lubricated with oil. He believed the mode of
cooling a brake-wheel thoroughly by water, contimially circulating
through the wheel, was first practised by Mr. Halpin. As to
using the Appold compensating-levers, more than twelve years
ago he directed attention ^ to the grave errors which might be
committed by not measuring the jiressure on the fixed point, and
advised experiments to be undertaken to ascertain the probable
amount of such errors. For a friction-brake, which he lately
designed for a new engineering college, he placed the arms of the
wheel at one side of the trough-shaped rim, boarded up the spaces
between the arms, and overhung the wheel, so that all the water-
siipply and take-off arrangements were at the one side only, and
the splashing from the water would be kept away from the engine
and shaft-bearing; the proportions were maximum brake HP. 150,
revolutions 150 per minute, diameter of wheel 9 feet, width of

EngineaHng, vol. xxii. (1876), p. 75.

Proceedings] CORRESPONDENCE ON FRICTION-BRAKE DYNAMOMETERS. 77

wheel 10 inclies, maximum pressure per square inch of wood Mr. Schon-
blocks 8 lbs, ; the straps were made of steel, very thin and flexible, "'^y^''^''-
and they encircled the wheel for its whole circumference.

Mr. J. E. Sweet in practice, for the sake of convenience, reversed Mr. Sweet,
the method adopted by nearly all other engineers. Instead of
producing resistance by raising a weight, he caused it by pressure on
the platform of a weighing-machine, at a point 5 feet 3 inches from
the centre of rotation of the brake-wheel, or the radius of a 33-foot
circle (Fig. 36). By this means the load could be changed hy
simply sliding the weights on the beam. To ascertain the amount

Ficr. 36.

for any given HP., it was onlj'- necessary to make a single division.
Thus, to set the brake for 15 HP. it was only necessary to divide
15,000 by the numl)er of revolutions made by the engine, and the
result was the number of lbs. at which the weighing-machine
must be set. The wheel was cooled by water ; the brake-blocks
were white pine, though he believed hard wood was better ;
cylinder-oil or salt pork was the lubricant. Notwithstanding
there was no compensating-device, there was very little trouble.
The service was simply making short tests to indicate and set
valves, and to adjust governors at varying loads.

20 November, 1888.

Sir GEOEGE B. BRUCE, President,
in the Chair.

The discussion on the Paper by Mr. William Worby Beaumont,
on " Friction-Brake Dynamometers," occupied the whole evening.

78 WILLIAMS ON THE WITHAM [Minutes of

27 November, 1888.

Sir GEOEGE B. BRUCE, President,
in the Chair.

(Paper No 2257.)

" The Witham New Outfall Channel and Improvement

Works."

By JoHX Evelyn Williams, M. Inst. C.E.

Probably few questions have received more attention from time to
time at the hands of engineers than the improvement of the Eiver
Witham.^ Following the observations of Kinderley in 1736, will
be found, amongst others, the reports of Smeaton, Sir John Rennie,
Sir William Cubitt, and Sir John Hawkshaw. In 1878, the Author,
in reporting upon the subject to the Witham General Commis-
sioners, derived much valuable aid from those earlier inquiries
about the regime of the river.

The Eiver Witham rises near the village of Market Overton, on
the northern boundary of Rutland, and thence flows in a winding
and northerly direction, past Grantham, Long-Bennington, and
Aubourn, to Lincoln. Here it passes over weirs at Bargate and
at Stamp-End, and then proceeds in a south-easterly direction
through the Fens to the Grand Sluice at Boston, and thence to
the Wash (Plate 1, Fig. 1). The length of the Witham is about
89 miles.

At Lincoln, the Witham is held up for navigation in connection
with the Foss-dyke, which joins the Trent at Torksey ; and its flow
seaward is regulated by the weirs at Bargate and at Stamp-End.
The water from Bargate weir, on the south side of Lincoln, passes
through Sincil dyke into the south Delph, and enters the Witham
immediately below Bardney lock. The water on the west side of
Lincoln, joining the Foss-dyke navigation, passes from Brayford
JVIeer, through Lincoln High-bridge, to Stamp-End weir and lock ;

> Previous communications on the Eiver Witham will be found in Minutes of
Proceedings Inst. C.E., vol. xxviii. p. 59 ; and vol. Ixvii. p. 205.

Proceedings.] OUTFALL IMPROVEMENT WORKS. 79

and the water between this point and Bardney lock, a length of
about 9 miles, is held tip for navigation. Between Bardney lock
and the Grand Sluice at Boston, a distance of 23 miles, the Witham
is also held up for navigation purposes, and a minimum depth of
5 feet is maintained.

The Grand Sluice is constructed across the Witham at Boston,
and has four openings, the sea-doors or gates of which are self-
acting, and close, so as to prevent the tide flowing further up the
Witham (Plate 1, Figs. 1 and 8). On the tide receding, the sea-
doors open with the pressure of the land water, which then passes
off to the sea. On the land side of the sluice, land-doors are fitted,
so as to regulate the fresh-water level and the scouring of the
channel during dry seasons.

The area of land draining through the Witham Outfall is about
762,215 acres; but only about one-fourth of this area, or 194,649
acres, consisting of the six districts of the General Commissioners
and the Black Sluice district, contribute towards the expenditure
incurred in improving and maintaining the Outfall. To defray
the costs of the new channel works these lands have been charged
for a period of thirty-five years, from the 6th of April, 1881, with a
uniform tax not exceeding 1«. per acre in any one year. The flood-
water passes into the Outfall through the Grand Sluice, the Black
Sluice, the Maud Foster Sluice, and the Hobhole Sluice (Plate 1,
Figs. 1 and 2).

In 1878, the Outfall, or tidal j^ortion of the Witham, was
most unfavourable, both for drainage and navigation. The re-
lative capacity of the river, for the discharge of ordinary floods
for a reach of 12 miles aT)ove the Grand Sluice, compared with
the sluice itself and the Outfall Channel through Boston, was as
follows: — Eiver Witham, 150; Grand Sluice, 100; and Outfall
Channel, 75. The restricted section of the circuitous channel
through Boston was further impeded by vessels moored in front
of the several wharves. The head of water, necessary to overcome
these obstructions in the Outfall Channel, increased the eleva-
tion of the floods inland, and nullified, in a great measure, the
benefit of all interior works of improvement. To remedy this, the
Author proposed the cutting of a shorter and more direct channel
for the flood-water, commencing in the river about 60 chains
below the Grand Sluice, and terminating immediately above the
Maud Foster Sluice, and that the circuitous loop of the old channel,
thus severed, should be converted into a scouring reservoir or
floating dock (see dotted channel, Plate 1, Fig. 1). This would
have removed the shipping from the flood channel, and rendered

80 ^^^LLIAMS on the WITHAM [Minutes of

the 0\itfall to the estuary more direct. Owing, however, to a
coutlict of opinion between the interests affected, this was not con-
sidered advisable ; and ultimately the enlargement and improve-
ment of the old channel through Boston was adopted. The most
restricted section of this was immediately seaward of the Grand
Sluice; and its enlargement was commenced in December, 1878
(Plate 1, Fio-. 4). The effect of this minor work of improvement
in the Outfall was so apparent, that it furthered materially the
o-eneral feeling in favour of the larger works that ultimately
followed.

The channel between Maud Foster Sluice and Hobhole Sluice,
a leno-th of 2f miles, was more favourable in direction and about
200 feet wide, but required regulating and dredging. The lower
reach of the channel between Hobhole Sluice and the estuary was,
however, not only shallow and circuitous, but untrained and broken
through a mass of shifting sands (Plate 1, Figs. 1 and 2). The
flood-waters rushing seaward, and impinging on the harder and
unyielding strata of the Scalp, were deflected to the westward into
the shifting sands, cutting frequent and successive steeps from 10
to 12 feet in height. These steeps kept tumbling into the channel
and chokino- it up, until the channel ultimately became distorted
and irretnilar, sometimes shifting a mile from east to west in a few
weeks. The flood-tide from the estuary swept over these shifting
sands, and rushed up the river to Boston, carrying a large quantity
of sand in suspension. This was deposited, during slack-tide, in
front of the sluices in the upper reach of the Outfall. In dry
seasons, owing to the absence of the fresh-water scour, this deposit
reached the level of 11 feet 6 inches above the sills of the Grand
Sluice in Boston, and rendered the flow of neap-tides insensible at
the sluice. In July, 1878, a tide which rose 21 feet in Clayhole,
onlv rose 14 feet 11 inches at Hobhole Sluice, and 12 feet 6 inches
at Boston. The duration of flow was five and a half hours in
Clayhole, three hours at Hobhole, and two hours at Boston. The
average rise of spring-tides in the estuary is 23 feet 4 inches,
and of neap-tides 9 feet 2 inches. At low-water of spring-tides,
when the river was swollen with flood-w^ater, the fall between
the Grand Sluice and Clayhole, a distance of 8 miles, was 1 7 feet
6 inches, or an average fall of 26] inches per mile ; whereas the
fall in the surface of the water, in a reach of 23 miles above the
Grand Sluice, was only 4 inches per mile. This clearly indicated
where works of improvement were most needed ; and the Author
advised the cutting of a new and shorter outfall-channel to
Clayhole, clear of the shifting sands, and also the dredging and

Proceedings.] OUTFALL IMPROVEMENT WORKS. 81

improvement generally of the Outfall between this new channel
and the Grand Sluice. The cutting of a shorter channel to the
estuary had been previously recommended, from time to time, by
many engineers, including Sir John Eennie, Sir William Cubitt,
and Sir John Ilawkshaw.

In August, 1879, the General Commissioners invited Committees
from the trusts interested to meet and consider the matter. It
was ultimately decided that the General Commissioners should
promote a Bill in Parliament in the ensuing Session ; and though
strongly opposed in Committee by the Eiver Welland Trustees, the
Eiver Witham Outfall Improvement Act, 1880, was obtained.
Under the provisions of this Act, the Witham Outfall Board was
constituted, and, on the l-lth of December, 1880, the cutting of
the new Outfall channel to Clayhole was commenced.

The new channel is curvilinear on plan, and its length from the
commencement at Hobhole to the termination in Clayhole, in the
estuary of the Wash, is 3 miles (Plate 1, Figs. 1, 2, and .5). The
bottom was cut 100 feet wide at Hobhole, increasing gradually
to 130 feet at its seaward termination in. Clayhole. The average
bottom width of the channel is therefore 115 feet, compared with
the Suez Canal of 72 feet, and the Amsterdam Ship Canal of 87 feet.
The bottom of the new channel at Hobhole was cut to the level of
3 feet below the sills of Hobhole Sluice, or 1 1 • 20 feet below ordnance
datum, with a gradual fall of 1 foot per mile to its termination in
Clayhole. The depth of water in the channel at Clayhole is 27 feet
6 inches at spring-tides, and 20 feet 6 inches at neap-tides. The
excavation through the enclosed land was about 23 feet in depth and
300 feet wide at ground level ; and the strata consisted chiefly of silt
and of brown and blue clay, with intersecting patches of peat, under-
lying which was a hard bed of boulder clay, m which the bottom
of the channel was formed for about two-thirds of its length.

The excavations were carried on by means of three powerful
steam-navvies, advancing in echelon or nearly abreast, together
with numerous barrow-and- wagon roads, attended by eight locomo-
tives and about seven hundred men. The material excavated was
deposited in embankment on each side of the new channel, and
a portion was utilized in forming the embankment to close the old
channel. Outside the old sea-bank, the new embankments were
extended simultaneously towards the low- water mark on the outer
foreshore, and then united in horse-shoe fashion, so as to exclude
the tides from as large an area of the work as practicable. By
this means the middle and heaviest section of the excavation was
executed in dry ground ; whilst the outer ends of the channel were

[the INST. C.E. VOL. XCV.] ij

82 WILLIAMS ON THE WITHAM []\[iiiutC8 of

completed by dredging. Between the edge of the cutting and the
toe of each side embankment, there was left a flat or foreshore
60 feet in width.

The total quantity of excavation in the new channel was about
2,000,000 cubic yards, the contract price for w^hich was Is. per
cubic yard, including dredging. The most suitable portion of the
excavations was selected for forming the exposed slopes of the
embankments, and fascine-work and cliff stone were used for the pro-
tection of the slopes where necessary. The ends of the new channel
were trained and protected by fascine-w^ork. In forming a training-
wall, the fascines were laid in the water so as to overlap in heading-
courses, and then weighted with a uniform layer of clsij so as to
form a solid mattress, the width of which depends uj^on the depth
and situation of the work. As each layer of fascines and clay sinks,
another is formed, and so on until the level of half-tide is reached.
The training-Avall thus constructed is finally covered with a layer
of cliff stone, to protect it from the effects of abrasion and scoiir ^
(Plate 1, Fig. 7). The first sea-going vessel passed through the
new channel on the 7th of April, 1884, and the permanent closing
of the old channel was then actively proceeded with. To effect
this, it was necessary to form an embankment i mile in length
across the old channel and foreshore, below Hobhole Sluice, con-
necting the parishes of Fishtoft and Wyberton. The maximum
height of this embankment was 35 feet, and its top was formed to
the level of 8 feet above ordinary spring-tides, with a minimum
top width of 15 feet, and side slopes of 5 horizontal and 1 vertical,
faced with clay puddle 3 feet in thickness. The embankment was
pushed forward simultaneously from the enclosure banks on each
side of the old channel ; and when the two ojiposite tip-heads had
advanced within a distance of 10 chains of meeting, two parallel
groynes, formed of fascine-work and cliff stone, were run out on
each side of the old channel. These groynes afterwards formed
the inner and outer toe of the new eml)ankment across the fair-
way of the old channel ; and as they advanced towards meeting,
the scouring energy of the tidal water increased so rapidly, that
it became necessary to load the gi'oynes with old rails before
effecting the final closure ; this was successfully accomplished on
the 29th of August, 1884. The advantage of the new Outfall then
became obvious, by the strengthening and concentration of the
ebbing current, and the general depression in the low-water level.
The incoming tides, instead of rushing up the river with a bore

' " Faseinn-Work at the Outfalls of the Fen Rivers, and Keclamatiou of the
Foreshore." By W. H. Wheeler. Minutes of Proceedings Inst. C.E., vol. xlvi. p. Gl.

Proceedings.] OUTFALL IMPROVEMENT WORKS. 83

as formerly, heavily charged with matter in suspension, now flow
in gently from the estuary comparatively clear ; and vessels above
2,000 tons navigate the new channel with ease, compared with
vessels of 300 tons, the largest the old channel could accom-
modate.

In addition, notwithstanding the exceptionally dry summer of
1887, and the consequent absence of scour down the Witham, the
accumulation of dejiosit by the tides only reached 6 inches at the
Grand Sluice ; whereas in 1874, with a larger rainfall, it reached
11 feet 6 inches, and neap-tides were insensible at the sluice.

The Outfall between the new channel and the Grand Sluice
has been improved generally by training-works and dredging,
and the easing of the abrupt bends through Boston. The channel
is now 8 feet deeper than it was in 1878, and there is a navigable
depth of 22 feet at spring-tides up to the Boston Dock, con-
structed by the Corporation of Boston under their Act of 1881.
The restricted section of the Outfall through Boston has been
enlarged and improved by dredging and other works ; and a
very contracted portion of the channel, where the houses abutted
immediately upon the river, has been widened by the construction
of a breastwork of timber piling (Plate 1, Figs. 4 and 6). These
works have been carried out by the Witham Outfall Board from
the designs and under the direction of the Author.

In contimiation inland of the improvement of the Outfall, the
Author advised, in his report of 1878, the enlargement of the
Grand Sluice, and also the widening and improvement generally
of the Witham for a reach of 12 miles above the sluice. Owing
to the seaward flow of the flood-waters being arrested during
high-water in the Outfall, the river above the Grand Sluice may
be termed, in addition to a conduit, an elongated reservoir for the
storage of the flood-waters diiring the period of suspended dis-
charge through the sluice. During this interval, at spring-tides,
the flood-water sometimes rose as much as 5 feet on the land side
of the Grand Sluice. It was therefore evident, that the enlarge-
ment of the storage capacity of the channel, above the sluice, would
tend to diminish the rise of the flood-water during this period.
To effect these improvements, the General Commissioners obtained
the necessary powers in 1881 ; and the works were undertaken
forthwith.

The Graiid Sluice was designed by Langley Edwards, and com-
pleted in 1766. The sluice had four openings, three 17 feet wide
and one 15 feet wide. The latter was a lock, but it was also
available for the passage of the flood-waters when necessary.

G 2

84 WILLIAMS ON THE ^^^THAM [Minutes of

The enlargement of the sluice comprisefl the demolition of this
lock, and the construction of a wider and deeper lock on its site
(Plate 1, Fig. 8). The sills of the Grand Sluice were 6-80 feet
above low-water of ordinary spring-tides in the estuary, 8 miles
distant ; and the area draining through the sluice was about
500,000 acres, only 34,726 acres of which, situated Lelow Lincoln,
contributed to the cost of enlarging the sluice and the improve-
ments of the river, under the -Act of 1881. The maximum flood
recorded at the Grand Sluice was during the winter of 1876-7,
when the flood-levels above the sill were 15 feet 11 inches at high-
water, and 10 feet 11 inches at low-water. Ordinarj^ spring-
tides rise 16 feet 6 inches above the sill, and neap-tides aljont
7 feet less.

The new lock is 30 feet wide, or double the width of the old
one ; and the sills are 3 feet lower, or 3 • 80 feet above low-water
of ordinary spring-tides in the estuary (Plate 1, Figs. 9 and 10).
The excavations were carried down to the hard clay, upon which
a bed of concrete was laid, 7 feet in thickness. The concrete was
composed of 6 parts of ballast to 1 part of Portland cement. Upon
this the floor was formed, consisting of 3 parts of ballast and 1 part
of Portland cement. The pointing-sills were formed of sandstone
ashlar, 3 feet in thickness, with radiating joints on plan so as to
project into and bond with the concrete floor. The heel-stones, to
receive the gate-pivots, were formed of granite, 5 feet by 4 feet,
and 18 inches thick; and the quoins and copings were formed of
sandstone ashlar. The hollow quoins were 4 feet by 4 feet, laid
in alternate courses of header and stretcher so as to bond with the
brickwork in the face of the side walls. The coping of the lock
Avails is 12 inches thick, drafted and picked. The Portland cement
was specified to be of such quality that a test-bar, moulded 1.', inch
square, or 2j inches in sectional area, should, after seven days'
setting in water, bear, without breaking, a tensile-strain of 500 lbs.
During the progTess of the Avorks one hundred and five tests were
made, and the average breaking-strain was 674 lbs.

The doors, or gates, six in number, were built of English oak
(Plate 1, Fig. 11). The outer pair are self-acting, and close so as
to prevent the tides floAving up the Witham. Their height is
24 feet 6 inches, and the span between the centres of the juA^ots is
32 feet 10 inches. The heel and nutre-posts were formed out of
timber 18 inches square ; and the top and bottom ribs are 18 inches
by 12 inches at the ends, and 21 inches by 12 inches in the middle.
The intermediate ribs are 18^ inches bj^ 12 inches, tenoned into
the mitre and heel posts, ajid secui'ed Avith doiible Avrought-iron

Procccdiugs.]

OUTFALL IMPROVEMENT AVORKS.

straps 4 inches hy j inch, and bolted through the ribs and posts
with 1-inch bolts. The planking is of oak, 2^ inches thick, tongned
and grooved ; and the gates turn freely ujion their j^ivots without
rollers. The top of each heel-post is secured to the side wall by a
wroiight-iron collar bolted through a cast-iron block forming the top
hollow quoin. The inner gates are fitted with valves for scouring
and locking purposes ; but during floods all the gates of the Grand
Sluice are thrown open, and secured back in recesses formed for
them in the side walls. The four openings of the sluice now form
a waterway 81 feet in width for the free passage of the flood-
.waters to the sea. The new lock was opened on the 8th of
December, 1883 ; and the beneficial effect of the enlarged and lower
waterway was immediately felt in the upper reach of the river.

The widening and improvement generally of the Withara
between the Grand Sluice and Tattershall Bridge, a reach of
12 miles, consisted of the removal of the continuous projecting flat
or foreland of the banks on each side of the channel (Plate 1,
Fig. 3). These projecting forelands, below flood-level, were a
source of expense and obstruction, owing to the large quantity
of flag that grew upon them, thereby virtually raising the bed of
the river, and obstructing the seaward flow of the flood-water.
The greater portion of these forelands were removed for the
entire length of 12 miles of channel; the waterway was thus in-
creased in width about 50 per cent, at the ordinary navigation
level ; and, in addition, the shoals were removed by dredging, and
the bends in the channel made easier. The slopes next the channel
were nowhere less than 3 to 1 ; and the excavated material, con-
sisting of clay and silt, was deposited chiefly so as to enlarge and
strengthen the flood-banks. Fascine-work was used for the pro-
tection of the river slopes at points where the strata were very
silty and yielding in character. The total quantity of the excava-
tions in this section of the works was 602,059 cubic yards, and the
average cost was 9 • 2d. per cubic yard.

The works have altogether efiected a material improvement in
the drainage and navigation. Not only has the depth of the
navigable channel of the port of Boston been increased 8 feet,
and the accumulation of deposit by the tides become almost nil ;
but the absolute gain or dejiression acquired in the low-water
level at the several sea-sluices is as follows : —

Ft.

In.

Ft.

Hobhole Sluice .

. 5

Black Sluice . .

. . 4

Maud Foster Shiice

. 4

Grand Sluice .

. . 4

This large depression in the Outfall practically means the raisinj

86 WILLIAMS ON THE WITHAM [Minutes of

of the Fen lands, and an immense benefit to the whole of the
districts and interests concerned.

The works were completed in May, 1887, and the total expen-
diture was approximately as under, viz. —

£.

The New Sea Channel and Outfall Improvements"! ,gg qqq
Act. 18S0 J '

The Enlargement of the Grand Sluice and Eiver"! ^, „qq
Witham Act, 1881 /

212.000

The plans and sections were presented to Parliament by the
Author, and the works were afterwards designed in detail and
carried out under his direction as Engineer-in-Chief.

The Contractor for the new channel was Mr. Thomas Monk ; and
the dredging of the iipper reach of the Outfall was partly executed
by him, and also by Mr. W. N. Smith. The Contractor for the
Grand Sluice Works was Mr. William Eigby; and for the river
piling, Mr. Samuel Sherwin. A portion of the dredging and fascine-
work, together with the whole of the works in connection with
the enlargement and improvement of the river above the Grand
Sluice, were carried out without the intervention of a Contractor.

The Paper is accompanied by six sheets of tracings, from which
Plate 1 has been prepared.

[Appendixes.

Proccodiugs.] OUTFALL IMPROVEMENT WORKS. 87

APPENDIXES.

I. Flood Keport. — 1883.
To the General Commissioners for Drainage by the River Witham.

My Lords and Gentlemen,

I regret to report that since your last Meeting the district under your juris-
diction lias been subject to a rainfall unparalleled for its severity in the history of
the Witham Drainage.

The rainfall registered at the Grand Sluice, Boston, for the twenty-four hours
ending 9 a.m. on the 30th ult. was equal to 310 tons per acre. This extra-
ordinary rainfall is 143 tons per acre in excess of the maximum for the same
period during the previous ten years, and 242 tons per acre in excess of the
rainfall of the disastrous flood of 1877.

The water-level in the Witham at Bardney rose 11 feet in twenty-four hours,
the maximum flood-level being 18 feet 8 inches on the 30th ult.

Considering the trojiical character of the rainfall, I feel convinced that, were
it not for the extensive improvement works now well advanced in the Witham
below Chapel Hill, the previous maximum flood-levels would have been ex-
ceeded and disaster would have ensued.

In the East Fen the rainfall was even more excessive than that registered at
the Grand Sluice. For the twenty-four hours ending 9 a.m. on the 30th ult. the
rainfall at Lade Bank was equal to 357 tons per acre, or fourteen times tlie
maximum quantity assumed to be pumped in the same time by the Lade Bank
engines.

When this enormous downfall came upon the district the gi'ound was already
saturated with a rainfall of 15G tons per acre during the previous week.

The upland waters came pouring down in immense volume, and the flood-
level in the catchwatcr drains rose far above any previous recorded height.
These drains rapidly filled, until the flood-waters overflowed their banks at
various points.

Steeping Eiver, with a watershed of nearly 30,000 acres outside your juris-
diction, became surcharged with the flood-waters from the uplands, which
rapidly topped its banks and flowed over them into the Fen, in some places
12 inches deep.

Much of this flood-water found its way into the upper end of the East Fen
catchwater, already surcharged and overflowing at intervals. Two small
breaches occurred in the left bank on Sunday, the 30th ult., the more important
of which I saw practically closed in a few hours.

In the interval a breach occurred in the right bank of Steeping Eiver above
Thorpe Culvert, which I had successfully closed the following morning.

Several dangerous slips had already taken place in the banks of Steeping
River, and it was only by cradging where practicable and other protective
measures that more serious disasters were prevented.

Under the exceptional conditions the Lade Bank engines are performing their
duty efficiently, but the flood-water in Hobhole drain has flowed back over the
doors in much greater volume than heretofore.

WILLIAMS ON THE AVITHAM

[Minutes of

It is perhaps unnecessary for me to add that a rainfall of 357 tons per acre in
twenty-four hours, or more than 60 per cent, in excess of the average rainfall of
a whole month during the previous ten years, represents a sudden and ex-
ceptional strain far in excess of the capacity of the works under your jurisdiction.

They were not designed on a basis to meet so unprecedented an emergency,
and the utmost that can be done under such appalling conditions is to minimise
disaster.

I cannot conclude this Keport without gratefully acknowledging the valuable
and timely co-operation so cheerfully extended to me by the Chairman of the
Fourth District Commissioners, and other gentlemen, during this disastrous
flood. — I have the honour to be, my Lords and Gentlemen, your obedient servant,

JOHN EVELYN WILLIAMS.

Witham Office, Boston, 5th October, 1883.

MAXDirM D.MLT RaINFALL.

1873.

July.

1874.
July.

1875.

Aug.

1876.

June.

1877.
Jan.

1878.
Aug.

1879.
Aug.

1880.

Sept.

1881.

July.

1882.

Oct.

1883.

Sept.

Inch.

Inch.
0-90

Inch.
1-67

Inch.
1-40

Inch.
113

Inch.
0-91

Inch.
1-10

Inch.
1-62

Inch.
1-06

Inch.
1-53

Inch.
310

117

Note. — The 3-10 inches for the twenty-four hours ending 9 a.m. on the 30th
September was preceded by a rainfall of 1 • 56 inch the previous week.

The rainfall during September was 6 '78 inches, the greatest monthly fall
registered.

II. Flood Eepoet.— 1885.
To the General Commissiojiers for Drainage by the Uiver Witham.
My Lords axd Gentlemex,

Since your last meeting the whole of the districts under your jurisdiction have
been subject to a long and excessive rainfall.

The rainfall during October was 419 tons per acre, or 4G per cent, in excess of
the average of the preceding ten years. The maximum daily fall was 155 tons
per acre on the 23rd, and during the last week in the mouth there was a fall of
246 tons per acre.

This was followed by a rainfall of 214 tons per acre during the first six days

Proceedings.]

OUTFALL IMPROVEMENT WORKS.

in November. I am pleased, however, to report tliat, comjjared with simikir
conditions of rainfall, and tidal oscillation, the depression in the level of the
flood-waters was conspicuous and general.

During the low-water interval the depression compared with the previous
maximum level was 3 feet 9 inches at Hobhole Sluice, 2 feet 4 inches at the
Grand Sluice, and 2 feet 1| inch at Bardney Lock.

In the East Fen, at the Lade Bank engines, the water only rose 2 inches above
the summer level.

This favourable condition of the drainage system is no doubt due to the
Works carried out under "The Witham Outfall Improvement Act, 1880," and
"The Witham Drainage Act, 1881."

With the improved and shorter Outfall Channel to Clayhole, together with the
enlargement of the Grand Sluice and the Witham below Chapel Hill, a much
greater volume of flood-water passed off between tides, and at no time was
disaster imminent as heretofore. — I have the honour to be, my Lords and
Gentlemen, your obedient servant,

JOHN EVELYN WILLIAMS,
Engineer.

Witham Office, Boston, 14th November, 1885.

III. — Witham Outfall. Tidal Curves at Boston before and after

COMPLETION of NeW ChANNEL. — FiG. 1.

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Proceedings.]

OUTFALL IMPROVEMENT WORKS.

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[Discussion.

92 DISCUSSION ox THE WITHAM [Miuutcs of

Discussion.

Mr. J. EvELYX Williams said that on the completion of the
new channel to Clayhole, which not only dried the sills of the
Hobhole Sluice, but effected a depression of 5 feet 6 inches in the
low-water level at that point, it became evident that before the
fourth district of the Witham drainage, nearly 74,000 acres, could
obtain the full benefit of the new outfall channel, an enlarged and
lower outlet at Hobhole Sluice was absolutely necessary. The
General Commissioners accordingly applied to Parliament, and
obtained the necessary powers under the " Witham Drainage Act,
1887." This Act enabled the Commissioners to apply the surplus
funds of the fourth district, acquired under the " Witham Outfall
Improvement Act, 1880," to the jnarposes of the works, so that no
drainage taxes were levied to meet the expenditure incurred in
constructing the additional and lower outlet at Hobhole. He had
just carried out that work, and as the sill was 3 feet lower than the
sills of the old sluice, the result was that a large area of low land
had now for the first time natural drainage, and the pumping-
engines at Lade Bank, which indicated 400 HP., erected under the
Act of 1867, had practically become so much power in reserve.

Mr. J. Clarke Hawkshaw thought every engineer who had had
anything to do with the Witham, must be gratified at seeing the
new outfall carried out at last. The old saying, of putting the
cart before the horse, could now no longer be applied to the works
on the Witham. It was not the fault of engineers that this
great improvement had not been carried out before. Mr. Lewin, in
his report in 1860, said that the matter had then been under
agitation for one hundred and twenty years. The reason why this
new outfall had not been made before was a consequence of the
divided jurisdiction which existed on the river. In a Paper, on
river-control and management, which he had read before the
British Association at Belfast, he quoted the Witham as an example
of a river where such divided jurisdiction existed. In that Paper
he described in some detail the jurisdiction of seventeen prin-
cipal sets of commissioners who ruled on the Witham, between
Grantham and Lincoln, and the Trent and Boston. He knew the
district pretty well himself. When Sir John Hawkshaw was
called upon to report on the drainage of the Witham in 1877,
Mr. Clarke Hawkshaw had spent some weeks there with Mr.
Vernon-Harcourt, and he traversed nearly the whole district
on foot, map}>iug out the area that was flooded at the time. In

Procccdiiif^s.] OUTFALL IMPROVEMENT WOEKS. 93

Jannary of that year there were about 40,000 acres under Jir. Il.iwk-
water, inchiding nearly 100 acres of the city of Lincoln, parts of '^^''^^''
which were flooded to the dei)th of 3 feet. He did not know
of any work which would tend more to i)revent such a disaster
occurring in future than the new outfall. As early as 1861, his
father had recommended it, and had always referred to it in
subsequent reports as one of the greatest improvements that could
be carried out. He thought the Author was to be congratulated
that it should have fallen to his lot to carry out such an important
work, which engineers had been trying to get done for nearly one
hundred and fifty years.

Sir Charles A. Hartley, K.C.M.G., observed that the results of SU- Chark-s
the work described in the Paper had been three-fold. First, the ^■'^^'''.^'•
navigable channel of the Witham outfall had been deepened 8
feet by dredging, so that there was now a minimum depth of
23 feet at high-water of spring-tides, and of 10 feet at high-
water of neap-tides, over a minimum width of 100 feet through-
out the 7 miles of improved channel between Boston and the
sea. Secondly, the drainage of a large area of the fen lands had
been very materially benefited by the widening of a reach of
12 miles, immediately above the Grand Sluice, by the enlargement
and lowering of the Grand Sluice itself, and by the depression
ac(pired in the low-water level of the three sea sluices between the
Grand Sluice and the head of the new cut at Ho1)hole. Lastly,
and this was a highly interesting fact, the accumulation of deposit
by the tides below the Grand Sluice had become almost inaj^preci-
able since the completion of the works. These gratifying results
afforded a striking illustration of the great advantages to be gained,
both as regarded improved drainage and navigation, by commencing
the correction of a tidal river of the Witham type at the sea outfall,
and by carrying the low- water level of spring-tides as far inland as
practicable ; that was to say, as far up-stream as the cost of the
work would seem to be justified by the attainment of the end in
view. The Author had made no mention of the changes which
had taken place in the bed of the Estuary at Clayhole since the
completion of the new cut. It would be interesting to learn
from him the importance of the changes. For his own part, Sir
Charles Hartley was of opinion that, to perpetuate the improve-
ments already effected, it would be necessary to prolong the banks
of the new channel seawards, from time to time, to kee}) j)ace with
the advance of newly formed sandbanks at the mouth of the river,
and to ensure the free flow of the ebb current into deep water.
He desired to express his admiration of the skill and energy

94 DISCUSSION ON THE WITHAM [Minutes of

displayed by the Author in the rai^d execution of a difficult and
important work at a comparatively small cost.

Mr. L. F. Verson-Harcourt observed that he had had the oppor-
tunity, as Mr. Clarke Hawkshaw had remarked, of making an
intimate acquaintance with the Witham in 1877, and he also
had the advantage of seeing the works during their construction
in 1883, and of going into the new cut when the excavators were
at work, and through which the river now flowed. It was not the
first time that the question of the Witham had come before the
Institution, for twenty years ago there was a discussion upon
it, and in that discussion the two chief points discussed were
the question of the removal of the Grand Sluice, and the outfall
cut which had now been made. There were considerable diffi-
culties in connection with the question of the removal of a sluice
which had once been established. There was the difficulty of
arranging about the levels of the water, the adequate strengthening
and raising the banks along each side to secure the land against
an inroad of the sea, and of introducing a large amount of tidal
water into a part where the tidal water had been excluded ; and
it would seem that it was the more natural thing to carrj^ out the
enlargement of the Grand Sluice. The great difficulties under
which the Witham had always laboured, had been the small
amount of fall from Lincoln down to the Grand Sluice, and the
impeded shallow shifting channel towards the sea. It was im-
possible to get a greater fall along that part of the Witham than
4 inches in the mile right down from Lincoln. Above Lincoln
there was a greater fall, therefore the water came down to Lincoln
more rapidly ; and in Lincoln itself, at the present time, there was a
great contraction of the channel and considerable obstruction to the
escape of the flood-waters. It was above and a little below Lincoln
that the chief flooding occurred in the winter of 1876-7, as de-
scribed by him in a discussion on the " Conservancy of Eivers," ^
in 1881. At that time Sir John Hawkshaw proposed, amongst
other means, to make a cut, away from the jiresent channel through
Lincoln, along some waste land which could be got outside Lincoln,
for carrying the flood-waters of the Brant and of the Witham down
to the South Delph, which was an artificial cut, carrying the
drainage waters of the Witham. Another defect in the Witham Avas
that the fresh water, which would naturally go down the main
stream, was, from the necessities of drainage, diverted to several
sluices and drains, such as the Hobhole, the Maud Foster, and the

' Minutes of Proceedings Inst. C.E.. vol. Ixvii. p. 283.

Proeecdings.] OUTFALL IMPROVEMENT WORKS. 95

Black Sluice. Therefore, the waters that should naturally be ^Ir- ^'l^l■^on-
scouring the upper portion of the tidal channel were diverted to '"^'^"' •
other places. There was also in those days, the great imjiediment
of the outfall, as well as the very narrow and inadequate channel
through Boston itself. The large projecting quay walls and jetties
as he saw them in 1877 were in a very neglected state. Then there
was the very sharp bend through Boston, which the Author had
proposed to change by introducing what would have been an
excellent thing for the river itself — the cut across it — but that,
of course, would have altered existing arrangements considerably,
and it might not have been acceptable to the Black Sluice Com-
missioners. Moreover there was the difficulty in dealing with the
Grand Sluice. The Grand Sluice not only provided a very
inadequate waterway in flood-time, but also was an absolute im-
pediment to the proper flow of the tide, which in old daj^s was
supposed to have flowed up as far as Lincoln. But even in 1877,
Sir John Hawkshaw did not propose taking away the Grand Sluice,
as had been suggested before, he merely suggested an enlarge-
ment ; and at that time it was proposed to increase considerably
the sectional area of the Witham above up to Lincoln, so as to
enable it to carry oft" the flood- waters, because it was thought that
it was practically almost impossible at that time to induce the
Witham Commissioners to approve of the outfall scheme which
had previously been unsuccessfully urged upon them. If the
enlargement of the Grand Sluice proposed by Sir John Hawkshaw
had been carried out, there would have been 110 feet width of
opening in place of the present 81 feet, and the sills of the sluice
were all to be lowered 7 feet ; in fact, the sluice, according to
his proposal, was to be rebuilt a little higher up than the existing
sluice, and its water-way more than doubled. There could be no
doubt as to the great advantages accruing from the alteration
of the outfall. It was an immense advantage to the river itself;
l)ut, of course, a great disadvantage to the Eiver Welland, that
river having previously had the benefit of the scour of the
Witham, which it had now lost. In most of the schemes proposed
for the improvement of the Witham, there were also training-
works proposed for the Eiver Welland to join it at Clayhole.
He believed it was want of funds that prevented the carrying
out of the training-works ; these would be very desirable, in
order that the Witham and Welland, as in former times, but
in a better direction, might have the same outfall. The Author
had compared the new channel with the Amsterdam canal, and
the Suez canal in section ; bxit it should be borne in mind that

90 piSCUSSION ON THE AVITHAJH [Minutes of

they were for different purposes. The Amsterdam canal had to be
made 16 miles long, just sufficient in section for the traffic carried
through it; whereas the Witham outfall was for the tidal flow
and the discharge of flood-water, as well as for navigation. The
same thing might be said with regard to the Suez Canal, 100 miles
long, which was solely for navigation ; it, however, was going to
be widened, so that it would be considerably larger in section in
future than the Witham cut. The Manchester Ship Canal, also,
would have a bottom width of about 120 feet. But there could
not be a doubt as to the advantage of the new cut, not merely in
lowering the low-water level, but also in preventing the silting up
that used to occur close to the Grand Sluice by the stoppage of silty
water brought up on the flood tide, which was now said no longer
to come up on account of the outfall channel being taken direct into
the deep Avater of Clayhole, instead of meandering through sandy
shoals. Credit was due to the Author for having at length carried
out an oftentimes proposed scheme, not on account of any special
difficulties in the work itself, but owing to the Witham Drainage
Commissioners having been at last induced to approve, and raise
money for a work which was beyond the limits of their ordinary
jurisdiction, and Avhich, whilst of great Ijenefit to the drainage by
improving the capacity for discharge of the outfall channel, and
lowering the low-water level at the several sluices, as predicted in
previous reports, might appear mainly a work of navigation improve-
ment, such as was usually carried out by a Harbour Board.
In spite of the greatly improved condition of the outfall, the
enlargement of the Grand Sluice, and the increased section of the
channel between the Grand Sluice and Tattershall Bridge, he
considered that the land bordering the Witham higher up, near
and above Lincoln, could not be regarded as secure from floods in
very wet winters, and that further works Avould be necessary, in
continuation of the present improvements, higher up the river, to
protect the Witham basin adequately from serious inundations.

Mr. A. Giles, M.P., Vice President, said that looking at the vast
improvement which had been effected in the navigation of the
Witham by the new cut, and by the straightening and deepening
of the channel, he could only express his surprise that the work
was not undertaken long ago. It appeared that the low-water
level of spring-tides was now within 4 feet of the dock sill at
Boston ; and as the rise of a spring-tide was 23 feet, it followed
that there was a depth of 19 feet over the sill at Boston, That
gave a navigation fit for a vessel of 2,000 tons, whereas before the
navigation was only fit fov vessels up to 300 tons. It was

Proceedings.] OUTFALL IMPROVEMENT WORKS. 97

evident when tliat improvement was going on that the Boston Mr. Giles.
people awoke to the importance of having a dock in their own
town, and they made it in consequence of the improvement of the
Witham. Some years ago he was connected with the Bill brought
into Parliament for making what was called the Boston Ocean
Dock. The navigation of the river was then so bad, that it was
thought impossible that it should ever Ite amended. The Ocean
Dock Bill was lost, and the Boston Dock Bill was carried, and
he congratulated the Boston joeople uj^on the fact. But the im-
provement to which he had referred represented only half of the
advantages of Mr. Williams' work, because, in consequence of the
improvement in the channel, and the capability of lowering the
drainage sluices all through the country, many thousands of
acres of land had been saved from being flooded. Would any
gentleman connected with agriculture say what was the vahie of those
acres now, compared with their value when sul)ject to floods ? The
improvement would pay the interest over and over again on the
money expended. Although so small a portion had contributed
to the cost of the work, he thought all the land that had been
saved from being flooded, in consequence of the lowering of the
sills of the sluices, ought also to contribute. Great credit was due
for the way in which the work had been carried out, and for the
smallness of the cost. He remembered the Witham when the cut
was being made, and he recollected the state of the navigation
before that time, when there were many feet of m\id against the
sill of the Grand Sluice ; but during last summer, the river
appeared as clear as could be expected, there being, 2)erhaps,
6 inches of mud on the sill, instead of several feet as before. The
question was one which was creating a considerable degree of
interest at the present time, not only in regard to the Witham,
biit to other rivers in the country, especially the river at Preston,
where, he thought, a similar course of procedure might be followed
with advantage.

Mr. H. J. Marten stated that he had visited the works on one or Mr. Marten,
two occasions whilst they were in progress. With the exception of
the enlargement and alterations at the Grand Sluice, they consisted
principally of estuary-excavation and embankment, and were exe-
cuted, to a large extent, by the stalwart limbs of the old English
navvy. When visiting the works, the onlj^ apprehension which
he had as to their success, was lest, after the old channel of the
Kiver Witham had been filled up by the accumulation of sand,
owing to the cessation of the planing action of the tidal- and flood-
waters consequent on the construction of the new embankment,

[tHK INST. O.E. VOL. XCV.] H

98 DISCUSSION ON THE WITHAM piinutes of

Mr. Marten, sand miglit then begin to drift round tlie end of the south
embankment into the new channel. The area between the south
embankment and the Eiver Welland, in which the bed of the old
channel of the Eiver Witham formerly lay, formed at the present
time a comjoaratively still-water reservoir or dejiositing-ground for
large quantities of sand ; and since the construction of the new
bank across the old channel of the Witham, this deposit had accumu-
lated at so rapid a rate, that in some parts, he understood, it reached
a height of 8 feet above the former level. So long as this great
reservoir had still some depositing-capacity left in it, he did not
apprehend the sandbank would spread beyond the ends of the new
embankments ; but when this depositing-groand was full, the
incoming sand, having no further room within the area indicated,
must necessarily go elsewhere, and in that event it would probably
creep round into and be deposited in the new channel, in larger
quantities than up to the present time. The accumulations of sand
in the old channel of the Eiver Witham were now commencing
to drive the channel of the Welland somewhat further to the south,
away from the mouth of the new channel, which point it had
hitherto passed. The entrance to the new channel would therefore
shortly lose the effect of the scour of the Welland in front of it,
which might have an important bearing on it in the future. He
therefore agreed that, as originally proposed by Sir John Hawkshaw,
the ends of the embankments of the new channel would in time
have to be carried a little further seaward. From the marked effect
of the embankments, however, in lessening the quantity of sand-
laden water entering the channel, from the much greater scour,
and from the better conservation of the erosive force of the current
passing along the bed of the new channel, the Author had probably
done wisely in not — at least for the present — continuing the
ends of the embankments further seaward. There could be no
doubt of the success of the work up to the present time ; and if at
some future period the banks should require to be extended, any
such extension could be carried out at a comparatively trifling
cost, and with the further advantage of experience. Any further
expense required for that purpose could well be borne, considering
the great benefit derived from the new channel, both above and
below the Grand Sluice. Eeferring to this latter work, he under-
stood that the outfall at the Grand Sluice had been practically
lowered some 8 feet below its former level. This was of great
service to the large area of land drained by that Sluice, not only
from an agricultural point of view, but even still more so on
sanitary grounds, as the lowering of the outfall 8 feet was practically

Proceedings.] OUTFALL IMPROVEMENT WORKS. 99

tantamount to raising the whole of the area so drained something Mr. Marten.

like that height above previous saturation-level. This meant a

greater freedom from diseases due to damp subsoil, namely, less

ague and fever, and fewer pulmonary complaints than heretofore,

with increased length of life and vigour over the whole of that

area.

Mr. W. Shelford said he had been familiar with the Witham Mr. Shelford
for thirty years. It was one of the group of four interesting
rivers which discharged the drainage water from a district of 6,000
square miles into the Wash, and which in fact formed the outlet
for the drainage of the great Fen-land of England, covering an
area of 1,306 square miles. The existence of that land was due
entirely to engineers, and its rivers had exercised the minds of
some of the greatest members of the Institution. The Fen-land
was also considered thirty years ago a splendid school-ground for
yoimg men. He could not help joining with other speakers in
congratulating the Author upon having to carry out a scheme
which had been desired by part of the inhabitants of the country
for one hundred and twenty years, and which had been proposed
more than once by men whose names were honoured by the
Institution. He also congratulated him upon the successful accom-
plishment of the work. But he wished to ask a few questions
upon the subject. It was a remarkable fact that in the Paper on
the Witham by Mr. W. H. Wheeler, M. Inst. C.E., of Boston,
twenty years ago, also in one published subsequently, and in the
present Paper, there was an omission of all tidal observations and
tidal diagrams. He thought such diagrams would be exceedingly
useful, and he hoped the Author would sTipi:)ly them. If they
were taken at sufficiently frequent intervals of time and space, and
were plotted, so as to show by isochronous lines the level of water
during the flood and on the ebb, he believed it could be shown
from the state of the diagram what was the cause of the de-
terioration of the old channel, and how far that cause had now
been removed. He also wished to ask why the Author had adopted
a slope of 4 to 1 in the new channel. He believed that was the
slope proposed by Sir John Hawkshaw; but it was worth while
to ask the question, because, in the adjacent rivers, the outfalls of
which were all artificial, and had been entirely made by engineers,
the slopes were much steeper, varying from 1^ to 1 to 3 to 1 ; and
it was found in the fen-rivers, as a matter of experience, that when
the tide had a free flow, and the silt which formed the bed of the
river was allowed to arrive at its own angle, 3 to 1 was the
angle of repose. But there was a peculiarity about the Witham.

H 2

100 DISCUSSION ON THE WITHAM [Minutes of

Whereas most of the fen-rivers ran through silt and sand, the
"Witham had a bed of boiilder clay. The boulder clay extended
from riamborough Head all along the east coast, underlying the
silt, and it was found in the bed of the Witham. The Scalp,
shown upon the chart and described in the Paper, was a clayey
shoal ; it had been cut through in order to make the new channel.
It would be interesting to know whether the slope of 4 to 1 was
adopted because the material was clay, in the expectation that the
clay would stand without any protection in the way of fascine-work
or stone ; and also to know whether it had been successful. He
would further ask whether it was the fact, as stated, that the Grand
Sluice at Boston had lieen designed by Mr. Langley EdAvards. Mr.
Smeaton had always been credited with it, and his recollection was
that it was proposed in a joint report by Mr. Smeaton, Mr. Langley
Edwards, and Mr. Grundy, in 1761. The Grand Sluice was the
characteristic feature of the Witham. It was put in, apparently,
as the result of a contest between the landowners and the mer-
chants, in which the landowners prevailed. In other words, it
was a case of drainage versus navigation, and the advocates of
drainage had the best of it. The sluice was 8 miles from the sea,
and cut off 23 miles of the tidal wedge, or three-quarters of it ; and
what was the result ? There were plenty of instances elsewhere
which confirmed the experience on the Witham. In the first
l^lace, the high-water line was raised above the level of high-water
at sea. At Boston it was raised 8 inches. That was one effect
always found in cutting off" the tidal wedge. Then slack water
being necessarily produced for some distance below the sluice, any
matter in suspension in the water would fall to the bottom and
raise the bed. That again raised the low-water line, and so there
was a deterioration of the river set up which went on in an aggTa-
vated form and with accelerated speed until the bore was formed ;
the action was then analogous to a breaker on the sea-shore coming
up, and bringing with it sand and shingle in its advance, which in
receding it was unable to take away. A river like the Witham,
under those circumstances, would silt up and be blocked, were it
not that the great fresh-water land floods kept it moderately open.
At the present time the Grand Sluice remained, and the water,
instead of being charged "vvith silt, came up comparatively clear.
Instead of there being a deposit of silt in summer to the depth of
11 feet 6 inches, there was, during the last dry year, only a deposit
of 6 inches. The question, however, was whether the channel
would be self-maintained. It was fouled with silt before, and now

Proi'ee(liu<,'8.] OUTFALL IMPROVEMENT WORKS. 101

the only reason why the water came iii^ clear was that the new -^Ir. Shelford.
channel was cut through clay, and there was no silt to bring. In
the course of time, the silt brought down from the upper country
would, in all probability, accumulate in the channel, and the
question might then arise whether or not the channel would
maintain itself in the absence of freshes by the simple action of
the tide. It appeared to him to be a case of the new broom sweep-
ing clean. That was, to his mind, by far the most interesting
point in connection with the Paper. A channel cut through clay
of that kind must, he thought, be in its best condition when first
executed. He believed it had been intended that the low-water
level should be lowered by the works 3 feet at the different sluices,
but it had in fact been lowered 4 feet ; and any one acquainted
with the fens would know how very important that result was.
It was practically lifting uj) the whole country, which was below
the level of the sea, bodily 4 feet.

Mr. G. J. Symons said that the Appendix to the Paper contained Mr. Symons.
an interesting report of a flood in 1883, which must have taxed all
the Author's skill and energy. It was a serious resj)onsibility to
be in charge of so large a watershed, during a great rainfall, with
the banks of the rivers liable to be broken down in all directions.
But the figures which the Author had given merely showed the
results of two rain-gauges, one at the Grand Sluice at Boston, and
the other at the Lade Bank pumping-engine, both in the south-east
corner of the watershed. However, the floods were obviously not
purely local floods falling in that one corner of the gathering-ground.
An organization now existed all over the country for determining the
quantity of the rainfall, and he thought that when engineers had
to deal with floods they should obtain all possible information on
the subject. Speaking on behalf of rainfall-observers he wished to
say that they were always willing to do everything they could to
co-operate with their engineering friends in that matter. In regard
to the storm in question, he thought that it would be interesting
to give some actual details of what had occurred, and he had jire-
pared a map for the purpose. The thick line showed approximately
the watershed of the Witham. He had not carried the line down
to the sea-coast because it was stated in the Paper that the flood in the
Steeping Eiver watershed was so tremendous that some of the
water got over into that of the Witham. At Boston and Lade
Bank, the fall exceeded 3 inches, and at Skegness 4 inches. He
had plotted all available records on the map (Fig. 2), and had
indicated by dot and dash lines the areas over which the rainfall was

102

DISCUSSION ON THE WITHAM

[Minutes of

respectively above 1 inch, 2 inches, and 3 inches. This proved
that the flood to be dealt with was not represented by the 3 inches
in the extreme corner of the watershed, but it might probably be
taken to be 1^ inch or 2 inches. He was anxious to see a little more
attention paid to the relative flow of water from large areas of
ground. It appeared to him that nearly all the water oif the
gathering-ground, which did not evaporate, came down through

Fig. 2.

the Grand Sluice, and if that were the case, valuable informa-
tion as to the actual flow from that large watershed could be
obtained by establishing instruments at the Grand Sluice so as
to get a continuous record of the volume of water passing
through it. There would be the input and the output from that
large area, and if it could be done, all woTild agree that the
results would be very valuable. The annexed Table contained
the particulars of the rainfall in Lincolnshire on the 29th of
September, 1883.

Proceedings.]

OUTFALL IMPROVEMENT WORKS.

103

Rainfall.

Mr. Symons.

Stamford, Northfields .
Bourne, Wytham-on-the-Hill
Long Sutton ....
Grantham, Saltersford .
„ Heydour Vie

Boston, High Street

„ Grand Sluice
Leake, Lade Bank engines
Stubton (Newark) .
Sleaford, Bloxholm .

Navenby

Skegness

Inches.

■14
•38
•49
•63
•10
•10
•10
•57
•49
•10
•38
•31

Horncastle, Miningsby .
Lincoln, Branston .
Spilsby, Partuey
Horncastle, Bucknall .
Lincoln Waterworks . .
„ Skellingthorpe .
Horncastle, Hemingby .
Alford, The Sycamores .

„ Suttou-by-the-Sea
Louth

„ Westgate .

Inches.

•43
•26
•82
•87
•19
•00
•69
•40
•25
•48
•37

Mr. A. C. HuRTZiG imagined that the new bed of the river shown Mr. Hurtzig.
on the section was the bed of the river as originally improved.
The Author had referred to the important fact that improvement
in the tidal propagation had also improved the tidal development,
and that, consequently, there would be a larger volume passing
in and out of the river after the old outlet was closed. He should
have thought that this action of the tide would be further to
deepen the channel which was originally dredged to a certain depth.
He also wished to ask why sandstone had been used in the hollow
quoins of the lock ? Was it on the gTound of cheapness ? Kubbing-
surfaces at important places, as in the case of hollow quoins of
the lock-gates, should be as hard and durable as possible ; and he
should have thought that the slight additional expense of granite
would not have been prohibitive, bearing in mind the possibility of
the gates getting leaky in a few years. He wished to ask, further,
whether in on-shore gales there was any tendency to silt up the
entrance? There might possibly be a tendency to sand-banks forming
close to the entrance, where they had not previously existed. At an
early date a scheme of works had been contemplated with more refer-
ence to drainage than to navigation. Since then the ideas on the
subject had developed, and there was now an important navigable
channel for the admission of large vessels to Boston, which might
in future become an important port. The development and
improvement in these days of a work like the Witham outfall,
from a navigation point of view, was of much greater interest
to engineers, at least marine engineers, than the other questions
concerned.

Mr. F. Wentworth-Sheilds asked what was the particular direc- Mr. Went-
tion of the flood-tide ? Judging from the indications presented by ^^'orth-SheilJs.
the outline of the coast, he presumed that the flood-tide was in the

104

DISCUSSION ON THE WITHAM

[Minutes of

Willi

direction of the immediate mouth of the channel ; in other words,
that the new channel had been so designed as to catch the flood-
tide, and so the deep-sea current entering the channel would
consist of clear water, which would account for that absence of silt
mentioned by the Author as a remarkable feature in the case.

Sir George B. Bruce, President, said a communication had been
received from Mr. Duff-Bruce, asking a question to which, perhaps,
the Author would reply, namely, whether he had any special
appliances for landing on the banks the material dredged from the
river between the Grand Sluice and Tattershall Bridge. The total
quantity of excavation, he said, on that section was stated to be
602,059 cubic yards, and the average cost 9 '2d. per cubic yard.
Of that, how much had been spent in landing the dredged material
on the banks ?

Mr. J. Evelyn Williams, in reply ujwn the discussion, stated
that no change injurious to either the drainage or the naviga-
tion had taken place in the bed of the estuary at Clayhole
since the completion of the works. The condition of the new
channel itself had actually improved, a fact illustrative of the
advantage attending the confining of a stream within a regular
channel, so as to concentrate its scouring action. There was no
apparent necessity, at all events at present, to prolong the banks of
the new channel, and he did not think anything further in that
direction would be required than the extension of the training
walls, so as to keep pace with any possible recession of the low-
water contour at Clayhole, and at the same time ensure the free
flow of the ebb current into deep water. The scour of the Witham
was not always advantageous to the Welland. During heavy floods
the rivers impinged at right angles, and the Witham, being the
more powerful, turned over the shifting sands into the fairway of
the Welland, thereby choking and deflecting the stream in its
jjassage to the sea. Frequently the two rivers flowed throiigh
separate channels into the Wash, and he was informed that the
drainage by the Welland had not been injuriously affected since
the opening of the Witham new outfall. With a view, however,
to secure the obvious advantage of the permanent and combined
scour of the two rivers into Clayhole, a clause was inserted in the
River Witham Outfall Improvement Act of 1880, to the effect that
if, at any time within twenty years after the comjiletion of the
Witham new channel, the Eiver Welland trustees should decide to
form an improved channel, from the point of confluence of the two
rivers at the Elbow Buo}' to the entrance of the new Witham
channel in Clayhole, one-h^lf of the cost of such works should be

Proceediugs.] OUTFALL IMPROVEMENT WORKS. 105

paid by the Witliam Outfall Board. The area benefited by the Mr. Williams.

works was certainly not less than 200,000 acres, and over this area

the aggregate cost of the works, described in the Paper, represented

a capital sum of only 21 -28. per acre. The large area affected by

the works was not only materially enhanced in value, but the

owners and occupiers were relieved of the anxiety and loss which

attended frequent and disastrous floods. An ordinary spring-tide

in Clayhole rose 23 feet 4 inches, and flowed for five and a half

hours. Before the opening of the new channel, spring-tides

rushed up to Boston with a bore 3 feet in height, heavily charged

with silt, and flowed for two hours. On the completion of the

works, the bore disappeared and the tides flowed gently in and

comparatively clear from the estuary. Sj^ring-tides now flowed for

three hours and neaps from four to six hours, according to the force

and direction of the wind. With reference to the slopes of the

new channel, a slope of 4 to 1 was a successful and economical one

in so exposed a position. It saved in a great measure costly works

of protection ; the same slope had been adopted on the Norfolk

Estuary Works by Sir John Eennie and Mr. Eobert Stephenson,

many years ago. It was the first time he had heard Mr. Smeaton

mentioned as the engineer of the Grand Sluice, local history

credited Mr. Langley Edwards alone wdth the work. He could

bear testimony to the great labour and care bestowed by Mr.

Symons in compiling rainfall statistics, the perusal of which often

aflbrded him much valuable aid. Mr. Hurtzig, like himself,

preferred granite to sandstone ; but no granite whatever was used

in the construction of any of the sea sluices. Quoins of Bramley-

fall ashlar were sufficiently hard and durable for such works, and

their cost was less than one-half that of granite. The new channel

was designed to catch the flood-tide, and at the same time to ensure

the free flow of the ebb current into deep water. He might state

in reply to Mr. Dufi'-Bruce that no special apjiliances had been used

for landing the material dredged from the river between the Grand

Sluice and Tattershall Bridge. The cost of landing the material

dredged averaged od. per cubic yard.

Correspondence.

Mr. P. Caland considered the cutting of a new outfall at the Mr. Caland,
mouth of the Witham to be an important work of river-improve-
ment. It comprised at once the widening and deepening of the
Grand Sluice above Boston, the draining of the lands formerly

106 CORRESPONDENCE ON THE WITHAM [Minutes of

Caland. exposed to flooding, the reinforcement of the action of the tide,
and with it the improvement of navigation, the two last mentioned
features being the purpose of every scheme of river-improve-
ment in the estuarj". Not every scheme of river-improvement
was so fortunate. It appeared from the Paper that while formerly
the depth of water at the mouth of the Eiver Witham at high-water
spring-tides was barely 15 feet, and the navigation difficult, if not
imiwssible, for vessels of more than 300 tons, the result of the works
had been to add 8 feet to the effective depth ; so that now vessels
of 2,000 tons, and drawing 23 feet, could reach Boston. As the
level of the low- water had been lowered not less than 5^ feet at
Hobhole Sluice, and 4 feet at Grand Sluice, the tidal action had
been greatly intensified, and the period between slack-water and
high- and low-water had been correspondingly lengthened, thus
greatly benefiting the navigation at flood-tide, and the drainage at
the ebb. And not only the depth of the river, but the direction of
the fairway, had been much improved by the construction of the
new outfall between Clayhole and Boston. In future, both on the
ebb and at the flood, the navigation of the channel would be
available at a much earlier period of the tide, owing to the
avoidance of the tortuous narrows, and channel encumbered by
sandbanks, which formerly rendered the navigation difficult, and
at times impossible.

Mr. M. F. FitzGerald observed that the Paper brought out
strongly the importance, where low-lying lands about a flat reach
of river were to be dealt with, of securing a free outfall at the
lowest possible level. Where such was not provided, the increase
of surface slope, which necessarily occurred during floods, might
cause flooding at a moderate distance above the discharging
sluices, even when this area was so great as to prevent any
rise, during floods, at the sluices themselves. He would like
to suggest, with reference to the great weight of floods referred to
in the Appendix, that the flow of rivers had sometimes been observed
notably to exceed that due to the rainfall, not only for a week or a
day, but for several weeks together, especially in winter floods after
long-continued wet weather. This point had been alluded to in a
Paper by Mr. Robert Manning, M. Inst. C.E.,^ and observations of
river flow giving such a result had been sometimes treated as
anomalous and necessarily incorrect. Fig, 3 represented the
average flow of the Shannon for a period of ten years, along with
the flow which would have taken place if the rainfall had been

Minutes of Proceedings Inst. C.E., vol. xxv. p. 459.

Proceedings.]

OUTFALL IMPROVEMENT WORKS.

107

discharged as fast as it fell. In this river the flow considerably Mr.FitzGerald.
exceeded the rainfall for the greater part of January and Fehruary.
The ratio of river to rainfall-flow for the months of November,
December, January, and February together was 1*2 to 1 ; for the
remaining months of the year it was, however, only 0 • 39 to 1 ; and
for the months of May, June, July, August and September, taken
together, 0'33 to 1. Evidently the flow of a single month could
not be compared with the rainfall of the same month, any more

Fig. 3.

cuaic ner

',000,000.

aoo.ooo-

600,000-

<oo,ooo-

200,000-
0.

• y

■••-.,.

■■

J A NY

fCBT

■AACH

APRIL

MAV

JBN£

juur

AUCT

SEpr

QtTf

NOV?

oecf

Fig. 4.

CUBIC FtBT
P£f1 MINUTE

•

/^ ^

.___ ^^

JUNE

JULY

AUGUST

RIVER DISCHARGE
RAINFALL „

than that of a day or an hour. The effect of continued wet weather
in increasing the ratio of river- to rainfall-discharge, embracing the
summer flood of 1861, was shown by Fig. 4. The data for both
these Figs, were partly derived from Mr. Bateman's Report on the
Shannon (1866), and partly from the gauge records kept at Killaloe
and elsewhere. The importance of paying regard to the seasonal
variation of the rainfall-discharge coefiicient was particularly
great in rivers bordered by low land of a spongy nature, and
it would be well if more attention were directed to this point as

108 CORRESPONDENCE ON THE WITH AM [Miuutes of

Hr.FitzGerald. the conditions were different from those regarding the quantity
of water which could be impounded by a given catchment area.
The effect of the new outfall channel on the Welland discharge-
channel should be beneficial, by diminishing the tendency of the
channel between Holbeach Marsh and the Scalp to shift ; but much
depended on the effect of the altered direction of the flowing tide
currents, about the Clayhole, reacting on those over the sands
between Holbeach Marsh and the Scalp. There seemed in some
instances, a tendency to produce an effect, which in this case would
be represented by the flushing over of the Welland Channel in a
northerly direction up to the Scaljo, followed by a closing of the
channel along its south-eastern border, and a deej^ening of that
leading towards the Gat Sand.

Mr. C. Bloys van Teeslong observed that three works of different
character, though nearly connected, had been almost simultane-
ously executed on the River Witham. By the excavation of a
new outlet a serious impediment to navigation had been removed,
and an unobstructed access of tidal waters obtained; by the
deepening of the tidal compartment a complete filling up and
emptying of the river had been assured ; whilst by the enlarge-
ment of the upper part and the Grand Sluice, the area drained by
the Witham had been greatly improved. He attributed these
favourable results to the measures being well combined, and
simultaneously executed. Measures of amelioration of the upper
part of the district, taken in former years, consisted chiefly in
shortening the length of the river, in the excavation of new drains,
and in deepening the bottom ; but these works produced only a
temporary alleviation. The shortening of a river, and the subse-
quent acceleration of the cuiTent, generally gave rise to a more rapid
erosion of the banks and bottom, and disturbed its eqiiilibrium ; and
if the river was prevented from regaining its original length, the
transport of materials, the result of erosion, tended to destroy the
effects of the improvement. By deepening a river the regime of the
stream was often injuriously affected, and the old conditions gradually
re-ajjpeared. The formation of new canals for drainage, separated
from a river, frequently proved injurious by abstracting water
which, by its scouring jjower, maintained the river. No objection,
however, could, he thought, be oflered to the widening of a river,
as had been done in the case of the Witham ; and especially was
this the case where the removal of material chiefly took place
above high flood-level. The erection of banks in early times
reduced the sectional area of river beds during floods, and it was
by neutralizing the prejudicial influence of this diminution of

Proceed in j?s.] OUTFALL IMPROVEMENT WORKS. 109

area, that excavation beyond tlie navigable channel conld be
useful. With respect to the Grand Sluice, he considered it was
difficult to decide, at present, whether its erection had been a
mistake, as its former surroundings were not now known, and
might have altered considerably since early days. He considered
the relatively small width of the Withani an important factor in
maintaining the tidal portion of its bed free from sand, which
would otherwise be brought in during flood-tide, especially in
stormy weather ; the influence of the fresh- water flow in the last
of the ebb would be especially beneficial. He approved of the
cut through the Scalp. Where two rivers, such as the Witham and
the Welland, joined at right-angles, and their common outlet was
encumbered with shifting sandbanks, a radical remedy seemed
perfectly justifiable. Moreover, by the formation of the new
mouth, a prolongation of the training-works could be easily ex-
ecuted iu the future if necessary. The cutting of the Hoek van
Holland, at the mouth of the Eiver Maas, the waterway to
Rotterdam, was the most interesting instance of a similar work on
the Continent. In the case of the Maas, it had been originally
contemplated to resort mainly to the scouring action of tidal
currents ; but though there had been considerable erosion, it was
found necessary, owing to the shifting and the shallowing of the
navigable channel at the entrance, to undertake extensive excava-
tion. The result was considered successful ; although, probabty,
owing to the relatively great width and straightness of the channel,
sufiicient depth could only be maintained by yearly dredging.
In another part of the Rhine delta, two small rivers, the Donge and
the Oude Maasje, as in the case of the Witham and Welland, formerly
joined nearly at right-angles to one another at the point of
discharge into the Estuary of the Amer. The first-named river
had in the course of time gradually altered its course in the lower
part, and now occupied a position much resembling that of the
Witham. At a short distance beyond the entrance, the navigable
channel shallowed, and moderate dredging was required annually
to maintain the depth of water equal to what it was higher up.
With regard to the question of keeping the outlets of the Witham
and of the Welland separate, in Holland, as a general rule, rivers
were kept apart as much as possible, if their drainage areas were
of a different nature, as for instance the Rhine and the Maas ; in
other cases, the uniting of branches was esteemed favourable to
their general condition. On the point of cost he thought it would
be advisable to bring the outlet of the Welland to Clayhole rather
than to Lynn Deeps. He found, from ancient charts, that

110 CORRESPONDENCE ON THE WITHAM [MinuteB of

Ir. Bloys van formerly both the Witham and the Welland discharged alternately
res ong. j^^^ Boston Deeps and Lynn Deeps, and that since the commence-

ment of the present century neither of the Deeps had materially
altered in capacity, though the latter had become narrower and
deeper. The width of the Witham, in comparison with other
marine waterways to an important town, was relatively small.
For a commercial town of the rank of Boston, a width of
channel of about 180 feet would have been adopted in Holland;
its nearly straight channel somewhat resembled a canal, but
the navigation was rendered more difficult by tidal currents.
By the shortening of the river, consequent on the new outlet,
the reservoir of tidal water had been diminished, impairing
the action of the tidal scour. He was of opinion that it
depended, in some degree, on the more or less rapid obliteration
of the Wash, whether the results obtained by the works on the
Witham would prove durable. Hitherto that had not occurred ;
but he thought it possible that this would occur, as soon as the
reclamation of land had reached some limit, though probably not
for many years. Boston Deeps was said to be maintained by tidal
action. If true, this might be, to some extent, explained by the
manner in which the tidal flow entered the W^ash. The tidal
water, following the deepest channel, did not enter Boston Deeps
directly, but took the direction of L;yTin Deeps, and passed across
the Long Sands. As to the ebb currents, it might be deduced
from the position of the banks and channels that they equally
diverged at the entrance of Boston Deeps. Under these circum-
stances, it was evident that the raising of the banks would greatly
improve the general condition as regarded navigation. To provide
an outlet for the Welland into deep water, he should recommend
the construction of a bank from the outer end of the W^itham bank
in a south-easterly direction towards Holbeach Marsh, leaving an
opening at Clayhole for the discharge of the W^elland waters.
The space, thus partly enclosed, would be protected against the
action of waves and strong currents, but filled up and emptied at
every tide, and rapid silting up, es;pecially at the angles, might be
anticipated. The lands thus formed might, as soon as suitable for
reclamation, be enclosed ; while the banks, constructed for this
purpose, would at the same time, serve to train the river. The
secondary branch, leading the Welland to Lynn Deeps, would in
this way be dammed off; that leading to Clayhole would remain
unaltered, and would probably not need deepening, as it originally
carried seawards the combined waters of the Witham and the
Welland. After some time,/ a situation would l)e obtained similar

Proceedings.] " OUTFALL IMPKOVEMENT WORKS. Ill

to that proposed by the Lincolnshire Estuary Company. At first, Mr. Bloys van

the Welland would be liable to shift its course in the large enclosed ^^^ °"°'

space ; but not so much as at present, secondary branches being

shut o&, and the position of the mouth being fixed. The outlet

of the Witham would, of course, be benefited by the scouring

action of the water passing the entrance to the partly enclosed

space.

Mr. J. Evelyn Williajms, in concluding the correspondence, Mr. Williams.
desired to add the following communication received from Mr.
Goodwyn Archer, the Clerk and Solicitor to the Ouse Outfall
Board : — " The improvement seems to be for the Boston Watershed
equivalent to what was done for the Lynn Watershed by the Eau
Brink Cut. Taking into account the difference of the areas of land
affected, the Eau Brink Scheme cost the contributors more than
twice the amount which your contributors have to bear." This
statement Mr. Williams felt sure could not be other than gratify-
ing to the land-owners in the Witham Valley.

112

ELECTIOXS, ETC.

[IMinutcs of

4 December, 1888.

Sir GEOEGE B. BEUCE, President,

in the Chair.

The following Associate-Members have been transferred to the
class of

Members.

Edward Appletox.

Haevet Bagxall, M.A., B.E.

Percival Fowler.

Philip Affleck Fraser.

Arthtr Egbert William Fulton.

James Edward Fflton.

Eai Bah-vdee Gaxga-Ea3i.

Arthur Staples Gerrard.
"William Harper.
William Hughes, B.A., M.E.
Charles Erxest Norman.
Willia^i Stuart Eendel.
Henry Goulton Sketchlet.
Edmund Casttell Bowyer Smijth.

The following Candidates have been admitted as

Students.

George Francis Adams.
Charles Frederick Bamford.
Sa^iuel Harry Hill Barratt.
Thomas John Bayne.
Cyril Holm Biss.
Frank Walker Bottle.
Arthur Walter Bradley.
James Wood Bragg, B.A.
Harry Bucknall.
Willia3i Edward Burgess.
James Hubert Cochrane, A.K.C.
Wilfred Arthur Cope.
Frederick Nutter Cox.
Henry Haryey Dare, B.E.
John Thomas Llewellyn DA^aES.
Albert Edward Dawxey.
John Smith Dawson.
Fraxk Bridgewater Debexham.
Archie Eussell Emdix.
NoRMAX Fitz, B.E.
John Fraxcis Foster.
Colin Proud Fowler.
Alexander Eraser.

Frax'k Horace Frere, A.K.C.

Herbert Ferdinand Friederichs.

Charles Humphrey' Gilbert Wh.Sc.

Henry Hallett.

WiLLiA^i Leigh HA^rrLTON.

Francis Joseph Harvey.

Harold Hawkins.

Charles William Hobley.

John Holliday.

Percy Winstanley Hull.

Alfred Jajies, B.A.

Charles Frewen Jexkin, B.A.

Herbert Harry Jones.

Harry Birch Killox.

Joshua Lambert.

William Hexry FitzEoy Landon.

Sydx"ey Aspland Lang.

Herbert Willia^i Lax'gley.

Alec George Yaugh.^n Lee.

Edward Sargint Lixtdsey.

Frederick Lambert Lordex.

Ernest Loyegroye.

Harold ]\Iacaxdrew

Proceedings.]

ELECTIONS, ETC.

113

Students, continued.

Lessel Stephen McKenzie.

James Maie, Wh.Sc.

Edward Charles Egbert Marks.

Ernest Meteor Martin.

Harry Powell Miles.

Charles Julius Alfred Mittel-

hausen.
Charles Joseph Anthony Patrick

Moore.
Alexander Douglas Moriarty.
Charles Shelley Oakes.
James Geofprie Musgrave O'Hara.
Frederick Charles Osborne.
Francis Davidson Outeam.
Percy John Paterson.
DiGBY Prescott Pedder.
Charles Leon Emile Pitot.
Walter Playfair.
John Portsmouth.
Alan Railton.
Arthur William Ranken, A.K.C.

Robert Newby Hartley Reid.

Joseph Peter Robinson.

George William Roome.

Alfred Schwartz.

Henry Chawner Hine Shenton.

William Sillem.

Holman Fred Stephens.

Edward Duncan Stoney.

Hugh Sidney Streatfleld.

William Archer Porter Tait, B.Sc.

Francis Manley Shawe Taylor.

Charles Wilson Thompson.

John Thompson.

Nicholas King Turnbull, Wh.Sc.

James Vicars, B.E.

James Whitaker, Wh.Sc.

Henry Thomas White.

Francis Houlton Wrench.

Alan Wyatt-Smith.

Maurice Edward Yonge.

The following Candidates were balloted for and duly elected as

Members.

Alexander Anderson.
John McKenzie Bell.
Oliver Budge.
William Lind Buyers.
David Cowan.
William Davidson.
Theodore Newel Ely.
Arthur Sumner Gibson.
John Richardson Hewitt.

Andrew Oliver Lyons.
Loudoun Francis MacLean.
Henry William Martin.
James Price, Jun., B.E.
Alan Wood Rendell.
Richard Oswald Robson.
Charles Arthur Rowlandson.
Frederick Cook Stephens.
Berkeley Deane Wise.

Associate Members.

William Wallace Andrews.
Llewelyn Birchall Atkinson, A.K.C,

Stud. Inst. C.E.
Walter Attard.
Philip Port Ayres.
John Banks.
Charles Arthur Albert Barnes

Stud. Inst. C.E.
Onward Bates.
John Beveridge.
Edward Philip Binet.

[the INST. C.E. VOL. XCV.]

William Blackshaw.

John Vaughan Brenchley, Stud.

Inst. C.E.
Samuel Edwin Burgess, Stud. Inst.

C.E.
Ernest Sydney Burman.
Henry Robert John Burstall,

Wh.Sc, Stud. Inst. C.E.
Clerke Burton.
William Robert Butler, B.E.
Fked Smith Button.

114

ELECTIONS, ETC.

[Minutes of

Associate Members, continued.

George James Chapman.

Edward George Clark, Stud. Inst.

C.E.
William John Clarke.
Henry Lowthian Cleaver, Stud.

lost. C.E.
CorRTENAY Thornton Clieton, Stud.

lust. C.E.
William Horace Coomber, Stud. Inst.

C.E.
Robert Cra^rtord.
Frederick Sol'thwell Cripps.
Charles Eichard Ernest Crook,

Stud. Inst. C.E.
John D'Aeth.
Morgan Williams Davies.
WiLLiAsi ArorsTUS Davies.
Thomas Ei'Sholm Dickinson.

WiLLIAJI DiESELHOEST.

Pai'l Doiier, A.K.C, Stud. Inst. C.E.

Edward Ellis.

George Wadhaisi Floyer, Stud. Inst.

C.E.
Egbert Maynard Gloyne, Stud. Inst.

C.E.
George Lacy Good.
James Walter Grimshaw.
George Higgins.
George Hobbs, Stud. Inst. C.E.
Alfred James Hodgkinson.
Edward Holmes.

Arthur John Ikin, Stud. Inst. C.E.
Nicholas Pavl Jasper, Stud. Inst. C.E.
William John Jenkins.
Henry Sydney Jones, Stud. Inst. C.E.
James Keith.
Eichard Johnson Lawton.
George Hilder Libbis, Stud. Inst. C.E.
Henry Littlejohn, Stud. Inst. C.E.
Theophilus Septiml'S McCallum.
Donald Grant Macdonald.
James Waddell Boyd Maclaren,

Stud. Inst. C.E.

William Snell Tandy Magee.

Warine Ben Hay Martindale, Stud.
Inst. C.E.

Stephen Martin-Leake.

Edward Alworth Mitchell Mere-
wether, B.E.

George Percival Milnes, Stud. Inst.
C.E.

Charles Edward Cage Montresor.

Percy Nevill, Stud. Inst. C.E.

Thomas Nisbet.

William Anthony Morgan Par-
tridge.

AUGUSTPS TiCHBORNE PeNTLAND.

Eichard Douglas Perceval.
Williaji Marshall Philip.
Arthur Powell.
Harry Ernest Prescott.
Eeginald Seymour Prinsep, Stud.

Inst. C.E.
Eichard Watkins Eichards.
WiLLiAJi Henry Eobins.
JA3IES Eochfort.
Ealph Baron Eogers, M.A.
Frederick Eose, Jun., Stud. Inst. C.E.
Norman William Eoy, Stud. Inst. C.E.
John Sampson.
James Joseph Shaw.
EoRERT Skelton, A.K.C, Stud. Inst.

C.E.
Edmund Paley Stephenson.
Percy Kendall Stothert, Stud. Inst.

C.E.
Clement Moriscrip Sykes.

EOBERT COCKBURN SySON.

Arthur Drew Thomas, Stud. Inst. C.E.

Alexander Walker.

Charles Leslie Walker, Stud. Inst.

C.E.
Thomas Henry Ward.
Williaji Warner.
William Wearing.
Walter James Weightman.

Associates.

Edward Miller Gard Eddy.
William Henry Jaques, Lieut. U.S.N.

William Alfred Perry.
Benjamin Willcox.

Proceedings.] ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 115
QPaper No. 2286.)

" On the Influence of Chemical Composition on the Strength

of Bessemer-Steel Tires. "

By John Oliver Arnold, F.C.S.

The importance of the subject dealt with in this Paper can hardly
be over-estimated. It is a question affecting the safety of thou-
sands of lives. In such a case it is impossible to have too great
a margin between working and breaking-strain.

There is a growing tendency amongst railway engineers to
specify for tires a steel possessing a high resistance to tension.
This no doubt is conducive to economy in wear ; but it remains
a debatable question whether such material is not more liable to
the risk of sudden fracture than a more ductile if less durable steel.
It is true that the framers of such specifications apparently provide
against such risks, by insisting also on steel of a high resistive
power to rupture under the impact of a falling weight, and of a
fairly high capacity to elongate and to contract in area when broken
by tension. But, in the Author's opinion, the chemical composition
necessary to obtain the anomaly of high tensile-strain, together
with high elongation, is such as to render steel liable to those
sudden or gradual molecular changes (the nature of which is at
present imperfectly understood), which doubtless produce from
time to time disastrous results. The Author purposes to lay before
the Institution the data upon which he bases this conclusion. The
question is rendered intricate : —

(a) By the fact that steel is a complex body, and that the
influences of its elements upon each other, with reference to
physical effect, have hitherto defied all attempts to reduce them to
formulas.

(6) The difficulty of insuring in pieces of steel, identical in com-
position, a uniform and constant molecular structure. In connec-
tion with the latter remark it may be stated, as a general principle,
that the more abnormal the proportions of the foreign and harden-
ing elements in a tire-steel, the greater the liability of the material
to injurious molecular change. In addition to the iron, the chemical
composition of normal tire-steel is approximately per cent. : —

Carbon.

Silicon.

Manganese.

Sulphur.

Phosphorus.

0-28

0-07

1-25

0-08

008

I 2

116 AKNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. [Minutes of

A test-piece, 2 inches parallel and 0-564: inch in diameter, 0-25
inch area, planed out of a tire possessing the above analysis, would
give on an average the following mechanical results, the figures
being calculated on the original dimensions : —

Te^^StZn.! Elongation. \ «f-f Fracture.

Tons per

Square inch.

Per cent.
26

Per cent. i Grey granular, ■with silky
47 1 edges ; shape convex
I and concave.

Such a tire, with an inside diameter of 2 feet 8 inches and a
sectional area of 11 inches, would behave under the falling- weight-
test in a manner indicated by the subjoined figures, the weight of
the tup being 22 cwt.

Fall in feet . . .

6 1 8

10 i 12

Deflection in inches .

1
*

3 13 q 1

Unbroken.

The falling- weight-test might have been continued much further ;
in fact until the tire was doubled up ; and often rupture can only
be brought about after rej^eated blows at 30 feet. Such a tire is
perfectly adajited to fulfil all requirements except that, like every-
thing else, it wears out in time. It possesses one highly important
property ; it is little liable to molecular change under sudden
heavy and rej^eated shocks. This is proved by the fact that a test-
piece, planed out of an untested tire, gives miich the same result on
the testing-machine as a piece planed out of a tire which has been
subjected to the falling-weight-test.

It may be accepted as an axiom that in Bessemer tire-steel the
carbon should lie between the limits of 0-25 and 0*32 per cent.
Taking the foregoing analysis as a fixed starting-j^oint, the efi'ect
of an increase in the proportions of silicon, sulphur and phosphorus
respectively will be touched upon. High silicon in Bessemer steel
is due either to underblowing, or to a very impure manganiferous
addition, and 0-20 per cent, is a highly dangerous amount in
a tire. High phosphorus is due to the use of originally impure
pig-iron, and 0-15 per cent, is dangerous. High sulphur may
be due either to impure pig-irons or to inferior cupola-coke. The
influence of this element is not so marked as that of silicon

Proceedings.] AENOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 117

and phosphorus, but it should nevertheless be kept as low as
possible. The effect of an abnormal proportion either of silicon or
of phosphorus in a tire is to produce brittleness. All three elements
must be regarded as impurities, under all circumstances to be kept
low, and to take no part in any adjustment of the hardening
elements of steel, to obtain any desired increase in the tensile-
strength of tires.

Suppose that it is desired to increase the tensile-strain of a
normal tire 5 tons, that is to say, to 42 tons per square inch, and
at the same time to obtain without rupture the normal deflection,
2 inches per foot of inside diameter, under the falling weight.
Such a result (always remembering that Bessemer tire-steel, from
the nature of the process by which it is made, must contain, to
insure soundness, about 1 • 25 per cent, of manganese) cannot be
safely obtained by an increase of carbon, because the additional
percentage of this element, necessary to give the required strain,
would render the tire liable to break under the falling-weight-test,
before the necessary deflection had been obtained. In other words,
a tire containing 1 • 25 per cent, of manganese and 0 • 40 per cent, of
carbon would give the required strain on the machine, but would
fail under the drop-test. Therefore the only means of arriving at
the desired result, without introducing a new element, is to
increase the manganese.^

The effect of such increase is denoted by the following data : —
Steel was made, having the following composition per cent. : —

Carbon.

Silicon.

Manganese.

Sulphur.

Phosphorus.

0-25

0-03

1-75

0-12

Oil

An ingot of this steel was hammered into a 4-inch bloom ; the
bloom was then rolled down into a bar, 1^ inch square; and from
this four test-pieces, 2 inches parallel, 0-5G4 inch in diameter, and
0 • 25 inch area, were turned.

* In the case of open-hearth steel, the comparatively small proportion of Fe O,
present in the metal at the termination of the oxidation, enables the steel-maker
to leave a much lower percentage of manganese in the finished steel, and
consequently allows greater latitude in the range of carbon and hardening
elements other than manganese.

118 ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. [MinuteB of

Hesults.

Tons.
Mean maximum strain per square inch . . . .42-1
Highest „ „ .... 43-3

Lowest „ „ .... 41*6

Per cent.

Mean elongation 18-0

Highest „ 18-8

Lowest „ 17 •!

Mean reduction of area 26 ■ 3

Highest „ „ 31-0

Lowest „ „ 21 "5

The fractures were flat, and devoid of that uniform fine grey
granular appearance and convex and concave shape characteristic
of highly ductile steel. They exhibited about 35 per cent, of
grey granules and 65 per cent, of fine crystals.

Although the actual falling-weight-test of the above steel cannot
be given, the mean result of the tests on many tires practically
identical in composition, 2 feet 8 inches inside diameter and
having a sectional area of 1 1 inches, is as follows, the weight of
the tup being 22 cwt. : —

Fall in feet

Deflection in inches

9 3 Q9

So far the conclusions to be drawn are that an increase of
manganese produces an increase of hardness, whilst at the same
time the tire is sufficiently tough under the impact of the falling-
weight. The loss of ductility is indicated by the rate of de-
flection.

Assuming the lower percentage of carbon and silicon in the
high manganese-steel, when compared with normal steel, to be
compensated for by the somewhat higher proportion of phosphorus
and sulphur, the two steels are practically identical in composi-
tion, except in the percentage of manganese ; and the influence of
this element on tensile-strain, elongation, reduction of area, and
rate of deflection under the falling weight may be approximately
summarized as follows: That the addition of 0-50 per cent, of
manganese to the normal tire has : —

(1) Raised the strain supported from 37 to 42 tons per square
inch.

(2) Reduced the elongation from 26 to 18 per cent.

Proceedings.] AENOLD ON THE 8TEENGTH OF BESSEMEB-STEEL TIRES. 119

(3) Decreased the rediiction of area from 48 to 26 per cent.

(4) Kequired an additional 15^ foot-tons to produce equal deflec-
tion.

The life of a tire possessing a tensile-strain of 42 tons is no
doubt longer than that of one breaking under tension at 37 tons
per square inch ; but experience shows that the former steel is
much more sensitive to the influences, rate of cooling, shocks and
vibration, which cause that mysterious rearrangement of particles,
converting steel from a tough substance, yielding under tension a
grey granular fracture, to a brittle material presenting a fracture
consisting of bright crystals.

But 42 tons by no means form the limit of the demands contained
in engineers' specifications. A tensile-strain of 48 tons, an elonga-
tion of 15 per cent., and a deflection of 2 inches to the foot have
been specified.

From what has been advanced it will be obvious that, to obtain
such a result as a breaking-strain of nearly 50 tons by means of
manganese, about 2 • 50 per cent, of that element would be neces-
sary. No steel-maker would risk the inevitable brittleness of such
a metallurgical deformity. Therefore the aid of another element
has to be called in, and that element is chromium. This substance
has been praised as a most valuable addition to steel ; it has also
been condemned as an altogether noxious ingredient. The facts
of the case, as far as its application to mild steel is concerned, will
now be stated. The conclusions drawn, from data to follow, as
to its efi'ects are : —

(a) That chromium added in small quantities raises the tensile-
strain of steel in a remarkable degree, without seriously diminishing
the ductility,

(b) That when added in too high a proportion it induces
brittleness.

The following is the percentage analysis of tire-steel, required
to stand a strain of at least 48 tons per square inch : —

Carbon.

Chromium.

Manganese.

Silicon.

Sulphur.

Phosphorus.

0-28

0-42

1-54 0-08

010

0-09

A test-piece was prepared by hammering a 14-inch square ingot
down to Ij inch square. This bar was then turned to 2 inches
parallel, 0*564 inch in diameter and 0*25 inch area, when the fol-
lowing results were obtained : —

120 ARNOLD ON THE STKENGTH OF BESSEMER-STEEL TIRES. [Miimtes of

Maximum
Tensile-Strain.

Elongation.

Reduction
of Area.

Fracture.

Tons per

Square Inch.

49-8

Per cent.
150

Per cent.
26-0

(Flat and finely
\ crystalline.

A tire, 2 feet 8 inclies in inside diameter and of 11 inches sec-
tional area, behaved as follows under a falling weight of 22 cwt. : —

Fall in feet . . . ' 2

4 6 8 10

Deflection in inches . |

1 111 lis Q I

11^5 Broke

A test-piece, 2 inches parallel, 0*564 inch in diameter, and 0-25
inch area, was planed out of the broken tire and gave the following
figures : —

'l\^r" Elongation.

Reduction
of Area.

Fracture.

S^uZl'lZ,. Percent.
47-7 3-0

Per cent.
6-4

Large crystals.

The molecular change set up by the shock and vibration of the
falling weight is thus indicated most clearly.

Although it is possible to get a strain of 50 tons per square inch,
together with great strength, under the drop-test, such tires are
very uncertain. Their molecules may or may not assume a struc-
ture capable of resisting sudden shocks. Their action is delicately
poised, and a slight external influence, such as too rapid cooling
after leaving the rolls, turns the scale.

The influence of slow cooling, on the arrangement of the
molecules into a form capable of resistance to rupture under shocks,
is well indicated by the subjoined tabulations of the deflections
obtained on a tire of 2 feet 8 inches inside diameter and 11 inches
sectional area. This tire was made from the same steel which,
under ordinary treatment, showed the deflections last tabulated,
but which, when buried in hot ashes and allowed to cool from a
blood-red heat during forty-eight hours, gave, under the falling
weight of 22 cwt., the following superior result : — ■

Fall in feet ....

Deflection in inches

9
16

915

10 12,'

15,',

Proceedings.] ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 121

The mean of four closely-agreeing tests from pieces planed from
various parts of the punished tire, the test-bars being 2 inches
parallel, 0-5G4: inch in diameter, and 0*25 inch area, is embodied
below : —

Maximum

Strain.

Elongation.

Reduction
of Area.

Fracture.

Tons per

Square Inch.

46-2

Per cent.
20-7

Per cent.
45-7

Granular.

This remarkable result indicates that not only does annealing
raise the ductility of steel, but also causes a molecular arrangement,
capable of great resistance to alteration under vibration and shocks,
achieving this result on a material previously very sensitive to
physical influences and to local molecular disturbance referred to
later on.

The liability of high-strain tires to assume a brittle crystalline
structure, instead of that arrangement of interlaced (?) molecules
so conducive to ductility, is indicated by the following data : —

A steel gave on analysis these results per cent. : —

Carbon.

Cliromium.

Manganese.

Silicon.

Sulphur.

Phosphorus.

0-32

0-30

1-46

Oil

0-05

0-07

A piece of this material, cut from an ingot and drawn down to
II inch square, then turned to 2 inches parallel, O'oG-l inch
in diameter, and 0*25 inch area, behaved on the machine thus : —

Maximum
Strain.

Elongation.

Reduction
of Area.

Fracture.

Tons per
Square inch.

Per cent.
16

Per cent.
29

Coarse gi-anular.

A tire, of 2 feet 8 inches inside diameter and 1 1 inches sectional
area, tested under a falling weight of 22 cwt., acted as follows : —

Fall in feet

12 14

Deflection in inches

31 Broke

122 ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. [Minutes of

A test-piece, 2 inches parallel, 0-564 inch in diameter, and 0*25
inch area, was planed from the broken tire with this result : —

Maximum
Strain.

Elongation.

Reduction
of Area.

Fracture.

Tons per

Square Inch.

48-4

Per cent.
60

Per cent.
6 ■ 0 Large crystals.

The loss of ductility resulting from the presence of too much
chromium is seen by comparing the subjoined data with the
analysis and tensile-test on the hammered bar of the material last
dealt with, the mechanical conditions being identical. A steel
possessed the following comj^osition per cent. : —

Carbon.

Chromium.

Manganese.

Silicon.

Sulphur.

Phosphorus.

0-28

0-64

1-41

0-11

1 0-07

0-07

A piece was cut from an ingot and drawn down to a bar 1^ inch
square, the size of the test-piece, being 2 inches parallel, 0 • 564 inch
in diameter, 0*25 inch area, with this result: —

Maximum

Strain.

Elongation.

Reduction
of Area.

Fracture.

Tons per

Square Inch.

50-4

Per cent.
10-0

Per cent.
13-8

Crystalline.

It is well known that the amount of work put upon steel has
a marked relation to the molecular structure, and consequently
to the ductility of the material. This point is illustrated by the
following experiments : — A 14-inch ingot was reduced by hammer-
ing to a shaft 8 inches in diameter. Two test-pieces 8 inches
parallel, 0*8 inch in diameter, 0*5 inch area, were planed out of
this shaft, and tested on the machine with the following results : —

—

Maximum
Strain.

Elongation.

Reduction
of Area.

Fracture.

No. 1 . . .
No. 2 . . .

Tons per

Square Inch.

42-0

41-4

Per cent. Per cent.

91 18-9

11-3 89-9

>Flat and crystalline.

Mean .

41-7 ! 10-2 29-4

More work was now put on the shaft ; it was hammered into a
3-inch bloom, and the bloom was rolled into a bar 1^ inch square, and

Proceedings.] ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 123

from this bar two test-pieces 8 inches parallel, 0 • 8 inch in diameter,
0 • 5 inch area, were turned, the results arrived at being as follow : —

Maximum
Strain.

Elongation.

Keduction
of Area.

iFracture.

No. 1 . . .
No. 2 . . .

Tons per
Square Inch.

42-3
42-4

Per cent.

15-2
13-7

Per cent.
39-9
32-3

(Grey granular, with silky
< edges. Convex and con-
1 cave in shape.

Mean .

42-35

14-45

36-1

An interesting, but rather expensive, addition to the above tests
would have been the results yielded by a pair of pieces planed out
of the unworked ingot. The elongation would probably have been
practically nil. It is curious that specifications are sometimes
drawn up requiring a certain percentage of elongation, but failing to
specify the length of the test-piece to which such percentage refers.
The eifect of varying lengths and diameters of test-pieces, on the
results obtained, is exemplified by the following series of trials : —
An ingot 14 inches square was hammered down to a 4-inch bloom.
The bloom was then rolled into a bar 1^^ inch square. From this bar
twenty test-pieces were turned. Their sizes and the figures jdelded
on the tensile-testing machine are tabulated in the subjoined
columns : —

Dimensions of Test-piece.

Maximum
Strain.

Elongation.

Reduction of

Area.

Parallel.

Diameter.

Area.

Inches.

Inch.

Square Inch.

Tons per
Square Inch.

Per cent.

564

Fig. A 2

800

985

564

Fig. B 4

800

985

564

Fig. C 6

800

985

564

Fig. D 8

800

985

564

Fig. E 10

800

0-985

0-75

42-1

13-8

30-9

124 ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. [Minutes of
The above results may be thus summarized in tabular form : —

Length of
Test-
piecfcs.

Inches.
2

Strain.

Elongation.

Reduction
of Area.

Per cent.
22-2

20-2

16-4

16-2

13-2

Per cent.
•1

Square Inch.
0-25

0-50

0-75

Strain.

Tons.
43-8

43-7

41-7

Elongation.

Per cent.
170

17-7

19-2

The analysis of the steel bar from which the test-pieces were
turned indicated the following percentage composition : —

Carbon.

Chromium.

Manganese.

Silicon.

Sulphur. Phosphonis.

0-27

0-26

1-69

0-04

012

Oil

It will be noticed that the tests vary considerably inter se,
although made on pieces identical chemically,^ and in the me-
chanical treatment they had undergone. The obvious inference is
that so sensitive is high-strain steel to physical change that it is
impossible, without annealing, to get even in one bar homogeneous
molecular structure.

Taking into consideration mean results, it will be seen : —

(a) That the length of a test-piece does not affect the strain or
reduction of area.

(b) That, if the elongation yielded by a 2-inch test-piece = 100
roughly; then that by a 6-inch = 80; and by a 10-inch = 60.

* Certain metallurgists and engineers have attempted to account for the
varying results, yielded by several mechanical tests from the same bar of steel,
by attributing their variations to the heterogeneous chemical composition of the
material. But the Author's tests on this point, extending over nine years, have
led him to the conclusion that the chemical composition of ingots of ordinary
size, which are set in a few minutes after casting, is practically uniform, the
slight differences found being such as to warrant their reference chiefly to errors
of analysis. At any rate, they are far too small to account, say, for the
differences existing between the tests of the two 6-inch pieces preceding Fig. C
in the Table, namely, 3 tons in the strain, 2 per cent, in the elongation, and
9 per cent, in the reduction of area. In ingots of large size, which remain liquid
for some hours, there is no doubt a decisive variation in the composition of
drillings taken from different parts of the block.

Proceedings.] ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 125

Figs. A, B, C, D, E, have reference to five test-pieces, each

marked into eight equal parts, in order to ascertain the exact
distribution of the elongation. Each pair of Figs, represents the
test-piece before and after testing. The value of each division is
expressed in decimals of an inch, and on each tested piece is also

126 ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES, [Minutes of

Proceedings.] ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 127

expressed the percentage-distribution when the total elongation is
represented by 100. The sketches are one-half full size, and the
distance of the point of rupture from the nearest division-point is
to scale. It is worthy of remark that the elongation obtained on
the 2-inch test-piece, 22 per cent., is by no means coincident with
that obtained in the 2-inch adjacent to the lines of fracture in
piece B, 32-5 per cent.

In dealing with the question of tires, the Author has endeavoured
to free his mind from bias, but his standpoint is naturally that of
the steel-maker. The other side of the question, namely, the view
of the engineer, has to be considered. The latter holds that a
certain resistance to ruj^ture under a falling weight, together with
certain results obtained on the tensile-testing-machine, form a
criterion of the capacity of tires to safely meet strains they may be
subjected to when put to work. This view is, no doubt, true in the
great majority of cases ; but the fact remains that the theory has
never yet been exhaustively proved. Engineers are naturally
reticent to the outer world with reference to the breaking of tires or
axles of the rolling-stock under their charge, though their silence
does not extend to the makers of the faulty articles. Nevertheless,
both engineer and maker often remain in the dark as to the cause of
failure. But when the fracture of an axle or a tire leads to some
fatal disaster, the engineer is to some extent called before the bar
of public opinion to account for the accident. In such cases his
explanation that the breakage was due to an " original but invisible
flaw " has become |)roverbial. However, the explanation is given in
perfectly good faith. An analysis and a tensile-test of the broken
article have been made, and the results obtained have thrown no
light on the matter. But the important question with regard to
the mechanical test arises : Was the test-piece planed from the
immediate vicinity of the fracture? The Author has obtained
data which prove, beyond doubt, that injurious molecular change
may be very local. For instance, a tire which has been much
punished under the falling weight will sometimes give widely
diverse results on the machine, such variations depending upon
the position from which the test-pieces were taken. Let Fig. F
represent a tire deflected under the droj?. Let a be the point of
impact, b the point opposite. Then a will obviously be the point
at which the most marked molecular change may be expected.
Next, in order of liability, will rank the point b. Whilst the
points c c, being the centres from which a bending motion of the
i)articles has taken place, may also be assumed to fall under the
influence of molecular change. The points x xxx are least liable

128 ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. [Minutes of

to physical rearrangement. This theory will be found with certain
types of steel to be borne out in practice. Test-pieces planed from
X will yield good elongations and graniilar fractures, whilst pieces
from a will give poor elongations and crystalline fractures.

Returning to the question as to how far the tests, to which tires
are subjected before leaving the makers' works, indicate their fitness
for the strains and vibrations they will subsequently meet, it may
be suggested that what is required to definitely settle the point is
a patient and extensive investigation upon the following lines : —

At the works, let tires be selected from groups made from the
same blows, each group being marked with a distinctive stamp.
Let representative tires from each group be subjected to exhaustive
chemical and mechanical tests. Let the exact mechanical treatment
from ingot to finished wheel be faithfully recorded. When the life of
one of these tires is finished, either from breakage or in the natural

course, let the chemical and the mechanical tests be repeated.
Such a series of tests would indicate whether the influences en-
countered by a tire are such as to bring about molecular change.
They would also show the chemical composition and the mechanical
treatment most conducive to injurious molecular rearrangement,
and those tires most likely to retain a permanently tough molecular
structure.

The data so far set forth in this Paper have reference only to
tires ; but if the theories deduced from the various results herein
tabulated are admitted, their application will extend to all classes
of steel. There is still much ignorance concerning the causes of
the various phenomena connected with the physical properties of
steel, although the effects produced by such caiTses are well known.
Thus it is known that a certain percentage of carbon endows steel
with the property of hardness, and that steel low in carbon will
not harden when plunged 'at a red heat into water or oil. The

Proceedings.] ARNOLD ON THE STRENGTH OF BESSEMER-STEEL TIRES. 129

visible eiFect of hardening is to change the fracture of the steel
from a coarse to an exceedingly fine texture. On the machine the
ductile, ragged, and convex and concave appearance of the fracture
of unhardened steel is replaced by a flat, sharp break. The results
obtained are exemplified by the following experiments.

A spring steel gave on analysis the following results per cent. : —

Carbon.

^Manganese.

Silicon.

Sulphur.

Phosphorus.

0-50

110

0-07 0-09 i 008

Three test-pieces, 2 inches by 1 inch l)y ^^^ inch, gave on the
machine the following figures : —

r Hf f^,..^ Tons per ' Elongation Reduction
Condition of Steel. Square Inch. percent. °f^^«^,
! j per cent.

Uuhardeued ....
Water-hardened .
Oil-hardened ....

50-8
69-4
88-0

14-9 31-4

10-9 .300

3-1 4-9

What has caused such astonishing molecular changes ? Chemical
analysis has proved that the carbon has undergone some alteration
in form, because in hardened steel it no longer communicates a
brown colour to nitric acid to the same extent as in the unhardened
material. There is a slight change in the specific gravity and
dimensions, the former being, no doubt, the result of the latter.
Beyond these three facts nothing is definitely known. Many
theories have been put forward, ranging from an idea that the
hardening is caused by the molecules being trapped, whilst ex-
panded by heat, into a rigid form by the sudden cooling action of
the water, to the dream of the theorists who hold that the harden-
ing is due to a conversion of the carbon into microscopic diamonds
throughout the steel. It is not at all clear why the expansion
theory should not apply to all metals, and the veriest t;^T0 in
analysis could easily demolish the diamond hypothesis.

On the other hand, it is found that a steel casting when it leaves
the mould has its molecules so arranged that it is quite brittle.
But the process of annealing, whilst bringing about no chemical
change beyond a slight oxidation of the exterior, causes the molecules
of the steel to assume some new arrangement, which converts the
casting from an article very liable to fracture under the effect of

[the INST. C.E. VOL. XCV.] K

130 ARNOLD ON THE STEENGTH OF BESSEMER-STEEL TIKES. [Minutes of

sudden blows to one possessed of great toughness. Tlie laws which
govern the molecular changes of steel, and their relations to
chemical and physical causes, require searching investigation.
Even the meagre knowledge at present extant is scattered in
confusion like the parts of a puzzle, steel-worker, chemist, and
engineer each holding a portion ; and until they jjlace them
together, and call in the aid of the microscopist, the puzzle will
remain unsolved.

Six drawings accompany the Paper, from which the Figs, in the
text have been reduced and engraved.

[Discussion.

Proceedings.] DISCUSSION ON STRENGTH OF BESSEMER-STEEL TIRES. 131

Discussion.

Mr. Edward Reynolds said he had not had any personal experi- ^^^- Reynolds,
ence in making Bessemer steel, and therefore could not approach
the subject from the same stand-point as the Author had done in
the Paper, which, although he might be disposed to criticise a
few of the Author's conclusions, he considered was on the right
lines, and must have required a large amount of patient investi-
gation. The main point in it appeared to be the non-desirability
of the modern practice of adopting very hard steel for railway
tires. It was no new point that hardness alone was riot, even from
a mechanical point of view, the crucial quality required to get
great power of resistance to wear. In a Paper read before the
Institution in 1875 by Mr. J. T. Smith, M. Inst. C.E.,i there was a
record of observation on the wear of rails of different tempers which
had been used on a long incline on the Furness Railway ; when it
was found, contrary to expectation, that the softer rails showed
least wear. Many analogies might be found to that experience, as
in the case of tool steel. About the beginning of last year he
received a piece of a tire from Mr. W. Dean, M. Inst. C.E., of the
Great Western Railway. It was a tire made before Mr. Reynolds'
Company had any other testing-machine than the falling-weight-
test, and before they made any regular chemical analysis. The tire
was 2 1 inches thick when rolled. It had been put on in October 1868,
and was taken off in December 1886. The diameter of the wheel
was 5 feet 9 inches, the weight on the wheels was 1 1 tons, and the
mileage 411,349. The piece was long enough to take a tensile-test,
and it was found that the tensile-strength was only 36 tons. That,
he thought, went to show partly that hardness alone would not
suffice, and that it depended upon how the hardness was produced.
A certain kind of homogeneity, which offered great resistance to dis-
ruption of the particles, was wanted. He was aware that attention
had been directed in the Paper to the sixbject of chemical composi-
tion, which would lead up to the point he had mentioned ; but,
unfortunately, in spite of the vast improvement in processes of
production, neither chemists nor engineers, nor users, knew exactly
how or why certain good irons gave the required quality. In
other kinds of steel the workmen termed it " body." In tool steels
the test for body was made thus : A thin cold chisel was made by a

Minutes of Proceedings Inst. C.E., vol. xlii. p. 74.

K 2

132 DISCUSSION ON THE STRENGTH [Minutes of

Royiiolds. man year after year, who was therefore enabled to get it approxi-
mately the same, and after being hardened it was tried by being
struck with a heavy hammer vertically upon a lump of iron. The
steel which would stand most of that treatment, when really hard,
without splintering, was held to have the most body. The class
of iron which would give that body, would give a sort of homo-
geneity, which in that, and in many other cases, led to long wear.
He might mention an example in a twin-screw ship, in which the
shafts on the two sides were by different makers, the softer one
showing scarcely any wear and tear of the journals, while the
harder one required frequent adjustment. That proved nothing,
but it Avas an example of the fact to which he wished to direct
attention. So far he agreed with the Author ; but there were
certain points in the Paper which he thought misleading, in the
manner in which he had arrived at his deductions. In regard to
molecular changes, an example was given (p. 122) of a test-piece
prepared by hammering a 14-inch square ingot down to 1^ incli
square. The bar was then turned, and showed 15 per cent, elon-
gation ; and then a piece planed from a broken tire, after being
tested, only gave 3 per cent, elongation. That could not be
accepted as any datum from which to form an opinion. Two
test-pieces, prepared under wholly different circumstances, could
not properly be compared. It would have been easy to take two
tires out of the same batch, and to try one without previous
shock testing, and the other as described in the Paper. But
his reason for mentioning the matter was not so much to cavil
at the mode of expression with regard to molecular change, as
to express a doubt, whether such change, in the true sense,
existed at all. Of course, breaking was a molecular change ; but
he thought that was not what the Author meant hy the expres-
sion. There was an old idea (which he had himself entertained
forty years ago) that there was a change of crystals, and so on, in
iron, simply from long use or from some reason of that kind ; but,
he thought, it had never been demonstrated that such changes
existed. The same bar of iron might be broken, alternately with
fibrous and crystalline fractures from one end to the other, accord-
ing to the way in which it was treated ; and although it was well
known that materials did get to a certain extent altered by long
use, he held that it was by what had properly been called " fatigiie."
He had before expressed his opinion that materials which were
jjcrfectly elastic, without friction amongst their particles, were
absolutely unknown, and that when a shaft, like the shaft of a
screw-steamer, Avas rotated under deflection, the friction amongst

Procccdiugs.] OF BESSEMEK- STEEL TIEES. 133

the particles gradually caused a separation, just as it was found ilr- Reynolds.

that by Lending a piece of lead backwards and forwards the

parts began to sever. The tire to which he had alluded went to

show that the mere vibration of use had not materially altered its

qualities, which were exactly what might be inferred from the

analyses that had since been made. A comparison of the analyses

with those mentioned in the Paper did not go for much, because,

as the Author had mentioned in a foot-note, superior classes of steel,

such as those produced by the Siemens process, could be made of

materials without so high a percentage of silicon, phosphorus and

other impurities, as was almost necessarily involved in the Bessemer

manufacture. The Bessemer manufacture was to a large extent a

question of cost, and it was in the highest degree creditable to those

who worked it out, that so good a result had been obtained with

what was, in his experience, an inferior material. But he fully

agreed with the Author that it was no nse to attempt to get a

very high tensile-strain with such material. If tool steel, for

example, were tried to be made of the material which had to be

used for the Bessemer process (cost being taken into account), no

" faking xip " by manganese would make it stand the body test

which he had described. His own feeling on the subject, which

was perhaps natural considering that he had been associated with

the higher class of steel-making, was that quality alone was to be

relied upon if high results were expected.

Mr. R. A. Hadfield had much pleasure in complimenting his Mr. Hadfield.
fellow-townsman on his very practical Paper, in which he had
brought forward important questions that would have to be dealt
with in fviture by the metallurgist. In regard to the Author's
statement as to hard steel being suitable to stand great wear and
tear, he might mention some interesting American experiments in
iron and steel practice by Dr. Dudley, specially with reference to
the manufacture of steel rails. This gentleman thought that
possibly some definite chemical statement might be drawn up for
the maniifactiire of steel for rails. But after much investigation,
and numeroiis tests, both chemical and mechanical, it was found
that no invariable rule or standard could be determined ; and that
chemical analysis alone could not be taken as the sole guide, in
ascertaining the kind of steel that would stand the most severe
wear and tear. In the Author's tests (p. 117) with steel containing
1 • 75 per cent, of manganese, he clearly found that a brittle per-
centage had been approached. If he had gone as far as Mr. Had-
field's experiments in regard to the effects of manganese upon iron,
he would have noticed that manganese between 2 • 50 and 7 • 00 per

13-1 DISCUSSION ON THE STRENGTH [Minutes of

Wr. Hadfield. cent., whilst adding to the hardness, added also very much to the
hrittlenessi It might also be interesting to refer to some tests
carried on by the Terre Noire Company in 1878 with test-pieces
of similar dimensions to those referred to by the Author, only
on a 4-inch length, averaging about O'oO per cent, of carbon, the
manganese increasing from 0 • 50 per cent, to 1 • 00 jier cent., 1 • 30 per
cent., and 2 • 00 per cent. The results showed that 0 • 5 per cent, of
manganese gave a tensile-strength of 34 tons per square inch with
24 per cent, elongation ; when oil-tempered, 43 tons and 14 per
cent, elongation ; 1 • 00 })er cent, manganese gave a tensile-strength
of 41 tons, the elongation being 23 per cent. Steel with 1 • 30 per
cent, of manganese gave a tensile-strength of 57 tons, and 9
per cent, elongation. In the oil-hardened sjiecimens the tensile-
strength went as high as 82 tons, but with scarcely any elonga-
tion. The Author mentioned that he used up to 1"75 per cent.;
this was getting dangerously near to the amount that might be
used with safety in ordinary steel. In fact, it was surprising
to hear that he had got so good a result. No doubt this w^as
owing to the carbon being so low, only 0*25 per cent. The
Author had referred to the effect of working the metal, which
was a very important jioint ; but he thought he had somewhat
overrated the effect of this on steel, because it had been clearly
pointed out by General Maitland,^ that there was very little differ-
ence in the tests obtained from blooms forged from 10-inch ingots
down to 7, 5, and 2 inches square. The last bloom with the
smallest area, when a test-piece was taken from it, gave no better
results than the first. He thought, therefore, this was a point that
should be carefully considered before pronouncing a decisive
opinion upon it. The matter had also been referred to by Mr. J.
Eiley, of the Steel Company of Scotland, in a Paper read before the
Iron and Steel Institute in 1887, on the treatment of mild steel. '^
There was no more eminent authority in the steel trade, and Mr,
Eiley had expressed his opinion in reference to mild steel (he did
not know whether the same thing would apply to hard steel), that
abundance of work put upon steel ingots rather tended to produce
a strong steel than to give more ductility. Indeed, he added that
if ductility was required, an excessive amount of work should not
be put upon the steel. That was also confirmed by Mr. William
Parker, of Lloyd's, who mentioned that from an ingot 24 inches by
15 inches, a plate 1 inch thick was rolled, Avhich had a tenacity

' Minutes of Proceedings Inst. C.E., vol. Ixxxix. p. 126.
- The Jt)ninal of the Iron and Steel Institute, 1SS7, p. 121.

Proceedings.] OF BESSEMER-STEEL TIRES. 135

of 27" 7 tons, with an elongation of 23 per cent, on 8 indies; and Mr. Hadfield.
a plate of similar size rolled from an ingot of half the sectional
area gave 2 per cent, more elongation. Although, perhaps, not
absolutely conclusive, this tended to show that the value of work
on steel might be too highly estimated. He specially mentioned
this matter, being personally interested in the manufacture of steel
castings in which it was necessary to produce a tough but un-
worked material. If a sound test-piece was obtained from a mild
steel casting, very considerable elongation, though perhaps not with
the same certainty, was obtainable, as with forged steel. The
Author had mentioned (p. 128) his method of selecting samples for
tests. Mr. Barker, of the Great Indian Peninsula Eailway, had
a very good system for testing steel tires ; but he did not know
whether all steel-makers agreed with it. He tested each one by
dropping it from a certain height, so that if there was the slightest
strain in it this was found out, and the tire rejected. He under-
stood, from a recent conversation with Mr. Barker, that in conse-
quence of that very careful method of testing tires, there had never
been any breakage in service. The subject of the structural changes
in steel formed a very important part of the Paper. It was a subject
with which steel-makers were not as conversant as they should
be. The methods of analysis were not perhaps perfect, but they
had been so much improved during the last ten years, that he
thought chemists could not well tell more than they had done
in regard to the composition of steel. Moreover, it had been
proved that chemists in steel-works laboratories could not detect
analytically the diflerence between two pieces of steel, which
might give very different results in the testing-machine. That
applied to castings as well as to forgings. What, therefore,
seemed necessary in the future was a closer examination of the
structure of steel. As the Author and he had pointed out, there
was much to be done in that direction. If the microscopist
could help, by all means let his aid be called in. But there was
another point on which a great deal was to be learned, and no
more able expositor of the subject had been found than Mr. Howe,
of Boston, U.S.A., in his work on the "Metallurgy of Steel," now
being published. He had found that in the heating of steel there were
several critical points of vital importance in determining its future
quality and temper. These critical j)oints varied according to the
particular temper of the steel being operated upon, and did not occur
at the same temperatures in hard as in mild steel. Unfortunately
the means of ascertaining these changes were not at present satis-
factory. When speaking of the heat to which a piece of steel had

13G DISCUSSION ON THE STRENGTH [Jlinutes of

Hadfield. been subjected, at present vague and loose terras were employed.
In fact, they were often quite indefinite, as diiferent persons often
judged diflerently of the same temperatiire. Dark red, Idood red,
cherry red, and the like, were used indiscriminately in describing-
lower temperatures, and the same remark applied to higher ones.
Yet from the investigations of Chernofi', Osmond, Pionchon, and
others, slight differences in temperature might make considerable
difterences in the future characteristics of the steel being treated.
This applied especially to hard steels, which were more liable than
the softer kinds to structural changes by the degree of heat
employed in their treatment, and therefore it would be of great
service to metallurgists to have more accurate means of knowing
what degrees of heat were really used in their operations. A good
p;yTometer would be of the greatest value, but although several
l^jTometers were in the market, they did not seem thoroughly
reliable. He had emjiloyed one made by Murray, of Glasgow,
which had given fairlj^ good results, but still at times variations
occurred with them, and these necessarily caused confusion in the
experiments. Many leading metallurgists fully agreed on this point,
and therefore it was to be hoped that some accurate, and yet sim2:)le,
instrument would before long be perfected.

Professor W. Chandler Egberts- Austen observed that the Author
had remarked that the process of annealing brought " no chemical
change beyond a slight oxidation of the exterior." Surely it was
well known that although ultimate analysis might show no dif
ference in the amount of carbon present in hard steel and in soft,
nevertheless the mode of existence of the carbon was totally
different in the two materials, and the mechanical properties of
the steel entirely depended on the mode of existence of the
carbon, that was, whether it was combined or free. The Author
had further stated that "Chemical analysis has proved that the
carbon has undergone some alteration in form, because in hardened
steel it no longer communicates a brown colour to nitric acid to
the same extent as in the unhardened material. There is a slight
change in the specific gravity and dimensions, the former being,
no doubt, the result of the latter. Beyond these three facts nothing-
is definitely known." Professor Eoberts-Axxsten thought that cer-
tainly a little more than that was known. Le Chatelier and Pion-
chon had shown, by independent methods, that, on cooling from a
temperature of aboiit 700° Centigi-ade,iron passed from one allotropic
state to another. Apparently the a, or soft, modification of iron
was present in the greatest quantity in slowly-cooled iron, and
when the iron was heated it really passed to the hard, or /?, modi-

Proceedings.] OF BESSEMER-STEEL TIRES. 137

fication. Osmond had further shown that, in carburized iron, a Prof. Roberts-
change in the relation of carbon and iron took place during cooling -^^i^^*^"-
from a high temperature. He had also shown that the final tem-
})erature at which that change took place sank lower and lower
with the proportion of carbon, until, in a steel containing 0 • 8 per
cent, of carbon, the passage of iron from one allotrojiic state to
another exactly corresponded with the temperature at which carl)on
itself passed from one allotropic state to another. When carbon
was in the proportion of 0 • 80 per cent, it simply hindered the iron,
which was being rapidly cooled, from passing from the hard modi-
fication to the soft. A pure iron would not harden at all, however
rapidly it might be cooled, because there was no foreign element
present to prevent it passing from the hard modification to the soft.
There was thus direct evidence of the possibility of iron being
prevented from passing from one allotropic state to another under
the influence of an added element ; and if, as was known to be the
case, added elements produced allotropic changes in metals, the influ-
ence of such added impurities ought to be governed by the periodic
law of Newlands and Mendeleef. Professor Eoberts-Austen had
tried to show that in the case of gold the influence of the added
impuritj^ was strictly governed by that law; and he had stated
that if certain elements were added to gold it might become as
brittle as sugar, and the larger the atomic volume of the added
impurity the greater would be the disturbance produced. It was
difticult in the case of iron to trace the influence of the added
impurity, because so few experiments had been made on the in-
fluence of a single element added in small quantities to pure iron ;
but he ventured to predict that investigation would ultimately
show that the larger the atomic vol^^me of the added element,
the less work would it be possible to do on the metal, to which it
was added, without rupturing it, either by longitudinal or by
transverse stress.

Mr. W. Mattieu Williams observed that there was one statement Mr Williams,
in the Fa]}er which he had heard with some surprise, namely, the
statement as to the growing tendency amongst railway engineers
to specify, for tires, steel possessing a higher resistance to tension
than formerly. He had discussed the subject twenty years ago
when writing on phosphorus in steel, and since that time he had
given further attention to the matter, and was satisfied that, in
increasing the tenacity of steel, as measured by a gradually applied
strain, the brittleness was proportionally increased until it reached
the brittleness of glass. Colonel English had made many experi-
ments at Sir John Brown's works in Sheffield, in connection with

138 DISCUSSION ON THE STRENGTH [Minutes of

Mr. Williams, the subject, especially with regard to the bolts used for bolting on
armour-j^lates, which were, of course, subject to violent shocks. In
practical work the qiiestion was not how much pull might be put
upon a thing, even the suspenders of a bridge, but how, when the
pull was ujion it, it would stand a vibratory shock. He might
mention an experiment which he had tried when he was chemist
at the Atlas works. He took a test-piece of plate-metal 3 inches
by ^ inch, and put it under strain, and w^hen it began to yield a
little he gave it a smart tap with a small rod of wire, and it
suddenly broke. On one occasion a steel rail when pitched on a
lorrie, in the yard of the works, struck the iron edge of the lorrie,
while the other end struck the iron pavement, and it broke in half
merely by the action of the double shock. It seemed hardly credible,
but on consideration the rationale of it might be understood. He
had himself occasionally tried a simj^le experiment bearing on the
subject. He had taken a rod of steel, of any convenient size, and
clamped it firmly to a table ; he then placed a marble at one end,
just touching it, and gave the other end a tap with a hammer. Al-
though the bar was not moved at all, the marble was shot off from
the other end. A wave of compression travelled along, terminating
at the end, and thrusting the marble off. In like manner, he
imagined that the breakage of the rail, like many other breakages,
was caused by a wave of compression, or perhaps by two waves
going in opposite directions, and meeting like two waves of
water. A great amount of compression and also of extension was
obtained in that way. The difficulty was to overcome it, to
enable the metal to resist a vibratory shock when under strain.
He had little doubt that the Tay Bridge gave way in consequence
of its inability to do that. The wind was producing a strain upon
every part of the bridge, and when the train arrived a vibratory
shock was produced, which, acting with the strain of the "wind,
proved fatal. He had been surprised to hear what had been
stated in the Paper, and elsewhere, with regard to the effects of
manganese, since he had arrived at a totally different conclusion
on the subject, namely, that manganese was simply a mischievous
impiirity in steel. He did not refer to Mr. Hadfield's alloy of iron,
about which he knew nothing ; he simply referred to manganese
in the proportion of 1 • 00 or 0 • 50 per cent. He once thought that
manganese was a great improver of steel and iron, and found an
easy method of introducing the required quantity, esj^ecially into
puddled steel or iron, and he had taken out a patent for the
purpose. His method was to use as the fettling of the puddle
furnace, either alone or mixed with hematite, a paste consisting of

Proceedings.] OF BESSEMER-STEEL TIRES. 139

black oxide of manganese. The metal was then poured in. Its Mr. Williams.
action produced a large supply of oxygen, which assisted one part
of the puddling process; and by the reduction of the oxide of
manganese, by the carbon contained in the iron, a certain amount
of manganese was produced. The results were tested by himself
and others, and the conclusion arrived at was, that the more
manganese there was in the iron, the worse the resulting metal
proved to be. Taking a given sample, its quality was improved
in proportion as the manganese was eliminated from it. The same
thing occurred with tool steel. His conclusion was that the man-
ganese first of all combined with the oxygen existing in minute
particles of the black oxide of iron, which seriously damaged the
iron, and then the oxidized manganese combined with the residual
silicon, forming a fusible cinder readily squeezed out in working.
In regard to the question of manganese improving the quality of
steel, and giving it a high tensile-strength, he might mention that
at the time to which he referred they were using spiegeleisen, and
the ordinary carbon test was 0 • 40 and 0 • 50 per cent, for rails, and
0*10 per cent, more for tires. In regard to the requirements of rail-
way engineers to which reference had been made, he would direct
attention to the specification of the Admiralty ten years ago for
ship-steel, which demanded that it should be raised to a cherry-red
heat and then plunged in water, and that the tensile-strain should
not be less than 26 tons nor exceed 30 tons jier square inch. If it
exceeded 30 tons the steel would be rejected, as in his oiunion it
ought to be ; 20 per cent, of elongation was required. The matter
was a very important one, it being a question of overdoing the
hardness and tenacity, at the expense of the brittleness of steel,
whether used for tires or rails or anything else liable to vibratory
shock.

Mr. E. A. CowPER said he entirely agreed with Mr. Eeynolds in Mr. Cowper.
thinking that a few blows on a tire would not alter its molecular
arrangement. If a piece of steel were bent, and a straight piece
ciit out of it, it would have undue strain on it, compression on
the one side and tension on the other. That would not be a fair
comparison with a straight bar ; and therefore a piece cut out of
a tire did not bear the same strain as it would when it was
straight, and before it was put into the tire. That was indepen-
dently of any 2)roof of molecular disturbance being set up in the
tire from the blows. If a tire was put on a wheel or circular
block and then hammered, the strain necessary to pull it in half
would not be found much less than what was required when it was
a straight bar. Some experiments were made many years ago on

140 DISCUSSION ON THE STKENGTH [Minutes of

the London and North Western Railway; as axles were said to
be crystallizing. These axles were made somewhat longer, and
after two years, when the ends were broken off, no difference conld
be found in the quality of the iron. But if an axle were turned
down to a square shoulder, and was much larger behind the wheel
than through the wheel, it formed a nick and would break there.
He had many years ago introduced the plan of having a very small
rounded shoulder behind the wheel. Steel axle castings were said
in the Paper to be quite brittle before being annealed. That he
must deny. Many steel castings in use were by no means brittle,
but they were not quite so tough as after they had been worked.
He also took exception to a 14-inch ingot drawn to Ij inch square
as a fair way of trying the diictility against a tire 5j inches by
2 inches. They were two different samples, and one of them had
had. a great deal more work put on it than the other, so that a great
difference would be expected. The Author had stated that " the
amount of work put ujion steel has a marked relation to the mole-
cular structure, and consequently to the ductility of the material."
That was well known, and he agreed with the statement. The
reduction of area and the extension dejiended upon whether the
bar gave way uniformly or at one point. But when it gave way
at one point, the reduction of area at that jDoint was nearly the
same whether the bar was long or short. It was very seldom
that the elongation was equal throughout the whole bar, hardly
once in one thousand times. The addition of a small quantity of
chromium, if it gave the reqiiired hardness, and at the same time
did not injure the ductility, would be a great point gained. He
denied that tires gave way frequently with the present degree of
hardness required. Accidents with broken tires were very few in
number, far fewer than formerly with wrought-iron tires, and than
when steel tires were first introduced. That might possibly arise
from the improved methods of manufacture, not entirely from the
tires being harder. Broken tires were now fewer than ever, and their
hardness was greater than ever. There had been recent examj)les of
large contracts for tires with a high tensile-strength and a very con-
siderable amount of ductility ; but he was sorry to say, that those
contracts had gone abroad, the conditions being found difficult to
fulfil in this country at the time the contract was given out.

Mr. J. A. F. AspiNALL stated, with reference to the question of
crystallization of steel after it had been at work for a long period
of years, that he had sent to the Institution some years ago a
short Paper, together with a series of photographs showing the
results obtained bv breaki'n"; a number of steel crank-axles whicli

Proceedings.] OF BESSEMER-STEEL TIRES. 141

had been in use for a long time. It so happened that in many ^Ir- Aspinall.
cases, the webs which had been originally cut out of these crank-
axles had been kept, so that tlie fracture of the material which had
not undergone any work could be compared with the fracture of
the crank-axle wliich had been in use. At the same time a number
of crank-axles of Yorkshire iron were broken up, but no com-
parison could be made with pieces of their webs, as they had
not been retained. The steel axles sliowed that they had under-
gone no change after many years' work, and the tensile-tests were
exceedingly good. Every one of the iron axles showed very large
crystals. With reference to the subject of annealing mild steel,
he had recently put some plates into the testing-machine, and after
they had been stretched 10 per cent, they were annealed ; and this
operation of stretching and annealing was repeated seven or eight
times with several specimens, which in each case gave an elongation
of from 85 • 5 per cent, to 89 per cent., the maximum load gradually
rising until it was 20 per cent, higher at the final test than witli
several specimens which had previously been tested witliout any
annealing, and which gave an elongation of from 2-t to 28 per
cent. With regard to tires, it was difficult to trace the work of a
tire from the day it left the manufacturer's shop until the day it
was taken off the engine. A good tire would last from five to ten
years, and it was not easy to watch experiments for so long a period.
The amount of wear to be obtained out of good 6 feet G inches
tires, on coupled engines carrying 15 tons on a pair of wheels, was
about -I inch for 40,000 miles.^ He could not agree with the
statement that engineers were demanding too high a tensile-test
for tires. He had had large numbers of tires made of steel by the
open-hearth process, giving a tensile-strength exceeding 46 tons
per square inch, and he had never known one of them to fail. The
steel of some of the tires made by this process which gave the best
results, contained 0-65 per cent, of carbon, 0*28 of silicon, 0*09 of
sulphur, 0*06 of phosphoriis, and 0*86 of manganese; and in the
case of another maker 0 • 60 jier cent, of carbon, 0 • 23 of silicon, 0 • 07
of sialphur, 0 • 02 of phosphorus, and 1-11 per cent, of manganese.
The composition advocated by the Author for tires would not,
he considered, be a desirable one, if a long period of wear was held
in view, for the wear and tear of the tire was often the measure of
the period during which tlie engine could be kept out of the
shops, which was a most important consideration. If a tire went
on to an engine 3 inches thick, and had to be taken oif again when
it was about 1^ inch thick, the maximum amount of wear and tear

' Minutes of Proceedings lust. C.E., vol. Ixxxi. p. 121.

142 DISCUSSION ON THE STRENGTH [Minutes of

shoiild be taken out of the first 1^ inch. There were tires in the
market possessing every desirable qualit}', which were perfectly
reliable so far as breakage was concerned, and which gave a
reasonable life.

Mr. W. B. Lewis was sure the members would agree that steel-
workers, chemists, and engineers should collate all the informa-
tion they individually possessed for the common benefit. He
thought engineers were using a steel of a very much higher
character than that dealt with in the Paper, and he rather objected
to the insinuation that they were doing so at a considerable risk.
The Victorian Government placed a contract with Messrs. Cockerill
and Co. for three thousand tires, the si^ecification being that the
steel was to stand a tensile-strain of 45 tons, with an elongation
of 20 per cent, in a length of 5 inches. Some trouble was at first
experienced, biit after sundry experiments and failures, the firm
succeeded in manufacturing uniform steel to answer those require-
ments. The analysis of the steel, as made by the chemists at the
works, was : carbon, 0 • 330 per cent. ; silicon, 0 • 220 ; sulphur, 0 • 041 ;
phosphorus, 0 • 057 ; manganese, 0 • 750 ; iron, by diff"erence, 98 • 602.
That, as a qualitative analysis, he believed was perfectly correct :
but he had reason to doubt it as a quantitative analysis. The
Inspector, in forwarding it, wrote : " I believe the standard used
for the carbon test gives a much lower percentage of carbon than
that generally used in the English works." That was confirmed
by an English analysis. General Maitland, who felt interested in
the subject, asked him to send some of the steel for examination
at Woolwich. This was done, and the General found that the
tensile-tests agreed with those taken at the works and those also
made by Mr. Kirkaldy and Professor Kennedy. He wrote, saying :
" The steel is very good, and tempers well ; our analyst makes
the carbon 0'516, the manganese !• 038, and the silicon 0-122."
Thus the carbon was much more than had been stated at the
works. He wished to direct attention to the circumstance that
the steel contained the same ingredients as those mentioned in the
Paper as belonging to the standard, or what the Author seemed
to take as his normal type. There was no chromium and no
special material to make it hard. As to the safety of the tires,
they were all subjected, not only to the test mentioned, a bar
being cut out of one in fifty tires ; but a complete tire was tested
by an impact-test of a 1-ton weight falling 5 feet, 10 feet, 15 feet,
and then ten blows of 20 feet. The extreme deflection under
the 15-foot blow was 3^ inches; from the 20-foot blow it varied
from 2i to 5^\ inches. He thought tires that would stand such an

Proceedings.] OF BESSEMER-STEEL TIRES. 143

amount of knocking about, might be used with confidence. The Mr. Lewis.
English makers had refused to tender for the tires at that time ;
but he was happy to say that since then they had made a great
number to similar si^ecifications, excepting that the elongation was
less. Three leading English manufacturers had subsequently been
engaged in supplying these tires. Two of the firms had made steel
possessing 45 tons tensile-strength, with 15 per cent, elongation on
a 5-inch test-bar ; but the area of the test-bar was ^ inch, whereas
in Messrs. Cockerill's case it was 1 inch. In the case of the third,
the tensile-strength was 45 tons, with 10 per cent, elongation. But
these tires had been subjected to greater tests than any others. The
ordinary test had been that of 1 ton falling 5, 10, 15, 20, and 25 feet,
and 30 feet twice. The highest deflection obtained under the 15-foot
blow was 3 inches, and under the 20-foot blow 4^ inches. It was
therefore much harder steel in every way than that which the
Author had mentioned. Out of a contract for four hundred tires,
six tests were made. One tire broke at the 30-foot fall, having
stood the 5, 10, 15, 20, and 25-foot falls. The five others stood the
two 30-foot blows, and remained unbroken. Under another con-
tract for nearly two thousand tires, in which thirty-four tests were
taken, four tires were broken ; one at the first 30-foot blow, and
three at the second, all standing the 25-foot blow. Another manu-
facturer made one thousand, with results equally satisfactory.
Again, another made over two thousand tires. Forty tests were
taken, and three tires failed; one at the 10-foot blow, qne at the
15-foot, and one at the 20-foot. The tests in this instance were
not quite the same. They were 1 ton at 5, 10, 15, and 20 feet,
repeated five times. He thought that steel which seemed to
contain the same ingredients as those mentioned by the Author,
but was very much harder, might be safely used. The tires,
however, had been made only a few years, and he could not yet
speak as to their wear in the same way that Mr. Reynolds had
spoken -of the Great Western Railway tire. They had not existed
long enough ; but there need be no fear to use a tire that could
stand so miich knocking about. Mr. Reynolds had referred to the
experiments tried on the Furness Railway, which, according to
the contention of Mr. Smith, of Barrow, showed that a soft iron
rail wore better than a hard one. In the first j)lace, he was not
sure that the analogy held good between a rail and a tire ; and
in the second place, he thought that the experiments were of a
very narrow range. He believed that the steel sustained a strain
of from 28 to 34 tons, which was very different from steel sustaining
45 tons. The universal practice of manufacturers, who had the

144 DISCUSSION ON THE STRENGTH [Miuutes of

highest reputation for making good tires, had been to strive after
harder steel. He hojjed, therefore, that the Aiithor was not war-
ranted in insinuating that engineers, in Tising hard steel of that
kind, were nsing that which involved any risk. The steel had been
made by the open-hearth process, and there had been no necessity
to nse chromium, nor any other unusual material, to get the
requisite hardness.

Dr. H. Clifton Sorby said he would confine his observations to
that part of the subject which had attracted his attention for many
years, namely, the microscopic structure of steel. He thought that
what might be seen by examining suitably prepared objects, with
high magnifying powers, would throw a good deal of light on some
facts that had been ascertained in an independent manner. The
microscopical structure of Bessemer steel was very interesting and
curious. It somewhat resembled, though to some extent it differed
from, the structure of certain portions of charcoal Swedish iron
containing a certain amount of combined carbon. The structure
was very complex. There was no difficulty in recognizing by the
microscope two totally distinct substances. One of them he took
to be free iron, or iron containing next to no carbon, if any, and
the other a chemical compound of a certain amount of carbon
with iron. The appearance of the two under the microscope, in
prepared sections, was so different, that one could not possibly be
mistaken for the other ; they were as distinct as any two minerals
could be. The conclusion at which he had arrived was that, in
cooling from a state of fusion, what he regarded as a comi^ound of a
certain amount of carljon with iron crystallized oiit first ; and that
in crystallizing it threw off the superfluous amount of iron and
entangled some of it, but threw out the greater portion towards the
outside ; so that, in looking at a section of the steel in the micro-
scope, a i^eculiar kind of network was seen, that network being the
outside of the crystals, also extending in a most intricate and
curious manner along what he took to be some important planes in
the crystals of the other compound. On studying the matter more
fully, he thought it might safely be said that there was good
evidence to show that the original crystals which crystallized out
in the first case, on cooling down to a certain temperature, under-
went a complete molecular change, so that they might be regarded
as not exactly pseudomorphs, but (to use a mineralogical term)
paramorphs ; that, in fact, after cooling to a certain point, they
underwent molecular changes, breaking up into a number of
crystals not necessarily related to the crystalline structure of
each original larger crystal. That appeared to him to be a satis-

Proceedings.] OF BESSEMER-STEEL TIRES. 145

factory way of explaining the peculiarities to be found in properly Dr. Sorby.
prej)ared sections of an ingot. In annealing the specimen, how-
ever, a complete change took place. Instead of having the curious
complex mixture to which he had referred, the two constituents
were separated from one another more completely, and on a smaller
scale ; the crystals were smaller and each one more simple. The
difference between the annealed ingot and the ingot in its original
condition, as seen under the microscope, was so great that no one
could hesitate to say that most important changes had occurred.
That, he thought, agreed well with some of the conclusions of the
Author. When the specimen was rolled or hammered, he believed
that his own specimen was rolled, a complete change took place; the
crystals were much smaller, and the two distinct substances were
broken up and made more uniform. It might well be believed
that the difference in structure between rolled and unrolled steel
was very great indeed. There were the same two constituents,
only on a smaller scale and more uniform, as in fact might well
be supposed would be the case. Light was also, to some extent,
thrown on the question of hardening. His experiments on that
subject were not with rolled steel but with the ingot itself. He
thought that, having a coarser structure to deal with, the differ-
ence in the structure after hardening would be more apparent,
and so it was. Taking a piece of an ingot in its natural state,
raising it to a red heat, and plunging it suddenly into cold
water, and then making a sectiou and examining it with a micro-
scope, a most remarkable and complete change could be seen ; the
whole was uniform as far as could be judged with the micro-
scope. The ultimate constituents were so small, that even with
a power of 400 linear, which could be used with perfect efficiency,
they could not be distinguished. The question of hardening would
probably prove one of the most difficult to deal with from the
microscopist's point of view, because the ultimate constituents after
hardening were so minute, that it would be difficult to distinguish
them even with very high powers. It appeared to him that there
were two important changes. In the first place, when a portion of
the ingot was raised to a red heat, it seemed that the two original
constituents mutually dissolved, so that at a high temperature
there was, to a certain extent, a reproduction of a state of fusion,
though not strictly fusion — the constituents were more uniformly
distributed — and when hardened, there was no time for them to
separate. He believed that, independently of there not being a
separation which occurred in annealing, and in a slowly cooled
ingot, there was some most important change very difficult to

[tHK INST. C.K. VOL. XCV.] L

146 DISCUSSION ON THE STRENGTH [IMimites of

investigate. Those facts, lie thought, threw much light on some
of the qiiestions under disciission. As far as he had been able
to judge by applying the microscope to the structure cf iron and
steel, there was so much still to be learned on the subject, that
speculation should not be carried too far. In order thoroughly to
investigate it, some of the young men of the day should devote
twenty or thirty years' study to it, as he had himself done to
the structure of rocks. After such an investigation they might
possibly know something about the constitution of that most
remarkable element, iron. His own work had shown him how
much yet remained to be learned, and if he had succeeded in
attracting attention to the subject, as one well worthy of in-
vestigation, he should feel amply repaid.

Mr. W. G. KiRKALDY desired to make a few remarks on the
subject from a mechanical point of view. He had had occasion
to make many examinations of tires under pulling and other
tests. No doubt the subject was interesting from a chemist's
point of view; but he thought engineers in their specifications
could deal with it very well by means of mechanical tests, without
tjdng down the manufacturer to a certain chemical composition.
It was no doubt needful to have very strict specifications as to the
mechanical requirements which would be suitable for tires to stand
wear and tear. It was not, he thought, necessary to make tires of
very hard steel, but rather to aim at great toughness. He had
examined tires from many different makers, and most of those
received from Krupp had shown remarkable properties for tough-
ness, and had given a very high strain, yet with such large
contraction of area that he did not think there could be any risk
in using them. The results showed that an increase in hardness
did not necessarily mean an increase of tensile-strength. In the
case of one specimen the ultimate tensile-strain was 50-9 tons and
the contraction 41 • 5 per cent., a high contraction for such a
strain. In another case the ultimate tensile-strain was 22 • 3 tons
and the contraction was only 2 ' 2 per cent. For his own part he
preferred specimens which bore witness that they were actually
out of tires, the heads showing the section. Unless the engineer
was very strict, to see how the tests were obtained, he might
be easily misled by results obtained from the small specimens
customary with manufacturers and others. Evidence of one
effort to obtain unduly high results was demonstrated by the
small specimens which Le submitted for examination. He had
called the engineer's attention to the fact that, although the
specimens sent prepared for testing might have been out of tires,

Proceedings.]

OF BESSEMER-STEEL TIRES.

147

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148 DISCUSSION ON THE STRENGTH [Minutes of

Mr. Kirka^dy. as represented by the maker, yet as they had been forged down,
instead of being turned from tires in normal condition, no reliance
should be placed upon them. The matter Avas one that should be
very carefully dealt with for the experiments to be thoroughly
reliable. There should also be a standard size in order that the
experiments might be compared. At present an engineer often
found that he could not compare the specimens tested at one
maker's works with tests sent to him from another maker ; but
if the same size were adhered to, which had been a great point
. witli his father for many years, that difficulty would be removed,
and the tests could be compared so far with each other. Engineers
should be protected from sham experiments. He had known
many cases in which they had been in danger of being misled
by results put forward by interested persons, but such results had
proved ultimately unfavourable to the English maniifacturer. It
was naturally important to makers to obtain good results; but if
the material on going out did not come up to what was repre-
sented, a reaction would set in. He had known several cases in
which, in consequence of failures in that respect, orders had been
given to a foreign firm, which had managed to keep its footing.
Keference had been made to some experiments said to prove that
work on steel did not necessarily improve it very much. Accord-
ing to his own experience, the fact was the very opposite. He
had seen the most conclusive proofs that work on steel had a great
deal to do with its character, and referred to an extensive series of
experiments upon Fagersta steel, by his father, which had been
piiblished in full detail. Any gentlemen, desiring to see the
niimerous specimens collected at his works having a bearing on
the subject under discussion, would be heartily welcomed, and he
felt confident they would gain information that would prove of
practical value. The tests in the Table (p. 147) had been selected
for the purpose of showing the difference in the qualities and
behaviour of various grades of tire-steel. They were a j^ortion of
the forty-two specimens of tires which he. exhibited.
Jlr. Berkley. ]yjj._ CrgoRGE BERKLEY, Vice President, Said it would be readily
admitted how very important chemical knowledge in regard to steel,
and other materials used by the engineer, had been, still was, and
was likely to be. Without this knowledge, Bessemer steel and
Siemens steel, two aids to the engineer probably as useful as any
that could be mentioned, would still have been unknown. He
was not satisfied with the reasons assigned by the Author for
attributing importance to the particular subject he had mentioned.
The Author had referred to the question as one affecting the safety

Proceedings.] OF BESSEMER-STEEL TIRES. 149

of thousands of lives. That was scarcely suitable for a scientific Mr. Berkley
Paper. He had also stated that it was impossible to have too great
a margin between a working- and a breaking-strain. Surely some-
thing more definite than this was required. The point was to
ascertain the admissible difference between the working- and the
breaking-strain. The Author had further stated that there was a
growing tendency amongst railway engineers to specify for tires
possessing a high resistance to tension. Looking at the specifica-
tions of other engineers, and also having regard to his own, he did
not think that the statement was a correct one. Eight or ten years
ago there was, unquestionably, an advance, which was justified by
the improvement in the manufacture of the material. The Author
probably did not mean it, but he appeared to attribute to engi-
neers a consideration for economy, even at the sacrifice of safety.
Nothing could be less accurate than such an inference. It had
been his duty to send tires abroad for thirty-seven years. He had
not been sufficiently industrious to examine all the analyses and
experiments during that time, but he had carefully scrutinized
them for the last ten years. During that period he had sent abroad
about thirty-five thousand tires, of which about thirty thousand
were for wagons and carriages. He had examined hundreds of
tests in regard to those thirty thousand tires, and they showed
that the average tensile-strain had rather exceeded 44 tons per
square inch ; the maximum had been 47 tons, the stretch on the
average had been over 20 per cent, in a 2-inch test-piece, and the
deflection under a drop-test had averaged 6 inches in a foot of the
diameter of the tire, instead of what the Author had called the
normal deflection of 2 inches in a foot. He assumed the Author
meant, by normal deflection, that commonly specified by many
engineers, who were satisfied that they had secured the safety of
the travelling public, if imder a drop-test the deflection amounted
to 2 inches in every foot diameter of the wheel. That had not
been his own practice. As the result of many hundreds of tests
he had obtained an average deflection of 6 inches. He had
examined fifty-six tests of engine tires made during the same time,
and the tensile-strength of those had been fully 46 tons per square
inch ; the stretch had been 22 per cent., and the deflection under
the drop-test had averaged from 3i to 8 inches in a foot. Fifty-six
tires had broken after receiving from five to twenty-one blows,
and on the average ten blows of 1 ton weight falling through
30 feet. The tire was placed on a block of cast-iron weighing
5 tons. A fact, not altogether without interest, was that on a
colonial railway, which liad a very great length and very uiany

150 DISCUSSION ON THE STRENGTH [Minutes of

curves of 300 feet radius, it was foimd necessary, in order to ensure
safety, to have much harder tires. With the softer tires the flanges
ground away so rapidly that they became like blunt knives after
running a comparatively short distance. Application was accord-
ingly made to a w^ell-known firm pre-eminent in the manufacture of
hard tires. What had been the result of sending out the objection-
able tires referred to by the Author, as those who had read the
Paper might, he feared, regard them? He had only known one
tire break about seven years ago, during the ten years he had
mentioned. That might perhaps be considered only negative
evidence. He had, however, the advantage of speaking during the
last few days to a locomotive superintendent who had received in
India about thirty thousand of the thirty-five thousand tires, who
stated that during his experience of thirteen or fourteen years he
had not known of a single broken tire. Other engineers had
without doubt been eqiially successful, so that he thought the
Author's apprehension might to some extent be soothed, and that
he need not anticipate, or lead others to anticipate, serious mishaps,
and the want of safety. The Author observed that it was accepted
as an axiom that from 0"25 to 0"32 per cent, of carbon was the
proper proportion for Bessemer steel, and that to get a strain of
42 tons was rather hazardous, and that if that were obtained, and
if 0 • 40 per cent, of carbon were put into the steel for tires, they
would fail under the tup-test. All the tires of which he had
sjioken had been under the tup-test, and with very rare exceptions
had not failed. The Author had further stated that the strength of
tires should not be increased by adding carbon, and suggested that
good might be done by the addition of chromium. He had not a
word to say against the addition of chromium, and he knew that
those who used it considered that it added to the ductility of steel.
But he wished to point out that the Author's limit of 0*40 per
cent, of carbon was not the limit of safety. The Author, at p. 122,
gave a steel with 0 • 28 per cent, of carbon, 0 • 42 chromium, and
1 "54 manganese, while (p. 129) he gave a steel with 0*50 per cent,
of carbon and no chromium. From his own statement something
very different in the ductility of the two steels might be expected.
But what were the facts ? Both of them bore as near as possible a
strain of 60 tons per square inch, and they stretched, one of them
15*0, and the other 14-9 percent.; the stretch represented duc-
tility equally with the bending from the tiip-test. He might be
permitted to refer to some experiments made for him by Professor
Kennedy and Dr. Riley in 1882. Of six specimens two had carbon
under 0 • 40 per cent., one With 0 • 425 of carbon had a tensile-strength

Proceedings.] OF BESSEMER-STEEL TIRES. 151

of 43 • 39 tons per square inch, and stretch of 23 per cent., breaking Mr. Berkley,
under a tup- fall of 18 feet; the deflection being 4 inches per foot.
In the next case the carbon was 0*433, the tensile-strain 45*5 tons,
the stretch 22 per cent., breaking at 27 feet fall, the deflection
being 5 inches per foot. In the next case the carbon was 0*441,
the tensile-strain 44 tons, the stretch 18 per cent., breaking at a
fall of 30 feet, with the deflection of 4 inches per foot. The next,
carbon 0*577, tensile-strain 45*74 tons, stretch 15 per cent., break-
ing under 20 feet fall, and deflection 3^ inches per foot. The
main object of the Paper appeared in the statement of the Author's
views, as to the test necessary to indicate the fitness of tires for
strains that they would subsequently meet. He said, " At the works,
let tires be selected from groups made from the same blows, each
group being marked with a distinctive stamp." That was the
practice of almost all engineers. " Let representative tires from
each group be sulijected to exhaustive chemical and mechanical
tests. Let the exact mechanical treatment from ingot to finished
wheel be faithfully recorded. When the life of one of these tires is

finished let the chemical and the mechanical tests be repeated."

It was a charming idea to go through an experience of years, from
the commencement of the manufacture to the end of the life of an
article. It was delightful to contemplate such a state of things,
but it was not practicable. The Author had naturally suggested
that chemical, as well as mechanical, tests should be made of the
material. No doubt occasionally an analysis of steel was desirable
to give the engineer information as to the chemical composition of
a material, which he had perhaps tested many times. But he knew
that, to a great extent, chemical tests could not be carried out in
practice. His principal objections to them were that they were
very costly, and that often they could not be carried out in time.
It would be a great inconvenience if manufacturers had to add
chemical tests to their other tests ; and even assuming that they
were trustworthy, which, however, he could not admit, he did not
think that an indirect method of ascertaining the mechanical
qualities of a material would be so good as a direct method, by
subjecting the material to the kind of work which it would sub-
sequently have to undergo. It was an assumption that he should
not like to vouch for, that, by the analysis of a piece of steel, it
could be foretold what the results would be when the specimen
was tried by a mechanical test. He had examined analyses made
for himself and others, and he did not hesitate to say, that if a
chemical test were specified, no engineer would be able to reject a
batch of tires which did not exactly conform to the chemical

152 DISCUSSION ON THE STRENGTH [Minutes of

analysis. As a practical engineer, therefore, he regarded a chemical
test as of little value, except as giving some information of the
general character of the steel. He would impress upon all present
the undesirability of having two tests. They might be incon-
sistent with each other, and then they would give much trouble.
It was far better to have one test and to stick to it. There was
one point on which he did agree with the Author, namely, his
recommendation to cool the tires slowly. It was of importance,
when a tire was made, to put it in some place, or protect it, in such
a way as to ensure its being cooled slowly, so that local strains
might not be set up by unequal cooling. If engineers would press
upon manufacturers to do that more systematically, they would
find a great advantage from it. He might, perhaps, be permitted
to enumerate shortly the mechanical tests which he had found to
be necessary. In the first place, he limited steel for tires of
wagons and carriages to a strain of 42 tons per square inch, and
for tires of engines to 44 tons, with a stretch of 20 per cent, in
2 inches. The next test he believed to be a very important one,
though it was not generally practised. Every tire after it was
cold should be dropped on to a block of cast-iron, weighing at least
2 tons, first in one direction, and then turned through an angle
of 90°, and dropped in the other direction. If the steel was too
hard so as to be at all dangerous, or if there were any flaws in it,
that test would discover the defect. Tires of different diameters
shoiild be dropped different heights. With diameters of 3 feet
6 inches they should be dropped o feet ; with diameters from 3 feet
6 inches to 4 feet 6 inches, 4 feet; with diameters from 4 feet
6 inches to 5 feet 6 inches, 3 feet 6 inches. More tires had been
broken in that way than had been broken by a tup of 1 ton
falling 30 feet. Every blow of the apparatus, or every charge of
the furnace, should, in his opinion, be tested. In his own practice,
the tires were put under a tup of 1 ton on a block of 5 tons, and
the drop was one of 30 feet. He was in the habit of specifying
that the tire should receive two such blows, which almost
invariably gave a greater deflection than 2 inches per foot of
diameter of tire. He also specified that the tires should be broken
with the tup. It took on an average about ten blows to break the
tire, and the deflection was at least equal to 6 inches in 1 foot of
diameter.
r. Tickers. Mr. T. E. YiCKERS should have attached more value to the Paper

if it had Iteen prepared with a little more experience. In the first
place, more attention should have been given to the size of the
sections of the tires testetl, and the tup for testing should have

Proceediugs.] OF BESSEMER-STEEL TIRES. 153

been of the usual weight of 1 ton. He did not think that the Mr. Vickers,
Author was justified in finding fault with engineers for specifying
a hard material which would wear well. They wanted a material
to wear as well as possible, and to have safety combined with it.
From many years' experience he held that the falling-weight-test
upon a tire was the best that could be applied to it. By adopting
uniform sizes, an idea could be obtained both as to the toughness and
hardness of the tire ; for tires of a given diameter and section and
equal hardness would always be uniform in their deflection. He
thought the results at which the Author had arrived were not due
to the hardness of the steel, but to its composition. His experience
had apparently been derived from steel containing 0*80 per cent,
of sul})hur, 0 • 80 per cent, of phosphorus, and 1 • 25 per cent, of man-
ganese. Mr. Vickers had no experience of tires of such a chemical
composition. His idea of a good tire was one containing from 0 • 50
to 0 • 70 per cent, of manganese, not over 0 • 035 of phosphorus, about
half the amount of sulphur mentioned by the Author, and as much
as 0 • 60 per cent, of carbon. Such a steel* would stand the dropping-
weight-test thoroughly well, even if the carbon reached 0"70 per
cent., and if a tire would stand this test it was perfectly safe. It
used to be said that this test was absurd, because a tire was never
subjected to such treatment in practice, and that the tensile-test
was the more suitable one. But there must be some test, and it
was not the tire itself, but the material of which it was made that
was tested, and for that purpose the falling- weight-test, he thought,
was the best. With uniform sections, it would show both the
ductility and the hardness ; but as the sections and the diameters
varied very much, it was necessary to have the tensile-test in
addition, to ascertain the hardness, in order to ensure suflScient
wear. Those were mechanical tests which he had adopted for nearly
thirty years. The Author had spoken of the molecular changes to
which steel of high temper was liable. He did not know whether
by that was meant the old idea of crystallizing by vibration, which
he had thought was now exploded. Neither iron nor steel, which
had small crystals to begin with, could by any process of vibration
be transformed into a structure containing larger crystals. The
Author, in one instance, had contradicted himself. He had stated
(p. 116) : " This is proved by the fact that a test-piece, planed out of
an untested tire, gives miich the same result on the testing-machine
as a piece planed out of a tire which has been subjected to the
falling- weight-test " ; while later on he stated that : " A tire which
has been much punished under the falling weight will sometimes
give widely diverse results on the machine, such variations de-

154 DISCUSSION ON THE STRENGTH [Miuutce of

pending upon the position from wliicli the test-pieces were taken."
If there was no difference between the tire tested and a tire untested,
there oiight to be no difference between pieces taken from different
parts of a tire which had been subjected to that punishment ; and
in practice he had found, from many trials, that tensile-test-
pieces, cut from different parts of a tire so tested, did not materially
vary. He had not much experience of chromium, except experi-
mentally, because he had always been able to get steel of the
necessary quality without the use of it. He simjjly relied on not
having too much impurity, and adding carbon, which was one of the
best constituents of steel to get hardness. Alhision had been made
to annealing, and Mr. Berkley had referred to the slow cooling of the
tires before testing. Although he agreed with almost everything
he had said, he certainly could not agree with him in that. It was
never known w^hat a tire would be subjected to after it had gone
abroad; it might be re-heated and allowed to cool qiaickly, or it might
when being j^ut on the wheel be heated too much and dipped into
water, the results of which would be to undo all the effects of an-
nealing. An experimental tire containing chromium, and cooled in
ashes during four or five days, was reduced in tensile-strength from
60 to 45 tons per square inch. The same tire re-heated, and allowed to
cool in the ordinary way in the open air, regained its former tensile-
strength, showing that it assumed the original form Avhich it had
when it left the rolls, and thus lost the effect of the annealing.
In order to ascertain the probable safety of a tire, it ought to be
subjected to a test in its most disadvantageous state, namely, its
state when it left the rolls. He did not olgect to tires being
re-heated, if they had been allowed to become too cold in the rolling-
mill, and afterwards cooled in the open air ; but he thought it was
a mistake to allow tires to be cooled in ashes, when removed from
the rolls, in order to facilitate the testing. He never ditl anything
of the kind unless expressly told to do so by the engineer, and even
then he always did it with great unwillingness.

Mr. W. Stroudley observed that the Author had advocated the use
of soft tires. Mr. Stroudley had used Bessemer tires for wagons,
and had worked ten thousand or eleven thousand pairs. He had
also used them on heavy goods engines running at low speeds.
He had found that the wear of Bessemer-steel tires in the case of
the engines, was more rapid than that of the superior quality of
steel made by the crucible process, or by the open-hearth system.
He could only find a record of one Bessemer-steel tire breaking on
a wagon out of the number he had mentioned. He had also
examined the records of engines fitted with steel tires, and, in

rroceedings.] OF BESSEMER-STEEL TIRES. 155

100,000,000 miles distance travelled, he had found only one tender Mr. Stroudley.

and one engine tire broken. He had tried the experiment of

locomotives with tires made of soft steel possessing about 36 or

37 tons tensile-strain. The wear of those tires was very rapid ;

they spread out quickly, so that they had to be frequently

turned. He had since adopted tires with a tensile-strain of about

47 tons per square inch. He had removed them after they had

been worn out, and cut sections from them, and had obtained

a tensile-strain of from 47 to 48 tons on a 3-inch specimen. He

therefore thought there could be no advantage in making a tire

soft ; but there was a great advantage in making it of steel that

would sustain a tensile-strain of 50 tons in the case of higher

class steel, and very near that in the case of Bessemer steel. No

accident had resulted from the fractures he had mentioned, and

the tire had not left the wheel in any case. The process used

in jiutting on the tires was to bore out the tire carefully, with

the usual allowance for shrinkage, to place it on the wheel and

let it cool without water, or any other means. As a railway man,

he saw no necessity for meddling with the chemical constituents

of the steel. He attached great importance to the thickness of

the rim of the whesl. He had observed that tires of wheels having

thin rims broke, whereas those of wheels having thicker rims did

not break. He thought that part of the wheel was very often

neglected.

Mr. Alexander McDonnell said he had not intended to speak Mr. McDonnell,
but for the remarks made by Mr. Stroudley and Mr. Vickers. He
was glad to hear the remark of Mr. Vickers on annealing, which
he regarded as exceedingly valuable when juoperly done ; but he
thought that it had sometimes done mischief. Where forgings
were left to soak, and to lie in hot sand for a long time after
being forged, instead of being allowed to cool in a slow uniform
way, they had been damaged, and their tensile-strength reduced.
Almost all the tires on wheels that he had seen broken of late years
had been on very thin rims, or where the rim had been broken.
He had observed a considerable number of wheels running with
a broken rim, and he had seen more tires broken upon defective
wheels of that kind than on any others. The Author woiild have
been j^erhaps frightened if he had lived in the time of welding
tires. Mr. McDonnell had stopped many hundreds of wagons for
broken tires, and great numbers of engine tires were broken when
tires used to be welded. That was almost unknown now.

Mr. J. Oliver Arnold, in reply, considered the Paper had been Mr. Arnold,
amply justified by the various and often mutually destructive

156 DISCUSSION ON THE STRENGTH [IMinutes of

Ir. Arnold. opinions expressed by the different authorities -who had taken
part in the discussion. For example, the Paper advocated a strain
of nearly 40 tons per square inch for Bessemer-steel tires ; but
the majority of the railway engineers who had spoken advocated
a strain of nearly 50 tons, while Mr. Mattieu Williams nailed his
colours to the mast at something under 30 tons. Mr. Eeynolds
had spoken of a property of steel which he termed " body,"
and which he defined as a certain kind of homogeneity, which
offered great resistance to the disruption of the particles. That
property depended upon two factors : the first, suitable chemical
composition, and the second, appropriate physical treatment. Mr.
Arnold altogether denied the existence of " body," in the sense
that it was a mysterious essence to be distilled from certain brands
of iron. Messrs. Eeynolds and Cow^ier had both taken strong
exception to the hammered bar, mentioned on page 120. He fully
admitted that the difference in the treatment of the two steels
somewhat vitiated the accuracy of the comparison ; biit he could
not admit that it accounted for the reduction in the extension
from 15 to 3 per cent. The former was inclined to deny the
existence of molecular change, and to substitute for it what
he called fatigue ; and he defined fatigue as a separation of
particles arising from the imperfect elasticity of the steel. Ko
doubt there was a great deal in favour of that view, but he failed
to see that the term " molecular change " was not a better expres-
sion to apply to it than the meaningless term " fatigue." The
tire that bore a strain of 36 tons, referred to by Mr. Eeynolds,
fully bore out the statement in the Paper that tires of moderate
strain were not subject to alteration from vibration. Again, a
doubt had been expressed whether hard tires had a greater
wearing capacity than soft tires. He thought that point had
been pretty conclusively settled by other engineers who had taken
part in the discussion. Mr. Hadfield supj^orted the view that
steel, identical in chemical composition, might vary very largely
on the machine. That he regarded as an important feature of the
discussion, and it was to be hoped that the theory that such varia-
tions proceeded from heterogeneous chemical composition was now
exploded, and that future research would be carried out on the only
lines likely to lead to good results, namely, that of heterogeneous
molecular or physical structure. Professor Eoberts-Austen had
denied the chemical identity of an annealed and an unannealed
steel casting, and had asserted that it was well known that
annealing totally changed the state in which the carbon existed.
So far, however, from its being well known, it was totally unknown

Proceedings.] OF BESSEMER-STEEL TIRES, 157

to many practical steel-makers, and his own experiments led to an Mr. Arnold.
opi)osite conclusion. Professor Roberts-Austen was j^erhaps con-
fusing two distinct sets of phenomena. It was well known that,
in rolling hard steel, a separation of the particles of graphite
sometimes took place, producing what was techically known as
black steel. That often occurred in the case of file steel. When
the steel was hardened, the whole of the carbon reassumed the
combined condition ; and Mr. B. W. Winder had obtained results
on annealing which showed that graphite reappeared in exactly
the same position as before hardening. But that was very different
from the case of a mild steel casting containing 0 • 50 or 0 • 60 per
cent, of carbon ; because if that steel, after leaving the mould,
was drilled, having been carefully cleared from scale, and a careful
colour-comparison was made and repeated after annealing, very
little diiference could be observed in the two colour-tests. He
was afraid that Professor Roberts-Austen's dream of a metal-
lurgical millennium, when the influences of the hardening elements
of steel were to be ruled by the periodic law of Newlands and
Mendeleef, would never be realized. Mr. Cowper had expressed
an opinion that unannealed steel castings were not brittle, and
stated that many steel castings were in use. Whether unannealed
steel castings were or were not brittle would be best proved by the
following experiments. Some two years ago he had to superintend
the metallurgical portion of the manufacture of several hundred
steel buffer cases. They were cast from crucible steel of the
highest quality, and contained perhaps, 0 • 50 or 0 • 60 per cent,
of carbon. The cases were tested by placing them base down-
wards on an anvil, and striking a heavy blow with a 4-ton
steam-hammer. The unannealed cases went to splinters at the
first blow, but the annealed cases stood from four to six blows ;
and the manner of rupture was totally different. In the latter,
a longitudinal crack was developed from the base, and in
some cases the bearing was actually crushed into the sjjring
chaniber. Messrs. Yickers and Reynolds had both expressed an
opinion that the tires, of which analyses had been given, were too
impure. The former particularly objected to phosphorus ; but
Mr. Aspinall had stated that the Siemens tires which gave the
best results had the following analysis: carbon, 0-65 per cent.;
silicon, 0 • 28 ; sulphur, 0 • 09 ; jihosphorus, 0 • 06, and manganese,
0-86. That was a direct contradiction to the views as to quality
expressed by Messrs. Tickers and Reynolds. Mr. Berkley had
altogether mistaken him on one point. He was rather severe on
him for stating that the limit of carbon should be 0*32 per cent.

1 58 DISCUSSION ON THE STEENGTH [Minutes of

ilr. Arnold. He was really referring to Bessemer steel, and Mr. Berkley must
have missed the foot-note on page 117 referring to that subject, in
which it was distinctly stated, that in steels low in manganese
there was a much greater latitude for the carhon. Mr. Berkley
thought it very curious that the spring steel (p. 129) with 0*50 per
cent, of carbon, and 1-10 per cent, of manganese shoiald elongate
as much as the tire-steel (p. 122), containing 0*28 per cent, of
carbon, 1 • 54 of manganese, and 0 • 42 per cent, of chromium, and
argTied that these results proved the inconsistency of the reasoning
in the Paper. Here was an example of the use of that chemical
analysis which Mr. Berkley valued so little. By its indications,
the chemist found in this particular case that 0*40 per cent, of
manganese, and 0*40 per cent, of chromium had much the same
hardening effect as 0*20 per cent, of carbon; and he thought it
inadmissible to build up an elaborate argument on the carbon
contents alone, ignoring altogether the influences of the variations
in the proportion of manganese and chromium. The same speaker
had also said that the assertion that the strength of steel tires was
a question affecting the safety of many lives, was not suitable for
a scientific Paper. But it was admitted in the Paper that the
precautions taken by engineers to ensure the safety of tires were,
in the great majority of cases, effectual. The information given
by Messrs. Cowper, Aspinall, Berkley and Stroudley, as to the
rarity of tire breakages was satisfactory as far as it went ; but it
was evident that tires did occasionally break, and should such
fractures lead to accidents, it would be very small consolation to
the injured to be assured that their case was exceptional, and that
so many tires ran so many thousands of miles with a minute
percentage of breakages. The question was. Why should there be
any breakages ? there must be a cause for them, and it might be
removed. The statistics given by Mr. Berkley were very valuable
and interesting, biit a similar record of the behaviour of 60-ton
tires on English railways would be still more instructive, because
on these, conditions in a great measure absent on colonial railways
existed, namely, high speed and continuous brakes, and consequently
much greater vibration. It would appear from statistics recently
})ul)lished, that English were more fortunate than German engineers
in the matter of tire fractures, the German record for 1887 having
been three thousand five hundred and fifty-two broken tires, and
that for the fracture of six hundred and thirty, or 33 i^ per cent, of
these, no cause could be assigned. Mr. Berkley's idea that so intricate
a problem, as the influence of molecular structure on the strength
of steel, should be solved \>y the indications of a single method of

Proceedings.] OF BESSEMER-STEEL TIRES. 159

testing, would not commend itself to those accustomed to research Mr. Arnold,
on o])Scure i)henoinena ; because experience has shown that such
questions were only satisfactorily answered by experiments made
from every point of view, namely, in this case, chemical, physical
and microscopical. Mr. Aspinall had referred to the superiority
of steel over wrought-iron crank-axles ; and it was highly de-
sirable that the use of iron for the manufacture of railway tires
and axles should be abolished, with a substitution of steel of
moderate tensile-strength, the latter being uniform in chemical
comjiosition ; whereas the lines of continiiity in wrought-iron
were broken Tip by the layers of admixed slag. Mr. Aspinall as well
as Mr. Berkley spoke favourably of the effects of annealing, and
it was to be presumed that tires made from steel of the extraor-
dinary composition quoted by the former were carefully annealed,
otherwise a tire containing 0*60 per cent, of carbon, nearly 0"25
per cent, of silicon, and 1-10 per cent, of manganese, if allowed
to cool in the ordinary way after leaving the rolls, would give a
strain approaching 60 tons on the machine, and snap under the
impact-test, long before the necessary deflection had been obtained.
Tlie contriluition of Mr. Lewis to the discussion would be
rather unpalatable reading for English steel-makers, indicating
as it did the superior skill of continental steel-makers. The
analysis of the Belgian steel showed it to contain 0 • 06 per cent, of
phosphorus, or nearly twice as much as the ideal tire of Mr.
Vickers, and yet it was asserted that the quality' of this steel was
so high, that it yielded tests which no English maker dared
guarantee. The divergences between the Belgian and English
analytical results were, however, so great, that it was difficult
to believe that the steels on which the chemical analyses were
made were identical. Engineers would do well to give careful
attention to Mr. Kirkaldy's significant remarks, and more par-
ticularly where he urged that "engineers should be protected
from sham experiments." Mr. Vickers depreciated the value of
the Paper because of the inexperience exhibited in its preparation,
founding this opinion, firstly, on the fact that the tup used in the
impact-tests weighed 22 cwt. instead of 1 ton ; and secondly, on
the want of uniformity in the sections and diameters of the tires
experimented upon. The aj^plication of a little arithmetic would
remove any inconvenience arising from the weight of the tup ;
and the second objection was wholly imaginary. The diameters
and sectional areas of the tires used were uniform throughout.
The sentences taken from their contexts (pp. 116 and 127), which
Mr. Vickers held to be contradictory, had reference tc steels dif-

160 DISCUSSION OK THE STRENGTH [Minutes of

fering widely in their chemical constitution, and consequently,
juechanical properties. It would be just as reasonable to charge
with inconsistency any one who stated that a steel containing 1 • 00
per cent, of carbon would harden, whilst a steel containing 0*10 per
cent, would not harden. In conclusion he trusted that the anoma-
lous and discrepant experiences, brought to light during the
discussion, might prove valuable as finger-posts pointing out paths
for further research.

Correspondence.

Ir. Aiijileby. Mr. C. J. AppLEBY regretted that the record of investigations
had been limited to metals containing chromium, and what seemed
to him exceptional proportions of manganese, and that but brief
reference (p. 128 J had been made to tempering in oil, and none at
all to the usual mode of annealing by lengthened exposure to heat
in a closed chamber. He had found that the results obtained by
the last named method were irregular and unreliable. As re-
gaided oil-tempering, he had made many experiments with open-
hearth, Bessemer and crucible steel, and, whether high or low in
carbon, he had found that immersion in oil, at temperatures
suitable to the character of the metal, invariably imjjroved its
quality, and more especially its tenacity. He thought that the
following list of tests of oil-tempered Bessemer-steel axles, made
in Sheffield, had a direct bearing on the question under con-
sideration, because, after all, a quality of steel was sought
which would be reliable under the severe conditions which tires
and axles must constantly fulfil. The axles referred to were
forged from ingots of the usual size, and the tensile-strength of
the steel when forged was 26*1 tons per square inch, with an
elongation of 28' 6 per cent, in a length of 8 inches, and reduction
of area of 60-2 per cent. The tests of the steel, after oil-
tempering, gave a tensile-strength of 27-5 tons per square inch,
an elongation of 26*87 per cent, in a length of 8 inches, and
reduction of area of 58 • 44. The dimensions of the axles were : —
length, 7 feet 4 inches ; diameter at wheel-seat, 5 j inches ; diameter
at centre, 4^ inches. The first test consisted of twenty blows from
a 1-ton tup, with 20 feet free drop on the centre of the axle, the
bearings being 3 feet apart. The axle was turned half round after
each blow, and the deflections were : — 1st blow, deflection 2| inches ;
2nd, straight; 3rd, 2^ inches; 4th, straight; 5th, 2j inches; 6th,
^ past straight; 7th, 2j^ inches; 8th, j inch past straight; 9th,

Procccdinf^s.] OF BESSEMER-STEEL TIRES. 161

2| inches; lOth, -^ inch past straight; 11th, 2 J inches; 12th, Mr. Appleby.
^ inch past straight; 13th, 2 inches; 14th, ^ inch past straight;
15th, 21 inches; 16th, ^ inch past straight; 17th, 21 inches;
18th, f inch past straight; 19th, 2} inches; 20th, ^ inch past
straight. The tests were then continued by giving the tup a fall of
26 feet with the following results : — 21st blow, deflection 2 J inches ;
22nd, I {r inch past straight ; 23rd, 2 j inches ; 24th, 1 inch past
straight; 25th, 2-^ inches; 26th, 11 inch past straight; 27th,
2V inches; 28th, 1} inch past straight ; 29th, 2 J inches; 30th,
1 g^ inch past straight, thus showing gradual fatigue ; but there
was no fracture, and nothing to indicate that these severe tests
had caused permanent injury to the steel. The bending-tests
were made on pieces 1^ inch square by 8 inches long, machined
out of the axles before and after oil-tempering, and were bent
double when cold. The untempered steel showed signs of tearing
in the bend, whilst the tempered pieces gave no indication of this
kind. There was a wide difference in the fractures, the un-
tempered steel being open and crystalline, whilst the tempered
specimens were much closer in the grain, with an entire absence
of crystals, and had a silky appearance, the colour being darker
than in the untempered steel. As might have been expected, steel,
higher in carbon, which had a tensile-strength of 35 tons per
square inch before treatment, increased in strength in a higher ratio
than the low-carbon steel above referred to. The increase in tensile-
strength after oil-tempering was 3 to 4 tons per square inch, but
there was no material alteration in the elongation nor in reduction
of area. The well-known fact, mentioned by the Author, that steel
low in carbon did not harden, might have gone far towards creating
the widely-held impression that Bessemer steel would not harden.
This was a fallacy; probably but few engineers were aware how
large a quantity of Bessemer steel was daily worked up into
springs, and even cutting tools of all sorts. Bessemer steel had
not quite outlived its character for uncertainty in quality ; but his
experience showed that steel, singiilarly even in quality, was
produced in those works where analyses of the pig-iron and
spiegeleisen were systematically made before they were charged
into the cupola, and of the ingot when cast, due care being
exercised in manufacture by using pure coke, &c. It would be
remembered that the effect of im:uersing heated steel in heated
oil was referred to at considerable length in the discussion on
General Maitland's Paper on "The Treatment of Gun-Steel."*

' Minutes of Proceedings Inst. C.E., vol. Ixxxix. p. 114.
[the INST. C.E. VOL. XCV.] M

162 CORRESPONDENCE OX THE STRENGTH [Minutes of

Mr. AjiiiloLy. In nearly all cases it was spoken of as " oil-hardening," perhaps
" tempering " would be a more accurate expression ; and it seemed
desirable that the difference between " hardening," which increased
the tensile-strength and largely diminished the ductility, and
" tempering," which added greatly to the tenacity of the metal
without materially reducing its dixctility, should be clearly recog-
nized. It seemed to him extremely doubtful whether exceptionally
high tensile-strength gave to tires and such like things the qualities
attributed to it. But even if high tensile-strain should be con-
sidered essential, he believed a judicious use of oil-tempering would
give results more reliable than any Avhich could be obtained by
the use of chromium, and the high percentage of manganese men -
tioned by the Author ; because the metal, being purer, would be
less liable to deterioration during manufacture, and to failures due
to change in molecular structure, than the less pure steel not oil-
tempered.

Mr. Brustlein. Mr. H. A. Brustlein observed that the metal experimented on
by the Author was really a manganese-steel with a small per-
centage of chromium ; whilst in his communication to the Iron
and Steel Institute,^ he referred exclusively to a carbon and chrome-
steel compared with carbon-steel alone, and his later practice had
confirmed the statement he had made on this subject. In his
opinion he could hardly admit that the diSerence between the
results shown in the first and third tables (p. 123) could be attri-
buted to the effect of the blows of the falling weight. He rather
attributed it to other circumstances which it would take too long
to explain. At the Unieux Works he had never recorded a like
observation under a blow, although since tool steel was especially
made there, steels containing so much sulphur, phosphorus and
manganese, and so little carbon, were never worked. As the
Author too observed, chrome-steels were verj'' sensible to annealing
and tempering ; but the readiness with which they could be put
in one state or the other, might be turned to advantage. Moreover
chromium had a great superiority over manganese, in that il
behaved well when associated in large proi:)ortions with carbon ;
whilst manganese alloyed with carbon, except in the very high
percentage adopted by Mr. Hadfield, rendered the steel brittle and
untrustworthy. The influence of the length of the test-pieces on
the results of tensile-tests had been carefully studied by Mr. J.
Barba of Creusot, who had communicated a Paper on the subject to
the Society of Civil Engineers of Paris. ^

> The Journal of tlik Iron and Steel Institute, 1886, p. 770.
^ Me'iuoircB de la Socie'tc' dcs Inge'nieurs Civils, ISSO, p. G93.

Proceedings.] OF BESSEMER-STEEL TIRES. 163

Mr. F. W. Harbokd stated that his experience in the manufacture Mr. Ilarbord.
of mild steel had led him to the same conclusion as the Author,
namely, that high tensile-strains in steel could only be obtained by
increasing the proportion of metalloids, and this was always at
the expense of ductility and general reliability of the material,
especially when it was subjected to continued vibration. He had
also found that chromium was a most useful element where high
tensile-strength was required ; and that within moderate limits it
could be employed without diminishing the ductility, or otherwise
deteriorating the material.

Mr. J. W. King observed that since the experiments quoted by Mr. King,
the Author had been made, now several years ago, there had been
a great advance by steel-makers in general in controlling the state
of crystallization of finished pieces of steel, such as axles, tires,
guns, &c., so much so that tire-steels could be made with great
regularity to register, after falling-weight-tests, strains as high as
from 45 to 50 tons per square inch, at the same time giving an
elongation and reduction of area equal to steel 20 tons lower in
tensile-strength.

Sir Alexander Eendel, K.C.I.E., could give no accurate infor- Sir A. Readel.
mation on the results of the present testing of steel tires, as he got
none from India. But there were few failures here in testing, and
he had no complaints, so far, of failures in Indii, except in two
cases where tires had been found broken on wheels just arrived in
India, the result evidently of their having been put on too tight.
He had raised his tests to their present standard, because well-
known makers of tires which had a high reputation, and which
were made to very high tests, wanted him to specify tlieir make.
This he declined to do, but specified their tests. Since then he
had experienced no difficulty in getting tires capable of sustaining
these tests from other manufactures, quite as well as fiom the
makers to whom he referred. He only specified tires i.y liiese high
tests for locomotives and tenders. They were made by the
Siemens-Martin process. He had been obliged to give up steel for
carriage and wagon axles altogether. The following was au
analysis of a steel tire made at Leeds by the Siemens-Martin
process. The analysis had been recently carried out by Mr. Arnold
Philip, one of the chemists employed at the Eoyal Indian
Engineering College, Cooper's Hill. There was no chromium in
the sample. The tensile-strain obtained with this tire was
45-3 tons per square inch. The contraction of tested area at tlie
point of fracture was 21 per cent. The extension on a length of
6 inches was 15-4 per cent. A weight of 20 cwt. was allowed to

M 2

164 CORRESPONDENCE ON THE STRENGTH [Minntes of

Sir A. Rendel. fall seven times from a height of 12 feet, until the tire deflected
^ of its diameter (5 feet 6 inches external^, but it showed no sign
of fracture : —

Per cent.

Carbon (by combustion) 0

Silicon 0

Phosphorus 0

Manganese 0

Sulphur 0

Copper 0

Tungsten 0

Titanium 0

Chromium 0

Arsenic 0

Iron (by difference) 98

100

Carbon (by colour-test) 0 • 575

527
148
052
492
101
050
000
000
000
018
612

000

Mr. W. SowERBY observed that the experiments recorded in the
Paper -were hardly on the exact lines as tests of the ability of tires
to endure the treatment to which they were subjected when in
use ; for, except when there was collision, they seldom or never
had to undergo such violent concussions as were indicated in the
experiments; nor were they ever subject to any tensile-strain.
But they had to undergo and endure constant and continuous
impact on the rails over which they travelled, and the amount of
such impact depended greatly upon the velocity of the trains, and
the gradients of the railways over which they passed. A train,
especially when at high speed, had a tendency to follow the
parabolic line of a projectile ; and, as it descended the gradient,
the foreparts of the wheels were very slightly raised above the
rails, and there was a continuous fall or thump. In ascending a
gradient this thumping was behind the wheel, and so distinct was
this thumping on steepish gradients, that anyone with a quick ear
could easily detect whether the train was going down or up an
incline ; and it was this continuous thumping to which railway
wheel-tires were subjected. If the material of which the wheels
were made was good metal, then this continued impact would
have a tendency to improve, toughen, and strengthen the tire ;
just as old horseshoe nails were said to be toughened by being long
worn, and thus subjected to similar impact. It was this kind of
continued impact or hammering that a Persian or Indian sword-
blade underwent to make it perfect. If the steel from which
the tires were made was not good, then the constant impact would

Proceediugs.] OF BESSEMER-STEEL TIRES. 165

have a tendency to crystallize and destroy the strength of the Mr. Sowerby.
metal, just as the constant blows of a hammer would destroy and
crystallize the best bar of iron if suspended vertically or hori-
zontally. The gradients of a railway having such an eiFect, the
natural conclusion was that they should be made to suit the cir-
cumstances. Italian engineers, he believed, had made some lines
with parabolic gradients ; and more than forty years ago he
graded the sections of some lines he was then engaged upon,
one being the London District of the Great Northern Eailway.
He found that such a system of grading would have had several
advantages, amongst others that of saving 25 per cent, in the earth-
work ; but it would be troublesome to lay down such gradients,
and he was somewhat surprised to find the idea carried out literally
on the Switchback Eailway at the American Exhibition. Whether
the Americans had adopted parabolic gradients on their railways
he was unable to say, but if they had, they had done wisely.
Much, doubtless, had been learnt from the primitive workers in iron
in India and in Spain, especially in the use of manganese and
chrome ores for making steel, and also in the mode of tempering
steel by cooling it in oil ; and there was still much that might be
learned from them in the way of preparing and mixing ores, fuel
and fluxes, and subsequent manipulation. It was by constant and
continued hammering or impact that the finest Persian, Damascus,
and Toledo blades were made, and they were tempered and marked
by waving or swinging them in the air whilst cooling. Even the
mode of making great steel guns by coils was not new to the Indian
" Lohars " ; for many years ago he saw just such a gun lying at the
hill fort of Teree in the Himalayas ; it was about 12 feet long,
5 to 6 inches bore, and it was built ujjon a spiral form exactly
on the same principle as the Armstrong guns, and that gun must
have been one hundred and fifty, or two hundred years old.

Mr. Bartlett W, Winder observed that his work had been more Mr. Winder,
especially confined to the higher grades of tool steel, and here
similar phenomena were met with, particularly and strikingly in
high-carbon steels. A portion of carbon, which in the ingot or
hammered bar had existed as combined carbon, assuming during
the rolling the free or graphite state ; the fracture, which should
have been of a close silky white colour, appeared as a coarse black
fracture, owing to the presence of the free carbon. The free carbon,
on hardening, disappeared or took another form, but did not again
return to its previous combined state, as on annealing it again
appeared in exactly the same position. What state the carbon
assumed on hardening could not, up to the present, be explained

166 CORRESPONDENCE ON BESSEMER-STEEL TIRES. [Minutes of

Mr. Wiuiler. even after the most careful analysis. How far this molecular
alteration would affect the after-working of the steel, he was not
prepared to say. In many other kinds of steel, equally marked
molecular change occurred, and very generally in irons. Fibrous
iron rapidly assumed the granular state. He fully endorsed the
Author's ojiinion, that until maker, consumer, chemist, and micro-
scopist united, this most vital question in the steel trade — the
change appearing so unexpectedly, so powerful in its action, and
about which so little was known — would remain unsolved.

11 December, 1888.

Sir GEOEGE B. BRUCE, President,
in the Chair.

The discussion on the Paper by Mr. John Oliver Arnold, "On
the Influence of Chemical Composition on the Strength of Bessemer-
Steel Tires," occupied the entire evening.

Pi'0ceediug3.] ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 1 G7

18 December, 1888.

Sir GEORGE B. BRUCE, President,
in the Chair.

(Paper No. 2138.)

"The Fric:ion of Locomotive Slide-Valves."
By John x\udley Frederick Aspinall, M. Inst. C.E.

The attention of the Author has been drawn to the fact that few,
if any, trustworthy data exist of the friction of slide-valves under
steam. Hence he was led to make experiments on locomotives,
with a view of ascertaining whether the amount of slide-valve
friction was as great as it is commonly assumed to be.

The only previous investigations of the friction of slide-valves
with which the Author is acquainted are as follow: — In 1866, a
Paper by Mr. Thomas Adams, " On the Friction of the Slide- Valve
and its Appendages," read at the Society of Engineers.^ In 1871,
a Paper by Mr. W. G. Beattie, " Description of a Balanced Slide-
Valve for Locomotive-Engines," was read at a meeting of the
Institution of Mechanical Engineers.^

Both these Papers were intended to show the sujieriority of
balanced valves over the ordinary valve. But the Author is not
aware that either form of balanced valve is now in use, as the
mechanical difficulty of keeping them in order outweighs their
other advantages. Mr. Beattie states that a valve 10^ inches long
and 17 inches wide, with a steam-chest pressure of 125 lbs. per
square inch, requires 6,160 lbs. to start it into motion. Mr. Adams's
Paper contains very extraordinary statements as to the friction of
valves. For example, that a force of 9,752 lbs. is required to
maintain the motion of a valve 18;^ inches by 9 J inches, with a
pressure on the back of 160 lbs. per square inch.

It seemed to the Author desirable that, instead of attempting to
deduce the friction of the valve from the difference of the steam-
chest- and cylinder-pressures, the valve should be made, by suitable
mechanism, to describe a diagram giving the exact force required to

' Transactions of the Society of Engineers for 1866, pp. 6-21.

^ Institution of Mechanical Engineers, rroccediugs, 1871, pp. 35-40.

168 ASPINALL ON FKICTION OF LOCOMOTIVE SLIDE-VALVES. [Miuutes of

move it at each poiut of the stroke. An apparatus was constructed,
as shown in Plate 2, Fig. 1, consisting of a cylinder and piston,
packed with cup leathers, which could be used as a pulling link,
replacing the ordinary pulling link which gives motion to the
valve. A steam-engine indicator was screwed on to a nipple at
one end of this cylinder, for recording the pressures in the cylinder
during the stroke of the valve. On the other end of the cylinder,
an air-valve was screwed on to a corresponding nipple. The
pistons, both of the indicator cylinder and of the air-valve cylinder,
were fitted with cup leathers, to prevent the escape of the fluid
when the apparatus was working. The hydraulic cylinder with
attached indicator and air-valve is shown on a larger scale in
Plate 2, Fig. 4. A second indicator was fixed on the front cover of
the steam-chest, its barrel receiving motion from the valve-spindle.
Thus, two diagrams are taken simultaneously, one from the
hydraulic-pressure cylinder which is driving the slide-valve, and
the other from the steam-chest. These give the force required to
move the valve, and the corresponding pressure on the back of the
valve. The steam-chest pressure-line has been plotted on the
hydraulic-cylinder diagram in each case.

The hydraulic cylinder was filled at both ends with oil, from
which air was expelled. In some of the earlier experiments, air in
the cylinder was found to disturb the diagrams so as to render them
unintelligible. The indicator cylinder below its piston, and the air-
valve below its piston, were also both carefully filled with oil before
attachment to the hydraulic cylinder. The cord from the indicator
barrel was attached to the back end of the cylinder, so that, as the
indicator moved with the valve, the length of diagram was equal
to the stroke of the valve. The air-valve on one end of the
hydraulic cylinder ensures that the pressure at that end is always
simply atmospheric pressure; consequently the pressure in the
other end of the hydraulic cylinder, which is recorded by the
indicator, is that which balances the force required to move the
valve. Without an air- valve it would be necessary to have an
indicator on both ends of the hydraulic cylinder, and to take the
difi"erence of the pressures recorded.

In the diagTams, the return-line comes a little below the atmo-
6j)heric line, but the pressures have been measured to the atmospheric
line only. Theoretically, during the return-stroke there should be
a negative pressure in the indicator end of the hydraulic cylinder.
For, when the piston is moving away from the indicator, the air-
valve closes, and the oil in that end of the cylinder is slightly
compressed. Consequently a vacuum must be produced in the

Procccdiugs.] A8PINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 169

indicator end of the cylinder, if its piston did not allow the passage
of air downwards. An accurate Bourdon gauge was attached to
the indicator end of the hydraulic cylinder, and the air-valve
replaced by a solid plug screwed on. In this condition, with a
calculated pull on the valve-spindle of 1,482 lbs., the gauge showed
a vacuum of 5^ inches, corresponding to a pressure on the hydraulic
piston of 40 lbs. If the tube of the gauge could have been completely
filled with oil, the vacuum would no doubt have been greater.

It will be seen that, when the diagrams are being taken, there
is a continuous very small movement, backwards and forwards,
of the hydraulic-cylinder piston. As the indicator piston rises in
obedience to the pressure, the hydraulic-cylinder piston must move
also, the volumes described by both being equal. The diameter of
the indicator piston was 0-75 inch; that of the hydraulic piston,
6 inches. Hence for a movement of j inch of the indicator piston, that
of the hydraulic-cylinder piston must be j X 0 • 75'-/ 6'-^ = 0 • 0039 inch.

Determination of the Friction of the Apparatus. — The recorded
pressures are affected by the friction of the hydraulic-cylinder
piston, that of the sjjindle of the hydraulic-cylinder piston, of the
friction of the indicator piston and of the air-valve piston. Pre-
liminary experiments were made, with the arrangement shown in
Fig. 5, to determine the amount of the friction of the apparatus.
This was filled with oil and arranged in working order. One end
of the spindle was fixed, the other attached to a bell-crank lever,
weighted on the long arm. The difference between the pressure in
the hydraulic cylinder, calculated from the weights and that
registered by the indicator, was taken to be equal to the total
friction of the apparatus.

Tai

!LE I. — Experiments on the Fkiction of tlio Apparatus.

Weight on
Lever in lbs.

Pressure in

Cylinder

calculated from

Weight.

Pull on

Valve-Spindle

calculated
from Weight.

Pressure
shown by
Indicator.

Pull on Valve-
Spindle shown
by Indicator.

Difference of

Actual and

Indicated Pull on

Valve-Spindle.

76
132
188
244
300
356
■ 412

Lbs. per
Square Inch.

11-9
20-8
29-5
38-3
47-1
55-9
64-7

Lbs.

316-5

549-6

782-8

1,016-0

1,249-2

1,482-4

1,715-6

Lbs. per

Square Inch.

5-0

12-0

18-0

26-0

33-0

400

48-5

Lbs.
132-5
318-1
477-2
689-3
874-8
1,060-4
1,285-7

Lbs.

184-0

231-5

305-6

326-7

374-4

422-0

429-9

170 ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Assuming that the pressures shown in cohimn 4 are a linear
function of those shown in column 2, the Author obtains the
following expression. Let L be the pressure shown by the
indicator, and L^ the real pressure in the hydraulic cylinder.
Then

Lj = a + feL,

w^here a and h are constants to be determined from the experiments.
The following values prove to be suitable, and are used in reducing
the indicator-diagrams of the hydraulic cylinder : —

Li = 5-61 + 1-26 L.

It may be stated that the friction of the valve-s2:)indle in the
valve-chest stuffing-box is inappreciably small. A diagram taken
with no steam-pressure on the valve shows only a slight thickening
of the atmospheric line, and the valve-spindle, when disconnected
from the pulling link, could be easily moved by hand. Many
preliminary trials were made with the apparatus to get it into
perfect working order, and to eliminate the small causes of error
always met with in new apjjaratus.

Method of dealing with the Diagrams obtained. — Diagrams have been
taken from two classes of engines, with valves of three different
forms, in both good and bad condition. A summary of the results
is given in Table II. In all the diagrams from the pulling-end of
the hydraulic cylinder the jiressures are lower than in those from the
pushing-end. The reason is that, as the valve-spindle works in a
dummy gland on the front of the steam-chest, the steam-pressure
on the end of the sjiindle is always acting in one direction.
This has been allowed for in calculating the diagTams. Sets of
diagrams were taken from one engine successively on the same
day. These agree closely both as regards form and height. On the
other hand different sets of diagrams, taken on different days and
under dissimilar conditions, often varied considerably. Either the
cylinders differed, or the valves, or the method of lubrication, or
the speed at which the engine was running. Besides this, there
must have been other causes of variation less easy to give an
account of, as, for instance, whether the steam was dry or wet, or
whether the boiler was priming.

The average pressure shown by the diagrams has been found by
the usual method employed for indicator diagrams. Although
theoretically this is not quite accurate for diagrams of the form
of the hydraulic-cylinder diagrams, it is sufficiently so for the
purpose.

Proceedings.] A8PINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 171

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172 ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Miuutes of

Samples of the diagrams and calculations selected at random are
given in Plates 3 and 4. For instance, taking Diagram 17, Plate 3,
Fig. 6, the average pressure per square inch from the hydraulic-
cylinder diagram is 27*25 lbs. By the formula put forward,
this, corrected for friction, gives as the true pressure, 5'614-
(1-26 X 27 • 25) = 39-94 lbs. per square inch. The area of the back
end of the hydraulic piston was 26*51 square inches. Hence the
total pull was 26*51 x 39*94= 1,058*8 lbs. To this must be
added 254*6 lbs., the steam pressure on the end of the valve-
spindle, making a total force to move the valve of 1,330*1 lbs.
For diagrams taken on the other end of the hydraulic cylinder,
the valve-spindle pressure must be subtracted.

In Table II the sixth column gives the average force acting on
the valve-spindle, from four diagrams in each case taken in quick
succession, calculated precisely in the way described. The Table
thus contains the results of one hundred and seven separate
experiments. In almost every case, the force calculated from the
pushing-diagTams exceeds that of the pulling-diagrams by an
amount varying from 4 to 10 per cent. The valve-spindle, pulling
link, and eccentric rods, form a long jointed strut, which, when the
valve is being j^ushed, will deflect to an extent depending on the
slackness of the joints, and this will cause a side pressure on the
back steam-chest gland, which will be absent when the valve is
pulled. It is difficult, however, to see that the friction due to this
side pressure could produce even as much as 4 per cent, additional
force to move the valve.

Discussion of the Eesults.

Diagrams, 1 to 16 and 61 to 107, were taken from a goods
engine with cylinders 18 inches in diameter and 24 inches
stroke, with six coupled wheels, 5 feet in diameter, and 4-inch
steam-pipe. Diagrams, 17 to 60, were taken from an express
engine, with cylinders 17 inches in diameter and 22 inches
stroke, with four coupled wheels, 6 feet 6 inches in diameter, and
3 2-inch steam-pipe. In Table II are given the steam-chest
pressures, the kind of lubrication of the valves, the descrijition of
the valves, and notes on the condition of the valves and valve-
chest faces.

In some cases, indicator-diagrams were taken from the cylinder
simultaneously with those from the pulling-link and the steam-
chest. Three of the cylinder diagrams are given on Plate 3,

Proceedinf^s.] ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 173

Figs. 6, 8, and 10, plotted above the corresponding pnlling-link
diagrams. Of these, diagram 1 7 is a pulling diagram in full gear ;
diagram 21 is a pushing-diagram in full gear; diagram 25 is a
pushing-diagram with the valve notched up to within 25 per cent,
of the centre.

It will be observed in the diagrams that the valve-resistance is
not uniform during the stroke, the variation being greatest with
the Allen valve. Table II shows that the valve-resistance is greater
with a short stroke than with a long stroke, and that to an amount
greater than is accounted for by the increase of pressure when the
valve has a short stroke.

Among the causes of variation of the valve-resistance, during
the stroke, may be mentioned : —

1. The variation of pressure on the back of the valve due to
variation of the steam-chest pressure during each stroke. This in
some of the full-gear diagrams amounts to 10 or 12 lbs. per square
inch.

2. The variation of pressure on the face of the valve, over the
area corresponding to the steam-ports. This can be determined
from the indicator-diagrams, when these were taken, as in the case
of No. 17.

3. The variation of pressure on the exhaust-area of the valve. If
this is assumed to be the same as that in the cylinder, it can also
be determined from the indicator-diagrams.

4. The form of the valve.

5. The inertia of the mass between the hydraulic piston and
the valve.

Variation of pressure on the back of the valve necessarily
involves variation of the friction. This is well seen in diagram 17,
Fig. 6, in the depression at each end of the steam-chest pressure-
line X Y, amounting to about 10 lbs. per square inch. This fall of
pressure is due to the opening of the steam-ports, and is absent in
the short-stroke diagrams where less steam is drawn off.

To examine the variation of pressure on the face of the valve
corresponding to the steam-ports, consider diagram 17, which is a
pulling-diagram ; that is, the valve is at the end of its travel
inwards when the diagram begins at the right-hand side. Then,
at the beginning of the stroke, the back steam-port is full open
and the front port is open to exhaust. At the completion of the
stroke, the front port is open to steam and the back port to exhaust.
The changes of pressure in the cylinder during the stroke are
shown on the indicator-diagram, the line A B C D E F corresponding
to the back end of the cylinder, and 5 4 3 2 1 to the front end.

174 ASPrSTALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [IVrmutes of

These steam-pressure lines are transferred to the valve-diagram,
where they necessarily ajjpear much distorted, because the phase
of motion of the valve differs from that of the piston by the angle
of advance. By marking on the valve-diagram the positions cor-
responding to the points ABODE, 54321, in the travel of the
piston, the pressures for those points can be transferred. Two
lines on the valve-diagrams are thus obtained, representing the
simultaneous steam-pressures in the two ends of the cylinder for
every position of the valve. Above these a short dot-line has been
drawn, showing the sum of the pressures at each point. This line,
which may be called the line of relieving-pressure on the valve-
face, gives the total pressure measured over the area of one port
opening (in this case 13^ inches by 13 inch) tending to counteract
the steam-pressure on the back of the valve. This line shows a
drop of about 40 lbs. per square inch, which, reckoned on the area
of a steam-port, gives a relief of pressure of 742 lbs. Assuming
a coefficient of friction, deduced later on, of 0*068, the variation
of effort on the valve-spindle will be 50-5 lbs., equivalent to a
rise of about 1 • 9 lb. in the hydraulic-cylinder diagram. The
small peak at p in diagram 17, which also occurs more or less
markedly in all the full-stroke diagrams at a point corresponding
to the opening of the steam-port, appears to be due to a vacuum,
formed under the valve-face by the sudden rush of steam into the
cylinder. The diminution of jDressure under the valve causes an
increase of friction, \yhen the valve is working near the centre
of the link, the compression is much greater, and the rush of steam
into the cylinder when the port opens is much less rapid. Hence,
in the short-stroke diagrams, an increase of valve-resistance at this
point is not shown.

There is no inside lap on the Allen valve, and the distance
between the inside edges of the steam-ports in the valve is
equal to the distance between the outside edges of the cylinder-
ports, the width of the bar in the valve being equal to the width
of the steam-ports. When the valve begins to open on one side
to exhaust, the valve-passage is already filled with steam at the
exhaust-pressure, which is suddenly released into the other end
■of the cylinder where compression is just beginning. The effect
is to raise a little the compression-line of the indicator-diagram
{at 2-3 in diagram 17), and at the same time to diminish the
relieving-pressure on the valve-face. Calculation for diagram 17
shows that there is a diminution of relieving-pressure of about
S3 ll)s. per square inch on 10*1 square inches of valve-face, or
altogether 939 lbs. This, \vith a coefficient of friction of 0"068,

Proceedings.] ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 175

gives an increase of valve-resistance corresponding to a rise of
about 2-4 lbs. in the hydra \ilic-cylinder diagram.

The third cause of variation of valve-resistance is change of
the pressure acting on the exhaust area of the valve. It is doubtful
if the exhaust pressure, shown on the indicator-diagram, is quite
the same as that under the valve, at least when the valve is just
opening or nearly closed. But taking the indicator pressure as
approximately the same as the pressure under the valve, then, when
exhaust opens, an area of 13 V X 6^ = 93 square inches is suddenly
exposed to the pressure shown at the point D, or say 90 lbs. per
square inch. This gives a total relief of pressure of 8,370 lbs.
With a coefficient of friction of 0"068, this would cause a diminu-
tion of the valve-resistance amounting to 570 lbs. This diminution
would continue, though decreasing in amount, while the valve
travelled from D to E on the lower Fig. in diagram 17. The
diagram shows, however, not a diminution, but an increase of valve-
resistance, and this is due to the fourth cause of variation of the
valve-resistance. Diagram 17 was taken with an Allen valve of
the form shown in Plate 2, Fig. 3. All full-stroke diagrams, taken
with this f(jrm of valve, show a more or less sudden increase of
valve-resistance at this part of the stroke. With ordinary valves
there is a less marked increase. The explanation may be that the
steam, rushing through a narrow opening, strikes the further side of
the exhaust-sjKice, making the pressure much greater against that
side than against the near side. This not only neutralizes the
eftect of the increase of relieving pressure, but even increases the
valve-resistance.

The last cause of variation of the valve-resistance is the inertia
of the moving parts driven by the pulling link. That inertia
will increase the effort necessary to move the valve during the
first half of the stroke, and diminish it during the second
half.

Suppose a mass of weight W, moved by a uniformly rotating
crank of radius r, the crank-pin having the velocity V. Then the
resistance due to inertia at the beginning of the stroke is —

Wt;2

ijr

Now in this case the valve has a travel of 3]^ inches, so that its
motion is practically the same as if it were driven by a crank of
radius 1-626 inch, or 0-1354 foot. Taking the sjieed of the
engine as 20 miles per hour, or 29-3 feet per second, and the

176 ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

driving-wheels as 78 inches diameter, the velocity of the crank-pin

driving the valve is

31
29-3 X — = 1-22 foot per second.
78 ^

Consequently the resistance due to inertia at the beginning of the
stroke is, for a weight of 155 lbs.

155 X 1-22'^
32-2 X 0-1354

62-8 lbs.

This would correspond to about 2 lbs. on the hydraulic-cylinder
diagram, a quantity to be added to the frictional resistance of the
valve at the beginning of the stroke, and deducted from it at the
end. At higher speeds, the eifect of the inertia of the valve will be
much more marked. Thus, in diagrams 77 to 91, at speeds of 168
to 224 revolutions per minute, the resistance due to inertia at the
beo'inning of the stroke of the valve will be from 203 to 361 lbs.,
corresponding to from 7*7 to 13*7 lbs. on the hydraulic-cylinder
diagrams.

Valve-Friction. — To determine the valve-friction it is probably
more accurate to take, not the mean resistance during the travel of
the valve, but the resistance at mid-stroke where the inertia resist-
ance vanishes. The valve-chest pressure is taken at the same
point. Table III has been calculated in this way.

Table III. — Pressure on Yalve and Yalve-Eesistance at Mid-stroke.

Starting

Friction

Dimensions of

Pressure in

E.xperimenter.

Friction.

of Motion.

Valve.

Steam-chest.

Remarks.

Lbs.

Inches.

Ll)8. per
Square Inch.

Adams

9,752

18J X 9^

160

Bcattie

6,160

4,620

17 X lOJ

125

Halpin

2,629

lOf X 9^

Aspiuall .

1,321

161 X 10

134

(■Brass Allen valve ;
( full stroke.

1,096

16J X 10

,na (Brass plain valve ;
|\ full stroke.

„ . •

982

16J X 10

127

(Cast-iron valve;
\ full stroke.

The average of the eight diagrams, 17 to 24, gives for the valve-
resistance at mid-stroke 1,321 lbs. Assuming the whole area of the
valve to be subjected to the steam-chest pressure, the load on the
valve is 16^ x 10 X 134 ="22,110 lbs. The relieving-pressure on

Proceedings.] ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 177

the area of one steam-port is 13.V X If X 97 = 1,800 lbs. The
relief due to steam in the valve-passage isl3^Xfx97 = 980 lbs.
The relief pressure over the exhaust area of the valve is at this
point of the travel zero. Thus the resultant load on the valve is
19,330 lbs. The coefficient of friction is therefore 1,321 -^ 19,330 =
0*068. Similar calculations, for diagrams 29 to 36 and 37 to 44,
give valve-resistances of 1,096 and 982 lbs., and coefficients of
friction 0-054 and 0*051. The former set of diagrams was for a
brass valve, and the latter for a cast-iron valve, working together
on the same pair of cylinders, the diagrams being taken on the
same day and under the same conditions. Both valve- and cylinder-
faces were in good condition. The lowness of the coefficient of
friction is surprising. It is ordinarily taken at 0*08 to 0 * 09 for
well-lubricated surfaces. It is the more remarkable as the valve-
surfaces were at a temperature of about 350^ Fahrenheit, so that
any oil reaching the surfaces must either have been vaporized or
very thin. The pressure per square inch of bearing surface is
about 380 lbs.

Table IV. — Percentage of Power Lost in Friction of Valves and Eccentrics.

atrake of

Valve
in Inches.

Revolutions

per

Minute.

Indicated
HP.

HP. to drive
Valves.

Per cent, of
Power lost.

56
56

343

212

4-6

4-8

1-34
2-26

The difference due to different modes of lubrication is shown in
Table II. Diagrams 77 to 91 were taken during a run of 50 miles
without any oil ; diagrams 92 to 99 with a sight-feed lubricator
feeding seven drops per minute ; diagrams 100 to 107 with the same
lubricator feeding sixty drops per minute. The valve-resistances, for
the full-stroke pulling diagrams, when reduced to the same steam-
chest pressure of 120 lbs. per square inch, were 1,868 lbs., 1,764 lbs.
and 1,359 lbs. For the short-stroke diagrams the corresponding valve-
resistances were 2,432 lbs., 1,898 lbs. and 1,475 lbs. These figures
show a decrease of valve-resistance with increase of lubrication.

In the case of the goods engine, the full stroke of the valve is
3| inches, and the mean valve-resistance is 1,592 lbs. Hence
the power required to keep two valves moving is per revolution

1,592 x-| X 4 = 1,791 foot-lbs. The work lost at the eccentrics

[the INST. C.E. VOL. XCV.] N

178 ASPINALL ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [MinuteB of

may be estimated thus : CircumfereBce of sheaves, 44 inches ; pressure
normal to sheave, 1,592 lbs. ; coefificient of friction (as ordinarily-
assumed), 0 • 08. Then, work lost per revolution at two eccentrics

44
= — X 1,592 X 0-08 X 2 = 933 foot-lbs. Work lost in friction of

two valves and eccentrics 2,723 foot-lbs. per revolution, or at
10 miles an hour, or 56 revolutions per minute, 4-6 HP. A similar
calcixlation for the short-stroke diagTams gives 4 • 8 HP.

The work lost in the friction of the valves and eccentrics is
about the same as that required to drag two and a half 10-ton
wagons.

The Author has to acknowledge the valuable assistance rendered
in the conduct of the exj^eriments and in the preparation of the
Paper by his assistant, Mr. E. Coey.

The Paper is accompanied by three sheets of illustrations, and
seven blue tracings of indicator diagrams, from which a selection
has been made for reproduction to form three Plates, 2, 3, and 4.

[Discussion.

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 179

Discussion.

Mr. J. A. F. AsPiNALL wished to mention that most of the Mr. Aspinall.
experiments referred to in the Paper were made in 1885, and some
in 1886. The Paper had been considerably abridged, so that
some of the explanations with regard to the progress of the experi-
ments might not be quite as clear as they otherwise would have
been ; but he should be happy to give any additional explanation
if required. The valves used were, of course, valves between the
cylinders as illustrated in Plate 2, Fig. 1. He had no doubt that
if experiments were tried with valves working on the top of the
cylinders, or with valves under the cylinders, somewhat different
results would be obtained. He regarded the whole series of
experiments as of a somewhat tentative character. He had not
been able to obtain much information upon the subject, and he
hoped the matter would be fully discussed. He might mention
that the chief difference between the diagrams taken with the
Allen valve and the ordinary valve would be seen by comparing
the Diagrams on Plate 3 with those on Plate 4. There was not
the sudden rise with the latter which took place at the period of
exhaust with the former. The serious drop, as between the boiler-
pressure and the steam-chest, was due to there being too small a
pipe. In the case he had mentioned the engine had a S^-inch
steam-pipe, and it was not large enough to take the steam of
17 by 22-inch cylinders when the engine was going at so low a
speed as 4 miles an hour.

Mr. W. Cross said the subject of the Paper was one, as tlie Mr. Cross.
Author had stated, about which very little was known, and very
few experiments had been published. The coefficient of friction
0-068 was extraordinarily low, especially as compared with
ordinary marine practice, which was usually taken at 0 • 250. From
the very careful manner in which the experiments had been con-
ducted, there was no doiibt that they were ai^proximately true;
but if so, how was it possible to account for the valve-spindles
breaking, as they undoubtedly did in locomotives, and especially,
as far as his experience went, in inside-cylinder engines ? He had
known two or three cases of valve-spindles of l|-inch diameter
breaking. The valves were of brass, and the valve-spindles of
the best Yorkshire iron. On changing the valves to cast-iron
no further trouble was occasioned. He would not enter into
the reason of it, but it showed that under certain circumstances
the coefficient of friction must be enormously increased. It would

N 2

180 DISCUSSION ON FKICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Mr. Cross, therefore he imjDossible, as would appear at first sight, to reduce
to any great extent the area of the parts driving the valve. A few
years ago his firm was engaged in running trial trips with a high-
speed man-of-war. He believed that the vessel was one of the first
fitted with high-speed piston valves. The dimensions were : cylin-
ders, 43 by 82 by 36 inches; 116 revolutions per minute, indicating
6,500 HP. ; both cylinders Ip. and hp. were fitted with double
piston valves, two to each cylinder. At certain speeds, with a
certain number of revolutions per minute, difficulty was experi-
enced owing to the vibration of the valve-gear. At about 90 revolu-
tions per minute, the engine would run quietly, but at 100 it
would be vibrating severely ; at a gradually increasing speed the
vibrations would die away altogether, and then at 112 or 115
revolutions, the vibration would be unsui^portable. The matter

Fig. 1.

Indicating Cylinder for MEASURmG Actual Strains in Valve.

Scale 1.

was, of coiarse, carefully investigated, and Mr. Marshall and he
finally constructed the apparatus shown by Fig. 1. It was almost
a reproduction of the Author's, except that there was no friction,
and that they trusted only to mechanical fitting. The strains upon
the two ends of the cylinders were exactly similar, as the spindle
went through, and consequently the acting area was only the area
of the brass piston. The stroke was exceedingly small, only
0 • 05 inch at each end. This dynamometer cylinder was fixed into
the centre of the valve-spindle in the same manner as shown by
the Author. There was an indicator at each end, the cord was
fastened to some convenient portion of the valve-gear. The stroke
of the valve connecting-rod being 7^ inches, it was too much for the
drum of the indicator ; but by connecting it with some moving
portion the stroke could be reduced to the amount required.

Proceedings.] DISCUSSION ON FEICTION OF LOCOMOTIVE SLIDE-VALVES. 181

Various liquids were tried, but thick glycerine was found to be Mr. Cross.
the most suitable material. The machine ran for many hours
without giving the slightest trouble. The friction of the piston-
valve, properly speaking, was practically nothing. The weight
of large valves was very serious. The cylinders were originally
fitted with piston-valves weighing 1,500 lbs. each, and it would be
seen (Figs. 2 and 3) that the shock at the two ends of the stroke
was exceedingly severe. They then stopped the experiments, and
instead of having heavy cast-iron valves they made phosphor-
bronze valves as light as possible, bringing the weight down to
600 lbs. Not only was the size of the diagram much reduced

Fig. 2.

Fig. 3.

110 REV$

(Figs. 4, 5 and 6), but taking also into account the weight of the
valves the shock upon the valve-gear was very much reduced.
The result had been that, although the engines had been running
some years, there had been no further trouble from this cause.
The indicator-cylinder was fitted with a compensating arrange-
ment, a kind of small by-pass valve fitted on the outside, whereby if
the glycerine leaked from one end to the other, by stopping the engine
it could be replaced in the centre. In some respects he thought
the apparatus was an improvement upon the Author's. In the first
place, he thought that the friction of the cup-leathers in the latter
was extremely doubtful. It varied enormously with the age of the
cup-leathers, the variation amounting sometimes to 60 or 70 per
cent. As far as he could follow the Aiithor's diagram, the dummy
end of the spindle was not balanced, and consequently the areas

182 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Mr. Cross, were diiferent ; but lie presumed that a correction would be allowed
for this. That the friction of the cup-leather had been excessive
was shown in Table I, in the case in which the machine was tested
by means of dead-weight. He therefore thought that the friction-
less apparatus, trusting entirely to mechanical fitting, was decidedly
siiperior for giving accurate results. He might be permitted to
refer to a Paper read by his partner, Mr. F. C. Marshall, and his
assistant, Mr. E. L. Weighton, on " High Speed Engines," ^ in
which the results of the diagrams exhibited w^ere fiilly discussed.
He hoped to hear something on the friction of diiferent metals at

Fig. 4.

100 REV?

Mr. Halj^in.

high temperatures ; this was exceedingly important, especially for
marine engineering in these days of very high pressures.

Mr. Druitt Halpix observed that indicating an engine under the
most favourable circumstances was not a pleasant thing, and indi-
cating an engine under the difficulties described, running 40 miles
an hour, was still less pleasant, and was often dangerous. The
Author had referred to previous contributions on the subject exist-
ing when his Paper was written, but since then a communication
on the same subject by Mr. C. M. Giddiugs, had been published with
illustrations, diagrams and results, in the Transactions of the
American Society of Mechanical Engineers,^ 1886. The experiments

* Transactions of the North-East Coast Institution of Engineers and Ship-
builders, vol. ii. p. 287.

* Transactions, vol. vii. p. 631.

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 183

were made with the apparatus shown by Plate 2. Looking at the Mr. Halpin.
matter broadly, he certainly thought that the Author's results were
almost too good to be true. Fig. 7 showed the general arrange-

FiG. 7.

ment of the instrument in side elevation. Fig. 8 was a diagramatic
section on the centre line, illustrating the relative positions of the
various parts of the instrument when a pushing force was applied

Fig. 8.

PUSHlNQi

Fig. 9.

to it. Fig. 9 was a similar section showing the instrument under
compression, and Figs. 10 and 11 were diagrams taken by the
instrument recording the actual friction due to the valve and the

184 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Mr. Halpin. stuffing-box. He should be afraid to design a valve-gear with the
expectation of such very low frictions. Mr. Cross had referred to
the errors that might arise by the use of the hydraulic cylinder
with his packing, and Table II contained the results of the actual
tests made by the Author, with the apparatus shown in Plate 2,
Fig. 5, giving the calculated and the measured pressures. Taking
the first, the calculated pressure was 12 lbs., and the recorded
pressure 5 lbs., being a difference of 138 per cent. Taking the
last, the calculated was 65 lbs. and the recorded pressure 49 lbs.,
or a difference of 33 per cent. These differences occurred when
the apparatus was at rest, and might become magnified when
it was in motion. He had plotted out the whole Table graphically,

Fig. 10.

Fig. 11.

and the result was a straight line, showing that the friction was
pretty uniform. Still it was a large amount, and, of course, it was
a varying amount, taking the condition of the packing leather into
consideration. The apparatus used by Mr. Giddings was very
ingenious and simple. Unfortunately the results obtained could
hardly be checked. One of the engines was a small engine with
a 6j-inch by 10-inch cylinder, going at various speeds ranging from
125 to 200 revolutions, and the friction varied from 2 per cent,
down to 1 • 4 per cent, of the whole dynamometrical power given
by the engine. That was with a balanced valve. With an
ordinary valve such as the Author had been using, not a balanced
valve, a 9-inch by 12-inch engine was used, and there the friction
varied from 4*5 per cent, to 7 -3 per cent. That was very
different from the frictions given in Table IV, which in one
case was 1*34 per cent., and in another 2-20 j)er cent.

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 185

That Table, he thought, needed a little further explanation. Jlr. Halpin.
In the first experiment the valve moved 3^ inches with 56 revo-
lutions, taking 4 • 6 HP. to drive it ; whereas, in another experi-
ment with the same number of revolutions, at only two-thirds
of the speed, it took rather more HP. to drive it. The Author
had stated as the first cause of variation of the resistance
during the stroke, " the variation of pressure on the back of the
valve due to variation of the steam-chest pressure during each
stroke. This in some of the fixll-gear diagrams amounts to 10 or
12 lbs. per square inch." The Author had given a verbal explanation
of that, stating that the steam-pipe was not good enough. Mr.
Halpin was of the same opinion ; but he thought that the Author
might have gone further. On referring to Table II, instead of
finding the variations of pressiire 10 or 12 lbs., he would find the
total difference of pressure between the boiler and the steam-chest
to reach as much as 50 lbs. Taking the Table as it stood, in the
case of the goods engine, which was the first, making 56 revolu-
tions a minute, assuming a constant piston speed throughout all
parts of the stroke, the velocity was 5,800 feet per minute in tlie
steam-pipe ; and taking the extreme case with 224 revolutions,
there was a velocity of 23,200 feet per minute, which was, of
course, far beyond anything it could be hoped to keep up, without
great loss of pressure, by means of steam-pipes of the proportions
now usually adopted in locomotive practice. He had never been
able to obtain a velocity of more than from 3,600 to 4,000 feet per
minute without a very serious loss of steam-pressure.

Mr. John Goodman said, that in 1885 he wrote a letter to Tlie Mr. Goodman.
Engineer,'^ giving a diagram, of which he now exhibited a copy,
of a similar apparatus to that used by the Author for ascer-
taining the friction on slide-valves. He was going to carry out
some experiments upon the same subject; but could not get an
engine of suitable dimensions. He thought, however, that the
apparatus might be improved by working upon a method of which
a great deal had been heard lately, namely, the Emery system of
testing machines. Here, instead of a piston, a thin diaphragm
was introduced in the cylinder, and an indicator with a Bourdon
tube was used instead of an ordinary piston indicator. In that
way the difference in the length of the valve-rod might be reduced
to a minimum, and the apparatus made to work frictionless. In
the apparatus which he had designed, he had arranged the
paper to work on a continuous roll. He thought it must be a

' Vol. lix. p. 186.

186 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Mr. Goodman, difficult operation to put a card on the indicator-drum when the
engine was going at a high speed, and that a continuous roll of
paper would be a great improvement. The Author had referred
to the friction of glands which, he said, was quite inappreciable.
It might have been inappreciable in that instance ; but persons
acquainted with the working of steam-engines would know that
friction on the glands might be enormous. Indeed, it was an easy-
matter to pull up an 8 or 10 HP. engine simply by tightening
the piston-glands. He admitted that it was a very injudicious
practice, but still it could be done ; and hence in any experiments
upon the friction of slide-valves, it might come in as a serious error,
and it might, to some extent, account for difference in the results
obtained by different experimenters. In the experiments, for
example, mentioned in the first paragraph of the Paper, the
coefficient of friction came out as 0"2o, while Mr. Halpin's
results, and those obtained in America, were much lower ; the
difference being probably due to the extra friction on the slide-
valve spindle-glands. Eeference had been made to the enormous
friction that sometimes occurred on slide-valves from the simple
reason that the buckles and slide-valve rods were not infrequently
broken. He thought that was easily accounted for. It was
well known that the friction of rest on all materials was far
greater than the friction of motion ; and not only with dry-
surfaces, but also with lubricated surfaces; in this case even
more so, because the valve when at rest, would be metal to metal
with the steam-chest ; but as soon as it began to move, a film of
water and steam would get under it, and would act as a lubricant,
and gTeatly reduce the friction. Eighteen months ago he saw a
balanced slide-valve, and the makers were showing how easy it
was to move the valve backwards and forwards with one hand.
A valve, about 8 inches square, was moved very easily in that
way. He tried several experiments with the valve, allowing it to
remain at rest for some minutes, tapping the steam-chest cover,
and then pulling with the hand as hard as he could. He could
not move it, although it was supposed to be a balanced valve ;
but after it was once started into motion it could be moved
backwards and forwards without trouble. The experiments of
Mr. Adams and Mr. Beattie were made by hanging a scale-jian
with a pulley on the end of the slide-valve spindle. Weights
were placed in the scale-pan until the valve began to move. That,
of course, would be the friction of rest, and the greatest possible
amount of friction that could come on the slide-valve. Hence, in
designing a valve-gear the maximum load likely to come upon

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 187

it should be taken, and he thought it would be advisable to Jlr.
adhere to the old-fashioned coefficient 0"25. The question of
lubricants was one of very great importance. Some of the so-called
valve oils were of no value. He knew of a case in which an
enormous quantity of a well-known lubricant was sent out to one
of the colonies, and after it had been at work three or four months
complaints were received to the effect that all the j)orts and all
the parts of the piston were choked with a hard mass of carbon.
The oil had been largely advertised as a valve oil, but it was
far from being suitable for the work. A few years ago he had
carried out some experiments for Mr. Stroudley, with reference to
suitable lubricants for slide-valve and piston work ; and he be-
lieved that the method adopted was the only one for ascertaining
whether an oil was siiitable or not. The oil proposed to be used
was heated on a plate to about the temperature at which it was
to be used in the cylinder. If after a reasonable time it turned
thick and gummy, and ultimately solid, it was rejected ; but if it
stood the heat for several hours, and ultimately almost entirely
evaporated leaving practically no residue, it was deemed to be
suitable oil for use in the cylinders. Recent experiments, especially
those of Mr. Tower, and some which he had himself carried out,
distinctly showed that with the ordinary system of lubrication,
such as that used with siphons, there was a great waste of oil.
He thought there was a wide field open for inventors to devise
some means of lubricating slide-valves by pad lubrication, instead
of the present method of allowing the lubricant to go drop by
drop into the cylinder. There was a method that he thought
might be worth trying, something similar to that adopted by
Messrs. Aveling and Porter at Eochester for lubricating their
traction-engine axles. It was a piece of wood ^-inch in diameter,
floating in a bath of oil touching the bottom of the axle. As
the axle revolved, the wood revolved and brought oil on to
the axle. That method had proved economical and efficient,
and he would suggest whether some such method could not
be used for slide-valves. A small roller might be inserted in
some part of the bars of the steam-chest (of course it would
not be of wood but of metal), and small quantities of oil could be
admitted to the centre of the rollers. That, he thought, would
be more economical and efficient in reducing friction than the
method of putting in oil drop by drop. The pressure required to
move the valves was considerably less when the valves were work-
ing full stroke than when they were notched up to one-quarter
stroke. It would be found that the work done in moving the

188 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Mr. Goodman, valve throngli the stroke was approximately constant. If some
apparatus of that kind were adopted for the use of piston-rods, so
as to indicate the work done by the piston, some valuable and
interesting results might be obtained, that would throw light
upon the friction of pistons and glands as well as of slide-valves.
Mr. Tower. Mr. Beauchamp Tower asked the Author how he had obtained
the results given in Table I. He presumed that he had added the
weights one by one from 76 lbs. to 412 lbs. on the lever ; that in the
first place he found that he had 132 lbs. indicated when the actual
pull was 316 lbs., and so on until he had 1,765 lbs. when the
indication was 1,285-7 lbs. He wished to ask whether the weights
were then taken off and the indication noted. In the case where
he had 1,715 lbs., and only 1,285*7 indicated, the friction amounted
to 429 • 9 lbs. It would therefore appear that he could go on taking
off the weights until the pull was 429 • 9 lbs. less than 1,285 • 7 lbs. ;
that was 855 • 8 lbs., without overcoming the friction of the appa-
ratus, and between 1,715*6 lbs. and 855*8 lbs. his indicator would
not have moved. The Author's formula, given on p. 170, would
clearly be useless in that case. With a frictional apparatus where
there were changes of force going on inside, of which there was
no external indication, such a formula would not apply. Finding
that the frictions were so great, he thought it was a pity that the
Author had not contrived some less frictional method, which would
have made his results much more valuable. He might have
adopted some such plan as Mr. Cross had mentioned, which, from
Mr. Tower's own experience, answered perfectly well. With oil or
glycerine there was practically no leakage and no friction. The
straight horizontal lines, which were characteristic of the diagrams,
clearly indicated the excessive friction of the apparatus. Within
certain variations of load the Author's indicator showed no variation
of force at all ; hence there was a straight line where there ought
to be a wavy one.

Mr. Stroudley. Mr. W. Stroudley thought the Author had done well to bring
the matter before the Institution, as it was one of great im-
portance, and deserved to be carefully studied. About the year
1855 he had charge of some locomotive express engines very
trou?jlesome to keep in order, the slide-valves having a very
small bearing-surface, and the pressure being high. He then
devised a plan of drilling two rows of holes down each face of the
valve, and filled them with pure block tin, which reduced the friction
so as nearly to double the life of the slide-valve. He afterwards
saw some extreme cases of friction, some engrines havino; slide-
valves 20^ inches by ll.j inches, working at 160 lbs. pressure, and

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 189

having 4\ inclies travel. They also were express engines, and Mr. Stroudley.
the slide-valves wore down a good deal within a month or six
weeks. The metalling of the valves just turned the scale.
Before being metalled he had seen the slide-valve turned over on
the edge, so that it would measure j inch more across, and the
exhaust-port would be reduced by f inch. That was the result of
extreme friction. Guided by previous experience, he had en-
deavoured to reduce the size of the valve as far as possible, so that
the load should not exceed a reasonable one, and that removed
much of the friction, as was proved by the wear that took jDlace.
The B and C class of engines on the Brighton Eailway, with slide-
valves placed below, ran for ^V inch wear on the face (equivalent
to 1 lb. of metal in a phosphor-bronze valve) 14,460 miles, the
wear including the re-facing of the valve. With a brass valve
the distance run was in some cases only 7,000 miles. There was,
however, extreme difference in the wear of valves, dependent, no
donbt, on the nature of the metal of the cylinders, as well as the
difference in the care exercised by the driver, the extreme varying
from 7,000 to as high as 77,000 miles per lb. of metal worn and
turned off the face. The phosphor-bronze valve was nearly twice
as durable as the ordinary brass valve. With the D class of valves
placed vertically, the wear was ■^, inch for 7,000 miles with a brass
valve, and 13,000 miles with a bronze valve. Nearly as good
results were obtained with a vertical phosphor-bronze valve as
with a horizontal brass valve. The friction had, in his opinion,
always been assigned a higher value than it ought to have. Many
years ago he tried experiments with the balanced valves (Adams's),
changing the proportions and reducing the friction. With a 17-inch
cylinder engine he could hold the reversing gear with one hand
standing at right-angles when running at full speed. In that case the
friction must have been very small, yet the consumption of coal
was not appreciably altered. The quantity of oil required to keep
the balanced valves from squeaking, and in working order, was
much greater than for the ordinary valve. The result of his
experiments was that the balanced valves were taken out and
thrown away. That went to prove, in his opinion, that the
friction must have been much smaller than it was genei'ally
supposed to be. With reference to the Author's estimate of the
friction and the power used by eccentrics and eccentric straps, he had
now a great number of eccentric straps of cast-iron that had been
running since 1872-3-4 with all classes of engines. If the friction
were as great as had been stated by previous writers on the subject,
those straps would have been worn to a much greater extent than

190 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Mr. Strouilley. they were, they not having been refitted in any way since their
construction. He thought that experiments made under any other
conditions than actual working ones were not of much value.
The Author's arrangement was well designed to illustrate what
actually took place in work.

Mr. E. A. CowPER said the Author had not done fall justice to
himself in Table III, where the various frictions of motion were
given, namely, Adams, 9,752 lbs. ; Beattie, 4,620 lbs. ; Aspinall,
1,321 lbs. with a brass Allen valve full stroke, 1,096 lbs. with a
brass plain valve full stroke, and 982 lbs. with a cast-iron valve
full stroke. He considered the Author had not laid sufficient
stress on the last being cast-iron, because it appeared that with
the cast-iron valve far less driving power was required than
with the other valves. He believed many people thought that it
was best to have a brass valve, so that the faces of the ports should
not suffer. With regard to the Allen valve, the Author had
mentioned cutting out the inside equal to the length of the ports.
That was a principle which Mr. Cowper had long adopted ; indeed
he had cut out the inside considerably more than the distance
between the ports, when working a single common high-pressure
engine expansively, so as not to have too much compression ;
more thorough expansion with a single valve was then possible.
He should have liked to have heard more about balanced valves.
For instance, there was Eobert Wilson's valve, which had a plate
on the back of it, carried, not by the slide-valve itself, but by two
sides or supports, one on each side of the slide-valve, and these
touched the slide face. This plate and its supports was stationary,
and the slide-valve worked under it, the plate taking the pressure
of the steam on its own back. Then, if water occurred in the
cvlinder, and the valve lifted off its face, the valve and plate lifted
together, and no harm occurred to the cylinder bottoms. The
mode of fitting up the plate to its place was to put a pressure on
the back, to spring it as much as the steam would, and then get it
up true, the back of the slide-valve being also got up true (without
pressure) ; then the two were put together, and the faces to bear
on the ports were got up true together, and thus no stuffing-box or
relieving-piston was required for the back of the slide-valve. This
valve worked very freely, and, he was informed, assisted in making
the steam-hammer quite easy to handle. He had further been
informed, by a thoroughly practical locomotive engineer, that if
the plate was allowed to travel a little, it wore away like the
slide-valve, and thus avoided the necessity of having a little taken
off the face, to keep it to fit to the back of the slide-valve. This

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 191

would seem to be an important point. With regard to a large Mr. Cowper.
valve with a short stroke, requiring more power to move it than if
it had a long stroke, it would appear that any lubricant would be
worked out more with a short and reciprocating motion, than with
a longer motion, and as a proof of this, he might instance the fact
that the axles of a common carriage placed on a railway truck
would, in a long journey, set fast in their boxes, if the wheels were
not tlioroughly well fastened to prevent motion. Also the old rock
shaft, formerly employed in Bury's engine, and others with the
"Gab-Motion," frequently cut, and even seized with the slight
motion they got when running. With regard to slide-rods break-
ing in marine engines, or engines with very wide ports and slides,
he had no doubt but that in some cases the edges of the slides had
caught against the ports, from their springing down or dropping
into the ports, from the pressure of the steam on their backs. This
might be expected if the valves were made too weak, as they often
were, and if the edges of the ports were not rounded off a little, as
they ought to be.

Mr. E. Woods, Past President, thought that the Author's re- Mr. Woods,
searches and experiments oi:ght to receive the attention of
engineers, especially as showing that the friction of slide-valves
was much less than had been commonly supposed. The first
application of the balance valve to locomotives was by Mr. John
Gray, about the year 1838, who applied it on the Liverpool and
Manchester Eailway to one of the engines used to assist in propel-
ling trains up the Sutton and Whiston inclined planes. To one
of the two, the " Sampson," or the " Goliath," he placed a short
cylinder at the back of the valve-chest with a piston in it, and
a connection between the piston-rod and the back of the valve, so
as to balance the pressure of the two. But, as Mr. Stroudley
had pointed out, the complexity of the method told against it, and
it was finally abandoned, it being found that on the whole the
friction was not actually reduced.

Mr. AsPiNALL, in reply, said he did not find that the breaking Mr. Aspinall.
of valve-spindles, as mentioned by Mr. Cross, often happened.
Speaking from the experience of a very large number of engines,
he found that it was not a frequent occurrence with valve-spindles
that had been properly proportioned, unless the glands were
screwed up too tight, or the valve was allowed to wear too thin,
and caught in the steam-ports. With regard to the use of thick
glycerine, he had no doubt that it would answer extremely
well. He did not think he had mentioned that oil was tried with
the apparatus shown in Plate 2, Fig. 5. No doubt, as Mr. Halpin

192 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VAIVES. [Minutes of

Mr. Aspinall, had said, the age of cup-leathers might affect the experiments, and
the greatest possible care was taken in that respect. Only once
diiring the experiments were the leathers changed, and then a fresh
set of experiments "was tried with the apparatus, and it was found
that the friction was the same as before. As to the question of
greater power being used in a short stroke, that had been
answered by Mr. Goodman. That it was more difficult to lubricate
valves when notched up than when going full stroke, was a matter
of practical experience. In reference to Mr. Halpin's remark as to
the reduction of jDressure, he meant that the very great reduction,
amounting to more than 30 lbs. in some cases, as between 160 lbs.
boiler-pressure and the steam-chest pressure, was due to the small
steam-pipe. In speaking of 10 lbs. or 12 lbs. he was referring to
those depressions in the steam-chest pressure due to the gulp of
steam taken by the cylinders. Mr. Goodman had stated that he
would prefer a diaphragm to leathers. No doubt such an apparatus
would be better in some ways as the movement of the piston was
so slight, and the result of his experiments had been to satisfy
him that his apparatus could be considerably improved. If he
were to start again he had no doubt that he could get better tackle
all round. But such matters required a long time, and there was
not always the opportunity of trying such experiments. The
question of gland-friction of course applied to the present case.
The greatest possible care was taken to ensure that there should
be no gland-friction, and that the packing should be properly done,
and when the valve-spindle was disconnected from the rest of the
gear, it could be put in by hand with ease. With regard to the
increase of friction, which might be caused by screwing or packing
the gland improperly ; it was only necessary to look at valve-
spindles when they came into the shop deeply cut by wear, after
being in the hands of a careless driver, to see how a driver might
increase the friction of the glands. In the case under consideration
the aim was to eliminate the gland-friction, and to get the valve-
friction. Mr. Goodman was right in saying that there was the
greatest difficulty in obtaining good oil for lubricating. Many of
the so-called cylinder oils produced a choking-up of the ports with
a black substance, which had to be chipped out when the engine
came into the shop. He had experienced something of that kind
quite recently. The objection to the balanced valves, apart from
any question of their deficiency as valves, was the fact that there
were so many loose parts to deal with. If Mr. Goodman's
suggestion as to little rollers were carried out, it would be intro-
ducing loose pieces into a part of the engine where it was most

Proceedings.] DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. 193

desirable to keep them out. Mr. Tower had spoken of the results Mr. Aspinall,
in Table I obtained by trying the ap2)aratus shown by Plate 2,
Fig. 5, and he appeared to think that if the weights were put on
and taken off one by one, the apparatus woiild not record any
movement. That was what he himself had anticipated, and the
apparatus was most carefully tested on that account. The weights
were placed on the end of the lever one by one, and taken off one
by one, and for every additional weight taken off or put on, the
indicator responded at once. Having tested them in that way,
they were tried by screwing up the apparatus at the end as a
whole, to see whether, starting with the whole weight (1,200 lbs.
in one case, or 1,700 lbs. in the other), the same results followed ;
and he was satisfied that, so far as the results were concerned, they
were as accurate as they could be under the circumstances.
Mr. Tower also spoke of the straight horizontal lines on diagram
17 (Plate 3) as indicating friction in the apparatus. These straight
lines were, however, not due to that cause but to the use of the
Allen valve. If the diagrams on Plate 4, taken with an ordinary
valve, were compared with those on Plate 3, taken with the Allen
valve, the former would be found to show curved wavy lines.
When the Allen valve was removed from the engine, and the
ordinary valve substituted, these straight lines disappeared ; when
it was put back again they reappeared. The explanation might
be that given on p. 175. He coiild quite bear out the remarks
of Mr. Stroudley as to the very slight wear with cast-iron eccentric
straps, which after running for a long time came into the shops
without the tool-marks being worn out. Mr. Cowper had spoken of
cast-iron valves, and had pointed out the fact that the friction was
lower within than with brass valves. That was shown clearly by
Table II, where it would be seen that the force reqiiired to
move the valve amoiinted to 992 lbs. in one case, and to 998 lbs. in
the other. As long as the kind of valve was right, cast-iron seemed
to do very well, and for engines starting and stopping repeatedly
extremely good results were obtained. Mr. J. C. Park, had told
him that, during the last two or three years, all the brass valves
had been taken out of the engines of the North London Eailway
Company, and cast-iron valves substituted. The result was a
good deal less wear and tear, and consequently less lubrication ;
and there had not been the slightest difficulty in reversing the
engines with the steam full on at a pressure of 160 lbs. He did
not think there could be better evidence as to the value of cast-
iron valves, under certain circumstances, where they could be well
lubricated by the steam. It was true that the North Lot'dou

[the INST. C.E. VOL. XCV.] 0

194 DISCUSSION ON FRICTION OF LOCOMOTIVE SLIDE-VALVES. [Minutes of

Proceedings.

Mr. Aspinall. engines did not run any great distance at one time. With an
express engine running long distances, he doubted whether cast-
iron valves would give the same results.

Correspondence.

llr. Park. Mr. J. C. Park remarked that slide-valve friction had been under
consideration for many years on the North London Railway, and
that experimental trials, with valves more or less balanced, had
been made from 1856 up to the present time, but without success.
On the North London Railway, where more than 7,000 stoppages
were made daily, the engine-drivers much preferred cast-iron
valves, as they were able, without effort, to work the reversing
lever quite easily with steam at 1 60 lbs. per square inch full on ;
whereas with brass valves they were compelled to partially close
the regulator. The wear was as 1 to 3 in favour of iron valves.
For the last six years cast-iron valves had been used on the North
London line, and he hoped in a short time all the engines would
be fitted with them. The valves were made of 1 part of No. 1
Carron and No. 3 Cleator hematite iron, and 2 parts of clean scrap.
The average mileage of these valves, if properly lubricated, was
82,491, with a wear of barely ^V inch, whereas brass valves were
completely worn out under the same mileage. He would, later on,
present fuller details to the Institution on this subject.

Sclocted GEIBBLE ON SURVEYING IN NEW COUNTRIES. 1^^

Papers.]

SECT. II.— OTHER SELECTED PAPERS.

{Paper No. 2301.}

" Preliminary Survey in New Countries, as Exemplified in
the Survey of Windward Hawaii."

By Theodore Graham Gribble, Assoc. M. Inst. C.E.

In January, 1887, the Author was requested to make a survey of the
windward side of the Island of Hawaii, Sandwich Islands, and
report upon the feasibility of a narrow gauge railway, 70 miles
long, to carry the sugar and other produce to the port of Hilo.
The country is entirely volcanic, sloping down from three extinct,
and one active crater to the sea. The engineering difficulties were
mainly those presented by the gorges, or " gulches," so graphically
described by Miss Bird in her " Six Months in the Sandwich
Islands."

The exports of the districts of Hilo and Hamakua have now
reached 45,000 tons of sugar alone. The fruit trade is increasing ;
and coifee of very fine quality has been produced above the sugar
belt, in small quantities only; but the new Government are
portioning out homesteads for cofiee-cultivation, which are being
freely taken up by the Portuguese settlers with their larg-e
families. At its present price, 005*06 will pay better for cultiva-
tion than sugar. The present outlets for the commerce consist of
timber landings with cranes, built out on promontories underneath
precipices. Here the sugar is received from the rope-way in a tram,
or cage, and conveyed to schooners or coasting steamers upon
boats or punts, when the weather permits. Sometimes the planta-
tion has to suffer a month's detention, at others the loss of a boat-
load of sugar.

The advantages of a railway in such a situation were undoubted ;
but it was a question whether a line could be constructed at a cost
which would yield a profit to the stockholders. The gorges above
referred to are about a hundred in niimber, running down from
the volcanoes to the sea, intercepting in every case the line of
route. The methods adopted on the survey were mainly those in
vogue in America; and the object of this Paper is to describe
them for the assistance of young English engineers who may use

o 2

196 GRIBBLE ON SURVEYING IN NEW COUNTRIES. [Selected

them in the Colonies. The survey occupied five months of field
work, and one month of oflSce work. The cost averaged £20 per
mile.

The original intention was to run in and out of the gorges by
means of forty back shunts. These were all dispensed with by
means of curves of not less than 143 feet radius. The curve limits
were combined with gradients as follows : a radius of 1 50 feet with
a gradient not exceeding 1 in 50 ; a radius of 300 feet with a
gradient not exceeding 1 in 40 ; and a radius of 450 feet with a
gradient not exceeding 1 in 33. Within these limits, one engine
will haul all the load required by the traffic. The estimate was
for a 3-foot gauge line, with a maximum engine "weight of 25 tons.
Two types of engines, four wheels coupled and six wheels coupled,
were used for ascertaining the maxima moments of flexure on
bridges ; and from these an equivalent uniformly distributed load
was determined for each separate span. Plate girders, on the
deck system, were adopted up to 50 feet span, and beyond that
truss bridges. The estimated cost was somewhat under the limit
prescribed by the promoters for assurance of financial success.
The demonstration of the practicability of the line was largely due,
in th.e Author's opinion, to the methods of telemetry adopted. A
list of the instruments used, and particulars about them will be
found in Appendix I.

A route survey, or reconnaissance, was rendered unnecessary by
the existence of excellent maps of the district, prepared by the
Surveyor General, Professor Alexander, and his assistant, Mr.
Curtis Lyons ; these maps show the coast-line, Government road,
the outline of the gulches, and most of the earlier mill buildings.
The geodetic survey, on the same lines as those of Great Britain
and the United States, is plotted to 500 feet per inch, and referred
to rectangular co-ordinates of latitude and longitude, which proved
of great service in checking the azimuths. The route was
determined by the situation of the mills, all of them close to
the sea.

It was brought out very clearly upon this survey that neither
triangulation of the gorges, nor chainwork in the more even
country, could afford the same degree of accuracy as the stadia work ;
and in respect of desjjatch, they were not to be compared with it.
The problems presented by the gulches were of great variety,
from huge gaps, a quarter of a mile wide and 400 feet deep,
necessitating a two-mile detour, down to openings which could be
cheaply spanned. The gulchwork was all done by optical measure-
ment ; chaining was out of the question. The sides of the gorges

Papers.] GRIBBLE ON SURVEYING IN NEW COUNTRIES. 197

sloped 35° on an average, but often reached 60°, with bh;ffs here
and there of crumbling lava rock, giving a bare foothold to the
men, and no place for an instrument. In addition to this, the
vegetation was extremely dense, having grown undisturbed for
centuries on the richest soil in the world. The Hau, or yellow-
hibiscus, is the greatest foe to the climber; its roots run several
hundred feet above and below ground, and its branches mat into
a web, pliable yet hard ; it resists alike axe, hatchet, or cane-knife,
and to cut a trail through it would take days. The system of
optical measurement only requires the clearing of a small spot here
and there to catch a sight of the staff, yet this often took from an
hour to two hours and a half. The location between the larger
gulches, including a considerable number of small ravines, was
done with the chain, transit, and level, by Mr. Lincoln Cabot of
Boston and a field-party. The whole of the traverse was plotted
to astronomical azimuths, corrected every now and then by obser-
vations. The compass was quite unreliable, as the magnetic attrac-
tion of the hills frequently caused a deviation of several degrees
within a few hundred feet. The azimuths were all determined by
solar observations.

The following four methods are recommended, of which only
the two latter were used —

(1) Observation of Polaris at its greatest elongation.^

(2) Observation of a pair of circumj)olar stars when in the same
vertical.'-^

(3) Equal altitudes of the sun.

(4) A single observation of the sun out of the meridian.

The two first require an illuminated axis in the transit. The
observer must, in either case, sit up to catch his stars, and chance
their being clouded. Methods 3 and 4, being diurnal observa-
tions, are more convenient ; but the calculation is more lengthy.
A close approximation to No. 3 is obtained, without calculation,
by taking the equal altitudes about two hours from the meridian,
and taking the mean bearing to be the meridian. This method
has the disadvantage of bringing back the observer to the same
point of observation to take his second altitude. The last is by
far the most useful method, both as being diurnal, and, as con-
sisting of only one observation. The calculation needs an ordinary

' This method is most common. See Trautwine's pocket-book, ' Hints to
Travellers,' ' Raper's Navigation,' &c.

^ This method is described by Professor Stockwell, of Cleveland, U.S., in the
Journal of the Association of Engineering Societies, and may be used without »
transit.

1£8 GRIBBLE ON SURVEYING IX NEW COUNTRIES. [Selected

table of logarithmic sines and cosines, and a Whitaker's almanac.
The importance of the obserTation for azimuth can scarcely be
overstated ; any error, either in the field or in the plot, is thereby
at once detected. Even a good surveyor will rarely run a line for
several miles in roiigh country without making some error;
but a frequent check of azimuth will enable him so to distri-
bute minute instrumental errors as to render them unscaleable
quantities.

The modus operandi of the optical work at the gulches varied
someAvhat according to the nature of the obstacles ; but the follow-
ing course was adopted where the diiBculties were greatest. The
transit was fixed on one side of a gulch, and foothold dug out ; the
observer gave his entries to a calculator, who booked them, and
worked up the position of each sight there and then. On the other
side of the gulch, the leader of the staff-gang held the levelling-
staff, the head chainman carried only a sight-stake, the tail chain-
man carried the compass clinometer, only the tape being used ; and
short distances of from thirty to fifty, and occasionally a hundred
feet, were run. The tail chainman booked distances, bearings, and
vertical angles. One of the axemen took the slopes of the hill at
right angles to the line. Thus the line was run through the bush
until a spot was reached suitable for a clearing. All hands then
went to work with axes, hatchets, and cane-knives, and cleared a
sight of the levelling-staff for the observer at the transit-station.
This observation determined : (1) the actual distance of the staff from
the transit, by observing the stadia hairs ; (2) the true azimuth of
the same by observing the horizontal limb ; (3) the elevation above
sea-level of the same, by observing the vertical lines. These points
were termed primary points, and were laid off first upon the plot,
from the transit-station. The compass-traverse, made by the staff-
gang, was then plotted on tracing-paper, and superimposed upon
the plot of the primary points ; the intermediate points were then
pricked through, the traverse completed, and the contours filled in.
When one side of the gulch was finished, the two parties changed
sides, and repeated the same operation. By this means, a net-work
of triangulation was obtained, serving as an independent check to
the stadia work. The use of the compass was thus limited to short
stretches between points accurately determined in elevation and
azimuth. The survey was plotted on a scale of 100 feet to the inch
on account of the steepness of the side hill, a difference of 10 feet
in height showing xerj little, even on this scale, when the slope is
60"^. The contours were drawn at every 5 feet of height in the
open country, and every 10 feet in the gulches. The alignment

Papers.] GRIBBLE ON SURVEYING IN NEW COUNTRIES. 199

was laid on from the contours ; after which the profile was plotted
on ruled profile paper, to a scale of -tOO feet per inch horizontal,
and 40 feet per inch vertical.

Telemeter station (T. S.), and staff station (S. S.), mean respec-
tively the positions occupied, at the time of observation, by the
instrument and the staff. When the instrument is shifted, say
from A to B, a backsight is first taken from B to A. The elevation
of the staff station B is now re-booked as the elevation of the
telemeter station B, and vice versa with A (Appendix II). The
plotting of the survey is simply the reproduction, on paper, of
points obtained by radial distances from the telemeter station, the
angles being the actual astronomical azimuths of the radial lines.
The detail of buildings was filled in upon the same principle,
but with the plane-table ; this instrument, of the simplest construc-
tion, was placed over one of the points previously fixed by the
theodolite, and carried a field tracing of the spot showing the
skeleton traverse. It was generally arranged to fix the plane-table
within 100 feet distance of the corners of the buildings, so that the
subsidiary radial lines could be taped at once. By this means, the
labour was divided and time saved.

The term elevation is the elevation of the point above mean sea-
level. The term optical axis means the intersection of the vertical
axis of the pivot with the axis of the telescope, and the abbrevia-
tion for its elevation is 0. A. The vertical component (V. C.) is
the product of the direct distance measured along the line of sight
by the sine of the vertical angle. The horizontal component (H. C.)
is the product of the said distance by the cosine of the said angle.
The backsight or foresight is the reading on the staff of the axial
hair. It is a backsight (B. S.) when used to determine the elevation
of the optical axis from the known elevation of a staff station, which
is only done to commence work and in shifting the instrument. It
is a foresight, or intermediate (F. S.), when the reverse oj)eration
is performed. The working out of the vertical component is some-
times done by the slide-rule ; but it is better to use a table of sines
to four places. The horizontal component is obtained from the
graduations on the inner side of the vertical limb of the instru-
ment, "ratio of hypotenuse to base." The multiplications of the
sines by the direct distance are done very rapidly by two office
hands, the one with the sine-table, the other with Dr. Crelle's
calculating tables.

In the example of field-book chosen (Appendix II), the direct
distances given are all just equal to the difference of the upper and
lower stadia readings, multiplied by 100. The divergences actually

200 GEIBBLE ON SUEVEYING IN NEW COUNTRIES. [Selected

existing at each 100 feet are usually booked on the fly-leaf of
the field-book, so that, without any further tables, the direct
distance can be corrected and entered at once from the sight. The
lower hair was, whenever possible, directed on the first joint of the
staff, so that a simultaneous reading of upper and lower hairs could
be obtained. The central or axial hair was always a mean reading
between the other two. It was not read except at a change of
telemeter station as a check, but it was left to the recorder to
work out.

Eule 1. — To obtain the elevation of the optical axis (0. A.) from
a backsight on a bench mark or other datum point, the known
elevation of which is booked as elevation of staff station (S. S.) :

(a) When the vertical angle is p/ws, 0. A. = S. S. -|- B. S. - V. C,
where B. S. is the backsight and V. C. the vertical component.

(6) When the vertical angle is minus, 0. A. = S. S.-f B. S.-f-V. C.

Eule 2. From the elevation of the optical axis, ascertained as
above, to obtain the elevation of any staff station (S. S.) :

(a) When the vertical angle is plus, S. S. = 0. A.-f-V. C.-F. S.,
where F. S. is the foresight or intermediate.

(b) When the vertical angle is minus, S.S. = 0. A. - (V. C. -f F. S.).
When the instrument is shifted, the new elevation of the optical

axis is obtained, as at first, by a backsight upon the known station
just left ; but an independent check is obtained by actual measure-
ment of the height of the optical axis above the new telemeter
station. This may be done by an ordinary tape ; but in the
Author's instrument, the plummet-chain terminates in a hook
exactly 2 feet below the optical axis ; a steel tape is hooked on,
and measures the height more -quickly and correctly. Even with
the iitmost care, there will generally be a slight error discovered
here, sometimes arising from fault of adjustment, sometimes from
incorrect reading of the stadia. If the discrepancy is divided
equally between the two stations, the error will be removed if it
arises from the first-mentioned cause ; if from the second cause, it
is impossible to locate it, and if it amounts to anything serious, the
sights should be repeated. The Author has levelled 100 feet in
one shot with only a divergence of y^ foot between backsight and
foresight; the vertical angle was about 15°, so the direct distance
was nearly 400 feet. Generally the discrepancy in such cases
averaged from 3 to 6 inches.

In conclusion, it is suggested that for rapid and effectual pre-
liminary survey —

(1) A telescope should be used which will discern Jupiter's satel-
lites, mounted either on the ¥, or transit plane of the theodolite.

Papers.] GRIBBLE ON 8UEVBYINQ IN NEW COUNTRIES. 201

(2) The micrometer and stadia systems should be combined in
the one instrument.

(3) The staff should be provided with sights and biibbles, to dis-
pense with double calculations by insuring a position of the staff
at right-angles to the line of collimation.

(4) An independent check of the levels should be made with
each change of telemeter station, by means of the measurement of
the height of instrument with the steel tape.

(5) The bearings should be all taken from the north point,
ascertained and frequently checked by astronomical observation.

(6) The plane-table should be used, both as a sketching-board
and also on its tripod ; but only as an auxiliary, and without any
of the expensive attempts at making it a universal instrument.

[Appendixes.

202 GKIBBLE ON SURVEYING IN NEW COUNTRIES, [Selected

APPENDIXES.

APPENDIX L

List asd Description of Instruments.

1. One 6-inch transit theodolite, with a telescope of 14" focal length eccentri-
cally fixed and counterbalanced in place of the ordinary one. Stadia hairs were
added, reading 1 foot per 100, correct at 500 feet, the intermediate values being
determined by a measured base in the usual way. The short telescopes usually
fitted with stadia hairs would not have sighted across the ravines.

2. One micrometer telescope, 2 feet focus, by Elliott, as supplied to the army.
It measures distances approximately from the height of infantry or cavalry. It
was modified to suit with observations upon a pair of disks 10 feet apart. A
tripod was added, fitted with tangent-screw ; the same tripod carried a plane-
table of cheap construction, as the two instruments were not used simultaneously.

3. One 14-inch dumjiy-level.

4. One box-sextant, by Troughton and Simms.

5. One 5i-inch aneroid, in sling-case, by Steward, reading with vernier to single
feet. This instrument is very distinct in its gi-aduation. The difterential scale
of elevations, and uniform scale of pressures, are transposed by means of a
" snail," so that the pressure-scale becomes ditferential, and the scale of elevations
uniform, thus permitting the introduction of the vernier. The scale of elevations
was specially worked out from Guyot's formulas, and found to be somewhat at
variance with those usually adopted by instrument makers. The instrument
was verified at Kew Observatory, and the errors at dift'erent pressures registered.
The climate of the Sandwich Islands is very equable, causing less fluctuations
in the barometer than in most countries ; but a lighter, cheaper, and more compact
aneroid is recommended, as the gain through precision of gi-aduation will be
often annulled by atmosjiheric changes. A 3-inch Sopwith aneroid would be
much handier.

6. Two Abney levels.

7. One compass-clinometer. Colonel O'Grady Haley's patent, by Elliott. The
prismatic compass is all that could be desired ; but the clinometer, being of the
plummet type, is too slow in its action. Messrs. Elliott now make a combined
prismatic compass and Abney level, of the Author's design, which will be found
quite as accurate and more rapid than the O'Grady-Haley instrument. The same
makers also construct the Author's telemeter-theodolite. It is a 7-inch Y theodolite,
surmounted by an 18-inch telescojje of twenty power, which may be also carried
in a sling-case for reconnaissance. Another telescope of forty power is provided
in the same box for astronomical purposes, and long-range stadia measurements.
The telemeter-theodolite is a combination of the micrometer-telescope and the
stadia-theodolite (Fig. 1). Though heavier than the ordinary theodolite, it can
be carried by one man, and is much less bulky than two instruments, each with
its own tripod. "\\'hen used upon its tripod for the actual survey, the ordinary
Sopwith staff is used, being read by the horizontal stadia-hairs. Two small
levels are attached to the staff, and a sight-vane for placing it always at right-
angles to the line of sight ; also a pair of sliding disks are fixed to the staff
when, by a signal from the leader," the assistant knows that an extra or check-

Papers.] GKIBBLE ON SURVEYING IN NEW COUNTRIES.

203

sight is required, by means of the movable micrometer hairs. The stadia
readings are used up to the limits of such observation ; and the micrometer
readings are taken occasionally as a check. Beyond these limits the micrometer
only can be used. The stadia hairs are fixed at 1 per cent., as is customary,'
subtending 1 foot on the staff for every 100 feet of actual distance. The instru-
mental constant is obtained, and the values of readings registered, by actual
observation at every 100 feet, and the intermediate by interpolation.

The Author's experience does not go to prove the extraordinary accuracy
claimed by the various inventors for the instruments of this type. If the
registration just referred to be perfectly made, it is clear that the limit of
accuracy with the stadia measurements will be in the same ratio as the power of
the instrument. An ordinary 5-iuch theodolite will only read the hundredths ou

Fig. 1.

Micrometer Head to Theodolite.

the staff at about 300 feet. The Author's two telescopes will read them at 600
and 1000 feet respectively. Therefore the limit of accuracy is 1 foot up to these
distances, and beyond them depends upon the experience with which the trained
eye can estimate the portion intercepted upon the tenths by the stadia hairs.
Beyond that limit, the accuracy is reduced to estimation between the feet-marks
on the staff. If the telescope were of sufficient power to observe with the micro-
meter hairs the precise extremities of the disks, the accuracy would be as gi-eat
at a mile as at 100 yards, but this is impracticable ; and the one method is about
as accurate as the other. The stadia hairs are needed for the shorter distances,
as being very much more conveniently reduced in the field-book ; the micrometer
cannot be dispensed with for the longer distances. The combination of the two
in one instrument has been a long-felt want of surveyors.

Minutes of Proceedings luat. C.E.. vol. xci. p. 285.

204

GRIBBLE ON SURVEYING IN NEW COUNTRIES. [Selected

APPENDIX II.—

Tele-
meter
Station.

Staff
Station.

Horizontal
Limb.

Vertical Limb.

Stadia Hairs.

Direct
Distance.

Horizon- I Vertical
tal Com- I Compo-
ponent. | nent.

BM
A.
A,.
A3
A,
A,
B

B.o

B,3

273° 05'
205° 18'
149° 28'
122° 30'
111° 40'
98° 48'

278° 48'

295° 35'

300° 05'

303° 03'

307° 38'

314° 07'

351° 29'

359° 42'

26° 20'

31° 40'

54° 35'

104° 27'

56° 05'

157° 18'

+ 2° 05'

— 3° 14
+ 3° 35'

— 1° 25'

+ 0° 06'

— 1° 20'

500\
780 f
5001
870/
500 \
535/
500 \

1,115/
500 \

1,260/
500\

1,390/
200\

1,430/

300\

1,530/
500 \

1,075/
500 \

1,085/
500 \

1,050/
500 \
980/
500 \
900/
500 \
790/
5001
665/
500\
745/
500\
850/
500 \

1,130/
500 \
553/
500 \
976/
500 \

1,148/
500\

1,250/

280
370
35
615
760
890
1,230

1,230
575
585
550
480
400
290
165
245
350
630
53
476
648
750

280

1,228

1016

Papei-8.] GREBBLE ON SURVEYING IN NEW COUNTRIES.

205

— FlELD-BoOK.

Elevation
of Tele-
meter
Station.

Height of
Instru-
ment.

Backsight.

Foresight
or Inter-
mediate.

Elevation
of Staff
Station.

Elevation

of Optical

Axis.

Remarks.

494

422

400-93

4-75

511

6-40

503-42

422
494

408
420
400

499

427

N. corner of hedge.

Hedge.

Junction of hedge.

»> >>

Hedge.

at corner.

Centre of road.

206

GRIBBLE ON SURVEYING IN NEW COUNTRIES. [Selected
Fig. 2.

^ ^^j£^ Bg It

-t:

/■■

' f:::^- '«. '" .>-^«

"^Si^, ^.

rT7" \

£"" DJS

hs \ \ / \ ^

Y*i-t. ■•% }\^ _^__i:^

/ t

|d,3 _.W;>^^ y j

"io / ''2*.?. \ /

1 ---f«\/

*=«

'" /xr—AG

F.8

: --^ \>^y

IlorUontaZ Scale 83S f'-l huJv Vertu>i.l Scale 75 f* — 1 1ruJo

Section of Px^bi.ic Road at Occvpation Road.

Papers.] GEIBBLE ON SURVEYING IN NEW COUNTRIES. 207

APPENDIX III.

General Principles of Telemetry and Telemeters.

The term telemeter, which was introduced by surveyors, has been appropriated
to so great an extent by electricians, that it is likely to be abandoned by the
former for the term tacheometcr. The simplest form of telemeter is the plane-
table ;' it is a graphic triangulation to attain the same end as the optical tele-
meters. The optical telemeter triangulates for distance upon the same principle,
but with the additional precision of the telescope.

1. One class of telemeters is that in which the measured base forms part of
the instrument itself. Such are Adie's 18-inch and 3-foot telemeters, described
in Heather's " Instruments," in Weale's Series, Piazzi Smyth's 5-foot telemeter,
Colonel Gierke's 6-foot telemeter, and Otto Struve's Ti-inch telemeter. The
disadvantage of this class is the error produced by expansion and contraction.
They are not much used now.

2. The second class is that where the measured base is at the point observed,
generally consisting either of a graduated staflF, or a pair of disks connected by a
rod. In this class there arc two subdivisions.

(a) Those which have a fixed base and a varying angle, as the Rochon micro-
meter telescope, furnished with a reflector by which the images of the disks are
made to coincide, as in a sextant, and the angle is then measured in terms of
distance. Elliott's army telescope, in which the fixed base is the height of
infantry or cavalry, where two wires fixed in the diaphragm are caused to
approach to or recede from one another by a micrometer screw ; the wires are
actuated so as to exactly include the object observed, and the distance is read ofif
either on the infantry or cavalry side of the screw, as the case may be. Binoculars
are made upon the same principle. The advantage of this method is that it may be
used approximately, by observing a man on foot or on horseback when impossible
to send out a man with a target ; but it may be also used with precision in cases
where the rod-man can hold up a target with a pair of disks whose extremities
are equal to 5 feet 11 inches, or 8 feet 10 inches.

Eckhold's omnimeter is a combination of the first class and subdivision (a) of
the second class just alluded to. The instrument is a transit to begin with ; it
is furnished with a graduated distance-plate on the horizontal limb, worked
by a micrometer screw, and read by a very powerful microscope at right-angles
to the telescope. At one operation, by observing top and bottom of a 10-foot
staff, the distance and elevation are obtained by means of calculation. The
instrument has given much satisfaction both in India and the Colonies ; it is,
however, more complicated than the stadia principle, takes longer to adjust and
to work, and is not more accurate.

(b) Telemeters which have a variable base and a fixed angle. This is the
stadia principle, described by Mr. B. H. Brough in his Paper on " Tacheometry,
or Rapid Surveying." ^

3. The third class of telemeters is that in which the base is measured on the
ground, at the point of observation. The Hadley sextant, though not, strictly

' Minutes of Proceedings lust. C.E., vol. xcii. p. 187.
- Ibkl, vol. xci. p. 282.

208 GRIBBLE ON SUEVEYIXa IN NEW COUNTEIES. [Selected

speaking, a telemeter, is used as such ■when a distant vessel is observed simul-
taneously from the deck and maintop. The Dudge-Steward omnitelemeter,' the
" Bates " range-finder, and many others of this class, are more suitable for
military than civil engineering. The measurement of a base upon the ground
at the point of observation, unavoidable wiih military engineers, has not yet
been successfully accomplished with that combination of celerity and accuracy
which is reached by the stadia and micrometric measurements.

Engineering, August 20th, 1886.

Papers.] TOPHAM ON RAPID SURVEYING. 209

(Paper No. 2330.)

"Rapid Surveying."

By Francis David Topham, Assoc. M. Inst. C.E.

Engineers are sometimes called upon to execute works, such as
roads or railways, in countries of which no maps at all exist. In
such cases the engineer has to explore and consider the advantages
of different routes before a detailed survey is begun. It will then
be of great subsequent convenience if he can make some rapid
sketch survey of the lines of route and surrounding country. The
Author has practised a method of making such surveys while
marching, and without retarding the speed of the march. A rapid
route survey will serve as an illustration, which he once made from
a place in the interior of Asia Minor to a seaport town, under the
directions of Mr. C. E. Austin, M. Inst. C.E., who has largely
employed this method. The route lay through a country of which
no maps exist with the least approach to accuracy, even such
features as mountains and rivers being entirely wrongly placed
on the best maps. In a survey of this sort, it is impossible to
actually measure the distance traversed ; but in a fairly flat and
even country, it is best determined by stepping, and recording the
number of steps by a pedometer, a trained man, by preference a
soldier, being entrusted with the duty. But the country through
which the above survey was taken, is most rough, rugged and moun-
tainous, where wheel traffic does not exist, and where the travelling
is scrambling and climbing, rather than marching. The only roads
are narrow mule-paths winding over mountain passes and pre-
cipices. Over such a road, the only way of arriving at the distance
is by estimating the pace at which the leading muleteer is
marching. This, after practice and checking by actual measure-
ment, can be done with a much closer approximation to accuracy
than one would think possible. All angles are taken within the
magnetic meridian by the prismatic compass, which gives a result
surprising in its accuracy ; for all angles being taken with the
same meridian, there is no accumiilation of errors, as there would
be if the angle on to each foresight were taken from the last back-
sight. The procedure is as follows : — The observer from horse-
back takes an angle on to the next forward bend of the road, and
notes the time of leaving the point at which he took the anarle. and

[the INST. C.E. VOL. XCV.] I'

210 TOPHAM ON RAPID SURVEYING. [Selected

the time of arriving at the point on to which he took the angle, and
notes also the estimated pace at which the distance from one point to
the other was travelled. Arrived at this point, he similarly takes an
angle on to the next bend beyond. After a little practice these
angles may be taken without halting. Wherever practicable, a
check angle should be read back on to prominent points of the
road behind, and on to all the prominent moimtain tops. The levels
of all mountain passes, river-crossings, and other important points
are taken by an aneroid barometer. The survey had to be done at
the rate of about 25 miles a day, much of it in very wet weather ;
and it can hardly be taken as an instance of what could be done
by the same method, if not more than 10 miles a day had to be
traversed.

A scale was prepared so as to plot off the distances, as expressed
in minutes, without reducing them to actual feet as follows : —
Divide any line into equal parts by the points A, B, C, D, and E.
At E, erect a perpendicular, and divide it into parts corre-
sponding to the distance travelled in a minute at the rate of
4 miles an hoiir. At B, C, and D, draw lines parallel to the line
at E. From A draw lines to these points in the line E, intersecting
the lines B, C, and D. Then if the spaces of line E represent a
minute of time at 4 miles an hour, the spaces cut oif by the same
pencil of rajs on lines B, C, and D, represent the distance travelled
in a minute at 1, 2, or 3 miles an hour respectively. In the
same way the scale for any other pace can be added. In plotting
the work, it will be necessary to choose a scale in which the
shortest interval of time between the angles, at the slowest pace
travelled, is not too small to measure conveniently with the
dividers.

Having made a complete circle of some 250 miles, the Author
found that the two lines traversed plotted in meeting at the
starting point very closely indeed. This shows the accuracy with
which work may be done with the prismatic compass ; and although
failing of itself to prove the accuracy of the scale, it indicates that
the Author had estimated the pace uniformly throughout.

The Author claims for this manner of surveying great rapidity,
and even tolerable accuracy, especially in an open country where
long straight sights can be taken, and that such a survey would be
of great use when making a subsequent detailed and carefully
measured survey.

TajxTS.] VICKERY ON SURVEYING IN AUSTRALASIA. 211

(Pajyer No. 2348.)

" The Practice of Surveying in the Australasian Colonies."

By Samuel Kingston Vickery, Assoc. M. Inst. C.E.

The conditions under which surveying operations are conducted in
countries in which settlement is in progress diifer so widely from
those prevailing in older countries, that the method obtaining in
the Australasian Colonies may be of interest to members of the
Institution, and of service to young engineers who may contemplate
practising their profession there. In those Colonies, there is no
branch of the profession of a civil engineer — if those which belong
to the architect and mechanist may be excepted — which is not
practised directly under the control of the State ; and this rule
applies more especially to the branches in which surveying occupies
a prominent part. Railway surveying, as well as construction, is
in the hands of the Railway Departments ; building surveyor's
work, so far as public works are concerned, is undertaken by the
Public Works Departments ; irrigation surveys, including storage
and reticiilation, by the Water Supply Departments ; underground
surveying by the Mining Department ; whilst subsidiary road
surveying, though now chiefly carried out by the local governing
bodies, is under departmental supervision, and the officers employed
are required to qualify themselves by examination- Surveys which
are immediately under the control of the departments of Lands and
Survey are performed almost exclusively by salaried officers, or by
those who are " authorized," on either Crown lands or sold lands
intended to be Ijrought under the operation of the Transfer of Lands
Statute. Plans of surveys made by unauthorised persons are not
officially recognized. All authorized surveyors are obliged to
comply with the regulations issued in the form of departmental
instructions, or bearing the force of an " Order in Coiincil."
Particulars about the examinations for selecting certificated sur-
veyors are given in Appendix I.

Each colony is usually divided into survey districts, and^eack
district is placed under the control of a salaried inspecting officer.
These districts are sub-divided into divisions, each being assigned
to an authorized surveyor, to whom orders for departmental work
are transmitted. This officer is not salaried, being remunerated by
fees fixed by regulation, and is removable at the pleasure of the

i> 2

212 VICKERY ON SURVEYING IN AUSTRALASIA. [Selected

Surveyor-General. "When a vacancy occurs in one of these divisions,
selection is made from the list of those holding a certificate of
competency obtained by examination. The inspecting oftlcer has
full control in his district. He makes periodical examinations of
authorized surveyors' work in the field, inspects their instruments,
field-books, &c., and certifies to all accounts. Inspecting surveyors
are under the immediate control of the Surveyor-General. The
higher classes of surveying, including minor triangulation, are
performed exclusively by staif officers ; and ordinary sectional or
block surveying, embracing the laying out of towns and roads, is
chiefly executed by authorized survej'ors. The latter work, though
theoretically simple, demands the exercise of considerable care,
judgment, and observation, on the part of the sTirveyor, who is
expected to study the interests of the State in all his operations.
The system of examination and departmental supervision is now so
complete in the various colonies, that a very high standard of
efficiency has been attained by those employed.

The Author has had occasion to test the accuracy of the siu'vey
of single blocks of 320 acres in the heart of steep, scrubby, and
heavily timbered ranges, in which the error of arc was found
to be under 1', and the error in linear measurement under three
links in either latitude or departure. Appendix II gives an
illustration of a block of 320 acres, through which a check line was
projected by the Author showing the errors of " closing " to have
been limited to 0^ 0' 30" in angular, and 0*1 link in linear measure-
ment. The survey had been made with a Cook's five-inch
theodolite, and a steel band of loQ feet. The form of plan shown is
that adopted by the Victorian Survey Department ; but those
required by other colonies are substantially similar. The dimen-
sions on the plan furnished must " close " geometrically, and the
maximum diflerence admissible between it and the field-notes is not
to exceed 2' in arc, or the tangential equivalent on the length of
any line. Chainage by the " stepj^ing " process is permitted ; but
when the slojie of the ground exceeds 5° from the level, it is
preferred that the angle should be measured on the vertical arc
of the instrument, and used for reducing the measurements to the
horizontal plane. Although in the illustration given, the " closing "
errors are very trifling, it does not follow that the work is as
accurate as the test would at first sight make it appear. Every
operation in the field, no matter how simple or carefully done, is
attended with a certain practical error ; and the summation of such
errors may be either cumulative or counteractive, and possibly in
the instance given they may have acted in the latter way Had

Paj^crs.] VICKERY ON SURVEYING IN AUSTRALASIA. 213

the survey represented by the plan been effected on a hot day in
summer, and the check line measurerl on a cold winter day, there
would have been a possible error in "closing" of 3*4 links in
latitude, and 4*2 links in departure. For a line 1 mile long,
measured in the winter time with a steel tape 66 feet in length,
may vary nearly 5 • 5 links from a line measured with the same
chain in the summer time, from the effects of the variation of
temperature alone in the Colony of Victoria. The mean monthly
range of temperature to which a surveying chain would be subject
there, varies from 43-8^ in winter to 54* 7^ in summer; and the
variation in length in 1 mile would be : —

Winter .
Summer

Length i Tenipera-

of ture of

Band. Atmusphere.

Increase in

Number

Lenf,'tli of 1 foot

of Steel lianii for

Chains

1"^ Fahrenheit.

In I mile.

Feet. Links.

66' X 43-8° X 0-000006886 x 80 = 1-592484 = 2-41
66' X 54-7° X 0-000006886 x 80 = 1-988787 = 3-01

or, between the winter and summer measurements (2*41 -f- 3*01)
5 • 42 links ; whilst, as there are some days in summer when the heat
is phenomenally great, it is possible for the expansion and con-
traction to exceed this estimate. Another cause which operates
against acciaracy in chaining is the error due to the unequal
tensile strain employed ; the extension in 1 mile with a 66-foot
steel band, having an effective sectional area of h" X -^s", being
0*667 link where a strain of 30 lbs. is used, the results varying
according to the strain and sectional area. A still more potent
cause of error is when the measurements are made on inclined
ground, necessitating the suspension of the tape used, " a steel tape
of 6 lbs., used with a tensile strain of 30 lbs., giving an error of
13-44 links per mile," ^ due to the sagging or curvature of the
tape.

Even with the aids of a thermometer to regulate the allowance
for differences in temperature, and a spring attachment to regiilate
the tensile strain, practical errors in linear measurement in the
general survey can only be eliminated where they are based upon,
or connected with, standard lines laid down in connection with
geodetic or trigonometrical work.

It is patent that in a new colony where the population is still
sparse, and the territory unalienated, a geodetic or trigonometrical

' Traiisactious of Vict. lust, of Surveyors, vol. ii. Paper by Ca]ttain Kielly.

214 YICKERY ON SURVEYING IN AUSTRALASIA. [Selected

survey should be iindertaken in the first place ; then the principal
streams and mountain ranges delineated, and the quality of the
land noted and classified ; and finally, the most suitable courses for
main roads determined before the sub-division of the colony into
blocks for the purjDose of settlement is commenced. This course is,
however, unfortunately seldom practicable, the preliminary vrork
being liable to be interfered with through influence brought to bear
on Parliament by those anxious for immediate settlement, and the
too fi'equent readiness of the Government of the day to abandon or
postpone scientific but unremunerative operations, in favour of those
which tend directly to feed the revenue. In some of the colonies,
however, minor triang-nlation, generally depending on either major
triangulation or meridional circuit, has preceded or is being
carried on concurrently with settlement and sectional surveys, by
which means future trouble is avoided by permitting the technical
descri2)tion of boundaries of each holding to be expressed correctly
with relation to the true meridian. But while neither the
meridional circuit nor major triangulation surveys are sxafiiciently
refined for purely scientific purposes, the data which they supply
will be of great practical value in the future, the referring points
being permanently fixed and available for obtaining azimiiths.

In the colonies, or parts of them to which geodetic operations
have not been extended, settlement or sectional surveys miist be
connected with or based on the nearest boundary, the accuracy of
the bearing of which has been recognized and adopted. Where no
reliable datum for bearings can be obtained within a reasonable
distance, the surveyor is reqiiired to project a true meridional line
on the ground by one of the approved methods, and base his work
ujion it.

Eepeated checks made by the Author have convinced him that,
with the use of a light steel band of length varying from one chain
to ten chains, according to the character of the country in which
the operations may lie, and a good o-inch transit theodolite, the
maximum degree of errors stated as being allowable by the Govern-
ment survey departments is not too small.

[AlTKNDiXtJi.

rnpcrs] VICKEEY ON SURVEYING IN AUSTRALASIA. 215

APPENDIXES.

APPENDIX I.

Examination op Surveyors.

Each flepartment has its own board of examiners; and the subjects for
examination, in order to obtain a license, depend upon the description of
work required. For examj^le, municipal surveyors, besides acquaintance with
the ordinary subjects, are obliged to jjossess all the knowledge necessary for
road and bridge construction, and the setting out of works ; mining surveyors,
in addition to underground surveying, must understand practical mining, and
the machinery and appliances used in connection therewith ; water-supply
surveyors must prove themselves acquainted with hydraulics ; and those
employed by the Lauds Departments, with whom this Paper deals more par-
ticularly, before receiving certificates of competency, are examined in (fi) the
construction, adjustment, and use of the theodolite, level, and other modern in-
struments ; (b) the principles and practice of subdivisional, topogi-aphical, and
road surveying ; (c) practical trigonometry ; (d) computation ; (e) jilotting by
ordinates and otherwise; (/) charting and drawing. Additional special subjects
are (a) practical geodesy, including the determination of latitude and longi-
tude by prime zenith distance, and by prime vertical observation of the true
meridian by astronomical observations, and of the relative latitude and longitude
by triangulation ; (b) spherical trigonometry and trigonometrical analysis ;
(c) setting out of curves, and computations therewith ; (d) levelling and mensu-
ration of earthwork. These examinations generally extend over a period of
from five to seven days of eight hours each; and about 30 per cent, of the
candidates presenting themselves succeed in passing. The subjects vary in
detail in the dilfereut colonies ; but the examinations are practically of equivalent
value. In some instances certificates are granted without examination, the fact
of their being so obtained being stated. In Victoria, these are granted only under
the following conditions : — Having passed some examination — eqiiivaleut in the
opinion of the board to that prescribed in Victoria — in Great Britain, the United
States of America, India, or some British colony, and having been in practice
during not less than one year ; having been engaged in that colony under some
authorized surveyor for not less than six months, and having a favourable report
on his qualifications from the Surveyor-General, or the Insj^ecting Surveyor in
charge of the district in which the applicant has been employed.

APPENDIX II.

Survey of Block, with Check Line.
Parish of Bunnugal. County of Ripon.

Geological Formation. — Newer volcanic, covered by recent tertiary.

Physical Conformation. — Fern-banks and swamps.

Soil. — Poor, sandy. Vegetation. — She oak, gum, pei^permint, and ferns.

216

VICKERY ON SURVEYING IN AUSTRALASIA. [Selected

Fig. 1.

G WALKER

cJa.„^S

C H.ARMYTAQE

smSS' 2g?£ -'

%^ ^ ^^

r. CAMERON

{SelBction/J

(Seledian/)

CTuajtB JO

Scaler 30 Ovaiits = 7 AM/.

^^%mni$

Closure and Area of Block.

Bearings.

Dist.

W. L.

Areas.
N. S.

S. 89° 59' E.
South . .
East. . .
S. 0° 3' E. .
S.71°53'W.
S. 33° 47' W.
S. 89' 58' W.
N 0^ 3'AV.

Links.
6,706
1,079
1,001
1,100
3,471
3,379
2,525
6,070

Links.
6,070

Links.
2-0
1,0790

l,l66-0

1,079-0

2,808-5

1-5

Links.
6,706-0

i,o6i-o

0-9

Links.

3,298-0

1,878-9

2,525-0

5-2

Links.

6,706-0

13,412-0

14,413-0

15,414-9

12,117-8

6,910-9

2,537-0

6-8

0-13412
.. 144-71548

.. 169-56390

.. 130-75106

194-93518

0-03805

0-41276

6,070 6,0707,707-97,707-1

0-41276 640-13779
0-41276

Area, 319a. 3r. 18p.

2)639-72503

A. 319-86251
E. 3-45004
P. 18 00160

Pa]x;rs.]

VICKERY ON SURVEYING IN AUSTRALASIA,

217

Closure of Check Lines, West Portion of Block.

Bearings.

Dist.

S. 89° 59' E. . .
S. 31° 3' E. . .
S. 71° 53' W. . .
S. 33° 47' W. . .
S. 89° 58' W. . .
N. 0° 3' W. . .

Links.
2,996-5
3,629-0
483-0
3,379-0
2,525-0
6,070-0

Links.

6,070-0

Links.

0-9

3,109-0

150-2

2,808-5

1-5

Links.
2,996-5
1,871-8

Links.

459-1

1,878-9

2,525-0

5-2

6,070-0

6,070-1

4,868-3

4,868-2

218 HUNTER OX THE MANUTACTUKE OF OIL-GAS. [Selected

(Paper No. 2233.)

" The Manufacture of Oil-Gas on the Pintsch System, and its
application to the Lighting of Railway-Carriages." ^

By Gilbert Macintyre Hunter, Assoc. M. Inst. C.E.

I. The Manufacture and Compression of the Gas.

(a) Manufacture.

The Author's object, in submitting this Paper to the Institution,
is an endeavour to make the process of oil-gas manufacture better
understood and appreciated, rather than to bring forward facts
previously unknown.

Generally, the gas is made from once-retined paraffin oil in cast-
iron retorts, the tar is removed, the gas condensed, washed, and
purified, and then passed to the gasometer, from which it is drawn
by compression pumps, and forced into cylindrical holders.

At the Cook Street (Bridge Street Station, Glasgow) Gasworks,^
which supplies the Caledonian Eailway,^ the arrangement is as
follows (Plate 5, Figs. 1 and 2) : — In the retort-house there are
two sets of benches that can be worked alternately, also an upright
boiler for suppl;^dng steam to a duplicate set of compressing pumps.
In the purifying-house are the condensers, washer, a double set
of purifiers, and the meter ; while the storage cylinders are in a
separate house at a short distance.

The retorts, Plate 5, Figs. 3, 4 and 5, are Q -shaped cast-iron
tubes 5 feet 10 inches long, and 10 inches wide, placed one above
the other, the lower one resting its whole length on a firebrick sole.
The flame from the furnace passes round both sides of the lower
tube, over the top, and there engages with the upper tube, finally
reaching the flue or combustion chamber. Thus the flame plays
directly upon all parts of the tubes, not unduly heating some parts
and others partially. The flues are built of ordinary firebricks.

> A Paper on " Compressed Oil-Gas and its applications," by Arthur Ayres,
M. Inst. C.E., was read and discussed at the Institution in the session 1887-88.
Minutes of Proceedings Inst. C.E., vol. xciii. p. 298.

^ Minutes of Proceedings Inst. C.E., vol. Ixxxvii. p. 392.

^ The company has another gasworks at Perth for supplying the northern
section of t)ie railway.

PajXii's.] HUNTER ON THE MANUFACTURE OF OIL-GAS.

2:9

Both ends of the tubes are fitted with mouthpieces or covers,
admitting of thorough cleaning.

The oil is pumped from barrels into a 15-gallon cistern on the
top of the retort-bench, which thus maintains a constant head and
a steady flow. It enters the upper retort, Plate 5, Fig. 4, in a thin
continuous stream from a micrometer cock, through a siphon pipe,
and falls upon an iron tray on the bottom of the retort. This
prevents the cold stream of oil coming in direct contact with the
hot retort, and thus reducing its temperature. Here it is partially
vaporized, and, passing through the tube, descends to the lower tube,
where it encounters a higher temperature, rendering it permanent
or "fixed." The object of this is to insure that every portion of
the vaporized oil shall be acted upon by the highest temperatiire,
without undue exposure to the heated surface of the retort. As
the gas leaves the retort, it is largely mixed with tarry and other

Figs. 1.

Section of Washer.

Plan of Underside of Tray.

vapours, which give it the appearance of smoke of a more or less
dense nature, in proportion to the quantity of such matters present.
It now passes through a tar pit or hydraulic main, filled with
water, where the first separation of the tarry matter is effected.
The condensers consist of two vertical cylinders, through which
the gas passes, entering at the bottom of one and passing up
through it and then down through and out at the bottom of the
other, the effect of which is to condense the tar. The gas now
passes to the washer (Figs. 1).

The inlet-pipe is vertical, with a tray over it having curved
arms or " spreaders " on the under or water side. The gas on
entering is turned downward by the tray, and driven through the
water in a circling fashion by the spreaders ; it finally passes
out of the water, through a series of perforations round the edge of
the tray, into an upper or gas chamber, and thence to the purifiers.
This washing process assists in removing the brownish or smoky
appearance of the gas, and arrests and deposits all the tar which

220 HUNTER ON THE MANUFACTURE OF OIL-GAS. [Selected

may pass with it. The quantity of tar in the gas varies with
the temj^erature maintained within the retorts, and also with the
quantity of oil run into the retort. There is also a great variation
in the quality of tar given off by different oils. Some classes
jield very light " thin " tar, which comes out at the overflow in
the washer, being lighter than the water ; while other classes give
off heavy tar, which sinks to the bottom, and is drawn off to the
tar tank. Both the condensers and the washer are i:)rovided with
siphons to remove the tar. Although the gas has been undergoing
purification, so to speak, in the successive stages through which it
has passed, it is now submitted to a final and thoroi^gh purification
for the removal of sulphur compounds, carbonic acid, and sulphur-
etted hydrogen. The purifiers are arranged in a double set, and
by means of a four-way valve the gas can be made to pass through
either one or other, or both. The purifying material consists of
slaked lime and sawdust in the proportions of 2 to 1, which is
renewed weekly. It is spread evenly about 2 inches deep over a
perforated tray, in the same manner as a coal-gas purifier. The
gas now passes to the meter, and thence to the gasholder, which
has a capacity of 1,700 cubic feet.

At night the main valve is shut, the dampers are closed, and
the covers over the tar pit are removed, to allow the gas in the pipe
to escape ; the manhole covers are also removed, and the tar and
pitchy matter drawn off. The mouthpieces are next taken off, the
retorts cleaned out, and the covers replaced ; the fires are drawn,
and afterwards banked for next morning. The fires are kindled
with coal and dross ; thereafter they are wholly maintained with
coke, which gives much better results than coal. After they have
been kindled for about an hour and a half, the oil is turned on.
The projDer heat has not been obtained yet ; but, owing to the
demands on the work, longer time cannot be spared, so that the
yield of gas per gallon of oil is comparatively small for the first
hour or so. When the retorts are irregularly heated there is a
large increase in the quantity of tar ; while, if they are overheated,
the distillation is attended with a separation of carbon in the form
of soot, and if insufficiently there is deposited in the retort a
carbonaceous substance resembling coke, in addition to an abundant
production of tar. The best temperature is a bright cherry-red
heat, verging on white; then there is only a small quantity of
carbon or soot.

A high illuminating gas ^ can be produced when the yield is

' Transactions of the lustitutioir of Engineers and Shipbuilders in Scotland,
vol. XXX. p. 236.

PaiK'l-s] HUNTER ON THE MANUFACTURE OF OIL-GAS. 221

small ; and conversely, with a high quantitative yield, the light-
giving quality of the gas will be diminished. A fairly good yield,
which can be obtained in every-day practice, varies from about
70 to 85 cubic feet, or 18,480 to 22,440 cubic feet per ton of oil, of
50 to 60 candle-i^ower gas. Mr. J. B. Macarthur has shown ^ that
a yield of 120 cubic feet per gallon was only equal to 40 candles,
and that when the yield reached 158 cubic feet (which was at a
bright orange heat) the candle power fell to 20 to 25.

While the oil is undergoing the process of distillation, there are
several means of ascertaining if this is proceeding continuously,
and under the most advantageous conditions. Supposing a given
(pxautity of oil per hour is flowing into the retort, and a suitalde
temperature is maintained, a glance at the meter will show what
quantity of gas is passing, and if regular in volume. Should the
latter be irregular, it indicates a stoppage somewhere, which can
be ascertained by reference to the pressure gauges, whether in
the tar pits, condensers, washer, or purifiers. At the same time
the gas would " blow " out from the water safety-valve, alongside
the main valve, and also at the siphon oil-pipe ; while, if any-
thing goes wrong with the gasometer, the gauge falls, and a blow
out takes place at the relief. The down pipe from the retort
to the tar pit is provided with a cock, which allows a small
jet of gas to escaj^e. If the escaping gas be of a light brown
colour, the distillation is perfect ; if, however, it be white, the
supply of oil has to be reduced, and if dark brown, or if it forms
flakes of soot, the supply has to be increased, and sometimes the
heat of the retort lowered. The tar must not be too thick when it
overflows at the siphon on the tar catch-pit, but jet black. If it
should contain oil, it is thin and flows freely, and a drop placed on
a piece of white paper will produce a transparent greasy border
round the tar.

No. 1 bench was worked continuously for fourteen weeks in the
winter of 1887-8, during which time 8,294 gallons of oil were
distilled, yielding 669,850 cubic feet of gas, or an average of 80* 76
cubic feet per gallon. This is the longest time they have been
worked without requiring a renewal of the retorts or the flues.
They usually last for about ten or eleven weeks.

During the year 1886 the average yield per gallon of oil was 72
cubic feet of gas, or 19,008 cubic feet per ton of oil; and, for the
year 1887, 81-22 cubic feet, or 21,442 cubic feet per ton of oil.
These are very satisfactory results from a work where the resoiirces

' The Journal of the Society of Chemical Industry, vol. vi. 1887, p. 811.

222 HUNTER ON THE MANUFACTURE OF OIL-GAS. [Selected

are taxed to the utmost. A certain qTiantity of gas must be manu-
factured each day, and at times it is difficult to supply the demand ,
therefore no time can be spared in allowing the oil to be " drawn "
to its utmost, as it might be, were there time. Dr. Macadam, F.C.S.,
while conducting some experiments,^ found that the apparatus
yielded from the gallon of oil, on the first occasion 90 "70 cubic
feet of gas of 62-50 candle power ; on the second occasion 103*36
cubic feet of 59 • 15 candle power, or an average of 97 • 03 cubic feet
of 60 • 82 candle-power gas. In both cases the firing of the retorts
was moderate, though in the second trial greater care was taken to
secure uniformity of heat, and the oil was run in more slowly, so
that there was more thorough splitting up of the oil into permanent
gas.

Approximately it takes about 5 tons of coke, 4^ tons of dross, and
10 cwt. of coal to make 100,000 cubic feet of gas, or about 4-46 lbs.
of fuel per cubic foot of gas. This includes kindling and getting
up the heat in the retort.

The cost of making the gas, including oil, fuel, wages, repairs,
&c. is 6s. 7'24f?. per 1,000 cubic feet.

(h) Comjyressian.

The gas is drawn from the gasometer l)y compression-pumps, and
forced into cylindrical store-holders at a pressure of 150 lbs. per
Square inch, or 10 atmospheres. The compression is effected by a
double-acting pump,'^ which has a ram-diameter of 6 1 inches, com-
pressing the gas to 60 lbs. per square inch, and a diameter of
4 inches, compressing to 150 to 180 lbs. per square inch. Although
the holders are tested to a pressure of 180 lbs., or 12 atmospheres,
they are seldom charged to more than 150 lbs. The compressing
cylinders are kept cool by a jet of water running round them.
These pumps are worked week about.

The freezing cylinder retains in cold weather, in the shape of
ice, any water particles that may be absorbed by the gas in the
gasometer. These water particles are much impregnated with
carburetted hydrogen, and, when thawed, may be drawn oif by
a cock. As a rule, there is never more than a trace of this. The
cylinder cools the gas, and serves the purjwse principally of a
reservoir, from which the pumps can draw without directly affect-
ing the gasometer. In fact, it serves the same purjjose as a gas

The Gas Institute. Transactions for 1887, p. 41.
Kevue Geuerule des Chemius do For, 1882, p. 127.

Papers.] HUNTER ON THE MANUFACTURE OF OIL-GAS. 223

bag to a gas-engine. In tlie engine-room there is a suction-gauge,
for sliowing if the pumps are drawing the gas regularly. There
are relief cocks on the pumps, which shut oif the high-pressure gas
from the cylinder valves after the store-holders have been charged,
and the column of gas in the pipe is allowed to pass back into the
gasometer.

The store-holders are mounted on trestles, each pair being con-
nected underneath the front end by a small pipe which leads to a
recipient encased in a box of sawdust for the hydrocarbon, from
whence it is drawn off into a drum. The pressure of the gas in
the holders drives oiit the hydrocarbon into the recipient, and
thence to the drum ; but, as a certain quantity of gas always
passes with the hydrocarbon into the drum, provision is made for
this gas to pass from the drum into the gasometer. The hydro-
carbon heing the principal constitiient of the gas, any diminution
affects the illuminating power of the gas. On an average it loses
fully 5 candle power by compression. The compression causes the
deposit of the hydrocarbon at the rate of about 1 gallon per 1,000
cul)ic feet of gas. It gives off an inflammable vapour at a temi)era-
ture of less than 45' Fahrenheit. It is, accordingly, rather a
dangerous substance to work with, and is generally drawn off from
the drum into smaller ones for transmission to manufacturing
chemists, on a dull, moist day.

II. Application to the Lighting of Eailway-Carriages.

From the works to Bridge Street Station (}r mile), and also to
Central Station (.V mile), jiipes are laid so that trains can be
charged with gas while standing in either of these stations. A
pipe is also laid to Giishetfauld's carriage-shed ^ (^ mile), and
carriages can be charged there before being taken out and mar-
shalled. Filling cocks are placed every 34 feet, so that a carriage
may come near each cock ; a 30-foot length of india-rubber hose is
attached to the filling cock on the carriage, and the pressure-gauge
records the volume of gas supjilied. It takes three minutes to
couple the hose and charge a standard carriage carrying six lamps,
if they be empty, but this is seldom the case.

Plate 5, Fig. 6 shows the general arrangement of the pipes and
fittings on an ordinary carriage. Each carriage is provided with
one or two recipients or cylinders, of a size proportionate to the
number of lamps it carries. The recijiients are made of y\-inch steel

' Miuutcs of Proccediugs lust. C.E., vol. Lxxxvii. p. 397.

224 HUOT^ER ON THE MANUrACTURE OF OIL -GAS. [Selected

plate, carefully bent. The joints are both, riveted and soldered, and
the flanged ends are then fitted in, fastened by screws, and soldered
over. The cylinder is afterwards tinned both inside and outside,
so that it is perfectly gas-tight. It was at one time imagined that
dangerous explosions might result from the presence of so much
gas under each carriage, in the event of a railway accident. In
order to settle this point, an experiment was made with a recipient
6 feet in length and 16 inches interior diameter, made of ^-inch
plate. This recipient was filled with gas at a pressure of 6 atmo-
spheres (90 lbs.), and placed under a scaffolding, supported at its
ends with a fire on each side. A weight of 400 lbs. was dropped on
it from a height of 15 feet, the weight falling exactly on the riveted
seam. At the first blow it was merely bent in, and became slightly
loosened about the rivets. A pointed piece of iron was then placed
on the recipient, and the weight allowed to drop as before. This
made a hole 5 inches in diameter, and, in opposition to the effects
which would have been exhibited by the explosion of a steam-
boiler, the gas simply escaped from the hole, and, being ignited by
the fire, burned with a high flame. There was nothing of the
nature of an explosion, and scarcely any noticeable concussion of the
air at a few paces distant. The test sufiicit n ly proved the com-
paratively harmless nature of the small volume of gas enclosed in
the recipient, and that the gas can escape only through external
jxjwer or an accident. This has been confirmed in several cases
where a broken tire made a hole in the recipient, the gas escaping,
harmlessly into the air before the train had come to a standstill.
Each recipient is tested under hydraulic pressure before being
attached to a carriage.

The size and position of the recipients vary with the different
modes of under-framing, and also the number of wheels for each
type of carriage. For a standard carriage they are fixed longi-
tudinally to the under-framing, one on each side, and connected by
a pipe. The filling cocks are fixed outside the framing on each
side, as also the pressure-gauge. A regulating or governing valve ^
reduces the pressure of the gas after it has left the recipient on its
way to the lamps. The valve consists of a cast-iron pan 12 inches
in diameter and 6 inches iil depth. The upper part is closed by a
membrane of specially prepared leather, to the centre of which is
fastened a rod connected at its lower end with a lever controlling
the regulator-valve. This lever is also controlled by a double-leaf
spring acting in opposition to the membrane ; and by this means

' The Etigtneer. vol. xlix. p. 293.

Papers.] HTTNTER ON THE MANUFACTURE OF OIL-GAS. 225

the regiilator-valve is rendered independent of the movement of
the carriage, so that accidental extinction of the light never takes
place. The gas passes the valve, which is adjusted for a pressure
of only that due to a -^-inch column of water ; and when the pres-
sure under the membrane is reduced helow this, the valve is closed,
and the jirocess of opening and closing is repeated until a balance
between the admission and the consumption is obtained. These re-
gulators are adjusted according to the number of lamps which they
will supply ; thus a foiir- or five-lamp regulator is adjusted to
30 millimetres, or 1^\ inch.^ From the regulator a low-pressure
pipe is carried up the end of the carriage on to the roof, and
connects the several lamps. On the end of the carriage there is a
by-pass valve, worked by a draw-rod, by which in the event of a
train standing emj^ty at a station, there being no occa-
sion for the gas burning, the lights can be shut down p^

without being extinguished. There is likewise a con-
cussion-box, which always contains a supply of gas, so
that, in the event of a sudden pull of the draw-rod, the
lights are not extinguished, as they otherwise might
be. The pipe is simply cut ; both ends are closed, and
the pipe is perforated with a few holes through which
the gas escapes, and fills the box, making it a g^s ^^^^^^^^^f,^^^
chamber, from which it is again drawn oft'. Above this cussios-Box.
is the main cock, which shuts off" the gas from, or admits it to, the
whole carriage.

The recipients are charged to 6 atmospheres (90 lbs.) for thirty-
six hoiirs' burning ; and no carriage is allowed to leave Central or
Buchanan Street stations with a lower indicated pressure than
2 atmospheres, or for twelve hours' burning.

In Fig. 3, which is a section of a standard lamp, the arrows
show the direction in which the foul air escapes, and the fresh air
enters to support combustion. It will be observed that sudden
gnsts of wind cannot directly affect the light ; that, the globe being-
perfect inside, the opening of the carriage-door has no eff"ect uj^on
the light ; and that sparks from the engine or other matters cannot
get into the inside of the lamp. The rich nature of the gas renders
the adoption of a special burner necessary ; because, the greater the
illuminating jjower of a gas, the smaller will be the consumption
to maintain a light of given brilliancy. The burner, a small fish-
tail, made of "speckstein" or steatite, gives a well-shaped, steady

All the pipes between the recipients and the filling cocks and the regulator
are under high pressure, and arc made of best special i)ipc of y^^^-inch bore and
5-iuch outside diameter.

[tHK INST. C.E. VOL. XCV.] y

226

HUNTER ON THE MANUFACTUBE OF OIL-GAS.

[Selected

flame. It is easily cleaned. The funnel and all the casing is^H
made of best tinned copper, and the body of cast-iron. Each jet ^^
has a thumb-cock, so that any light can be turned off, while the
others remain burning in the same carriage. There is also a
regulating spindle, which can be worked with a special key from
the inside of the carriage, for raising or lowering the flame. The
connecting pipe between each lamp is screwed into the socket, a.
For saloon and such types of carriages the globe of the lamps is
hinged on the inside, to admit of the passengers lighting them at
pleasure. They also have hoods for shading off the light.

The luminary being a permanent gas, it can remain for any
length of time in the recipients without deteriorating, either in

Fig. 3.

Section of Lamp.

Scale i.

illuminating power or in pressure. Dr. Macadam says : ^ — " I have
also examined samples of the gas taken by me from various cylinders,
where the gas had been stored for several months under a pressure of
10 atmospheres ; and in all cases the gas was found to be practically
equal to the above quality,^ and hence was of a permanent cha-
racter." The permanency of the gas may be further illustrated by
the fact that the carriages, which are charged at Gushetfauld's shed
or at Central Station, maintain the same pressure on the gauges as

' The Gas Institute. Transactions for 1887, p. 45.

^ The quality of the gas obtained was very high, owing to its containing a
large percentage of heavy hydrocarbons, of which there were respectively 39 -25
and 37-15 per cent., or an average of 38-20 per cent.

Papers.] HUNTEK ON THE MANUPACTUKE OF OIL-GAS. 227

those at the works, and that after having travelled J mile through
pipes to each place.

The disadvantages of the old system of lighting carriages with
oil-lamps are well known. The removal of dirty lamps to the
lamp-room, cleaning them, filling the cisterns and replacing them
in the carriages, rendered necessary the employment of a staff of
men at terminal stations. Again, the breakage of globes, and
damage to the framing, formed a heavy item of cost per annum.
This is now obviated, as, the lamps being fixtures, all that is
required when cleaning the lamps is to lift the cover, remove the
reflector, and lift the gas-bracket. The lamp being now open, the
inside of the globe, the enamel on the reflector, and other parts can
be cleaned and all replaced.

Taking the present price of oil as Is. lid. per gallon, and the
cost of gas as Gs. 7-24(Z. per 1,000 cubic feet less the residual pro-
ducts, the oil will burn for one hundred and eighty-four hours,
while the gas will burn thirteen hundred and thirty-three hours,
and the cost would be 0-125(Z, and 0-05944fZ. respectively per hour.
This is a saving of 0-06556d. per hour, which, for 1,000 cubic feet,
represents a saving of 87-391, or 110-29 per cent. The value of
the residual products, hydrocarbon and tar, for 1887, amounted to
Is. l-24:d. per 1,000 cubic feet.

The cost of fitting a standard carriage with six lamps, including
recipient, regulator, gauges, valves, pipes, &c., is £33.

The tests to determine the illuminating power of the gas, as
given in the Appendix, were undertaken with the view of showing
the value of the gas as used in the carriages. The fittings on the
photometer were supplied by Pintseh's Company.

In conclusion, the Author begs to acknowledge his indebtedness
for information to Mr. Stewart Kershaw, Manager for Scotland of
Pintseh's Patent Lighting Company, Limited ; and to Mr. Samuel
Stewart, F.I.C, Chemist, Stores Department, Caledonian Eailway,
who supplied the photometric tests.

The Paper is accompanied by three tracings and several dia-
grams, from which Plate 5 and the Figs, in the text have been
prepared.

[AppENorx.

228 HUNTER ON THE MANUEACTUKE OF OEL-GAS. [Selected

APPENDIX.

Experiments to test the Caxdle power of Gas.

The gas was taken from a recipient charged to over 10 atmospheres.

Specific gravity of the oil (Clippeu's " Straiton ") at 60^ Fahr. . . 848-2

Weight of 1 gallon of oil 8-482 lbs.

Number of gallons of oil per ton 264

Flashing-point of the oil, Fahr. (close-test) 268''

Firing-point of the oil, Fahr- 294°

Specific gi-avity of the hydrocarbon at 60° Fahr 845-2

Weight of 1 gallon of hydrocarbon 8-452 lbs.

Firing-point of the hydrocarbon, Fahr. (below) 45°

Gas.

Time of test

Temperature, Fahr

Pressure of the gas in tenths of an inch

Eeduction in pressure, from 7 - 35 to 5 - 75 atmospheres .

Gas consumed per hour, cubic foot

Illuminating value of the gas as taken by i^hotometer, 1

and reckoned in standard sperm caudles, consuming } 8 - 25 8-25 8 • 0 8-0

120 grains per hour )

5 cubic feet are equal in intensity to 55*7 candles . .

Illuminating value of 1 cubic foot of the gas in gi-ains\

e ( 1,336

of sperm } '

Illuminating value of the gas from 1 gallon of oil in i

lbs. of sperm / ^^'^^

Total illuminating value of the oil yielded by 1 ton of 1

oil, and given in lbs. of sperm / ' "^^

Volume of oil running into each retort per half-^

minute, oz J *

A''olume of gas yielded by each retort per minute, as~i

shown by the meter, cubic feet j

Total volume of gas yielded per hour b}' the two'i

retorts, cubic feet /

Average yield per gallon, cubic feet 80 - 48

Which, calculated to the ton of oil, gave, cubic feet . 21 ,246-72

min.
0

mms.
15

mins.
30

mins.
45

63°

64°

7-5

7-75

7-25

7-5

960

Papers.] SMITH ON HUKST's TRIANGULAR PRISMATIC FORMULA. 229

(Paper No. 2,336.)

" Hurst's Triangular Prismatic Formula for Earthwork
compared with the Prismoidal Formula."

By James William Smith, Assoc. M. Inst. C.E.

In this communication references to Hurst's " Handbook of For-
mulas, Tables, and Memoranda," ai)23ly to the 12th edition, 1879 ;
and references to Molesworth's " Pocket-Book of useful Formulae,
and Memoranda," apply to the 19th edition, 1879.

In the first of these Handbooks Hurst's Triangular Prismatic
Formula is given at p. 257 as follows : —

" To measure the solidity of earthwork over large areas of
irregular depth : — Divide the surface into triangles, and multiply
the horizontal area of each by one-third of the sum of the
vertical depths taken at the angles, and the result will equal the
solidity."

This is quoted by Molesworth, p. 52, but without the following
im^portant note by Hurst :— " The surfaces of the triangles must be
true planes, or they must be taken so small as to approximate to
planes."

The well-known Prismoidal Formula is given by Molesworth at
p. 46 as follows : —

[Sum of areas of both ends -|- (area of middle X 4)] x length

6 *

The convenience and simplicity of Hurst's triangular prismatic
formula is incontestable ; but it has been looked upon with dis-
favour, owing to the diiferent results obtained according to the
manner in which a quadrangular figure may be divided by a
diagonal into two triangles, and to the difference between either
of those results and the result obtained by the prismoidal formula.
The object of this Paper is to point out the reason of these divergences
and to provide a remedy.

Hurst's formula is undoubtedly mathematically correct, provided,
as he takes care to explain, the surface of each triangle is a
true plane, and any three points of a surface can be connected by a
true plane. But in practice, levels being taken for convenience
at stated intervals, on parallel lines at stated distances from one

230 SMITH ON hurst's TRIANGULAR PRISMATIC FORMULA. [Selected

anotlier, the surface to be dealt with is primarily divided into
quadrangular figures ; and the subsequent division into triangles
is purely arbitrary. Of course, if the engineer knew that a line
between any two angles would touch the surface all along, that
line would represent the proper diagonal to be drawn on the plan,
and there would be no reason to further investigate the ap-
plication of Hurst's method ; but, as a rule, he cannot know this.

As, however, except under the rare condition of the whole
surface of the quadrangle being a true plane, the result obtained
by Hurst's method, if the quadrangle be divided by a diagonal
between any two angles, will diifer from that obtained by dividing
the quadrangle by a diagonal between the other two angles, a
mean result, easily arrived at, is a desideratum. Though such
a mean may not be based upon a strictly mathematical principle,
yet if only a mean, it should be welcome ; and since it can be
shown that the mean corresponds with the effect of the prismoidal
formula, which has received universal acceptance, it should be
deemed entitled to general adoption.

The mean is most easily obtained if the area be divided into
parallelograms, and it is not often in practice an area would be
otherwise divided. In these cases the earthwork (whether filling
or excavation) would consist of prisms whose ends are parallelo-
grams. The formula for the solidity, giving the mean of the two
ways in which Hurst's formula may be applied, is simply : —

.„. Sum of the four depths

(Z) ^ X area.

In the examjiles which follow, the depths are enclosed within
circles, and are taken more divergent from one another than they
would generally be in practice, in order to more severely test the
applicability of the above formula.

ExamjjJe 1. — Plan of rectangle, area = 72.

Eeqiiired the solidity of Fig. 1, depth at each angle being given.

{a) By Hurst's formula, if divided as in Fig. 2 : —

Solidity = { -\-

Total solidity = 732

Papers.] SMITH ON HURST's TRIANGULAR PRISMATIC FORMULA. 231
(h) By Hurst's formula if divided as in Fig. 3 : —
9 + 6 + 18 _ 72
Solidity = { +

X y = 396

18 + 11+9 72 ^^^

— ■ — X -TT = 456

3 2

Total solidity = 852
(c) Mean of a and & = 792.

Fig. 1. Fig. 2.

(d) By new formula (quadrangular) Z : —

18 + 11 + 9 + 6

Solidity =

X 72 = 792, i.e., the mean of a and 6.

(e) By prismoidal formula, observing the following directions
in Hurst's Handbook, p. 257 : —

" The sections are to be taken parallel to each other, and the
area of the middle section to be calculated from the mean dimen-
sions, and not by averaging the areas of the ends."

The figure then becomes as follows, the depths (12) and (10)
being calculated respectively as the means of 18 + 6 and 11 + 9 : —

Fig. 4.

e -■■-

18 + 11

6 + 9

2
12 + 10

X 6 = 87 = sectional area at one end,
X 6 = 45 = „ „ „ other end,

X 6 = 66 = „ „ in middle.

232 SMITH ON HUKSt's triangular prismatic formula. [Selected

+ 45

+ (66x4=) 264

396
X 12 the length.

6;4752

Solidity = 792 i.e., the same as by the quadrangular for-
mula (Z).

The prismoidal formula might be applied by taking the sections
in the other direction (i.e. longitudinally), but the result would be
■precisely the same.

Example 2. — Plan of rhombus, area = 60.

Eequired the solidity of Fig. 5, depth at each angle being given.

Fig. 5.

(a) By Hurst's formula, if divided as in Fig. 6 : —
Solidity = 210 + 190 = 400.
Fig. 6.

(h) By Hurst's formula if divided as in Fig. 7 : —
Solidity = 220 + 250 = 470.
Fig. 7.

(cj Mean of a and h = 435.

(d) By new quadrangular formula (Z) : — ■

Solidity = i^±l±l±i,X 60

435, i.e., the mean of a and h.

Piipers.] SMITH ON HURSt's TRIANGULAR PRISMATIC FORMULA. 233

(e) By prismoidal formula, the depths (8^) and (6) heing cal-
culated, the former as the mean of 10 -(- 7 and the later as the
mean of 4 + 8 : —

Fig. 8.

>> - -- TO ■ — - >.

Sectional area at one end = 70 ;
„ „ at other end = 75 ;

„ „ in middle = 72^.

Solidity = 435, i.e., the same as by the quadrangular
formula (Z).

The same result would have been obtained if the sectional lines
had been taken as 6 long instead of 10, and the length of the figure
as 10 instead of 6.

When the area of the surface is a trapezoid, not often occurring
in practice, a somewhat different method has to be adopted.

Taking the two parallel sides of the trapezoid, as the respective
bases of the two triangles into which the trapezoid may have
been divided, the formula, to obtain a mean result, will be as
follows : —

Mean of the two depths opposite base |

/^rx <.,.■,. + sum of the two depths at the base I x < f ^®^ i
(Y) Solidity = -!- — -i ^ 1 triangle

o J

The solidity in each triangle must be calculated separately.
Exam^ple 3. — Plan of trapezoid. Fig. 9, area of smaller triangle
= 24, area of larger triangle = 60.

Required the solidity, the depth at each angle being given.

234 SMITH ON hurst's triangular prismatic formula. [Selected

(a) By Hurst's formula, if divided as shown by the dotted
diagonal : —

9 + 11 + 3
^ ^ X 24 = 184

3 + 7 + 9

X 60 = 380

Total solidity = 664

(h) By Hurst's formula, if divided thus : —
Fig. 10.

11 + 9 + 7

11 + 3 + 7

X 24 = 216

X 60 = 420

Total solidity =636

7 + 3

+ 11+9

X 24 = 200

11 + 9

+ 3 + 7

X 60 = 400

Solidity = 600, i.e., the mean of a and 6.

(e) By prismoidal formula, the depths 7 and 8 being calculated,

Fig. 11.

the former as the mean of 1 1 + 3, and the latter as the mean of
9 + 7 :—

Papers.] SMITH ON HURSt's TRIANGULAR PRISMATIC FORMULA. 235

Sectional area at one end = 40 ;
„ „ at other end = 50 ;

„ „ in middle = 52^.

Solidity = 600, i.e, the same as by the formula (Y).

In the case of a trapezium, no simpler method has been found
than to take the mean of the two results, arrived at from the
application of Hurst's formula to the two triangles obtained by
drawing the diagonal in one direction, and to the two other
triangles obtained by drawing the diagonal in the other direction.
The trapezium is, however, a figure to be avoided in areas of
earthwork ; the surface should be divided into parallelograms
and triangles, the triangles being formed only when necessitated
by the irregular direction of the boundaries. Formula (Z) should
be applied to the parallelograms, and Hurst's formula to the
triangles.

A trapezium may be divided into a trapezoid and a triangle, an
additional level being taken on the ground, at the point where the
line drawn parallel to one side of the trapezium from one of the
angles cuts the side opposite to the angle. Formula (Y) may be
applied to the trapezoid, and Hurst's formula to the triangle.

When a surface is divided into parallelograms of equal area,
the application of formula (Z) is much simplified by placing the
depths in columns ; the depths which belong to only one parallelo-
gram in one column, those which are common to two parallelograms
in another, and those which are common to four parallelograms in
a third column. The sums of the second and third columns are
multiplied by 2 and 4 respectively, and the products added to the
sum of the first column, and then multiplied by one-fourth of the
area of one parallelogram, give the total solidity.

In calculations for earthwork, it will be found preferable to use
the actual reduced levels, or those levels minus an easily deducted
whole number, rather than depths, each one of which is a probable
source of error, as it involves a more or less complicated subtraction ;
besides, when the finished surface is to be sloped, a separate
calculation is necessary to ascertain the reduced level of the
finished surface at each point.

For instance, suppose that the lowest reduced levels of a surface
to be excavated are between 80 and 90 on the datum, then if 80
be deducted from each reduced level, and the remainder used as a
depth, the result will be the solidity if the surface be excavated
down to 80 on datum. The difierence between 80 and the reduced
level to which the surface is to be finished, if used as a depth in

236 SMITH ON hurst's triangular prismatic formula. [Selected

connection with the whole area, will, in one single calculation,
give the contents to be either added to or deducted from the
previously ascertained solidity, as the case may require, in order
to arrive at the total or net solidity. Even if the finished
surface is to be sloped, the mean reduced level will generally be
seen almost at a glance, and one calculation for the addition or
deduction will be sufficient.

It is obvious that quantities of filling may be arrived at in a
similar manner.

Besides the benefit of avoiding a multiplicity of minor calcula-
tions afforded by this method, there is also the advantage of all
the actual reduced levels used in the computations being preserved
and recorded in the measurement book. In the use of depths only,
there is no record of the reduced levels.

The Paper is illustrated by sketches in the manuscript from
which the eleven Figs, have been prepared.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 237

(Paper No. 2339.)

" Alpine Engineering."
By Leveson Francis Vernon-Harcourt, M.A., M. Inst. C.E.

The passage of the Alps has always been a fascinating object to
mankind — not indeed from their forming the most insurmountable
harrier in the world, for the Himalayas, the Andes, and other
moimtain-ranges exceed them in height and inaccessibility — but
owing to their being the chief obstacle separating some of the
most fertile regions of the earliest civilized quarter of the globe.
The crossing of the Alps by armies under Hannibal and Napoleon,
has invested the passes which they traversed with an historical
interest ; whilst the skill of engineers has crowned them with
marvels of road-making and mountain railways, and pierced their
iimermost recesses with the principal tunnels of the world,
(riate 6.)

Alpine Passes and Eoads.

Plate 6, Fig. 2.

Some of the Alpine passes were known and used as means of
communication in very early times ; but the first recorded instance
of the conveyance of an army across the Alps was when Hannibal,
marching from Spain for the invasion of Italy in the second Punic
war, siirmounted the pass of the Little St. Bernard. Several of
the passes were known in later times to the Romans, who desig-
nated the highest point of the ascent as " Mons," from which the
prefix "Mont," given to several of these passes, has been derived,
referring to the summit of the pass, and not to neighbouring peaks
of greater altitude. Caesar ai)pears to have crossed Mont Genevre
with an army, to check the incursion of the Helvetii into Gaul ;
and vestiges of Roman works maybe traced on the pass. ^ Augiistus
made a carriage-road across the Little St. Bernard, which Avas
allowed to fall into decay ; but nevertheless, being one of the
easiest of the passes, it could be traversed by artillery and light
carriages ; and it possesses the advantages of its approaches and

' "Passes of the Alps." W. Brockcdoii, vol. i.

238 VERNON-HAECOUKT ON ALPINE ENGINEERING. [Selected

summit, 7,192 feet above the sea, not being exposed to avalanches.
The Brenner pass, on the route between Innsbruck and Yerona
(Plate 6, Figs. 2 and 4), being the lowest of the passes across the
principal Alpine chain, only 4,588 feet above sea-level, was the
first of these passes regularly used by carriages; the first record
of this pass dates back to the year 13 b.c. It was by the Brenner
that Attila led his invading army into Italy; and this was the
route of later barbarian incursions. The Austrians formed a road
over it in early times, to provide proper means of communication
with their jDossessions in Lombardy ; and it was made practicable
for carriages in 1772. The Col di Tenda, with its summit 6,158 feet
above sea-level, the most southern of the Alpine passes, lying on
the road from Turin to Nice, was made j^racticable for carriages
in 1789, and was improved by Xapoleon. A new road has been
formed, passing through a tunnel, 2^ miles long, lighted by elec-
tricity, in place of the numerous zigzags by which the old road
surmounts the pass. These two passes, the Brenner and the
Tenda, lying at almost the extreme limits of the Alpine range,
possessed the only two carriage-roads previous to the commence-
ment of a carriage-way across the Simplon in 1801. The pass of
the Great St. Bernard, situated near the highest peaks of the Alps,
with Mont Blanc to the west, and the Matterhorn and Monte Eosa
to the east, was traversed by the Romans in 100 B.C. ; it was more
used after the foundation of Aosta in 26 B.C. ; and the road was
improved by Constantine in 339. It is now best known from its
hospice at the summit of the pass, 8,120 feet above the sea, and
the bravery of the monks and their dogs in rescuing travellers
from the snow ; and it has been rendered famous by the passage of
Kapoleon across it, in May 1800, with his army and artillery on
his way to the campaign of Marengo. Owing to the difficulties
experienced in this march, when the ordinary obstacles of the
narrow and rugged tra-ck were enhanced by the quantities of snow
•still encumbering the pass, and the danger of avalanches, Napoleon
projected several roads across the Alps, to which he was also
prompted by the desire to provide easier communication befrvi'een
France and the annexed kingdom of Italy. The Simplon pass was
selected for the route of a carriage-road across the Pennine Alps,
constructed in 1801-6, which, though one of the most difficult of
the Alpine passes for the formation of a road, is much lower than
the Great St. Bernard (6,590 feet as compared with 8,120 feet),
and more accessible ; and it provided a much-needed passage about
midway in the Alpine range (Plate 6, Figs. 2, 5 and 9). It is,
however, exjwsed to avalanches towards the summit ; and several

Papers.] VERNON-HARCOUKT ON ALPINE ENGINEERING. 239

galleries and refuges liave been provided for shelter. The pass of
the Mont Cenis, with an altitude of 6,772 feet, lying on the direct
road between Lyons and Turin, and situated about half-way
between the Simplon and Tenda passes, has been the most fre-
quented road between France and Italy (Plate 6, Figs. 1, 2 and 6) ;
portions of the road were very difficult to traverse, even on foot,
in early times ; but the second Duke of Savoy made the worst
portion (known as les echelles) practicable for carriages in 1670;
and Napoleon, by large works, begun in 1803 and completed in
1810, made the road passable at all seasons. A road was also
constructed by order of Napoleon, between 1802 and 180-4, across
the Mont Genevre, on the route between Grenoble and Turin,
situated a little to the south of the Mont Cenis, and rising 6,102
feet above the sea ; but the road contemplated by Napoleon across
the Little St. Bernard, to connect Grenoble and Aosta, was not
carried out, thoiigh a carriage-road has recently been constructed.
The St. Gothard is the next pass of importance to the east of the
Simplon (Plate 6, Figs. 1, 2, 5 and 7) ; it lies on the direct line
between the Lakes of Lucerne and Maggiore, and rises only 6,936
feet above sea-level ; but though used by barbarian hordes in
invading Italy, and the scene of several conflicts between the
French and Austrians in the campaign of 1799, it was not made
available for carriages till 1832. Accordingly, in the early part
of the century, the traffic was diverted to the new and more acces-
sible routes, till the carriage-road, commenced in 1820 by the
Cantons of Uri and Ticino, restored its importance. The road
is in places much exposed to avalanches ; snow-storms and ava-
lanches are most prevalent on the southern side, and the great
snow-drifts do not always entirely disappear in the summer.
Several passes intervene between the St. Gothard and the Stelvio,
further to the east. The Bernardino pass, known to the Eomans,
and having an elevation at the summit of 6,769 feet, was made
accessible for carriages by a road constructed in 1818-24 by the
inhabitants of the Grisons Canton. The Spliigen pass, a short
distance to the east of the Bernardino, rising to an altitude of
6,945 feet, was one of the most frequented roads in the fifteenth
century (Plate 6, Figs. 2 and 5) ; and both it and the Bernardino
were made use of in the campaigns of Napoleon, the passage of the
Spliigen by the army of reserve under Macdonald, in the winter of
1800, being one of the most difficult marches ever accomplished. A
carriage-road was formed over the Spliigen by the Austrian Govern-
ment in 1819-24. These two roads provided more direct com-
munication between western Germany and Lombardy ; and roads

240 VERNON-HARCOUET ON ALPINE ENGINEERING. [Selectea

over the Julier (siimmit-level 7,503 feet), the Maloya (5,942 feet),
and the Bernina (7,658 feet), have since been added (Plate 6,
Fig. 2). The road over the Julier, completed in 1827, is little
exposed to avalanches ; Augustus constructed a military road over
the Julier and Maloya passes, and the road over the Bernina is
the second highest in Europe. The carriage-road over the Stelvio
pass is the highest in Europe, reaching at its summit an altitude
of 9,213 feet above the sea — about 800 feet above the normal limit
of perpetiial snow in those parts, and more than 1,000 feet higher
than the summit of the Great St. Bernard. The construction of
this road, in 1820-25, was dictated by political exigencies, for
connecting the German and Italian dominions of Austria without
passing through foreign territory, as its height, the heavy works
required to protect the approaches to the summit from avalanches,
and the cost of maintenance, would have precluded its selection
for purely commercial purposes.

The road over the Arlberg pass, though not crossing the main
Alpine chain, is of considerable importance in aftbrding direct
communication between Switzerland and the Tyrol (Plate 6, Figs.
1, 2, 5 and 8). The summit of the pass, 5,902 feet above sea-level,
lies on the ridge separating the basins of the Ehine and the Danube.
Several other roads and bridle-jiaths have been formed across the
Alps ; amongst the latter, the most remarkable is the path over
the Gemmi pass, formed in 1736-41, which descends an almost
perpendicular cliff, 1,660 feet high, to Leukerbad, a distance of over
2 miles, by zigzags cut into the rock.

Great skill has been displayed in the tracing of the Alpine roads,
through rugged valleys, exposed in places to avalanches and land-
slips, and crossing torrents which are subject to raj^id floods. The
torrents, however, are confined, for the most part, in their rocky
channels ; and the bridges, by which the roads cross from one side
of the valley to the other, to avoid formidable obstacles, are usually
considerably above the reach of the waters. The grandeur, indeed,
of the adjacent moimtains, and the depth of the valleys, enhance
the appearance of these works ; for the celebrated Devil's Bridge,
on the St. Gothard road, crossing the Eeuss torrent at a consider-
able height has a clear span of only 26 feet. Avalanches are
avoided by carrying the road through covered galleries, or under
overhanging rocks ; projecting points are pierced by tunnels ;
steep slopes are skirted by terraces ; ravines are crossed by high
viaducts ; and the gTadients are regulated, where necessary, by
means of zigzags. The rugged, bleak, and desolate regions
through which these roads pass, the steepness of the sides of the

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 241

deep valleys, and the short period during which works can be
carried on in the higher portions of the passes, give an importance
to these works, which roads formed over hard rock would not
otherwise possess ; and most of these works were executed at
periods when rock excavations and tunnels were exceptional and
difficult engineering works, in the absence of modern appliances.

The great development of travelling, and the demand for rapid
transit, produced by the introduction of railways, soon led to
schemes for extending the facilities of railway communication
across the barriers of the Alps. Locomotives, however, of the
ordinary type could not ascend the steep gradients, nor turn the
sharp corners by which the Alpine roads surmount the passes ; and
accordingly, the crossing of the Alps by railways necessitated
works, the execution of which was delayed by their unprecedented
magnitude and cost.

Semmering Eailway.
Plate 6, Figs. 1 and 3 ; and Plate 7, Fig. 1.

The first railway which surmounted the Alps does not cross the
main Alpine chain, but traverses the outlying Styrian Alps at the
Semmering pass, which is only 3,248 feet above sea-level. The
object of the Semmering railway was to connect Vienna with its
seaport, Trieste ; and the most practicable route lay along the
Semmering pass, whereby any necessity of constructing a long
tunnel was avoided, though the gradients and works were neces-
sarily heavy and costly. The scheme was first considered in 1842;
a definite line was jiroposed in 1844, which was finally approved
in 1848, when the works were commenced; and the line was
completed and opened for traffic in 1854,^ at a cost of about £98,000
per mile for a double line throughout.

The railway ascends the north-eastern slope of the pass, from
Gloggnitz, by contouring the valleys in a winding course (Plate 6,
Fig. 3), going through fourteen tunnels, and passing over sixteen
viaducts,^ before reaching the Semmering tunnel at the summit,

' "Atlas Pittorcsque du Chemin de For du Semmering," Carlo di Gliega,
p. 10, aud plates 1 and 2.

* The tunnels are from 14^ to G64 yards long, with a total length of 3,113
yards. The viaducts are from 33 to 249 yards long, with a total length of
1,620 yards, and from 36J to 150 feet maxima heights; and four of them have
been constructed with two tiers of arches.

[the INST. C.E. VOL. XCV.] 11

242 YEENON-HAECOURT ON ALPINE EKGmEERING. [Selected

1,562 yards long (Plate 7, Fig. 1). This tunnel was constructed
by the aid of nine shafts, of which five were left open, after
completion, for ventilation. The summit-level of the line, 2,892
feet above sea-level, is inside the Semmering tunnel ; and the rise
from near Bayerbach, where the steep gradients commence, is 1,305
feet in 13.V miles, making the average rise 1 in 53j. The average,
however, is reduced by the introduction of level portions, or gentle
gTadients, at the stations and towards the summit ; for the ruling
gradient of 1 in 40 extends over 5V- miles, whilst the next most
frequent gradient of 1 in 45 occujiies 3j miles. The south-western
slope is much less rugged, so that without any special contouring,
no tunnels or viaducts were required to bring the line down to
Murzzuschlag, nearly 7.^ miles from the summit. As the difference
of level in this distance is 710 feet, the average inclination on this
slope is 1 in 55.V, which is less than on the oj)posite side, though the
descent is more rapid near the summit. The worst gradient on this
side is 1 in 41i for 700 yards; three gradients intermediate between
this and 1 in 45 have a total length of over 1 mile ; and the most
frequent and longest gradients are 1 in 45 and 1 in 47, extending
together over 3j miles.

The length of the line between Gloggnitz and Murzzuschlag is
25^ miles ; and the line is curved for veiy nearly half this distance.
Very few of the curves exceed 1 9 chains in radius ; and there
are ninety-six curves of this, or smaller radius extending over
11 J miles, of which the sharjiest curves, thirty in number, have a
radius of only 9^ chains for a total length of 4^ miles.

The gTadients of this line, though not quite unprecedented,
were unusual on main lines in those days ; and as they extended
over several miles almost continuously, and were combined with
very sharp curves, special locomotives were required for traversing
this portion of the line. From the results of trials of various
locomotives submitted for conducting the traffic, Baron Engerth was
enabled to design a locomotive suited to the requirements of the
line.^ The passenger locomotives were able to draw trains of
100 tons, exclusive of the engine, up the inclines at a speed of
11^ miles an hour, and of 115 tons at 9.^ miles an hour, the
respective speeds arranged for passenger- and goods-trains ; whilst
the goods loconiotives, with six wheels coupled, could draw up
trains of 115 and 130 tons at similar speeds res^^ectively ; and a

* " Die lokomotive dcr Staats Eiscnbahn iiber den Semmering," W. Eugcrtli ;
Minutes of Proceedings lust. C.E., vol. xv. p. 353 ; and Zeitsclnift des Oester-
rL-ichischeu lugeuieur- und Arcbilekteu-Vereins. 1854.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 243

modified locomotive subsequently introduced, with, eight wheels
coupled, could draw up a train of 175 tons at the lower speed.^
These loads had to be reduced by one-fourth in bad weather, fogs,
or great cold ; but they could be somewhat increased in ascending
from Murzzuschlag, owing to the more favoured situation of the
south-western slope, and the shorter and slightly better gradient on
that side — a fortunate circumstance, as the greater traffic is in that
direction towards Vienna. The goods-trains, weighing generally
350 tons without the engine, had originally to be taken up in
three divisions ; but with the modified locomotives, they could
be taken in two divisions. For some time it was considered
that the curves of only 9^ chains on the Semmering, sometimes
reversing without the intervention of a straight portion, precluded
the employment of an engine behind the train, to assist the engine
in front, and thus draw and push up a goods-train of 350 tons in
one operation. Some experiments, however, showed that with the
helj:) of a counter-pressure steam, or a vacuum-brake to control the
motion, an engine could be placed in the rear of a train wdthout
any disadvantage. Accordingly, since 1869 this system has been
adopted on the Semmering line, obviating the inconvenience of
dividing the goods-trains, and avoiding accidents from the breakage
of couplings.

The cost of traction is necessarily much heavier on the Semmer-
ing section than on the rest of the line ; but it has been gradually
reduced by increasing the grate-area of the engines, and thereby
diminishing the consumption of fuel, and also by improvements in
the engines, the better utilization of their power, and the reduc-
tion in the price of materials, advantages which have been shared
by the rest of the line. Thus, in 1860, the cost of traction,
including maintenance of rolling-stock, which was 2s. 5d. per
train-mile on the remainder of the southern lines of Austria,
amounted to 3s. 7§cZ. for passenger-trains, and 10s. llfL for goods-
trains, drawn up in three divisions, on the Semmering section.
These prices were reduced by 1865 to Is. 3d. per train-mile on the
whole of the southern lines, and to 2s. 4d. and 4s. Sd. for the
passenger- and goods-trains respectively, on the Semmering, the
goods-trains being separated into two parts. By 1868, the con-
tinuous reduction in price appears to have reached its limit ;
for though the cost per train-mile was Is. 7^d. in 1877 on the
Semmering, as compared with Is. 9^d. in 1868, it had risen

' Memoires de la Socie'te des Ingeuieurs Civils, 1862, p. 117; 1861, p. 208;
1865, p. 241 ; 1866, p. 140; 1867, p. 359; and 1868, p. 477.

u 2

244 VERNON-HAECOUET ON ALPINE ENGINEERING. [Selected

higlier than in 1868 in some of the intervening years ; and on the
other soiathern lines, it was Is. 2},d. in 1877, or higher than the
price of Is. Id. per train-mile in 1868. As, however, the mean
load of the trains rose from 125 tons in 1868, to 132 tons in
1877 on the Semmering, and from 193 tons to 227 tons on the
other lines, the ton-mile affords a fairer standard of the varia-
tion in the cost of traction. ^ The cost per ton-mile decreased
from 0-173^. in 1868, to 0-152(7. in 1877 on the Semmering, and
from 0 069(?. to 0-064d. on the remainder of the southern lines;
but was higher than in 1868 in several of the intervening years.
The above fignires indicate that, as regards cost of traction, the
inclines of the Semmering section are equivalent to the addition
of nearly 50 per cent, to the length of this section to the total
length of the southern lines, or of 26 miles X Ij = 39 miles,
in a total length of l,035j miles, comprising the whole of the
State southern lines of Austria with their branches, and including
the Semmering section. This virtual addition to the length
illustrates the well-known importance of steep gradients in the
relative working expenses of railways, and is a consideration of
special importance in judging of the respective advantages of
different transalpine routes in shortening the distance between
certain points. In this particiilar instance, the addition, which is
\erj large as regards the Semmering section alone, becomes some-
what merged in the length of the whole system, and is, moreover,
somewhat reduced by the existence of other steep gradients across
the Julian Alps near Trieste. It appears to have been imagined
that another line connecting Vienna with Trieste, by a detour of
110 miles, opened in 1868, would have diverted the heavy traffic
from the Semmering. This might have occurred if the cost of trac-
tion and method of working on the Semmering inclines had remained
the same as in the earlier years ; but the improvements in these
respects had become so great by 1868, that the Semmering route
was able to compete successfully with the new line ; and instead
of a reduction in traffic, the distance run by passenger and mixed
trains, on the Semmering section, rose from 61,010 miles in 1868,
to 80,034 miles in 1877, and by goods and military trains, from
171,800 miles in 1868, to 271,567 miles in 1877, in conjunction
wdth a steady gradual increase in the gross average load of the
trains.

Though the railway does not ascend as high as 3,000 feet above
the sea, the trains on the Semmering are sometimes impeded by

' Memoircs de la Societe' des Ingc'nieurs Civils, 1878, p. HO, and Table 10.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 245

snow ; and the average annual cost of clearing the line from snow
lias been reckoned at £13 8s. per mile.

The Semmering railway serves also to connect Vienna with
Italy by means of a line which, crossing the eastern Alps, and
reaching the summit-level at St. Lambrecht, only 2,917 feet above
the sea, descends by Tarvis to Udine in Italy, and thence proceeds
on to Verona and Bologna (Plate 6, Fig. 1).

Brenner Eailway.
Plate 6, Figs. 1 and 4 ; and Plate 7, Fig. 2.

The success achieved in crossing the Semmering led the
Austrian government, in 186-i, to embark upon the more formid-
able enterjirise of crossing the main chain of the Alps, to provide
railway communication between the Tyrol and Venetia, and the
rest of the empire (Plate 6, Fig. 1). The route selected was
naturally the Brenner pass, which, besides being suitably situated
between Innsbruck and Verona, is the lowest of the main Alpine
passes, and, lying at a distance from the highest peaks, is freer
from snow than the others. The slopes on each side of the ridge
are such that, by contouring the hills with curves having a
minimum radius of 14 J chains, it was possible to attain a summit-
level 4,497 feet above the sea, 91 feet lower than the pass of the
road, with gradients not exceeding 1 in 40 on the northern slope,
and 1 in 44 on the southern slope, and without any tunnel at the
summit (Plate 6, Fig. 4 ; and Plate 7, Fig. 2). The works were
commenced in March 1864, and the line was opened for traffic in
August 1867. The line is double between Innsbruck and the
Brenner station at the summit, with the exception of a portion
of single line, 2^- miles long, between Matrei and Steinach, where
the gradients are less steep ; but it is single on the opposite side
of the summit, between the Brenner Station and Botzen, except
from Franzensfeste to Brixen, where there is a double line for
6.\- miles. ^ The total length of the line from Innsbruck to
Botzen is 78?, miles, of which only 26? miles are laid with a
double line.

The railway rises 2,586 feet between Innsbruck and the summit,
in a distance of 23 miles, with gradients of 1 in 40 along 17^

' Nearly 50 miles of the heaviest portion of the line appear to have cost about
£70,000 per mile, considerablj^ less than the Semmering line, which, however, is
a double line throucrhout.

246 VERXON-HAKCOUKT ON ALPINE ENGINEERING. [Selected

miles of this length, so that even with the levels, or flat
gradients, at the stations, and the easier gradients between Matrei
and Steinach, the average gradient between the Innsbruck and
Brenner stations amounts to 1 in 46 • 88. This portion of the line
passes through fourteen tunnels ; the length of the longest is
948 yards ; and their total length is 3,839 yards, some of them
being very short. The descent from the sxammit to Botzen
amounts to 3,624 feet, in a distance of 55^ miles, giving a mean
inclination of 1 in 80-86; but the steepest gradients occur between
the summit and Sterzing, where the fall is 1,385 feet in 13i^ miles,
or an average gradient of 1 in 52 • 54, the maximiim gradient, on
the southern slope, of 1 in 44, extending over 10| miles of this
length. In the next 18 miles, between Sterzing and Brixen,
the fall is 1,240 feet, so that the average gradient along this
section is reduced to 1 in 76*74; and the 1 in 44 gradient only
occurs along a length of 5i miles, with about § mile of 1 in 46,
and 1 mile of 1 in 50. There is a fall of only 999 feet in the
23| miles from Brixen to Botzen, making the average gradient 1 in
125 '21 ; and the steepest gTadient on this portion is 1 in 67, for a
length of 5i miles. There are three tunnels between Brenner and
Sterzing, with a total length of 1,038 yards, of which one is
832 yards long ; and there are five tunnels between Brixen and
Botzen, having a total length of 823 yards, one being 426 yards
long. No tunnels occur between Sterzing and Brixen ; so that as
regards both gradients and works, the southern slope is more
favoiirably circumstanced than the northern slope. The line is
curved along nearly half its length; the sharpest curves of 14,V
chains have a total length of 91 miles, or nearly one-eighth of the
whole distance ; and 4^ miles of this length occur between
Innsbruck and the summit.^ The line is laid with Bessemer steel
rails, weighing 65|- lbs. per yard, on wooden sleepers ; and admits
of locomotives with 13J tons on a pair of wheels running over it.
The locomotives employed are similar to the improved Semmering
types. The express passenger-trains are drawn up the inclines by
an engine with six wheels coupled, at a speed of lo^ miles per
hour, and descend at a speed of 233- miles an hour. The mixed
trains and goods-trains, drawn by engines with eight wheels

• Full particulars of the gradients and curves, with the exact length of each,
and of the tunnels, between Innsbruck and Botzen, together with a longitudinal
section of the railway, are in the library of the Institution, having been furnished
by IMr. Karl Jenny, in response to iinjuiries made by the Author through Mr.
Forrest, Sec. Inst. C.E.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 247

coupled, ascend and descend at a rate of from 9.\ to Hi miles
an hour, the weight of the train being 200 tons. Owing to
the easier curves on the Brenner than on the Semmering, heavy
goods-trains were always taken up the Brenner inclines in one
piece, by engines at each end of the train ; so that, in 1867, a train
of 3G9 tons, with two engines and tenders weighing 131 tons,
making a gross load of 500 tons, surmounted the incline. The
sharp curves, however, on the Semmering aided the brake-power
in the descent ; so that the working of the trains in descending
the Brenner was more difficult, till improved brake-power on the
Le Chatelier system was introduced.

The traffic on the Brenner line increased steadily during the
first ten years of its existence, the number of miles run by pas-
senger and mixed trains having risen from 125,154 miles in 1868,
to 229,398 miles in 1877, and by goods and military trains, from
154,639 miles to 310,535 miles; whilst the gross mean load of the
trains increased from 100 tons in 1868, to 138 tons in 1877. In
comparing the Brenner railway with the Semmering, it must be
remembered that the working of the Brenner was commenced with
the great advantage of fifteen years' experience on the Semmering.
The cost of traction on the Brenner, which was Is. lO^d. per
train-mile in 1868, or Id. higher than on the Semmering in the
same year, was reduced to Is. Gd. in 1877, or l^d. less than on the
Semmering at the same period. The cost per ton-mile, however
which forms the proper basis for comparison, shows a more steady
and greater reduction, owing to the considerable rise in the train-
loads, having fallen from 0-178tZ. in 1868, to O-OQld. in 1877,
slightly greater than the similar cost on the Semmering in the first
year, but less than two-thirds of the cost on the Semmering in the
latter year.^ This latter difference may be attributed mainly to
the good loading of the trains in both directions on the Brenner,
whilst the main traffic on the Semmering is from Trieste to
Vienna ; and also to the Brenner railway being three times the
length of the Semmering railway, which reduces the proportionate
expenses, and to the curves being easier, and the total average
gradient lighter on the Brenner than on the Semmering, namely,
14i-chain curves, instead of 9.V chains, and 1 in 66*7 average
gradient as compared with 1 in 60 • 7.

The reduction in cost of traction, between 1868 and 1877, was
still greater on the rest of the Tyrolese lines than on the Brenner,
having fallen from O-l-ild. per ton-mile in 1868, to O-OG'Id. per

' Mcmoiios dc la Socicte des lugeuicurs Civils, 1878, p. 110, aud TaMc ^<'.

248 VERNON-HAECOUET ON ALPINE ENGINEERING. [Selected

ton-mile in 1877, partly owing to the increase in the aA'erage
train-loads from 121 tons in 18G8, to 209 tons in 1877. In the
latter year, the cost of working on the Brenner was about half
as mnch again per ton-mile as on the rest of the Tyrolese lines ;
so that the Brenner gradients were equivalent, in this respect,
to an addition of 39 miles to the whole system. This length is
identical with the virtual addition of length due to the Semmer-
ing gradients and curves at the same period, in spite of the much
greater actual length of the Brenner railway, owing to the great
reduction in cost of traction on the Brenner ; so that under
the conditions existing in 1877, the 78^^ miles of steep gradients
on the Brenner did not add more to the cost of traction per ton-
mile than the 25 \- miles on the Semmering. The above addition,
however, only relates to the cost of working, and not to the time of
transit, which is aifected by the length of the ascending gradients,
and has an important influence on the route to be preferred for the
mails and express passenger-trains. The Brenner railway has a
much more considerable bearing on the Tyrol system, of which it
forms part, than the Semmering on the southern State railways,
owing to the comparatively short length of that system, which
comprised only 190 miles of railway altogether in 1877, the Brenner
line accordingly being about two-fifths of the whole.

The Brenner railway, besides being the first to cross the main
barrier of the Alps, has its summit-level higher than any of the
lines which have hitherto been constructed across the Alj)s, with
the exception of the temporary Fell railway; for the summit-
level in the Mont Cenis tunnel is 10-i feet lower, in the Arlberg
tunnel 198 feet lower, and in the St. Gothard tunnel 711 feet
lower, than at the Brenner (Plate 7, Fig. 7). It also retains the
peculiarity of being the only Alpine railway without a tunnel at
the summit, which the moderate elevation of the j^ass, and its
favourable position, rendered it possible to dispense with.

The Brenner railway not only connected Austria with its
TjTolese possessions, and with Yenetia, which it lost before the
completion of the line, but also placed Germany in direct railway
communication with Northern Italy, and with the port of Brindisi,
and thus established a very valuable link between northern and
southern Europe.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 249

Mont Cenis Fell Eailway.
Plate 6, Fig. 2.

When the passage of the Alps by railways was contemplated,
attention was naturally directed to the principal passes, which
afford the easiest and most direct access by road between various
places. No other pass, however, across the main Alpine chain,
except the Brenner, is suitably situated at a low enough level to
enable an ordinary railway to be carried over the summit ; for the
line of the celebrated Corniche road, avoiding the Alps in entering
Italy by skirting the sea-coast, is too circuitous to be of more than
local importance in providing railway communication between
Marseilles and Genoa, and to the intervening towns. Accordingly,
the Alpine railways have gradually been carried up the valleys
on each side of the principal passes, till at length the exigencies
of through traffic have led to schemes for traversing the gaps
between the two ends of the several lines, by a railway rising with
steep gradients, and piercing the insurmountable intervening
ridge by a summit tunnel of considerable length.

The Mont Cenis pass, forming the main line of communication
between France and Italy, was proposed for the route of an
Alpine railway in 1 852 ; but the uncertainties attending the con-
struction of a tunnel over 7^ miles long, through the hardest strata,
without shafts, delayed the commencement of the works till 1857.
The piercing, however, of the tunnel by hand labour, at the
beginning, progressed so slowly that Mr. Fell, in 1863, revived
the idea, first suggested in 1830, of using horizontal wheels on
a locomotive, gripping a central rail, for obtaining additional
adhesion, and thus enabling trains to travel safely over very steep
inclines and sharp curves. Mr. Fell jiroposed to utilize this
system for traversing the break in the line between St. IMichel
and Susa, a distance of 48 miles, by constructing a railway of this
type along the Mont Cenis road. After two experimental trials,^
the first on the High Peak Eailway in Derbyshire, in 18G3 and
1864, and the second on a portion of the Mont Cenis road,'^ 1^^ mile
long, in 1865, permission was obtained to construct the line for
conveying the traffic till the completion of the tunnel. When

' Minutes of rroceedings lust. C.E., vol. xxvi. p. 313 ; Report of the Meetiug
of the British Association in 1866, p. 143; and Ecport on the Mout Cenis Eail-
way to the Board of Trade by Capt. Tyler, R.E., 1865.

' Auuales des Pouts et Chaussees, 4th series, vol. xi. 1866, p. 95, plate 116;
and "Etudes sur la loeomoliou au moyeu du Kail Central," M. Desbrierc, 1866.

250 VERNOX-HARCOURT ON ALPINE ENGINEERING. [Selected

the works were commenced, in March 186G, it was supiDosed that
the line would be open for traffic in about a year ; whilst it was
estimated that the tunnel would require over eleven years more
for its completion.^ The estimated cost was £320,000 ; and it was
calcTilated that, with only seven years of working, the railway
would, beside paying 7 per cent, per annum interest on the
capital, both repay the capital expended, and also leave a hand-
some margin of profit for division on winding uj) the company at
the opening of the tunnel.'^ None of these golden anticipations,
however, were realized. The completion of the railway was
delayed by an unusually high flood of the Arc in the autumn of
1866, which not only washed away portions of the railway, but
also did much damage to the road for some miles above St. Michel.
The railway followed the road, except in a few places where
diversions were made to obtain a more uniform g-radient, and to
avoid villages ; it occupied 13 feet in width of the outer portion
of the road, and was laid to a gauge of 3 feet 7f inches, with
curves having a minimum radius of 2 chains, the central rail, laid
on its side, being raised 7.j inches above the ordinary rail-level.
The maximum gradient of the line was 1 in 12 ; but the greater
portion of the slope on the French side is so much gentler than
on the Italian side, that the mean gradient from St. Michel to
Lanslebourg, a distance of 24 miles, was 1 in 60, with a very-
short length of 1 in 12; whereas, for the remainder of the ascent
from Lanslebourg, at the turn of the road some distance beyond
Modane, to the summit, 6,772 feet above sea-level, and in the descent
to Susa, the average gTadient was 1 in 17, and the j^revailing
gradient 1 in 12, as only at two places, one near the summit and
the other close to Susa, did the gradient exceed 1 in 25. The
rise from St. Michel to the summit is about -±,600 feet ; and the
fall from the summit to Susa about 5,300 feet. The central rail
was laid along all gTadients exceeding 1 in 25. The railway
passed through 9 miles of covered way, to protect it where most
liable to snow-drifts, made of masonry where exj^osed to avalanches.
The first train was taken over the line in Aiig-ust 1867 ; but
owing to defects in the working of the locomotives first em-
ployed, and other causes, the railway was not actually opened
for traffic till June 15th, 1868, when an engine, weighing 22 tons
when loaded, drew a train of 17 tons from St. Michel to Susa,
the time occupied in transit, exclusive of stoppages, being four

* Engineering, vol. i. p. 7.
- The Eiifjiiuei; Jau. 18(y(;, p

Papers.] VERNON-HARCOUKT ON ALPINE ENGINEERING. 251

hours and fifty minutes, or a rate of 10 miles an liour.^ The
railway was worked regularly from this time till the opening- of
the tunnel line in September 1871, with only a few interruptions,
once by torrents of rain two months after the opening, and two or
three times by snow; but for a time the want of sufficient loco-
motives hampered the traffic. The trains ran with remarkable
freedom from accident, by aid of the central rail and brakes, in
spite of the steep inclines and very sharp curves, for the only
casualty during the working of the line was a goods-train leaving
the line, owing to the negligence of the engine-driver in reversing
his engine, for returning down the incline on a stormy night,
without first applying the brakes. The greatest load taken over
the railway was a train weighing 36 tons, and the heaviest loco-
motive employed weighed 26 tons.

The financial resiilts of the enterprise were naturally not satis-
factory, for the limited life of the railway was shortened at the
beginning by delays in opening, and at its close by the increased
rate of progress of the tunnel, so that the railway was only in
operation for about three and a half years, instead of the antici-
pated seven to ten years. Moreover, during that period consider-
able modifications in the locomotives, and additions, proved
necessary ; and the working expenses were very heavy, owing to
the frequent repairs of the engines, which experienced great wear-
and-tear in going round the very sharp curves, and the cost of
keeping the line clear of snow in the winter. The cost of con-
struction also had risen to about £450,000, an increase of two-
fifths over the original estimate.'^ The railway, too, never quite
sujDcrseded the diligences, for in the last complete year of its
working it carried twenty-eight thousand passengers, out of a
total estimate of forty-two thousand persons annually crossing the
Mont Cenis, or two-thirds only of the whole number.^ In con-
sequence of these various causes the railway never paid a dividend,
and a large portion of the original capital was sunk.

From a purely engineering point of view, the railway over the
Mont Cenis was a decided success ; it proved that a railway could
be worked in perfect safety on the steep inclines, and over the
lofty summit of an Alpine road ; it efi'ected a saving of about six
hours in the transit as compared with the diligences, and it enabled
an accelerated mail-service to India, via Brindisi, to be established

Enrjineering, vol. v. pp. 598 aud 620.

Ibid., vol. vii. p. 10.

The Engineer, Oct. 1871, p. 231.

252 VERNON-HAECOUET ON ALPINE ENGINEERING. [Selected

more tlian a year earlier than would otherwise have been prac-
ticable. If the scheme had been started in 1852, when the Mont
Cenis route was first proposed, instead of when the tunnel works
had made considerable progress, it is possible that the adoption of
a long tunnel might have been deferred ; and in any case the
railway would have had ample time to pass completely beyond
the experimental stage, and to acquire engines fully adapted to
its requirements, and would have had a fair prospect of financial
success.

Though the suggestions, made at various times, for crossing the
Simj)lon, St. Gothard, and Lukmanier passes by a Fell railway, in
preference to a long tunnel, so as to reduce the capital cost, have
not met with approval, the experience gained on the Mont Cenis
has not been fruitless. The central-rail system has subsequently
been adopted for steej) inclines on the Wellington and Feather-
stone Eailway, in New Zealand,' and on an extension of the
Cantagallo Eailway in Brazil.- The New Zealand line, with a
3 feet 6 inches gauge, ascends a continuous gradient of 1 in 15 for
about 2^ miles, for crossing the Eochfort saddle, with curves
having a minimum radius of 5 chains, and a train weighing
53 tons is drawn tij) by an engine of 36 tons ; whilst the saving in
capital cost by the adoption of the steep gradient, instead of an
ordinary line, was estimated at £100,000. The Brazilian line
crosses the Serra about 3,000 feet above the Cantagallo Eailway,
rising to this altitude in about 10 miles, with gradients of from
1 in 20 to 1 in 12, and with curves round the projecting spurs of
from 2 to 5 chains radius, and descending with easier gradients to
Nova Friburgo. The gauge of this line is 3 feet 7-^ inches, like
the Mont Cenis ; and the locomotives used on it resemble the latest
type of the Mont Cenis engines, with the machinery of the
ordinary and of the horizontal wheels disconnected, which made
the working much easier, and with further improvements.^ It
was anticijjated that these new locomotives would effect a large
reduction in the cost of working, which amounted to 5s. per train-
mile on the Mont Cenis. The system has also been recently
proposed for carrying branch railways over the Tenda and Genevre
passes, for which the cost of long tunnels could not be entertained
(Plate 6, Figs. 1 and 2). The central-rail system has the advantage
of effecting a very considerable saving in capital cost in mountainous

' IMiuutcs of Proceedings Inst. C.E. vol. Ixiii. p. 50.

■ lleport of the Meeting of the British Association in 1870, p. 210.

^ 3Icmoires de lu tfociete des IngJuieurs Civils, 1S72, p. 118, and 187(5, ]). 155

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 253

districts, with, in some cases, as on the Xew Zealand line, a rednctiou
in length as well. On the Mont Cenis railway the length was 6}} miles
greater than by the tunnel-line, and the time of transit ahout four
hours more, taking into account the time spent in trans-shipment.
But the saving in cost, even for a more solid and more efficiently pro-
tected permanent surface-line (estimated by Mr. Fell to cost £20,000
a mile) would have been very large as compared with the tunnel-
line. Against this saving must be set off the additional cost of
working with special engines, and the lower speed ; the cost of
clearing the line from snow, at the greater heights in Alpine
regions, and the probable interruptions of traffic by storms and
snow-drifts ; the delays and inconvenience of a double trans-ship-
ment, unless the line was made to the ordinary gauge; and the
smaller loads which could be conveyed, necessitating a division of
the trains, and involving a considerably less capacity for traffic.

Considerations affecting Main Lines through the Alps.

A variety of circumstances have to be considered in determining
the proper routes for railway communication across the Alps.
Besides selecting the lines of greatest probable traffic, it is essential
that the shortest and easiest route should be adopted, as far as
physical conditions will permit, otherwise a competing line may
be constructed, and divert the traffic which has been secured at a
large cost. Moreover, the gradients of the approach railways,
on each side of the Alps, as well as of the connecting line, must
be taken into account, as a more circuitous route with lighter
gradients may be able to convey the traffic at a lower cost ; and a
large outlay on the connecting line may prohibit an adequate
lowering of the rates to attract the traffic which should naturally
pass over the system. Eapidity and regrxlarity of transit attract
passengers, and low rates determine the route adopted for goods ;
and these are incompatible with heavy gradients, exposed situations,
and a large capital cost. In deciding between two or three
adjacent passes, the height to which the line must ascend in the
open air, the nature of the works with the practicable gradients
and curves of the lines of access, and the length of the summit
tunnel, and its maximum depth below the surface must be con-
sidered. If the railway is carried high up the valleys, on each
side, before entering the summit tunnel, the gradients must be
made steeper and the curves sharper, or the works heavier, as the
slope of the valley increases on ascending, and the railway is much

254 YErtNOX-nARCOURT ON ALPINE ENGINEERING. [Selected

more liaLle to l)e blocked with snow ; -whilst if the tunnel is
entered at a comparatively low level, the tunnel is longer, and
the internal heat in the tunnel, towards the centre, during con-
struction is gTeater, owing to the increased depth below the
surface. The limit of height for an open line, in the centre of the
Alps, appears to have been reached by the Mont Cenis railway,
4,270 feet above sea-level ; for this line, and also the St. Gothard,
with a maximum height outside the tunnel of only 3,756 feet
above the sea, have been occasioiaally blocked by snow. The
limit of depth below the surface appears to have been nearly
attained in the St. Gothard tunnel, where the heat during con-
struction became trying to the workmen, with a maximum depth
below the surface of 5,733 feet. A divergence of opinion, however,
on these points is exhibited in some of the proposed schemes for
traversing the Alps ; for the open portion of the Great St. Bernard
route would greatly exceed the first limit, with the object of
avoiding the second ; whilst the Mont Blanc route, though much
below the height of the Mont Cenis, would have the depth of its
tunnel, below the highest peak, nearly twice the maximum depth
of the St. Gothard tunnel (Plate 7, Fig. 7). Assuming other
conditions to be similar, the preference should undoubtedly be
given to a low-level route, provided the length of tunnel is not
much greater, and the internal heat not likely to be excessive, as
moderate gradients, a smaller ascent, and immunity from interrup-
tion of traffic, are important factors in the competition for traffic.
The distance also between the ends of the completed railways, on
each side, has a bearing on the choice of route, as affecting the
cost of the reqixisite connecting link.

It is impossible that many lines across the Alps could all afford
an adequate return for the large cost which each would necessitate,
and therefore it is the more important that the lines selected should
be the best attainable. Not only, however, have the interests of
the two countries, which are to be connected by the proposed
railway, to be consulted, but if the line is to pass through Switzer-
land, the approval of that country is essential. Moreover, the
success of the line depends, not merely upon the traffic between
the two or three countries combining to construct it, but especially
upon the throiigh traffic from other countries it may attract. The
Brenner line, though lying wholly in Austrian territory, profits
largely by the through traffic between Germany, Italy, and the
sea-coast. The Mont Cenis line also, connecting France and Italy,
obtained a considerable through traffic between north-western
Europe and Italy, and with the East via Brindisi, though some of this

Papers.] VEUNON-HARCOURT ON ALPINE ENGINEERING. 255

traffic was diverted from Marseilles. These two first Alpine routes
appeared marked out Ly nature for serving central and western
Europe without any antagonism ; but when a third intermediate
route was proposed, various alternative schemes were suggested.
The St. Gothard line, which was given the preference by the in-
fluence of Switzerland and Germany, has gathered its traffic from
regions formerly served, more or less, by one or other of the older
lines; it is acknowledged that the St. Gothard has drawn away a
considerable amount of traffic from the Mont Cenis line ; and it has
])robably affected the traffic on the Brenner railway. The injury,
indeed, to French trade by the diversion of traffic from France into
Belgium and Germany, by the opening of the St. Gothard railway,
has been so marked, that a fourth Alpine line is proposed, which,
whilst improving the means of communication of certain districts,
is mainly designed to compete with the St. Gothard, and to bring
back into France a portion of the traffic which originally passed
])y the Mont Cenis. Accordingly, the novel element of regulating
the balance of national trade has been added to the considera-
tions affecting Alpine routes.

Mont Cenis Eailway and Tunnel.
Plate 6, Fig. G, and Flate 7, Fig. 3.

As early as 1840, Fourneaux to Bardonneche was recognized as
the proper direction for a sub- Alpine tunnel to connect France and
Italy; but the first definite proposal for the construction of the
tunnel was made in 1852, and the works were only commenced
in 1857.

Mont Cenis Railway. — The railway across the Mont Cenis had to
connect the French terminus at St. Michel with the Victor
Emmanuel Eailway at Bussoleno, the junction for the branch line
to Susa about 5 miles distant. The section of the Mont Cenis
railway fairly resembles, in its general outline, the section of the
Brenner line (compare Plate 7, Fig. 3 with Fig. 2), though the
necessity for a long summit tunnel completely modified the
conditions of its construction. The railway had already commenced
the ascent before reaching St. Michel ; for the portion between
St. Jean de Maurienne and St. Michel j^asses through three tunnels,
and has some gradients of 1 in 5U to 1 in 37^ on it, with an
average gradient of 1 in 70, rising 577 feet in about 7?- miles
(Plate 7, Fig. 3). The distance between St. Michel and Bussoleno
is 4G^ miles; the rise from St. Michel to the summit, inside the

256 VEHNON-HARCOURT ON ALPINE ENaiNEERING. [Selected

tunnel, is 2,061 feet in nearly 17 miles, and the fall from the
summit to Bussoleno is 2,806 feet in 29j miles, giving an average
gradient of 1 in 43 • 3 on the French side (reduced to 1 in 49 • 1 if
reckoned from St. Jean de Maurienne), and 1 in 55 on the
Italian side. The steepest portions of the line are near the
Fourneaux entrance, and in the tunnel on the French side, where
gradients of 1 in 43_j to 1 in 38 ^ are continuous for 5 miles, and
between Salbertrand and Bussoleno, where the gradients average
1 in 38 for 13 miles. There are 4i miles of gradients of 1 in 40 ;
and steeper gradients than 1 in 40 extend over 6^- miles on the
French side, and lOj miles on the Italian side, the steepest
gradient on the line being 1 in 33^ for a total length of 7| miles,
of which 5f*Q miles are on the French side, comprised mainly
between St. Michel and Lapraz. There are fourteen tunnels
between St. Jean de Maiarienne and the Mont Cenis tunnel, with
a total length of 4,789 yards, one having a length of 1,143 yards,
and the rest ranging between 743 yards and 61 yards. The works
on the Italian slope are considerably heavier, for the line passes
over eight viaducts, and through twenty-six tunnels in the 25
miles between the Bardonneche end of the tunnel and Bussoleno.
These tunnels have a total length of 8,835 yards, the longest being
1,933 lineal yards, two others 1,203 and 1,196 yards long, and the
remainder from 588 to 49 yards in length. The line is not so
tortuous as either the Semmering or the Brenner railway, there
being only one decided loop close to the Fourneaux entrance to the
tunnel (Plate 6, Fig. 6) ; but it is curved for three-sevenths of its
length. The curves are sharpest on the French side, for on that
side, the most frequent curves of 24 • 8 chains extend over a length
of about 03- miles, three curves of 20 and 17^ chains have a total
length of over ^ mile, and there is one curve of 17 chains radius
in the loop betAveen Modane and Fourneaux f mile long ;
whereas, on the Italian side, the curves of 24*8 chains occupy
only 626 lineal yards, and there are only three sharper curves,
with a radius of 23 • 8 chains, having a total length of h mile.^

Comparing the Mont Cenis railwaj^, between St. Jean de Mau-
rienne and Bussoleno, with the Brenner railway between Innsbruck
and Brixen, it appears that the average gradient throughout is
slightly steeper on the Mont Cenis than on the Brenner, 1 in 52

' Full particulars of the gi-adients and curves, with their respective tenths,
together with some indications of the tunnels, viaducts, and bridges, are given in
a longitudinal section of the railway between St. Jean de Maurienne and
Bussoleno, in the library of the Institution, presented by Mr. Jules Michel, in
response to a request made by the"^ Author through Mr. Forrest.

Papers.] VERNON-HARCOUET ON ALPINE ENGINEERING. 257

as compared with 1 in 55 • 5, but for a somewhat shorter distance,
53| miles instead of 5-lf miles. The ruling gradient also of the Mont
Cenis is 1 in S'A^, whilst on the Brenner it is 1 in 40, and the ap-
proach works are considerably heavier on the Mont Cenis ; but on the
other hand, the curves are much easier on the Mont Cenis, for no
curves on the Mont Cenis are as sharp as the curves of 14^ chains
so common on the Brenner, and extending over a much gTeater
distance than the most frequent curves of 24-8 chains on the
Mont Cenis (See Appendix).

Mont Cenis Tunnel. — The first long tunnel through the Alps has
generally been designated as the IVIont Cenis tunnel, on account of
its aiibrding the same communication by railway which was
formerly effected by road over the Mont Cenis pass. But though
the railway skirts the road from St. Jean de Maurienne to Modane,
it shortly after diverges, and entering the tunnel at Fourneaux,
follows a south-south-easterly course, passing under the Col de
Frejus at the French boundary, several miles south-south-west of
the Mont Cenis pass, and emerging at Bardonneche in Italian
territory (Plate 6, Fig. 6).

The Mont Cenis tunnel was driven in a perfectly straight line
from each end, thereby reducing as far as possible the chances of
error in direction, but with gradients of 1 in 43^ on the French
side, and 1 in 2,000 to 1 in 1,000 on the Italian side, rising from
the Fourneaux end to attain a higher level on the Italian side, and
from the Bardonneche end solely to ensure a fall for drainage. The
straight tunnel was subsequently joined, at short distances from its
extremities, by two curved tunnels to the approach lines on each
side, increasing the actual length of the tunnel, as used for traffic,
from 7"6 miles to 7 "97 miles; the curved tunnel at the French end
was made 464 yards long, to a radius of 24 • 8 chains and a gradient
of 1 in 43^, and at the Italian end, 891 yards long, with a portion
to the same radius, and a gradient of 1 in 33^. The exact line of
the straight tunnel was determined by very careful triangula-
tion, and indicated by marks along the surface ; and it was
maintained by lines given from observatories established in the
direct line on the further side of the valleys opposite each end of
the tunnel.

The work of driving the heading at the face of the tunnel,
which Avas commenced at Ijoth ends towards the close of 1857,
progressed very slowly till the Sommeiller boring machines were
introduced, in 1861 at the south end, and in 1863 at the north
end ; the greatest advance made in one year at both ends by hand
boring being 502 lineal yards in 1858, as compared witli 1,788

[tIIK INST. C.E. VOL. XCV.] S

258 VEENOX-HAKCOURT ON ALPINE ENGINEERING. [Selected

yards in 1870, the year of greatest progress with the machines, the
strata penetrated at both jieriods being schist. The upper
diagram (Fig. 1) shows the yearly rate of progress of the advanced
lieadings at each end, from the commencement at the close of 1857
till the headings were joined on the 25th of December 1870, and
the strata through which they were driven, together with the
temperatures observed in the tunnel on the Italian side during
construction. The rate naturally varied according to the strata ;
and after the introduction of the machines, the greatest and the
least monthly advance occurred on the French side, amounting to
12-9 feet per day in May, 1865, when traversing carbonaceous
schist, and to only 1'17 foot per day in April, 1866, through
quartz; whilst the total advance in 1866 was only 232 lineal yards
at the northern forehead, being Avholly in quartz, and 901 yards at
the southern forehead through calcareous schist. Two years later, in
1868, the progress was greatest at the northern forehead (745 yards
as compared with 698 yards) when both the headings were
traversing calcareous schist ; but, as a rule, a better rate was
maintained in the southern portion, which was solely in calcareous
schist, than in the northern portion where the strata varied. The
perforators were worked by compressed air, the air being
compressed by water-power at each end of the tunnel. The
machinery emjdoyed, the method of driving the headings, the
stages of enlargement, and the cross section and lining of the
tunnel have been fulty described, and particulars of its cost have
been given, in two Papers by Mr. T. Sopwith,^ M. Inst. C.E.

The tunnel proved to be 15 yards longer than calculated, and
the heading on the French side 1 foot too high in level, jirobably
a result of the miscalculation of length ; but the direction was quite
correct. The driving occujiied thirteen years and one month ; and
the average daily progress was 2*57 lineal yards. The total cost of
the tunnel, amounting to £3,000,000, was equivalent to about £224
per lineal yard. According to Mr. Sopwith's estimates in 1863, the
introduction of machinery increased the cost of driving the
advanced heading's nearly in as large a proportion as it improved
the rate of progress ; but the machinery was novel and on a large
scale ; and it is certain that with the improvements effected in the
machinery, and the increased advance, the cost of the machine

' IMiinites of Proccediugs lust. C.E., yoI. xxiii. p. 258, .iiid vol. xxxvi. p. 1.
Further details will also be found in " Traforo delle Aljii tra Bardouuecbe o
Modanc,Kclazionc," Torino, 18G3. G. Sommeiller ; Annales dos Fonts et Cliaussccs.
4th seri(!8, vol. v. p. 1 and plates 37 to 40 ; and Engmecrimj, vols. xi. and xii.
" The Mont C'enis Tunnel," bv Francis Kossuth.

Papers.] VERNON-HAECOUBT ON ALPINE ENGINEERING. 259

. (879

*■ - XiX- ' -

. '880 1

LANGEN

° MICA

-ECM

■2 «l

:"!-.

PT.O.i'

9CM

oy/M

f^ ST ANTON

260 VERNON-HARCOURT ON ALPINE ENCxINEERING, [Selected

work must have been considerably reduced before tbe close of the
works. The large cost at first was due to the novelty and
experimental nature of the work ; and the above cost per lineal
yard must by no means be regarded as the actual cost at a later
stage of the work, for it is supposed that the contractors made a
profit of over 100 per cent, on the 4,798 yards of tunnel remaining
to be constructed in 1867, let to them at £167 12s. per yard. The
experience, however, of the application of boring-machinery
worked by compressed air at the Mont Cenis tunnel, though
purchased by the French and Italian Governments at a high cost,
has been most vahiable for subsequent similar works. Whereas,
also, the slow progress of the tunnel works, during the earlier years,
diverted attention for a time to the more novel and more visiljle
works of the Fell railway, yet as soon as the success of the tunnel
was established, a great impetus was given to other similar
schemes. The railway was opened for trafiic towards the end of 1871,
nearly fourteen years after its commencement, the longer duration
of the works of the Mont Cenis railway than of the Brenner
railway, by about eleven and a half years, being wholly due to the
construction of the summit tunnel.

Owing to a gradual settlement of the recent glacial deposits at
the Fourneaux end of the tunnel, and consequent dislocation of the
tunnel near its entrance, a new curved entrance, 1,718 yards long,
was driven through the carbonaceous schist, clear of the glacial
deposit, in 1879-81, which shortened the total length by 252
yards. ^

To promote the ventilation of the tunnel, the air-compressing
machinery was left at Bardonncche to supply air under pressure
in an 8-inch pipe, laid all along the tunnel, from which it coiild
be drawn through cocks at intervals when required ; and the
exhausters, which had been employed at the Fourneaux end for
drawing out the foul air from the tunnel during construction, were
maintained for drawing air along a passage, laid at the bottom
of the tunnel, through apertures opened at pleasure in diflerent
parts of the tunnel.^ The ventilation thereby afforded is very
inefficient, except near the ends of the tunnel where it is least
wanted ; but fortunately natural ventilation, j^artly due to
differences in the atmospheric conditions at the two ends of the
tunnel, partly to the greater heat towards the centre, and

' Minutes of Proceedings Inst. C.E., vol. Ixvi. p. 41.3.

^ Ibid., vol. liii. p. 1G4; iind Rapport des Experts siu- le rerecnient dn
Simi>lon. p. 24.

Papers] VERNON-HARCOURT ON ALPINE ENGINEERING. 261

occasionally to the wind, keeps the tunnel generally fairly clear of
fonl air.

Influences of the Mont Cenis Bailway. — The opening of the
railway passing under the Col de Frejus, not only joined the Paris,
Lyons, and Mediterranean Eailway to the Italian system of
railways, and placed Paris, Lyons, and Geneva in direct communi-
cation with Turin, Genoa, Florence, and Kome, but also rendered
Brindisi the most suitable port to the East for Great P>ritaiu
and a large portion of France, in place of Marseilles. The
distance between London and Alexandria was reduced l)y
adopting the Brindisi route, being 2,431 miles, instead of 2,534
miles via Marseilles. A great saving of time, moreover, was
effected by substituting a route by land for a considerable portion
of the sea route, since a train travels faster than a steamer.
Thus the route by the Mont Cenis and Brindisi, by reducing
the sea route from 1,701 miles to 954 miles, and increasing the
land route from 833 miles to 1,477 miles, was reckoned by Captain
Tyler,^ Assoc. Inst. C.E., to effect a saving in time in the journey
from London to Alexandria of forty-two hours. The diversion from
Marseilles was not favourable to the interests of the Paris, Lyons,
and Mediterranean Eailway Company, which therefore naturally
evinced no eagerness for the completion of the line. Nevertheless,
the change must have come sooner or later by some route; and
that company had the advantage of being the first in the field
for accommodating Western Europe.

St. Gotharu Eailway and Tunnel.

Plate G, Figs. 5 and 7 ; and Plate 7, Fig. 4.

Proposals for constructing a third railway across the Alps were
not delayed till the success of the Mont Cenis tunnel was assured,
for Mr. Flachat suggested the Simplon route in 1859, and the St,
Gothard scheme was brought into notice in 1866. If it had been
decided at the outset that one line only besides the Brenner should
be constructed across the main Alpine chain, the Simplon line
would have possessed the best claim to be selected, as the most
central between the Brenner railway and the Corniche road, and
as the nature of its api^roaches was easier, the length of line
remaining to be constructed was shorter, and its summit-level

' Report ou the Mout Ceiiis Eailway to the Uuard of Trade by Capt. Tyler,
R.E., 18(;:).

262 VERNON-HAKCOIJET OX ALPINE ENGINEERING. [Selected

would be lower than that of any other route. The only objections
that could be raised against the Simplon were the length of its
tunnel, and the heat that might possibly be encountered in tunnel-
ling at a considerable depth below the surface. As soon, however,
as the Mont Cenis route was undertaken, the conditions were
changed, as the St. Gothard route then became the most central
between the Mont Cenis and Brenner railways ; and the Simplon
line would have trenched upon the Mont Cenis zone of traffic,
without fully accommodating the district lying between it and
the Brenner (Plate 6, Fig. 1). Two other routes besides the
Simplon were put forward as rivals to the St. Gothard route,
namely, the Lukmanier route, which would have terminated at the
same point, Biasca, as the St. Gothard railway, and the Spliigen
route which would hai^e joined the main line at Milan (Plate 6,
Figs. 1 and 5). The Spliigen route was much nearer the Brenner
than the St. Gothard, and traversed only a narrow portion of
Switzerland ; and it was rejected owing to its minor commercial
importance. The Lukmanier route, lying between the St. Gothard
and the Spliigen routes, would have started from the same point,
Chur, as the Spliigen route, and therefore equally near to the
Brenner; and though its approach railways would have been
shorter, its gradients easier, and its summit-level lower, than those
of the St. Gothard, its summit tunnel would have been longer.
Eventually the Swiss Government gave the preference to the St.
Gothard route over the Lukmanier and the Simplon, as being the
most central of the three ; and it was naturally more acceptable to
Germany than the Simplon, being far better situated for German
traffic and trade.

St. Gothard Railway. — Till the St. Gothard line was opened,
Switzerland possessed no direct railway communication from
north to south, as both the Brenner and Mont Cenis raihvays
passed outside its boundaries ; whereas the St. Gothard railway
traverses it nearly centrally, and at its widest part.

The St. Gothard railway, authorized in 1869, is situated at an
altogether lower level than the Mont Cenis and the Brenner, for
not only is its summit-level considerably lower, but it also descends
to lower levels at its extremities, especially on the southern side
(Plate 7, Fig. 7). The ascent commences at Erstfeld, 1,501 feet
above the sea, but becomes steeper at Amstag 3 miles further on ;
and from thence to Goeschenen, at the entrance to the summit
tunnel, the line rises 1,842 feet in 142- miles, giving an average
inclination of 1 in 42^. This is the steepest portion of the line;
and the gradients, excejit foi* short lengths at the stations, are from

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 263

1 in 45 V to 1 in 38^, the steeper gradients predominating. Owing,
however, to the smaller rise between Erstfeld and Amstag, and the
flatter gradient of 1 in 172 in the northern part of the tunnel, the
average rise between Erstfeld and the summit, a distance of
23-j miles, is 1 in 56*3. The descent from the summit, 3,786 feet
above the sea, to Biasca, is 2,815 feet in 32^- miles, giving an average
gradient of 1 in 60 • 6 on the south side. The steep gradients are
not so continuous on the southern slope as between Amstag and
Goeschenen; but there are several gradients of 1 in 38^ scattered
about, one being about 2,^ miles long; and there is a gradient of
1 in 37 on each side of Giornico station. The gradients average
1 in 45.^ between Fiesso and Bodio, a distance of 17 J miles; and the
steepest section is l^etween Lavorgo and Giornico, the site of the
helicoidal tunnels, where the average gradient is 1 in 42.^ for 4";
miles.' The curved portions of the line occupy nearly half of the
length between Erstfeld and Biasca. Curves of 14 chains to under
15 chains, which are the sharpest on the line, have a total length of
2i miles; curves of 15 chains and under 20 chains are the most
frequent, extending over 15 j miles; whilst curves of 20 chains and
under 30 chains occupy 5^ miles of the line.

A special peculiarity of the St. Gothard railway is the manner
in which the steep portions of the slojjes have been surmounted
by a spiral and two adjacent loops at Wasen, and by two spirals
between Fiesso and Faido, and two spirals close together near
Giornico, by means of which the line doubles back upon itself at a
different level, and enables the gradients and works to be kept
within reasonable limits (Plate 6, Fig. 7). The railway passes at
these places througli eight helicoidal tunnels, four on the northern
and four on the southern slopes, two of the former and all of tlie
latter being nearly 1 mile each in length, and the other two f mile
long. Including these helicoidal tunnels, the railway passes
through twenty-one tunnels on the northern slope, with a total
length of 8,061 yards, and through twelve tunnels on the southern
slope, having a total length of 8,685 yards, giving a total length of
9^ miles of tunnels on both approaches. These tunnels, moreover,
are comprised within 13 miles between Amstag and Gojschenen, and
within 7^ miles between. Fiesso and Faido, and Lavorgo and
Giornico. With the sunnnit tunnel, the total length of tunnelling
in the 56 miles between Erstfeld and Biasca amounts to 18 J miles,

' A section of the line giving the heights, gi-adicuts, distances between the
stations, and the lengths of the tunnels, is appended to tlic Rapport Triiuestriel,
No. 22, snr la liguc du St. (Jothard, I Jan. an :!l Mars, 1S7S.

264 VERNON-HARCOURT ON ALPINE ENGINEERING. [Selected

or actually one-third of the Avhole distance. The timnels on the
northern slope were driven by hand-boring, except the Pfaffensprung
helicoidal tunnel, where, after 170 yards in length of the heading
at the lower end had been driven by hand, at an average rate of
1 • 0 foot per day, 204 yards were driven by the Frolich percussion
drill ^ worked by compressed air, advancing on the average 3 j feet
per day ; and the remaining 709 yards of heading, driven from the
lower end, were accomplished by the Brandt rotatory drill,- worked
by water-pressure, at an average daily rate of 5' 94 feet. The
progTess of the heading at the upper end of this tnnnel, driven by
hand, averaged 1 • 93 foot per day ; whilst the average daily advance
of all the headings driven by hand on the northern slope was 1 • 67
foot. The Pfaffenspmng tunnel and four of the other tunnels
passed entirely through gneissic gTanite ; the strata traversed by
the tunnels included also granite, gneiss, mica schist, moraine, and
debris. The Frolich percussion drill was employed in driving the
headings of foiar of the tunnels on the southern sloj)e, after a
commencement had in each case been made by hand. The total
length of headings thus driven in the Freggio, Prato, Piano-Tondo
and Travi helicoidal tunnels was 4,190 yards, at an average daily
rate of 4.V feet, through gneiss and gneissic mica schist ; whilst the
headings driven by hand in these and the other tunnels on the
southern slope, amounting altogether to 4,409 lineal yards, advanced
at an average rate of 1 • 8 foot per day. Machine-boring was partially
adopted at the lower face only of the Prato tunnel; but both
headings in the other three tunnels were mainly driven by the
percussion drill. It had originally been proposed to construct the
tunnels through hard rock for a single line only, leaving the
doubling of the section till the traffic should require it. The
variable nature, however, of the rock rendered considerably more
length of lining necessary than had been anticipated, so that
eventually the arch was built almost throughout for a doixble line,
leaving the enlargement at one or on both sides till a future time
where practicable.

The original scheme for the approach railways had been drawn
wp from rough small-scale plans ; so that when the working sections
were prepared, it was discovered that the railways could not
possibly follow the lines originally traced out, and that the works
would considerably exceed the original estimate.^ Accordingly,

' A description, with drawings, of this drill is given in Eapport Trimestriel,
No. 32, de la ligne du St. Gothard, p. 85.
- Ihid. p. 8'J.
^ Auuales des Pouts ct Chuuss'Jes, 5th series, vol. xiii. 1S77. p. -16.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 265

the construction of the approach lines, as definitely laid out in 1876,
had to be delayed till arrangements could he made for raising the
additional capital ; and though the summit tunnel works were
continued without interruption, the approach works were not pro-
ceeded with till near the close of 1878. The bridges and viaducts
were mostly constructed with iron lattice-girders resting on masonry
piers, iron being adopted to exjiedite the works. ^ The approach
works, however, owing to the delay, were not completed till the
1st of June, 1882, five months after the long tunnel section had been
opened for traffic.

The St. Gothard railway between Erstfeld and Biasca, 50 miles
long, slightly longer than the movmtain sections of the Brenner
and the Mont Cenis, has an average gradient of 1 in 58*72,
distinctly flatter than the 1 in 52 on the Mont Cenis, and slightly
flatter than the 1 in 55 • 5 on the Brenner. The ruling gradients
of the St. Gothard of 1 in 38^ on the northern slope, and 1 in 37
on the southern slope, are intermediate between the 1 in 33*3 of
the Mont Cenis, and the 1 in 40 and 1 in 4-1 of the Brenner.
Whereas, however, the St. Gothard has the advantage in gradients
over the Mont Cenis, it has sharper curves than the Mont Cenis,
and a much greater length of curves under 20 chains radius ; but
it is superior to the Brenner as regards curves (see Appendix).
The tunnels on the slopes of the St. Gothard are much longer
than on the Brenner or the Mont Cenis ; their spiral form, to gain
length for the rise, is peculiar to the St. Gothard ; and the approach
works generally were specially heavy. The St. Gothard railway
is formed for a single line, like the Mont Cenis and portions of the
Brenner, except in some of the tunnels and at the stations.

St. Gothard Tunnel. — The summit tunnel under the St. Gothard,
like the Mont Cenis tunnel, was driven in a straight line from end
to end, and constructed for a double line throughout. As there is
a difference of level of only 118 feet between the summits of the
approach lines at each end of the tunnel, it could be formed with
the easy rising gradients towards the summit of 1 in 172 on the
north side, and 1 in 500 to 1 in 2,000 on the south side ; the gradient
on the south side being simply to ensure drainage, and on the north
side to allow for this rise and the higher level at the southern
end. The straight tunnel, as driven, had a length of 9-26 miles;
but with some modifications at the northern entrance at Goescheuen,

' Small elevations of the bridges and viaducts, and sections of the tunnels,
defence walls, &c., are given in the plans belonging to the Final Ecport on the
St. Gothard, in Kapport Trimestriel, No. 40.

266 VERNON-HAKCOURT ON ALPINE ENGINEERING. [Selected

and a curved portion to connect it with, the apjiroach line at
Airolo, the actual length of the tunnel traversed by trains is 9 "SI
miles. The driving of the timnel was commenced in September
1872, with the advantage of the thirteen years' experience at the
Mont Cenis tunnel ; and dynamite was introduced for blasting,
whereas gunpowder only was employed at Mont Cenis. The
boring of the advanced headings at each end was commenced by
hand; but machines were introduced at Ga3schenen in April 1873,
and at Airolo in July 1873, though the regular compressors did not
begin working till about a year after the works had been begun.
The machine drills first employed at the two ends were Dubois and
Franc^'ois', but they were superseded by the Ferrous drill ; and
eventually, after various trials, the Ferroux drills were exclusively
used at the northern heading, and McKean drills at the sox;thern
heading, from November 1875 till the work was completed.' Water-
power at each end of the tunnel worked turbines acting on
machinery for compressing the air required for the drills. The
progress of the advanced headings by hand-labour at the commence-
ment was necessarily slow, with a maximum monthly advance of
29 yards on the north side, 43 yards on the south side, and 53 yards
on the two sides together. The progress, however, increased
rapidly with the introduction and improvement of the machinery ;
so that the advance, which was only 8G0 yards at the two headings
in the first year, 1872-73, during which hand-labour had pre-
dominated, increased to 1,816 yards in 1873-74, and reached 2,653
yards in 1874-75, a rate which was only exceeded in 1878-79, when
the advance in the year amounted to 2,793 yards at the two headings
combined (see Diagram Fig. l,p. 259). The maximum progress in
a month was 159 yards on the north side, which occurred in
October 1878, and 187 yards on the south side in August 1878,
during which month the maximiim advance on the two sides of
304 yards was achieved. The maximum advance in a year was
1,500 yards on the north side in 1878-79, and 1,316 yards on the
south, side in 1874-75. The advance was greatest at the northern
side in every year except the first, and the portion of 1879-80 pre-
vious to the junction of the headings on the 29th of February, ] 880,
so that the length pierced from the northern side was 631 yards
more than the other. The driving of the headings occupied seven
years and five months, only a little more than half the period

' Particulars about the drills and compressors will be found in the Eapports
Trimestriels de la lignc du St. Gotliard, and also in Minutes of Proceedings
lust. C'.E., vol. xlii. p. 22S, aud vol. Ivii. p. 2'S'J.

Papers.] VEKNON-HAECOURT ON ALPINE ENGINEERING. 267

required at tlie Mont Cenis ; lout as the tunnel is nearly 2 miles
longer, the average daily advance was more than twice as great,
namely, 6*01 yards as compared with 2-51 yards. When the
junction of the headings was elFected, a difference of onl}^ 13 inches
was found in the direction of the two lines, and only 2 inches in
the level. The length of the tunnel proved to be 25 feet shorter
than had been estimated.

The strata traversed were very variable, consisting chiefly of
granite, schist, and gneiss with mica in the northern portion, and
cpiartzous schist, mica schist, and gneiss in the southern portion ;
and veins of serpentine, cipolin, and hornblende were also met
with.^ The state also of the rocks varied considerably, lieing
much disintegrated and fissured in places. The dip of the strata
is considerable throughout, and in some parts is almost vertical,
favouring the influx of water, which came in to a eonsideral)lc
extent at various places where fissures were jiierced. The tem-
perature of the rock in the tunnel rose gradually as greater
depths were reached ; ^ and towards the centre of the tunnel in
January and February 1880 attained on the average 86^-7, the
highest observed being 87'^ "4. The actual temperature in the
tunnel corresponded very closely with the predicted temperature ;
but the undergroimd temperature showed a greater divergence
from the temperature at the surface under the high plateaus than
under the highest peaks. The temperature of the rock near the
centre of the tunnel was found to have fallen to about 7-i:h^ in
May 1882, or about 12° in two years and four months; and it
was expected that it would eventually descend to 68°.

The workmen suffered considerably from the effects of the
increased temjierature, combined with the humidity of the air,
the inadequate ventilation, and the defectiveness of the sanitary
arrangements ; and there was a great mortality amongst the horses.
No provisions, however, had been made to meet these contin-
gencies ; biit the ventilation was gradually improved by introducing
more fresh air at the faces, and Mekarski's compressed-air engines
were used for removing the excavated material ; ^ and as soon as the
headings were joined, natural ventilation took place whenever

' A description and a geological section of the strata traversed by the timucl
are appended to Rapport Trimestriol, No. 31, de la ligne du St. Gothard.

^ A diagi'am of the temperatures observed is appended to Rapport Trimcstriel,
No. 30.

^ A description and drawings of these engines are given in Rapport Trimestriel,
No. 14.

268 VERNON-HARCOUET ON ALPINE ENGINEEEING. [Selected

there was a difference in the atmospheric pressure at the two ends.
A supply of fresh air can be procured at intervals along the tunnel
from a conduit filled with comjiressed air, to supply the workmen
who may have to he in the tunnel when an equilibrium in the
atmospheric conditions at the two ends puts a stop for a time to
the natural ventilation.

The tunnel was completed and opened for traffic on the 1st of
Janiiary, 1882 ; and the whole line was opened on the 1st of June,
1882. The considerably longer period which elapsed between the
junction of the headings and the completion of the tunnel at the
St. Gothard than at the Mont Cenis, namely, twenty-two months
in place of nine months, was due to the enlargement works not
being able to follow so closely the headings, driven along the top
at the St. Gothard, as the bottom headings of the Mont Cenis.

The tunnel cost about £142 per lineal yard, making a total sum
of about £2,327,000 ; so that, in spite of its greater length, its cost
was less than four-fifths that of the Mont Cenis tunnel, and only
two-thirds of the cost of the Mont Cenis per lineal yard. Accord-
ingly, both in rate of construction and cost, the St. Gothard
tunnel exhibited a very considerable improvement on the Mont
Cenis tunnel.

Aelberg Eailway axd Tunnel.
Plate 6, Figs. 1, 5 and 8; and Plate 7, Fig. 5.

Soon after the completion of the St. Gothard railway, Austria,
for the third time, undertook an Alpine railway, in order to obtain
direct railway communication with France, without traversing
any foreign countrj^ besides Switzerland. The Arlberg railway,
like the Brenner railway, lies Avholly in Austrian territory ; but
whereas, in crossing the main Alpine chain at the Brenner, it was
possible to dispense with a summit tunnel, the Arlberg railway,
though only crossing an outlj'ing spur of the Alps, rises almost as
high as the Brenner and Mont Cenis railways, and necessitated
works little inferior in magnitude to those of the Mont Cenis
(Plate 7, Figs. 5 and 7). The line commences at Innsbruck, the
starting-point of the Brenner railway, and proceeds almost due
west, so that it runs nearty at right-angles to the Brenner, and
after passing under the Arl mountain in a tunnel about 6| miles
long, it terminates at Bludenz near the Swiss frontier, where
it joins another railway connecting it with the Swiss lines (Plate 1,
Fig. 1).

Arlberg Itaihcaij. — The actual ascent on the eastern side only

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING, 269

really commences at Landeck, 44:} miles from Innsbruck, as the
average gradient up to this point is only 1 in 369. Fx'om Landeck
to the summit, inside the tunnel, the railway rises 1,750 feet in
20 miles, giving an average gradient of 1 in 60 • 3, the maxima
gradients of 1 in 39| to 1 in 45 occupying 10^ miles (Plate 7,
Fig. 5). The railway descends 2,465 feet on the west side between
the summit and Bludenz, a distance of 19| miles, making the
average gradient 1 in 42 • 7 ; but the average gradient amounts to
1 in 36 for over 14 miles from the end of the tunnel to 1^ mile
from Bludenz, and the maxima gradients of 1 in 32^ to 1 in 34
extend over 10;-- miles. ^

The line is curved for 16f miles out of a total length of nearly
40 miles ; there is a short curve of 10 chains close to Landeck, and
curves of 12 V chains are the most frequent, extending over 8? miles,
whilst curves of under 30 chains occupy altogether 15j miles.

There are three tunnels on the eastern slope, having a total
length of 341 yards, and six tunnels on the western slope, having a
total length of 837 yards ; the longest of them is only 1 furlong
long. The principal bridges are the bridge over the Inn near
Landeck, 197 feet sjian, and 60 feet above the river; the Trisana
viaduct, with a central sjian of 377^ feet, raised 282 feet above the
Eiver Trisana, and two side spans of 131{ feet; and the Schmeid-
tobel bridge, with a span of 229 1 feet.

The Arlberg railway, between Landeck and Bludenz, has a
general average gradient of 1 in 50, which is steeper than that of
the Brenner, the Mont Cenis, or the St. Gothard ; but it is more
than 10 miles shorter than any of these lines. Its sharpest curve
of 10 chains radius is only exceeded by those of the Semmering of
9\ chains, and it has a greater length of curves under 14 chains
than any of the other lines. It has the steepest ruling gradient of
1 in 32 J on the western slope of any Alpine line, but the ruling
and average gradients on the eastern slope are less than those of
the Mont Cenis and St. Gothard (see Appendix).

Arlberg Tunnel. — The tunnel under the Arl mountain, 6}^ miles
long, was constructed, like the Mont Cenis and St. Gothard
tunnels, in a perfectly straight line, and with the advantage of
the experience gained at both of these works ; and like those
tunnels, it was formed with gradients rising towards the summit,
on the east side 1 in 520, to provide for drainage, and 1 in 72 on

' A plan and a section of the Arlberg railway, with the gradients and curves,
and elevations of tlie principal bridges, are given in Zeitschrift des Oester-
reichischen Ingeuieur- und Architekten-Vereins, 18S2

270 YEEXON-HAKCOURT ON ALPINE ENGINEEKING, [Selected

the west side to reach the higher level of the summit of the
eastern slojie (Plate 6, Fig. 8, and Plate 7, Fig. 5). The driving
of the headings was commenced in July 1880, and they were
joined three years and foiir months later, namely, on the 13th of
November, 1883, so that the average rate of progTess was about
2 miles a year. The Ferroux percussion drill, worked hy com-
pressed air, was employed at the eastern heading, and the Brandt
grinding rotary drill, worked by water-pressure, at the western
heading, both which drills had been previoiisly used with satis-
factory results in piercing the tunnels on the St. Gothard. The
water-power for working the air-compressors, and providing the
water-pressure, was obtained from reservoirs formed at each end.
In the first four months the driving was performed by hand till
the machines were ready, and the progress was necessarily slow ;
but the average daily progi-ess with the machine-drills in 1881,
1882, and 1883, was 4*52, 5*73, and 5-95 lineal j-ards on the
eastern side, and 3 "17, 5 -03, and o'9-i yards on the western side
(see Diagram Fig. 1, p 259). The rock traversed on the eastern side
consisted of hard compact schist, with a large i^roportion of quartz,
approximating to gneiss, with a very little water ; whereas on the
western side there was a large proportion of mica in the schist,
which was fissured with veins of clay and yielded considerable
quantities- of water.^ The variable nature of the rock at the
western heading, and the tendency to slips, delayed the progress
of the Brandt drills, so that they pierced 825 yards less than the
Ferroux drills ; whereas when they worked in similar strata,
towards the close of the work, their rate of progress was equal.
Moreover, the Brandt drill expended less force and less ex2:)losives,
and could be worked with fewer men. The heading was driven
along the bottom ; and shafts, opened upwards from the heading to
the roof at intervals, enabled an upper g-allery to be driven from
them in both directions, and thus the enlargement and lining
followed close up to the advanced heading.

The Arlberg tunnel cost £1,209,400, which, for a length of
11,027^ yards, is equivalent to £107 18s. 2d. per lineal yard, being
a reduction of £34 per lineal yard on the cost of the St. Gothard
tunnel, and less than half the cost per lineal yard of the Mont
Ceuis tunnel. Moreover, the progress of the Arlberg tunnel
headings was half as rapid again as the St. Gothard headings ; and
the completed tunnel followed much closer on the heading at the
Arlberg than at the St. Gothard, owing to the different method of

Minutes of Proceedings Inst. C.E.. vol. Ixxx. \). 382.

PaiKirs.] VERNON-HARCOURT ON ALPINE ENGINEERING. 271

construction adopted. The Arlberg tunnel, accordingly, exhibits
as notable an advance on the St. Gothard tunnel as the latter
does on the Mont Cenis, both in rate and cost of construction.
The length, however, and the internal heat of the Arlberg tunnel
w^ere less than at the St. Gothard.

The railway was opened for traffic in September 1884, more than
a year earlier than was anticipated at the outset.

PROrosED Alpine Eailways and Tunnels.
Plate G, Figs. 1, 5, and 9 ; and Plate 7, Figs. 6 and 7.

The St. Gothard railway, by drawing a large amount of traffic
eastwards, has so affected the traffic and trade of France that
schemes, which were dropped for a time when the construction of
the St. Gothard railway was decided upon, have again been
revived, with the object of trying to bring back a portion of the
traffic to its former channels. The three routes proposed for this
pur})ose traverse the Alps between the Mont Cenis and the St.
Gothard, namely, the Mont Blanc route, the Great St. Bernard
route, and the Simplon route, an old rival of the St. Gothard
(Plate 6, Fig. 1). They would all be easily accessible from French
railways ; the Mont Blanc and Great St. Bernard routes converge
vipon Turin, and the Simplon line would join the St. Gothard line
at Milan. Merely regarded as routes on a map, the Great St.
Bernard route divides the district between the Mont Cenis and
St. Gothard the most centrally, as the Mont Blanc route ap-
proaches the Mont Cenis, and the Simplon converges on the St.
Gothard. The distances between Calais and Brindisi by the
several routes are as follows: 1,360 miles by the Mont Cenis,
1,386 miles by the St. Gothard, 1,32-1: miles by the Mont Blanc,
1,326 miles by the Great St. Bernard, and 1,322 miles by the
Simplon.

Mont Blanc Railway and Tunnel (proposed?). — The line proposed
for the Mont Blanc route would start from an existing railway
near Bonneville, a little to the south of Geneva, and following the
valley of the Arve would ascend by gradients of from 1 in 259 to
1 in 93, and after passing Sallenches and St. Gervais, would enter
a summit tunnel not far from Chamonix, 11^ miles long, and
emerge at Pro St. Didier in the valley of the Dora Baltea.^ It

* "Projet d'un Clicmin de Fer International a faibles pentes a travors Ics
Appenuincs ct Ics Alpcs jiar la chainc du Mont-Blanc," Joseph Bonelli. Turin,

1880.

272 VERNON-HARCOURT ON ALPINE ENGETEERING. [Selected

would then descend along this latter valley by Morgex, Arvier, and
Yilleneuve, with g-radients of from 1 in 06^ to 1 in 82^, to Aosta,
where it would join the line leading to Turin and the other Italian
railways (Plate 6, Fig. 1). The line of the tunnel passes under
Mont Maudit of the Mont Blanc range, at a depth of about 11,390
feet below the surface ; but it would be possible to sink a venti-
lating shaft, 1,550 feet deep, into the tunnel, from the Veni valley,
4 miles from the Italian entrance. As the entrance to the tunnel
on the French side would be not more than -40 feet lower than the
Italian entrance, both the gradients rising to the summit in the
centre oi the tunnel would be gentle. The summit proposed is
only about 3,280 feet above sea-level, much lower than the summit
of any Alpine railway hitherto constructed, except the Semmering ;
for it would be 500 feet lower than the St. Gothard summit, and
more than 1,000 feet lower than the summits of the Arlberg, Mont
Cenis, and Brenner railways (Plate 7, Fig. 7). The strata traversed
by the tunnel would consist of calcareous and aluminous schists,
crystalline gneiss, and granite. The cost of the tunnel is estimated
by Mr. Bonelli at £1-45 -is. per lineal yard, or about £2,938,000;
and the total cost of the line, assuming that the authorized exten-
sions towards Chamonix can be utilized, is estimated at about
£3,480,000 ; but this can only be regarded as a rough approxi-
mation, as the scheme does not ajDpear to have been worked out in
any detail. Other schemes for the same route have been proposed
besides the one sketched out, diifering somewhat in the line of the
tunnel and its altitude, and consequently in the length of the
tunnel, its maximum depth below the surface, and the gradients
of the approach lines. ^ They, however, all indicate a line with
gentle gradients and a long summit tunnel.

The route possesses the merit of having a low summit and easy
gradients, as compared with previous Alpine railways ; but it has
the disadvantage of a tunnel at least as long as the St. Gothard,
and in most schemes about 2 miles longer, and reaching an un-
precedented depth of at least 9,800 feet below the surface.

Great St. Bernard Bailway and Tunnel (proposed). — The Great
St. Bernard railway, as sketched out in some detail by Mr.
Vautheleret in 1884, would start from the Martigny station, at
1,545 feet above the sea, and by contouring the valleys with three
long loops (Plate 6, Fig. 1), would rise by gradients of from 1 in
62 to 1 in 47 '4, to a height of 5,314 feet above sea-level, in a
distance of 36| miles, passing through several tunnels in its

' Minutes of Proceedings Inst.'C.E., vol. Ixiii. p. 380; and vol. Ixiv. p. 391.

rapcrs.] VEKNON-HAECOURT ON ALPINE ENGINEERING. 273

course (Plate 7, Fig. 7).^ It would then enter the summit tunnel,
5f\f miles long, under the Col de Ferret, a little to the west of
the Great St. Bernard pass, and traverse the houndary between
Switzerland and Italy, on the summit of the ridge, at a depth of
3,478 feet below the surface. The gradients in the tunnel, rising
towards the centre, would he gentle, as the entrance on the Italian
side would be only 7 feet higher than on the Swiss side ; and it is
proposed to sink three shafts in the tunnel, 722, 754, and 410 feet
deej) respectively. The railway woixld then descend to Aosta,
43^ miles distant, and 1,903 feet above sea-level, with gradients of
from 1 in 53 to 1 in 80, passing through several tunnels, and
forming long loops near Courmayeur and Morgex. The line is
laid out to be in curve for half its length. The sharpest curves
on each slope are designed to be 17g chains, and the most frequent
curves are 20 chains radius, the remainder being mainly 25-chain
curves. The summit tunnel would pierce sandstone and slate,
intersected by numerous layers of quartz. There would be fifty-
six tunnels on the approaches, having a total length of 16,- miles,
and seven viaducts from 240 to 650 feet long and from 72 to
95 feet high, together with numerous bridges. The works,
accordingly, would be exceptionally heavy on this line, which,
even with its comparatively short summit tunnel, would be in
tunnel for a little over a quarter of its total length of 86 miles,
irresi:)ective of the 9 J miles of covered galleries proposed on each
side of the summit tunnel, where the line rises higher than
4,600 feet above the sea-level, as a protection against snow. The
approach works would, indeed, compare with those of the St.
Gothard in magnitude, whilst extending over 30 miles greater
distance. The estimated cost of the line from Martigny to Aosta
is about £3,403,000 or £39,570 per mile.

The Great St. Bernard railway presents a remarkable contrast
to the Mont Blanc railway, for whereas the Mont Blanc railway
affords easy gradients, short approaches, and a low summit-level,
the Great St. Bernard railway takes a circuitous course, with very
long approaches, sharper curves, steeper gradients, heavier approach
works, and an exceptionally high summit-level, in order to obtain
a much shorter summit tunnel. In fact, the gradients are mainly
considered in the Mont Blanc scheme, and the summit tunnel in
the Great St. Bernard route. The estimated cost is approximately

' A plan and section and other particulars of this scheme are given in
Mdmoires de la Socie'te' des Ingenieurs Civils, 1884, vol. i. p. 454, and plates 74,
75, and 70.

[the INST. C.E. VOL. XCV.] T

274 TEEXOX-HAECOUKT ON ALPINE ENGINEEKING. [Selected

the same for both lines ; but the Great St. Bernard line has been
examined in greater detail, and is not made dependent, like the
Mont Blanc line, upon the completion of somewhat -uncertain
extensions.

Simplon Eailway and Tunnel. — The Simplon route has long been
the object of special study, and since it was first proposed by
Mr. riachat, in 1859, up to the present time, few j^ears have
passed without the appearance of some publication dealing with
the project. For some time it was a serious rival to the St.
Gothard scheme, till the influence of Germany and Switzerland
procured the construction of the St. Gothard railway. Though
the carrying out, however, of the St. Gothard raihvay diminished
the advantages of the Simjjlon route, the scheme was never allowed
to drop ; and now that the prejudicial influence of the route by the
St. Gothard to the traffic and trade of France, which was feared
at the outset, has become an accomplished fact, increased interest
has been manifested by Frenchmen in the Simplon scheme, as a
means of restoring the equilibrium of their trade, and bringing
back the through traffic to the East into French territory. In
1886 the various schemes for forming a railway communication
between France and Italy through Switzerland, across the Simplon,
were laid before a Commission of experts, who reported their
decisions in the same year.^ The scheme, as approved in this
report, consists of an ordinary single-line railway, starting from
the line to Brieg, near Yisp, in the Ehone Valley (Plate 6, Figs.
5 and 9), 2,133 feet above sea-level, and rising by a uniform
gradient of 1 in 50, for 5j-L- miles, to 2,690 feet altitude at Glyss-
Brieg station; after which it enters the summit tunnel, nearly
10 miles long, having easy gradients on each side, rising to a
summit-level of only 2,773 feet above the sea, as the level of the
southern entrance is only 33 feet higher than the northern
entrance (Plate 7, Fig. 6). From thence the line descends, near
the Swiss boundary", into Italy, to form a junction with the railway
at Domo d'Ossola, 14^ miles distant, with gradients of 1 in 40
between the stations, down to 896 feet above sea-level. The
average gradient from Visp to the summit is 1 in 90 • 6, much
easier than any of the existing Alpine lines ; and from the summit
to Domo d'Ossola it is 1 in 54-2, steeper than the southern sides
of the existing lines, but easier than the average gradients on the
northern sides of the Brenner and the Mont Cenis, and than the
west side of the Aidberg railway. The total average gradient of

' Eapport lies Experts sur le Percemeut du Simplon. Lausanne, 188G.

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 275

the Simplon line is 1 in G3 • 2, for a total length of about 30 miles,
which is easier than the average gradient of any existing Alpine
line ; and it extends over a much shorter distance than any of the
other lines. The line, as laid out, is curved for less than one-
third of its length, but the sharpest curves, of 15 chains radius,
extend over 3i miles ; and, as regards curves up to 20 chains
radius, it is less favourably laid out than the Mont Cenis (Appen-
dix). The line passes through one tunnel on the northern slope,
and through seven tunnels on the southern slope, with a total
length of 1 mile 717 yards, the longest tunnel, as designed, being
492 yards long. Except close to Glyss-Brieg station, the heavy
works will be confined to the southern slope (Plate 7, Fig. 6).

The summit tunnel will traverse gneiss, granite, mica-schist,
limestone, and cipolin. It is proposed to make it in two straight
lines from each end, meeting at an angle near the centre, so as to
avoid the highest ridges of the mountain, and reduce the thickness
of superincumbent rock, with the object of keeping clear of exces-
sive underground temperatures. Nevertheless, the surface of the
ground, at its highest j)oint, will be 6,895 feet above the tunnel,
1,102 feet more than over the St. Gothard, and with a tunnel
f mile longer. After careful consideration, however, the experts
came to the conclusion, with the experience of the Mont Cenis and
St. Gothard tunnels before them, that though the temperature of
the rock in the Simplon tunnel might exceed the maximum in
the St. Gothard tunnel of 87° -4 for a distance, in the centre, of
2^ miles, and even reach 100° -4 to 104° for 1^ mile, it would be
possible to execute the work by special methods of ventilation, and
by cleansing and cooling the air at the faces. ^ It is pointed out
in the report that the progress achieved in electricity would
render the transmission of power much easier, and would afford a
more complete illumination for the work in the tunnel.

The cost of a tunnel for a single line is reckoned at £1,877,000,
or, for a length of 17,573 yards, £106 16s. per lineal yard, to
which is added a sum of about £80,000, to provide for the cost of
reducing the temperatiire in the central part of the tunnel, in the
event of its being high. The total cost of the line, from near
Visp to Domo d'Ossola, is estimated, for a single line throughout,
at about £2,118,000, very considerably less than the estimated cost
of the other two schemes.

The Simplon railway would afford the shortest route between
Paris and Milan; but the St. Gothard line would be shorter for

' Eappoi'ts clos Experts sur le Pcrccmcnt du Simplou, p. 28.

T 2

276 VERNON-HAKCOURT ON ALPINE ENGINEERING. [Selected

going between Belfort and Milan, Bale and Milan, Belfort and
Genoa, and Bale and Genoa. The actual distance between
Boulogne and Piacenza would be shorter by the Simplon ; and the
virtual distances, allowing for the gradients, would be 856 miles
by the Mont Cenis, 829 miles by the St. Gothard, and 812 miles
by the Simplon.

Comparison hetween the three Alpine Schemes. — The Simplon route
possesses the lowest summit-level of any existing or proposed
Alpine railway (Plate 7, Fig. 7, and Appendix), and the Great
St. Bernard considerably the highest; whilst the Mont Blanc
tunnel would be the longest, and at much the greatest depth
below the surface. The Great St. Bernard route has much the
longest approaches, with the heaviest works, but a tunnel of about
half the length of the others ; the Mont Blanc has the easiest
gradients ; and the Simplon, with the steepest gradients of the
three, has a length little over a third of the Great St. Bernard
line.

The Mont Blanc line, with its easy gradients, might compete
successfully for traffic with the Mont Cenis ; but, from its position,
it could have little influence in diverting the traffic from the
St. Gothard. It would be of little use to Italy, which is adequately
served in that quarter by the Mont Cenis ; and its only advantage
to France would be in expediting somewhat its traffic, and as this
could only be done by diverting the traffic from the Mont Cenis,
it does not appear worth the expenses it would entail. The only
place of importance it would decidedly benefit is Geneva, by
affording it more direct access to Italy. Moreover, the great
length of tunnel, the uncertain character of portions of the strata
to be traversed, and especially the excessive heat that might be
experienced at the gTcat depth below the surface which the tunnel
would have to traverse, might well cause hesitation in attempting
even the most desirable scheme in other respects. The little
advantage that the Mont Blanc route ofiers to France, and the
excessive heat liable to be encountered in constructing its summit
tunnel, appear to the Author adequate reasons to preclude its
adoption, in spite of its easy gradients.

The Great St. Bernard line, with its comparatively short tunnel,
might have offered inducements when the experience in long
tunnels was small ; but its very long ascents render it unsuitable
for a competing line ; whilst its high elevation would render it
very liable to be blocked by snow-drifts, and therefore not advan-
tageous for a through route, whose prosperity depends upon its
regularity. Its position, liowever, is more favourable than that of

Papers.] VERNON-HARCOURT ON ALPINE ENGINEERING. 277

tlie Mont Blanc roiite for opening ont fresh communications, and
it would be of more value to Switzerland.

The Simplon line, though less intermediate between the Mont
Cenis and the St. Gothard than the Great St. Bernard route, is
well situated for Switzerland, and for opening up fresh lines of
traffic by Milan ; and, from its very proximity to the St. Gothard,
is specially well suited for competing for its traffic, and drawing
it back over French railways. Its low summit-level is particularly
favourable for quick through traffic ; and, as pointed out above, it
would shorten the distance from Paris and Boulogne to Brindisi,
and thus probably secure the carriage of the Eastern mails. More-
over, its construction is estimated to cost much less than either of
the two other schemes. The only objection that can be raised
against the route is the possible high temperatures which may be
encountered in constructing the summit tunnel ; but with special
provisions for meeting this contingency, it does not appear
sufficiently formidable to bar its execution, as might be the case
under Mont Blanc. The prospects the Simplon route offers to
France appear adequate to induce that State to afford financial aid,
without looking for a direct return from the capital invested ; for
the State benefits by the prosperity of the nation, and a restoration
of lost trade and traffic to France would fully compensate for a
considerable outlay.

The Paper is illustrated by three sheets of tracings to a small
scale, from which Plates 6 and 7, and the Fig. in the text, have
been engraved.

[Appendix,

278

VERNON-HARCOUET ON ALPINE ENGINEERING. [Selected

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Papers.] MACALISTER ON THE RIVER CLYDE. 279

(Paper No. 2341.)

"The Eiver Clyde."
By Daniel Macalister, Assoc. M. Inst. C.E.

(Abstract.)

In this Paper the Author describes some of the changes which have
taken place in the navigable and in the subsidiary channels, and
in the shoals of the Clyde from Dumbarton to Greenock, between
the years 1860 and 1880. He also makes a few remarks ^^23on
tidal scour.

The first part of the Paper is based upon surveys made in the
above-mentioned years by order of the Admiralty, of which the
charts that have been issued afford a ready means of comparison.
The history of earlier changes and improvements will be found in
the Paper on " The Eiver Clyde," by Mr. Deas.^

The main features of these charts show a navigable channel
near the centre of the river at Dumbarton, approaching the south
bank as it proceeds seawards to Port Glasgow, from whence it
continues along the bank until it reaches the estuary at Greenock.
On the north side, a shoal extends from Dumbarton to opposite
Greenock, and is divided by two subsidiary channels into three
parts, named respectively, the Pillar, the Cockle and the Greenock
banks.

The navigable channel is defined as that in which the depth is
greater than 12 feet at low-water; and a good idea of the state of
this channel will be obtained by examining the distance apart of
the 2-fathom lines upon either side of the channel.

In 1860, the navigable channel was very irregular and tortuous,
and presented considerable difficulties to safe navigation. The
width at Garvel Point, Greenock, was only about 190 feet ; at Port
Glasgow, the 2-fathom lines touched one another; and at Garmoyle,
^ mile below Dumbarton, the width was 180 feet. The depths at
these points at low-water were respectively 14, 12, and 13 feet.
Above Port Glasgow, a second channel, known as the " Old
Channel," had a depth of 11 feet, or only 1 foot less than the main
channel.

With regard to the subsidiary channels and shoals on the north

Miuutcs of Proceedings lust. C.E., voL xxxvi. p. 124.

280 MACALISTER ON THE EIVER CLYDE, [Selected

side in 1860, the channel between the Pillar and Cockle banks had
a minimum dejith of 7 feet at low-water for a distance of 1^ mile,
and a maximum depth of 17 feet ; and it seems probable that at no
very remote time it was the main channel of the Clyde, or at all
events, of equal imjDortance to that which occupied the site of the
present navigable channel. The channel between the Cockle and
Greenock banks had a minimum depth of 4 feet at low-water. The
Pillar bank extended from the mouth of the Leven at Dumbarton,
along the north bank of the river to Ardmore Point ; and the
Cockle bank from opposite Port Glasgow for nearly 1^ mile along
the northern side of the navigable channel. This bank had an
area of 1,160,000 square yards above low- water, and its greatest
elevation was 3 feet ; while the Greenock bank had an area of
1,261,500 square yards above low-water, and the greatest elevation
was 2 feet.

In 1880, the irregularities in the navigable channel had been in
a great measure removed ; and from Greenock to Dumbarton there
was a fairly uniform channel with easy curves, presenting few
difficulties to navigation. The following is a comparison of the
state of the channel at certain points in 1860 and 1880 : —

Width between ; Depth below Width between Depth below
2-fatbom lines, i Low-water. 2-fathom lines.' Low-water.

Feet.
Garvel Point . . ! 190

Port Glasgow . . . ' Nil
ISO

Garmoyle, h mile below 1
Dumbarton . . . /

In 1860, a vessel drawing more than 12 feet could not get further
up the Clyde at low-water than Port Glasgow; whereas, in 1880, a
vessel drawing 16 feet could get up to Garmoyle.

The " Old Channel " at Port Glasgow had only 8 feet at low-
water, having silted up 3 feet in twenty years.

The channel between the Pillar and Cockle banks had silted up
to a remarkable extent ; but the " Pool," which had been 17 feet deep
in 1860, was in 1880 only 1 foot less, which the Author attributes
to a whirlpool action caused by the ebb of the river meeting the
first of the flood-tide at this point. Among other changes, a slight
scour had taken place in the Pillar bank, liut the area of the
Cockle bank above low-water had been reduced to about one-half

Pfipcrs.] MACALISTER ON THE RIVER CLYDE. 281

what it was in 1860, and the whole of the Greenock bank above
low-water had disappeared.

These changes are so great, and their effects on the navigable
channel below Garvel Point so important, that the Author jiroceeds
to investigate their probable cause, by considering the tidal
capacity and the scour of the river. He estimates that in 1860,
the capacity of the Clyde above Garvel Point was 2,750,000,000
cubic feet ; and that the sectional area between Garvel Point and
Ardmore Point at low-water was 56,000 square feet, and at high-
water 158,000 square feet, the mean being 107,000 square feet.
The mean discharge of the upland water, or river-flow, was
estimated by Mr. Ure at 48,000 cubic feet per minute. The
duration of the flood-tide at Port Glasgow, 2 miles above Garvel
Point, was six and a quarter hours, and of the ebb six hours ; so
that the total flow of upland water during the flood was 18,000,000
cubic feet, and during the ebb 17,280,000. The volume of water
l)assing Garvel Point on the flood-tide was therefore 2,732,000,000
ci;bic feet ; the mean velocity being 1 •1348 foot per second ; and
on the ebb the numbers were respectively 2,767,280,000 cubic feet,
and 1 • 1973 foot per second.

The Author further estimates that the tidal capacity of the
Clyde had increased in 1880 to 2,804,000,000 cubic feet; that the
vohime of water passing Garvel Point on the flood-tide was
2,786,000,000 cubic feet, and on the ebb 2,821,280,000 cubic feet ;
that the sectional area of the river at this point at low-water had
increased to 66,500 square feet, and at high-water to 159,500 square
feet, the mean being 113,000 square feet; and that the mean
velocity of flood and of ebb had diminished respectively to
1'0947 foot and 1*1559 foot per second. In other words, at
Garvel Point in 1880, the tidal capacity had increased 2 per cent.,
and the mean sectional area of the river 5 • 6 per cent. ; but the
mean velocity of the flood had decreased 3 • 6 per cent., and of the
ebb 3 • 5 per cent.

From the foregoing it is evident that although the imjirovement
of the navigable channel has increased the tidal capacity of the river
in the upper reaches, this gain is more than counterbalanced by
the increased sectional area of the Clyde at Garvel Point, due to the
scouring away of the Greenock bank ; and the same remark applies
in a lesser degree to the Cockle bank. Simultaneously the velocity
of the current in the channel between the Pillar and Cockle banks
was reduced ; the deeper portions formed reservoirs and silted up,
and the shallower portions were deepened.

These great changes are illustrated by sections, which are

282 MACALISTER ON THE RIVEK CLYDE. [Selected

preserved for reference. They show generally that the up-stream
sides, and the surfaces of the banks had been scoured away to a
considerable extent, and that the materials had been deposited on
the down-stream sides of the bank, opposite Greenock. The same
action had been going on further down at Eoseneath Patch, a shoal
in the centre of the estuary. With the increase of the sectional
area from Greenock to Ardmore Point, due to the improvement of
the navigable channel and the scouring of the bank, the velocity
of the ebb woiild be reduced ; consequently silting had taken
place in the north or convex side of the navigable channel opposite
the Albert Harbour, Greenock ; and scouring had been caused by
the flood-tide on the northern side of the Pillar bank.

The Author anticipates that unless the subsidiary channels are
dammed up, and the faces of the banks forming the northern side
of the navigable channel are protected by stone to above low-water
mark, from above Port Glasgow to Greenock, the scouring away of
the Greenock and Cockle banks will continue, until the sectional
area has so much increased that this action ceases owing to the
diminished velocity of the tide ; but as the velocity in the navigable
channel will be correspondingly reduced, silting will take place
in it.

By multiplying the square of the mean velocity of the river by
the volume, the Author estimates the scouring power of the el)b-
tide, at Garvel Point in 1880, to have been 13 per cent, greater than
that of the flood-tide.

Papers.] FAILURE OF THE KALI NADI AQUEDUCT. 233

(Paper No. 2358.)

" The Failure of the Kali Nadi Aqueduct on the Lower
Ganges Canal."

(" Selectious from the Records of tlie Grovernment of India. Public Works
Department. No. ccxl. 1888.")

Abstracted by Walter Hampden Thelwall, M. Inst. C.E.

The following is an abstract of a series of reports and other
official documents relating to the aqueduct for carrying the Lower
Ganges Canal over the Kali Nadi stream. This aqueduct was
designed in 1870-73, built soon after (the date of construction
is not given), partially destroyed by a flood on October 2nd, 1884,
and completely swept away by another flood on January 17th,
1885.

Original Design.

The drainage-area of the Kali Nadi above the aqueduct was
estimated at 3,025 sqxiare miles. Very few data were available for
estimating the maximum flood-discharge, but it was assumed that
the greatest rainfall in twenty-four hours would be 6 inches, and
if one-fourth of the fall were to flow off in the same time, the dis-
charge would be 38 cubic feet per second per square mile of
drainage-area, or a total of 114,950 cubic feet per second ; whereas
the greatest recorded flood (calculated apparently from sections
and high-water marks) was 20,382 cubic feet, or 8-7 cubic feet per
second per square mile. That is to say, if the maximum rainfall
was G inches in twenty-four hours, only ^ inch, or one-eighteenth
of the fall, would be discharged in the same time. This difference
between the estimated and the actual discharge was considered at the
time to be due to two causes : first, that the greatest rainfall in any
locality is not continuous over large areas, and secondly, that owing
to the flatness of the district, the rainfall from the distant parts of
the area must take a considerable time in reaching the point of
discharge. It was considered that a sufficient margin would be
allowed if the discharge were taken at 12 cubic feet per second
(instead of 8-7), giving a volume of 30,300 cubic feet. To dis-

284 FAILURE OF THE KALI NAM AQUEDUCT. [Selected

charge this at a velocity of 10 feet per second, seven spans of
35 feet by 15 feet were provided in the first design, and it was
calculated that during high floods the water up-stream would be
headed up 2 feet behind the bridge.

The volume of water in the canal to l:ie carried across the
aqueduct was 5,374 cubic feet per second ; the depth was fixed at
9 • 4 feet, and the width was determined by the consideration that
the velocity should not exceed that against which boats could be
towed by ordinary means. This velocity was taken to be 4^ feet
per second, or 3 miles per hour, and the width of channel was
accordingly fixed at 127 feet. A roadwaj', 12 feet wide, was also
provided on one side of the canal.

Revised Design.

When the design was submitted to the Sujierintending Engineer,
this officer rej^orted that he considered the waterwaj' proposed
larger than was necessary. He calculated the highest known flood
at 9,500 cubic feet per second, or 3*66 cubic feet per second per
square mile, a revised survey of the drainage-area showing this to
be only 2,593 square miles. This discharge was admitted to be
very small, but was accounted for by the fact that the soil was very-
sandy, and that the drainage was intercepted at various places by
public works. These figures were moreover confirmed by the fact
that about ^ mile down-stream there was a native bridge more
than a century old, having seven openings of 10 feet 6 inches span
and 14 feet 6 inches high from floor to flood-level, and two side
openings 8 feet by 5 feet, giving a total water area of 1,146 square
feet. It was found by watermarks that the stream was headed
up 1^ foot, the velocity of approach was taken as 1 • 48 foot, and
the discharge calculated (taking c = 0-6) at 8,436 cubic feet per
second. A further check was obtained from measurements taken
at a point 39 miles above the bridge, during a flood said to be the
highest known. Adding to this measured volume a proportion for
the additional drainage-area at the site of the aqueduct, the volume
here was estimated at 7,033 cubic feet per second.

In spite of these calculations, however, the Superintending
Engineer considered that a discharge of 3*66 cubic feet per second
per square mile of catchment-basin was too small to be relied on,
and determined to provide for 7 cubic feet, a qiiantity which he
stated was often used in dealing with long and large catchment-
basins, and, on such a sandy soil, might be adojited without risk.

Papers.] FAILURE OF THE KALI NADI AQUEDUCT. 285

The aqueduct and adjoining river-lied, if properly protected, might
also easily stand a current equal to that which was supjwsed to
have passed under the old road-bridge, viz., 7^ feet per second.
From these data the waterway was fixed at five openings of
35 feet by 14 feet, or more than double that of the old bridge
1 mile lower down the stream, and the discharge estimated at
about 18.000 cubic feet per second.

The width of the canal carried by the aqueduct was increased to
192 feet, so as to diminish the velocity to 3 feet per second, as it
was considered that 4^ feet per second would be dangerous to the
earthen embankment at the end of the aqueduct, and would involve
a heavy expenditure in pitching the slopes and bed of the canal.
The aqueduct was accordingly built to this design, namely, five
segmental arches, each 35 feet span ; height, from springing of
invert to sjmnging of arch, 14 feet 8 inches ; versed sine of invert,
1 foot 4 inches, and of arch, 4 feet 8 inches. The reduced levels of
the principal points were as follow : —

Level of zero of flood-gaugro.

The abutments and piers were 212 feet long, and were founded
on wells sunk in sand to a depth of 19 feet below the bed of the
Nadi, or 514*5, with curtain wells sunk 10 feet.

A flood-gauge was fixed on the down-stream side of the aqueduct,
the zero being fixed at the level of the springing of the invert.

Previous to October 1884 the highest flood recorded rose to
16*3 feet on the gaage, or E.L. 551*14.

Partial Destruction of the Aqueduct.

On October 2, 1884, the aqueduct was partially destroyed by a
flood which rose to 18*7 feet on the gauge, and was headed up
3-5 feet higher (or 22*2 feet) on the up-stream face. The
discharge while the aqueduct was still standing was calculated at
37,000 c^^bic feet per second, and the mean velocity (including a
velocity of approach of 5 feet per second) at 11-7 feet, c being

Crown of invert* .

. . 533-50

Springing of „

. . 534-84

,, arch .

. . 549-50

Crown of arch .

. . 554-19

Canal-bed .

. . 558-07

' This was not a brick invert, but block kunkur pitching 2 feet tliick,
grouted.

286 FAILURE OF THE KALI NADI AQUEDUCT. [Selected

taken at 0 • 74. The discharge, after the Ijreach in the work was
made, was roughly estimated at 4-i,000 cubic feet per second. The
destruction began by the stream, as it rushed through the openings,
washing away a part of the kunkiir floor, and then undermining
the wells, when about one-fourth of the structure gave way and
fell into the river. Nearly all the curtain wells were washed
away. Out of the seventeen foundation wells in each pier, one
pier lost twelve, another five, and another one, while one pier and
the two abutments remained intact. In the worst ydace, however,
there remained a width of about 50 feet of the canal bed, and
advantage was taken of this to form a temporary aqueduct, by
bxiilding a revetment-wall for the canal, and in three months and a
half after the accident occurred a reduced volume of 1,500 cubic
feet per second was passed down the canal.

A flood of 44,000 cubic feet per second represented for the
drainage-area of 3,025 square miles, a discharge of 14*7 cubic feet
per second per square mile. The old road-bridge which had been
relied on as justifying the waterway for the aqueduct was not
injured, but the approaches at both ends were carried away, and
the water poured over the road for a length of ^ mile and cut
through the embankment in several places.

When the extent of the damage had been fully investigated, it
was decided that it was useless to attempt to repair it, but that
the remains must be removed and a new aqueduct built consisting
of nine spans of 35 feet. No reasons are given for the adoption of
this waterway, nor does it appear that any further investigations
were made in regard to possible floods in the future.

Complete Destruction of the Aqueduct.

On iTuly 17, 1885, a far heavier flood than that of October 2, 1884,
came down the stream and completed the destruction of the
aqueduct.

Mr. Good, the Executive Engineer, witnessed this catastrophe,
and described it in his report on the subject. Between noon and
6.30 P.M. on July 16th the down-stream water-level rose from
546-4 to 549-0. By 4.30 a.m. on the 17th it had risen to 553-20
down-stream, and to 559 - 0 up-stream, but no damage had appa-
rently occurred to the work. Immediately after, however, the
water-level up-stream rose 4 feet in one wave, and the work began
to fall in. At about 5 a.m. it became evident that the canal
channel was doomed, as cracks began to appear in the new right
revetment-wall, and the arch rings of Nos. 3 and 4 arches Ijegan to

Papers.] FAILURE OF THE KALI NADI AQUEDUCT. 287

separate from the backing. The left revetment-wall and roachvay
over arches Nos. 3 and 4 and part of the arches themselves
subsided at 6.15 a.m. By 8 a.m. the flood at up-stream side had
risen to w^ithin 6 inches of the top of the new right revetment-wall
(567-50), and surged over it in waves 10 or 15 feet high, and then
the whole of this revetment, from abutment to abutment, and
arches Nos. 3, 4, and 5 collapsed. Arches Nos. 2 and 1 were blown
up shortly after, but leaving about 50 feet of the old revetment-wall
supported by the piers, which obstructed the passage of the flood,
and was at 9.30 a.m. the only vestige of the structure visible.
The surface velocity of the current, taken by timing floating
bodies through the 219 feet length of the abutments, was 18*25
feet per second.

The action of the stream below the aqueduct was terrific. The
water in the main stream was piled up in waves 20 feet high at
intervals of about 100 feet apart, and laterally, especially towards
the right, spread out into a formidable swirl which was fast cutting
away the outer slope of the bank.

Ultimately the water cut its way through the canal-banks on
both sides of the bridge for a length of 50 feet behind the right
abutment and about 300 feet behind the left, and the only parts of
the aqueduct left standing were about two-thirds of one abutment
and two wing walls.

The maximum up-stream flood-level was about 569-00, the down-
stream level at the time being 556-00, the water being headed uji
13 feet. The gap behind the left abutment was 100 feet, that
behind the right abutment, 50 feet. Before the arches gave way
the up-stream level was 566-00 and the down-stream 556-00. The
length between the up- and down-stream faces of the aqueduct was
212 feet.

The rainfall in the district on July 16th was 17-6 inches, and
3 inches more fell on the 17th, the whole 20 inches having fallen
in a little more than twenty-four hours.

Design for new Aqueduct.

Although engineers were on the spot diiring the catastrophe and
noted the facts as they occurred, they were unable to obtain
sufficient data from which to calculate accurately the volume of
the flood. For instance, though the lengths of the gaps behind
the abutments were measured, it was obviously impossible to
obtain sections of them, and hence the sectional area of the flood

288 FAILURE OF THE KALI NADI AQUEDUCT. [Selected

could only be approximately estimated. The dimensions taken for
the calculations were : —

Width between abutments 5 X 35' + i X 7' = 20.3 feet.

Breacli behind left abutment 100 ,,

„ right ,, 50 ,,

Up-stream flood-level 569-00

Down-stream „ 556 '00

Bottom of stream 532 • 00

The breach behind the left abutment must have been obstructed
by the fallen masonry of the heavy land wings, and by the kunkur
pitching on the left bank of the Xadi, and that behind the right
abutment by the up-stream land- and river-wings, which were
still standing, so that the width of the breach was taken at

( 200 -| ^ ) = 275 feet. The volume was then calculated,

taking the width as 275 feet, depth at the down-stream face 24
feet, heading up on up-stream face 13 feet, velocity of approach
3 feet per second. Taking c at 0 • 5, the volume was found to be
132,475 ciibic feet per second. To provide for a similar flood in
future, a design was prepared for a new aqueduct, having eleven
spans of 60 feet. The soil in the bed of the Nadi under the
aqueduct, and for 50 feet above and below it, was to be dredged
out to 15 feet below the bed, or E.L. 519, and a sunken floor laid
of heavy concrete blocks 5 feet in thickness, the surface-level of
the floor being E.L. 524. The waterway available down to this
level, with a velocity of 8 feet per second, would have been
sufficient for a flood of 137,456 cubic feet per second, equivalent to
58 cubic feet per second per square mile of drainage-area, estimated
at 2,377 square miles.

The length of the aqueduct being increased from 200 to over
700 feet, it became a matter of great importance to reduce the
width, and it was necessary to consider what depth and velocity
could be given to the water in the canal consistently with the
safety of the earthen channel along the embankment. This
channel was 192 feet wide at the bottom, with slopes 1^^ to 1, and
the gradient was 0*5 foot per mile or 0*095 per 1,000. The
supply required was 4,100 cubic feet per second. After making
a series of calcxxlations as to the relative volumes which could be
passed down the earthen and masonry channels, it was decided to
allow a depth of 8 feet, a width in the latter of 130 feet, and
a gradient of 0'15 per 1,000, giving a supply of 4,111 cubic feet per
second at a velocity of 3 • 95 feet. In the event of the depth being
increased to 9 feet, which was the greatest that the earthen

Papers.] FAILURE OF THE KALI NADI AQUEDUCT. 289

channel could carry, tlie mean velocity in the aqiiednct would be
4-21 feet and the discharge 4,926 cubic feet per second. A
reference to the Solani Aqueduct on the Upper Ganges Canal
showed that the mean velocity with the full supply was 4*24 feet
per second, and proved that the proposed velocity of 4' 21 feet was
not excessive. To protect the earthen channel it was decided to
pitch the slopes for a distance of 310 feet above and below the
aqueduct, and the bed for a distance of 310 feet below and 100
feet above.

When the design was completed it was submitted to Colonel
Brownlow, E.E., Insj:)ector General of Irrigation, who, on examining
the reports of the flood and the calculations founded on them,
considered that the discharge had been greatly underestimated.
With the data previously given he was of opinion that the co-
efficient c should have been taken as = 0 • 75 at least, instead of 0 • 5,
which would add 50 per cent, to the estimated volume.. However,
he considered that it would he sufficient to give fifteen spans of 60
feet. These spans he proposed to divide into three sets of five each
by two abutment piers, and this design was adopted. In addition
to the width of 130 feet for the water channel, a road 11 feet wide
was provided on one side of the canal and a bridle-path 6 feet wide
on the other, the whole width from face to face of the arches being
148-7 feet.

In determining the number of foundation-wells and the depths to
which they should be sunk, it was decided that the pressure on
the foundations should not exceed 2^ tons per square foot, and that
140 lbs. per square foot might be taken as the frictional resistance
of the wells in undisturbed soil. Where the ground had been
previously dredged out no reliance was to be placed on frictional
resistance. Each abutment and pier-abutment was to be founded
on a double row of wells of 12 feet diameter, and each pier on a
single row of 20 feet wells. Ultimately the calculations as to
stability appear to have been used only to ascertain the minimum
depth allowable, and it was determined to sink all the wells to a
depth of 50 feet. The total number of wells will be 268, and
the aggregate depth of sinking 15,000 feet. The backs of the
abutments and river wings will have a row of sheet piles 15 feet
long and 4g inches thick driven behind them to prevent any
settlement of earth.

The available height from the bed of the Nadi (E.L. 534) to
the bed of the canal (558-27) is 24-27 feet, and has been disposed
of as follows : — Concrete over arch 0-35 foot, arch ring 4-15 feet,
versed sine of 60^ arc 8 feet, Nadi bed to springing 11-77 feet.

[the INST. C.E. VOL. xcv.] u

290 FAILITKE OF THE KALI NADI AQUEDUCT. [Sc4ected

The sunken floor will be laid with its upper surface at E.L. 524,
or 10 feet below Xadi bed, to a distance of 25 feet above and below
the faces of the aqueduct, and will end with aprons 25 feet long,
slo2:)ing downwards at an angle of 1 in 6 to E.L. 519, so as to
protect the main portion of the floor. The excavation for this
floor is to be done partly by pumping and ordinary excavation,
and partly by dredging from barges by hand and by steam-power.
The thickness of the arches varies from 4*15 feet at the crown to
4*58 feet at the springings. Spandrel arches of 4 feet span, 0"83
feet thick, with piers 1 • 7 foot thick, Avill be built. Over them will
be a course of flat bricks in Portland cement. The floor and sides
of the channel will be rendered with Portland cement to make
them watertight. In building the arches each set of five will be
turned separately. There will be five sets of centerings, each
about 32 feet long, or eqiaal to one-fifth of the length of the arch.
Each arch will therefore be built in five sections, the difierent
sections l)eing joined together by masonry wedges built afterwards.

The whole site of the works will be enclosed by embankments
raised well above maximum flood-level, so that there can be no
interruption to the work except during the periods of actual
rainfall.

The estimate for the aqueduct itself is Es. 30,52,000, but other
subsidiary works, including canal and Xadi diversions, railway and
sidings for l;>ringing materials, buildings, tools, plant, establish-
ment, and miscellaneous expenses, bring up the total estimated cost
to Es. 49,98,810.

The collection of papers concludes with a report showing the
amount of work executed up to the end of October, 1887.

Vapers.] LOPES ON THE REPARATION OF BETCHWORTH TUNNEL. 291

(Paper No. 2338.)

" The Reparation of Betchworth TunDel, Dorking, on the
London, Brighton and South Coast Eailway."

By George Lopes, B.A., Camb., Assoc. M. Inst. C.E.

The Betchwortli Tunnel, on the direct Portsmouth line of the
London, Brighton and South Coast Railway, is about j mile
south of that company's Dorking station, in the Lower Greensand
formation, 136 feet at its maximum depth under Deepdene
Park.

The tunnel is straight, 385 yards in length, and has a rising
gradient of 1 in 80 southwards towards Holmwood. It was originally
designed with slightly curved side walls 1 foot 10^ inches thick,
and with a segmental arch of similar thickness, and, except for a
length of 12 feet near the north face, an invert was dispensed
with.

In the northern portion of the tunnel the greensand is quite
hard, in some places approaching rock, presenting a straight and
solid face, and needing but the merest skin of brickwork lining to
secure its retention in place ; but gradually this changes to sand,
mixed with boulder-stone, which again gives place to sand piire
and simple, of the finest quality, wholly dry, and devoid of the
least cohesion. Indeed, with the exception of a portion about
25 yards long, 40 yards from the north entrance, no water was
found.

The original tunnel was opened for public traffic in May, 1867,
and formed the most important work on the Horsham and Dorking
section of the railway.

During the twenty years that had elapsed since the construction
of the tunnel until the collapse, on the 27th of July, 1887, when,
without warning, a portion of it fell in, only ordinary superficial
repairs of decayed bricks were necessary or were made. In fact,
repairs of this character were in progress in a portion of the tunnel
when the collapse occurred ; but no kind of doubt had been enter-
tained of the perfect security of the work, as it exhibited through-
out every sign of stability and solidity. The sudden failure is all

u 2

292 LOPES ON THE KEPAKATION OF BETCHWORTH TUNNEL. [Selected

the more surprising as tlie summer had heen exceptionally dry,
and in that part of the tunnel no repairs were, or had been, in
hand. A failure was first suspected at about 5 p.m. on that day by
a foreman of plate-layers, who noticed that the brickwork at about
70 yards from the south end was badly cracked, and appeared to be
giving way, a fine stream of dry sand coming through the fissure ;
the fracture extended longitudinally, at a height of about 12 feet
above rail-level.

At the time this was noticed a train from Horsham was due, and
having waited to see it through the tunnel, the man, observing
that the crack was increasing, at once ran out towards Dorking
station and stopped a " do'mi " train which was about to enter ;
on his return the tunnel was wholly blocked.

Early on the 28th of July the tunnel was visited by the Chief
Engineer, accompanied by the General Manager of the railway and
the Author. From the north end up to the stoppage the brickwork
appeared sound and intact ; but here the tunnel, from rails to soffit,
M^as completely filled with fine dry sand, which had been probably
driven down by the weight of the superincumbent mass from
the surface of the park above, and had extended far beyond the
place where the collapse had occurred. The merest cracks could
be perceived in the soffit at the crown, close to the sand. On
examining the ground above the tunnel, a depression, extending
for 45 yards, and varjdng in width from 10 yards to 27 yards, and
at its deepest part 21 feet, was found (Figs. 1). The south end was
then visited, and it was apparent that the dry sand had run in as
through a funnel, choking the line for a length of 58 yards, and
filling every crevice until a slojie of about 2 to 1 at both ends was
formed. Eather clearer signs of settlement in the soffit were
visible, but practically the sand hid everything, and the full extent
of the failure could only be surmised.

The result of this inspection was a prompt decision to tunnel
through the slip in a right line, and make good the work from
below, the execution being entrusted to Mr. J. T. Firbank, as
contractor, and the Author being appointed Eesident Engineer.

Both north and south of the slip the arch showed signs of
weakness, and the fii'st thing undertaken was shoring it against
falling in. Six skeleton ribs of elm were fixed under the arch at
both places, tightly wedged and supported on sills and struts,
carried down into the solid ground and to the level of the founda-
tions of the side walls.

To do this, a trench about 2 feet wide was sunk through the
slij), from the soffit of the~ old arch to the foundations, the end

Papers.] LOPES ON THE REPARATION OF BETCHWORTH TUNNEL. 293

nearest the slip and the side being close-poled with 3-inch deals,
and stretched to the walls ; the polings were liberally packed with
hay to stojD any of the sand running. Then 12-inch by G-inch

Figs. 1.

CROSS SECTION N9 I.

CROSS SECTION N° 2.

CROSS SEaiON N9 3.

Scale 1 inch = 50 feet.

timbers were laid, and 9-inch by 9-inch props placed njion them,
on which a top sill, 12 inches by G inches, was put, and these
received the skeleton ribs. Between the ribs and the soffit,

294 LOPES ON THE REPARATION OF BETCH WORTH TUNNEL. [Selected

laggings, about 2 feet apart, were run in and tightly fixed against
the arch by page-wedges driven between them and the ribs.

The arches having thus been practically secured, a start was
made to close-timber the broken end by poling from the crown.
Poling-boards, 2 inches thick by 3 feet long, were inserted verti-
cally, and a stretcher, aboiit 6 feet long by 10 inches square, was
got in about 3 feet down from the soffit, the ends being carried
well behind the old work. The sand was thrown back on the
slope, to assist in forming a scaffold, and also as a counterbalance
to the more central body of the slip. The poling was then con-
tinued, the 10-inch stretcher acting as the waling, and another
stretcher was duly inserted 3 feet lower as before.

In the same manner the face timbering was carried down to the
heel of the rib, when it was stopped and a top heading commenced.
The bottom waling was previously angle-strutted from the side
walls by 12-inch by 12-inch timbers, let into the walls and tightly
wedged therein, the other end being birds-mouthed. The top
heading, 4 feet wide by 6 feet high, was then cut through the face
polings at the level of the soffit, and driven 20 feet into the slip, at
a rising inclination of 24 inches in its length, and, this point
gained, the heading was returned towards the face, rising 24 inches
more, and again returned with another 24 inches. This, allowing
2 feet 3 inches for the thickness of the arch, gave 2 feet for the
crown bars and 1 foot 9 inches drop. The heading, close-timbered
throughout, was poled at the sides with 1^-inch boards, and on
the top with 2-inch boards. The head and side trees were 9 inches
die-square, placed 3 feet 6 inches from centre to centre on 12-inch
by 6-inch foot-blocks each 18 inches long. The feet of the side
trees were stretched across with the same sized timbers, all well
dogged with iron " brobs " and laced with long boards 1 inch
thick.

When the 20-foot length of heading was finished, a crown bar of
pitch-pine, 2 feet square and 18 feet long, was put in position, one
end being run back 3 feet over the crown of the existing arch, and
the leading end being supported by a 10-inch square back prop,
placed on a foot-block. The heading was widened piecemeal, by
removing setting after setting and close-poling, until room for
another bar alongside the first was obtained, great quantities of
hay being used all the time, lantil five crown bars had been fixed
and propped.

A nipper sill 16 inches by 8 inches and 12 feet long was then
laid in, and the five bars were prop})ed again from it. The top
heading, in its width, thiis-disa2ipeared, and mining for a 12-foot

Papers.] LOPES ON THE REPARATION OF BETCHWORTH TUNNEL. 295

length proceeded, the sides always being close-hoarded, and three
bars on each side inserted until the sill bed-level was reached.
The bars, with few exceptions, were of larch. Back props, 10 inches
by 10 inches, were then got in, resting on foot-blocks, the sill of
pitch-pine, 16 inches square, was drawn into place, and a wooden
saddle, 8 feet long by 16 inches by 8 inches, was fastened to the
upper side.

Each bar was supported over the sill by 1 0-inch props, radiating
with the curve of the arch. Stretchers, 16 inches square, were
fixed between the old brick face and each end of the sill, and
angle-struts or judkins raking from the brickwork to about 4 feet
on each side of its centre. The two rakers, 46 feet long, running
7 feet into the solid ground, with foot-blocks, were fixed and
wedged, birds-mouthed at the sill, and with two wrought-iron
glands to each near the upper ends. The rakers were themselves
stretched by a 9-inch by 9-inch stretcher near the top end, and by
a 12-inch by 12-inch stretcher about halfway down.

The length was then deemed practically secure, and a gullet,
about 6 feet wide, was driven through the loose sand from the face
at the middle sill-level, the sides being still close-poled and
stretched. The face near the upper sill being gained, three back
props, 10 inches by 12 inches, were got in with foot-blocks to each,
and the gullet was widened until the upper sill was supported by
eleven back props, all being close-j^oled, and the sides of the tunnel
were reached. Three more bars on each side were then fixed, and
the middle sill followed similar to the upper one. Twelve upright
props were fixed between the upper and middle sills, and sill-
stretchers from the brickwork to the sill ends were put in, and
rakers with foot-blocks. A bottom gullet, 6 feet wide at rail-level,
was now driven as before, and eleven back props were got under
the middle sill, and close-poled until the sides were again reached,
when two more bars on each side were fixed. The bottom sill,
14 inches square in one length, was then placed in position, and
eleven vertical props, 10 inches square, were inserted between it
and the middle sill, and 12-inch sill-stretchers put in; 10-inch
square rakers, with foot-blocks, followed, and the excavation was
complete, being fully timbered to the level of the rails.

The mining for the invert was then proceeded with, the face
only being timbered. The curve for the invert, being shallow,
was not poled.

Between the top bars, twelve in number, short stretchers were
fixed about 3 feet apart, and single stretchers between the rest, a
9-iuch cross-stretcher, or cock-roost, running between the fourth set

296 LOPES ON THE REPARATION OF BETCHWORTH TUNNEL. [Selected

of bars. All props were dogged top and bottom, bi;t no bolts were
used, driving and page-wedges, however, being plentiful. The
back props were fastened to the sides by 9-inch by 3-inch angle-

FiG. 2.

TRANSVERSE SECTION

Scale 1 inch = 8 feet.

ties, and the bottom uprights and the lower sills were laced by
1-inch boards.

Figs. 2 and 3 represent the full timbering for a 12-foot length of
inverted section.

Papers.] LOPES ON THE REPARATION OF BETCHWOETH TUNNEL. 297

The brickwork was then put in hand, invert moulds and leading
frames being first placed in position. The side stretchers and bars
were removed as the brickwork was got up until the side walls
were ready for the skeleton centres. These, three to each 12-foot

afcf- i.i' e'

LONGITU Ol N Al. SECTION.

Scale 1 inch = 8 feet.

length, were made entirely of elm in three thicknesses. The middle
centre leaves 1\ inches thick, and the leading centres 3 inches and
grooved, with laggings 7 inches by 3 inches, were supported on
*J-inch props on brick piers 14 inches square, built out from the

298 LOPES ON THE REPARATION OF BETCHWORTH TUNNEL. [Selected

invert with 12-incli by 6-incli sills, and placed on beech slack
blocks 18 inches by 7 inches by 3^ inches.

As the arch progressed the side bars were taken out until six
crown bars remained, which were built in, and the spaces between
them filled in tight with brickwork to the poling-boards. The
keying-in for 1 foot 10 inches wide was effected by block laggings
fixed transversely on grooved laggings speciallj- prejDared. These
})lock laggings were 22 inches long by 7 inches by 3 inches,
notched at each end to fit the grooves, and the key of the arch
was made good from one end outwards. The whole of the poling-
boards were left in.

The length being thus finished, the mining for another pro-
ceeded as the first, and the whole length was executed in precisely
the same manner. Another length followed until three lengths
from each end were completed, when a top heading was driven
through to connect the two faces. Both faces were kept in hand
until an interval of 36 feet remained, when the north end was
stopped and the south only jiroceeded with. When this length was
finished, the north was completed and the junction only was left.
Here the bars were supported on the toothings of the arches on
either side, and as the brickwork was finished eight bars were
built in with it, thus 37 yards were completed.

The skeleton ribs were left standing about ten days, by which
time the cement was well set. Notwithstanding, and in spite of
the bars being bricked in solid, the excessive weight of the super-
incumbent sand in the slip broke the toothings at the junction of
every length, causing a slight crack, the gTeatest being ^ inch
wide ; these cracks were immediately stopped, and there was no
further settlement.

Where the old arches at both faces showed signs of cracking and
weakness, which was for a length of 10 yards at the south end, and
8 yards at the north end, the inverted section was continued, and
here it was built in lengths of 6 feet. The skeleton ribs already
fixed were made the base for the work, 12-inch timbers being thrown
across from sill to sill with planks over them. An upper scaffold
was then made of 3^-inch by ^-inch double irons slung from the
sides of the ribs with cross-bolts, upon which die-square timbers
were placed and plank -sheeted to enable the miners to start breaking
into the key of the old arch.

As the brickwork was cut away, short polings were got in until
the 6-foot length was removed, when a crown bar 12 inches in
diameter, one end resting on the new brickwork and the other on
the old work, was inserted. The mining was continued, bars being

Papers.] LOPES ON THE REPARATION OF BETCHWORTH TUNNEL. 299

put in about 1 8 inches apart for the extent of the arch, below which
bars of 9 inches, die-square and 2 feet apart, sufficed, until all the
old, brickwork in the length had been removed, the face of the sand
being close-poled all the while and the end face secured by waling
12 inches square strutted by 9-inch timbers from the new brick

Fig. 4.

Segmental Centre Supporting Relieving Arch.

Scale 1 inch = 8 feet.

invert. Each 6-foot length was carried out in the same way, except
at the ends where the inverted section was to be abandoned. Here
the arches were gradually projected over longitudinally beyond the
walls until at the crown they led for about 9 inches. This was to
act as a shield to a lower arch.

The very unsatisfactoiy character of the old brickAvork, thus

300 LOPES ON THE REPARATION OF BETCHWOKTH TUNNEL. [Selected

exposed, suggested a complete examination of the rest of the tunnel,
and with hardly an exception the work was found to be defective.
Accordingly Sir John Fowler, K.C.M.G., Past President Inst. C.E.,
the Consulting Engineer to the Company, was invited to confer with
Mr. Banister and to determine on the course to he pursued as re-
garded the remaining 330 yards of the tunnel.

It was then decided to remove the whole of the side walls, to
rebuild them in Portland cement, to turn a relieving arch, also in
cement, at a lower level than the old one, and to dispense with an
invert. The new side walls, being 18 inches thick instead of
1 foot lOj inches like the old walls, were backed with cement
concrete to the sand, and carried up with the new relieving arch of
sufficient thickness to underpin the old arch until the relieving
arch was clear of it. The new arch was 18 inches thick, and the
space between the crown and the old soffit was filled in with old
dry bricks tightly wedged and packed (Fig. 4).

The work was built in cement throughout and ten break-ups
were put in hand at once, which, as the work proceeded, was found
to be the extreme limit for safety. Four skeleton ribs were fixed
at each place, the middle ones 9 feet apart and sheeted with 7-inch
by 3-inch laggings, tightly wedged. The level of the under-
pinning was first ascertained and the brickwork cut away for
9 inches thick, when die-square timber was put in and strutted off
the ribs, and another 14 inches got out under that and strutted in
like manner. The back being thus reached, the brickwork was
gTadually removed to the footings, and the sides were close-poled,
packed with hay, and stnitted by larch bars 12 feet long, 9 inches
thick and 2 feet apart, their ends being let into the brickwork on
each side.

As soon as the old brickwork had been removed the new was
inserted, great care being taken in the underpinning, which was
most tedious and difficult, the old brickwork being practically
loose with every tendency to fall. As length after length was
executed, the old side walls were in many places splintered and
cracked, and more skeleton ribs had to be erected, and the mining
lengths reduced from 9 feet to 7 feet 6 inches. By this arrange-
ment, however, the work was completed without accident. AYhere
the relieving-arch section joined the new inverted arch (Fig. o)
a wall 14 inches thick was built as face packing, and at the south
entrance the whole of the spandrels and parapet were taken down
and rebuilt.

The ribs for the relieving arch were made in two sections of
6-inch timber, the struts raking from crown to heel with cross-ties

Papers.] LOPES ON THE REPARATION OF BETGHWORTH TUNNEL. 301

and queenpost, and could be taken in pieces and reunited The
tie-beams were kept sufficiently bigb above the rails to leave room
for the contractor's six-wheeled locomotive which worked throuo-h
the tunneL ^

The time occupied in the 55 yards of new inverted section in the
slip was from the 8th of August to the 30th of December, 1887 and
m the remaining 330 yards from the 7th of November, 1887, to the

Fig. 5.

i^ INVEnj-£0 SECTION J

<...60 I^.. .J^ IZ'q' Lengths.. .^ _ ^ £ nti «

._ .i ies.o' - i -A

^^^^m

v//////////////////////^^^^^

//////////////y

RAIL V LEVEL \

Vertical scale, 1 inch = 30 feet.
Horizontal ,, „ = go

7th of February, 1888, continuously day and night, with the
exception of Christmas-day.

In the reconstruction, one of the two lines of railway throu-h
the tunnel was taken up and the other slewed to the centre for the
convenience of the contractor.

Although there was little water in the tunnel, the long cuttin-
at the south end on a gradient falling towards the tunnel rendered

302 LOPES ON THE REPARATION OF BETCHWOBTH TUNNEL. [Selected

necessary tlie preservation of the original drainage arrangement,
which was by a 12-inch pipe.

During the busiest part of the reconstruction three hundred men
were employed night and day with six horses and one locomotive.
The bricks, of which two and one-third millions were used, were
the best Horsham stocks. Cement was supplied by the Sussex
Portland Cement Company, Newhaven, to the extent of 780 tons,
and this was mixed with 2,000 cubic yards of sand, part from pits
at New Cross, and part from beds at Oxted. Water was at first
provided in tanks from Horsham and Holmwood, but afterwards
from the main of the Dorking Water Company, by a 2-inch pipe
laid through the tunnel with junctions and bib-cocks where
necessary.

The following materials were supplied, viz. : — 62 elm skeleton
ribs; 114 segmental centres; 16,500 cubic feet of timber; 3,030
cubic feet of larch ; 37,400 lineal feet of 3-inch by 7-inch battens ;
40,600 lineal feet of 3-inch by 9-inch deals ; 52;^ fathoms of poling-
boards ; 48,700 page-, driving-, and raking-wedges ; 760 slack
blocks; 10 tons of hay; 10,525 gallons of naphtha, and 3,474 lbs.
of candles.

The slip comprised about 33,000 cubic yards, and of this the
bars in a 12-foot length of the inverted section bore 10,500 tons
during the mining.

The cost of the work per lineal yard of the inverted section was
£145, and of the relieving-arch section £30. The exceptionally
heavy expense of the former was caused by the enormous quantity
of timber necessary to support the slip, and to the necessity of
building in so much of it.

The tunnel was opened for traffic on the 1st of March, 1888.

The Paper is accompanied by several diagrams, from which the
Figs, in the text have been prepared.

Papers.] WOKTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. 303

(Paper No. 236 1.)

" The Permaiient-Way of some Eailways in Germany and
in Austria-Hungary." ^

(Translated and abstracted by William Barton Worthington,
B.Sc., M. Inst. C.E.)

This Paper is a digest of a series of illustrated articles describing
in considerable detail tlie permanent-way of certain railways in
the German and in the Aiistro-Hungarian States. The principal
dimensions of rails and metal sleepers are given in Tables I and II,
in which will be found some further particulars relating to each
railway.

Table I. — Rails.

[Length.

Alsace-Lorraine Railways.

I. Steel rails on wooden cross-
slcejiers

29-50

II. Steel rails on iron cross-sleepers j
III „ „ [ „

with Haarmaun hook-plates |
IV. Rteel rails (Hartwich) for local I nq . en

lines /

Austrian North-Western Bailway.

I. Steel rails on steel- sleepers, Vgq. en

Holienegger system . . . / '
II. Steel rails on wooden cross- 1 nq . -^

sleepers j

III. Steel rails on specially large 't I

bearing-plates ^ . . . • /, "

Deptb.

Width I Thick- Width ^^'eight

of ness of
Head. ; Web.

of
Foot.

per

I/neal

Yard.

Inches. Inches. Inch. Inches. Lbs.

514

4-90
4-90

2-31

7-07 1-96

2-23
2-23

0-54

0-39

0-43
0-40

I
3-96 74-30

4-71

3-54

4-09

73-76

58-86
66-52

' The original articles appeared in the Organ fiir die Fortschritte des Eisen-
bahnweseus, 1888, p. 1 et seq.

" Bearing-plates 13-7 inches x 5-1 inches.

304 •R-OKTHINGTON ON THE PERMANENT -WAY OF EATLWAYS. [Selected
Table I. — Rails — continued.

Length.

Depth.

"Width Thick-

of ness of

Head. Web.

Width

of
Foot.

Weight

per
Lineal
Yard.

Feet.

Inches.

Inch.

Inches.

Lbs.

Bavarian State Eaihcays.

I and II. Main and secondary lines
III. (a) Local lines

(h)'Do

(c)Do. (Hartwich). . . .

29-50
29-43
29-50

5-10
4-00
4-32
5-90

2-28
1-81

0-43
0-31

o'-'35

4-10
2-67
3-54
4-71

63-00
38-20
44-25
58-46

State Bailways of Saxomj.

I. Main and branch lines.
II. Local lines, normal gauge
in. „ „ narrow ,,

24-60
24-60
29-50

5-11
4-32
3-43

2-27
2-00
1-60

0-43
0-39
0-31

4-12
3-37
3-10

69-24
49-00
31-40

Bhenish Bavarian (Palatinate).

I. Main lines, iron cross-sleepers
II. „ „ wood „
III. Secondary lines, wood ,,

26-24

5-26
4'-'l2

2-27
2'-'03

0-42
o'-'39

4-12
2'-"54

68-50
50'-'34

Hessian Ludicigs Bailivay.

I. Steel rails on iron cross-sleepers
,, „ wood „

24-60

5-11

2-27

0-56
J)

3-93

71-8

Baden State Bailways.

I. Main lines, steel rails on iron'i
cross-sleepers /

II. Local lines, steel rails on wood |
cross-sleepers . . . . /

29-50
24-60

5-08
4-08

2-36
2-04

0-54
0-43

4-12
3-54

73-00
53-40

Austrian Southern Baihcay.

32-80

5-00

2-25

0-50

4-00

68-54

Austrian State Bailicays.

I. (a) Steel rails, iron cross-^

sleepers (Heiudl) . . /

(b) Steel rails, wood cross-1

sleepers /

II. (a) Steel rails, iron cross- "1

sleepers (Heindl) . . j

(h) Steel rails, wood cross-1

sleepers j

24-60
24-60

4-91
4-71

2-27

>>
2-23

»>

0-46

>>
0-46

4-32

)>
4-32

71-10

»
63-93

Huncjarian State Bailways.
I. Main lines, 1st rank . . . |

II. „ „ 2nd „ • • •)

26
23
19
26
23
19

251

68 1

251

68)

5-00
4-32

2-28
1-85

0-46
0-43

4; 08
3-54

67-00
50-22

III. Secondary lines |

19
16

68,
40/

314

1-49

0-39

2-75

30-24

.it

Papers.] WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. 305
Table II. — Metal Sleepers.

Width Width ' „ ,
below. I above. , P '

Thick-
Length. ! ness of
top.

Weight.

Alsace-Lorraine Hallways.

Inches.

Feet.

Inch.

Lbs.

II. Steel rails ou iron cross-sleepers

8-05

4-32

2-90

7-87

0-35

110-00'

III. „ „ „ „ \
with Haarmaun hook-platesj

10-34

511

3-54

8-85

0-31

150-42 2

Austrian North-Westerii Railway.

I. Flat-bottomed steel rails oui
mild steel longitudinal- (
sleepers (Hohenegger sys-
tem) j

11-81

6-6

2-94

29-25

0-35

577-60

Bavarian State Railways.

I. Steel rails ou iron cross-sleepers,"!
closed ends (Heindl system) /

9-44

5-12

3-54

8-20

0-35

138-88

II. Secondary lines. Commencing in 1888, these lines will be laid with per-
manent-way similar to No. 1, but lighter.

III. (a) Steel rails on iron longi-"l q.nc
tudinal-sleepers . . ./
(h) Steel rails ou iron cross- M n.nq
sleepers /

Rhenisli Bavarian (Palatinate)
Railways.

I. Steel rails on iron cross-sleeiDcrs

Hessian Ludivigs Railway.

I. Steel rails on iron cross-sleepers
closed at the end .

5-91
3-90

2-32 29-43

2-96

j9-25j (6-301 (4-93|

to > < to > < to
14-30, 3-20 |2-76

Austrian State Railways
la and Ila. Steel rails ou iron cross-

spersj g.gQ

Ilrt. Steel rails ou iron cross-"! i a . oc
sleepers (Heindl system) . /

Baden State Raihvays.

iel rails on iron cross-sleejiersl q r,p.
(Hilf pattern) . . . .]\

4-70

5-90

4-60

2-75

3-93

2-40

-20

8-50

-20

7-87

7-95

0-31
0-35

0-43

0-40

0-35

346-10
87-00

114-603

114-20

157-50

94-30

' Old pattern. ^ New pattern.

^ Minutes of Proceedings Inst. O.E., vol. xci. p. 492.

[the INST. C.E. VOL. XCV.]

306 WORTHINGTON ON THE PERMAXENT-WAY OF RAILWAYS. [Selected

Alsace-Lorraine State Eailways.

There are foiir kinds of permanent-way in use on these railways.

I. Steel rails on wooden cross-sleepers ^
II. Steel rails on iron cross-sleepers I

1 'ill 1^9-lD.

Ill Steel rails on iron cross-sleepers with ,.

Haarmann hook-plates
IV. Steel rails (Hartwich system) for local lines.

I. The inner cover of the fish-joint is 18-7 inches X 3-29
inches x 0-78 inch, and weighs 10-86 lbs. The outer cover is
an angle of the same length and weighs 20 lbs. The fish-bolts are
0-93 inch diameter, and weigh 1-6 lb., and are spaced 4-4 inches
apart centre to centre.

The rail-bearing plates are 6 • 87 inches x 6 • 87 inches X 0 • 47 inch,
with raised edges 1 • 4 inch wide and 0 • 4 inch high, and weigh
5 • 9 lbs. each. They are used only at the sleepers on each side of
the rail joint, and are let into the sleeper at the inner edge so as to
give the 1 in 20 cant to the rail.

The rail is attached to the sleeper by three screws passing through
holes in the bearing plate, two on the inside and one on the out-
side of the rail, the head of the screws bearing on the edge of the
foot of the rail. These screws are 4 • 1 6 inches long, including the
head, and 0-74 inch diameter below the head; they weigh ^ lb.
each. The sleepers are of creosoted oak, 8-2 feet x 10*4 inches
X 4-1 inches.

There are ten sleepers to the 29 feet 6 inches rail-length, spaced
from centre to centre, 23*9 inches at the rail-joint, 29*5 inches
next, 37-4 inches next, and 39*4 inches (1 metre) the remainder.

The weight of iron and steel in one rail-length, 29 feet 6 inches,
of this permanent way is : —

2 rails 1,464

4 rail-joint plates 61

4 fish-bolts 6

5 rail-bearing plates .... 23
60 screws 44

31 lbs.
75 „
50 „
40 „
91 „

Total . . . 1.600-93

or 162 '7 lbs. per lineal yard.

II and III. The rails and rail-joints are the same as in I. The
older iron sleepers differ from the Yautherin section only in having
a thickening of triangular section, the apex of the triangle being

rapprs] WORTHINGTON ON THE PERMANENT -^V AY OF RAILWAYS. 307

downwards, along the bottom edge of the sides ; the newer sleepers
are of larger dimensions. The ends of the sleepers are closed.

II. In the older form the sleeper is bent at the middle so as to give
the 1 in 20 cant to each rail. The rail rests directly npon the
sleeper, and is held in place by two clamp-plates, throTigh each of
which passes the bolt which fastens it to the sleeper. The bolts
are 0 • 78 inch diameter, and weigh 0 • 8 lb. each. The head of the
bolt is oblong, as is the hole in the sleeper through which it passes,
half a turn being given to the bolt to fix it. Between the clamp-
plate and the sleeper is a packing with a projection on its lower
side which fills up the open portion of the oblong bolt-hole in the
sleeper and prevents the bolt from turning.

III. In the newer pattern the 1 in 20 cant is given to the rail by
a wedge-shaped " hook-plate " (Haarmann's pattern). At the outer
end this plate is formed into two hooks, one of which passes down,
through and forward under the top plate of the sleeper, while the
other turns wp and back over the foot of the rail. The inside of
the rail is secured to the sleeper by a clip and olilong-headed fang
bolt, the clip having on its lower face a projection which fills the
superfluous portion of the bolt-hole in the sleeper. The hook-f)late
weighs 4 lbs. and the clip about 1 lb.

In the 29,;^ feet rail-length there are ten sleepers spaced from
centre to centre: 23*2 inches at the point, 29-9 inches next, 37*4
inches next, and 39*4 inches the remainder.

The weight of one rail-length of this newer pattern is : —

2 rails

4 rail-joint plates

4 fish-bolts
10 sleepers
20 hook-plates
20 dips ....
20 bolts . . .

Total . .
or 326 '3 lbs. per lineal yard.

,4G4

3i lbs

•76 „

50 „

564

40 „

25 „

15 „

22 „

211

59 „

IV. The rails are of steel and laid on the Ilartwich system.

The angle joint-plates are 24 inches long, 5 • 9 inches high, and
Aveigh 34 • 6 lbs. each. The rail-joint is made with eight bolts
0'78 inch diameter in two rows 2*36 inches apart, centres. The
distance of the centre of the bolts from the end of the rail is, in the
upper row, 2-75 and 8*26 inches; in the lower row 5*11 and
10-62 inches.

The gauge is kept T)y cross-ties 1 inch in diameter, 9 feet 10. inches

X 2

308 WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. [Selected

apart (centres), and weighing, together with the two nuts at each
end, which form the attachment to the rail and by means of which
the gauge is regulated, 16* 75 lbs.

The 1 in 20 cant of the rails is obtained by wedge-shaped
washers between the web of the rail and the nuts of the ties.

The weight of one rail-length, 29 feet 6 inches, of this permanent-
way is : —

2 rails 1,443-65 lbs.

4 angle-joint plates 138 '43 „

8 fish-bolts 8-10 „

3 cross-ties and nuts . . . . 50 ■ 35 „
12 washers 10 85 „

Total .... 1,651-38 „
or 167-78 lbs. per lineal yard.

AusTPJAX North- Western Eailway.

The permanent-way for main lines is of three kinds.

I. Flat-bottomed steel rails on mild steel longitudinal sleepers
(Hohenegger system),
II. Flat-bottomed steel rails on wooden cross-sleepers with
ordinary bearing plates.
III. Flat-bottomed steel rails on wooden cross-sleepers with
specially large bearing plates.

I. The fish-plates for rail-joints are 19 '68 inches long. The inner
plate is a flat plate of 11 lbs. weight, the outer is an angle-plate
with a projecting member at the top reaching half-way up the head
of the rail, and weighs 25 • 62 lbs.

The joint of the longitudinal sleepers is made by a wrought-iron
box with open ends, the bottom of which is a flat plate 16 j inches
wide, and 15f inches long, on to which is bolted a plate bent to fit
the inside of the sleeper. To this bent plate the sleepers are
fastened by six bolts. The bottom plate of the joint-box is hori-
zontal, and the top plate is so shaped as to give the inward cant ot
1 in 16 to the sleeper and rail. The joint-box weighs 35 j lbs.

The bolts for the rail-joints and sleeper-joints are 0*86 inch in
diameter; the former weigh !•! lb., the latter 1*3 lb.

The rail is fastened to the sleeper by bolts of 0 • 74 inch diameter,
passing through a square clip, one edge of which fits exactly
to the sloping outer edge of the rail foot, and the other fits against
a sloping rib formed along the edge of the top surface of the
sleeper.

Papers.] WOETHINGTON ON THE PERMANENT -WAY OF RAILWAYS. 309

The weiglit of one rail-length of the road is : —

2 steel rails 29 feet 6 inches long . . . 1 , 158 ■ 74 lbs.

2 mild steel sleejjcrs 29 feet 3 inches long 1,155 -21 „

4 angle-irou cross-ties 238 '09 „

2 rail-joint angle-plates 51'14 „

2 „ flat-plates 22-04 „

2 sleeper-joints 70 • 53 „

8 rail-joint bolts 10-58 „

20 sleeper bolts 22 ■ 04 „

16 cross-tie bolts 14-11 „

36 rail bolts 27-78 „

130 washers, &c 95-15 „

Total .... 2,865-41 „
or 290-7 lbs. per lineal yard.

II. The fish-plates at the rail-joints are angle-plates ; the outer
one has a projection at the top, is 27*55 inches long, and weighs
26 "44 lbs. The inner one is 25 '19 inches long, and weighs
19" 17 lbs. The bolt-holes nearest to the joint are 6*7 inches from
centre to centre, and the outer holes are 4*6 inches from these.
The fish-bolts are 0*86 inch diameter, and weigh 1*3 lb. each.

Between the rail and the sleeper is a bearing-plate, 7*9 inches
long, 5 • 5 inches wide, and 0 • 4 inch thick, with a rim ^ inch high
along the outer edge, against which the outer angle fish-plate rests.
The rails and plates are fastened to the sleeper by three octagonal
spikes, 0 • 7 inch diameter, and 6 • 3 inches long, two on the outside,
and one on the inside of the rail.

The wooden sleepers are 8*2 feet long, 9*8 inches broad below,
at least 5 • 9 inches above, and 5 • 9 inches deep. At the joints they
are spaced 23*6 inches from centre to centre ; the remaining spaces
increase from 32*27 inches to 33*85 inches at the middle of the
rail-length.

The weight of iron in one rail-length of this road is : —

2 rails 29 feet 6 inches long . . . 1 ,309-55 lbs.

4 angle-joint plates 91-25 „

8 fish-bolts 10-58 „

8 washers 1 - 38 „

22 rail-bed plates 10-14 „

66 spikes 55-34 „

Total .... 1,478-24 „

or 150-2 lbs. per lineal yard.

III. This permanent- way combines the rail fastenings of I with
the wooden sleepers of II. The rail rests upon a bearing-plate

310 WOKTHINGTON ON THE PERMANENT- WAY OF RAILWAYS. [Selected

13* 7 inches x 5"1 inches, to whicli it is attached hy two holts
passing throngh clips, the oblique outer edges of which rest against
the sloping faces of corresponding ribs formed upon the top of
the bearing-plate, while their inner edges lap orer the edges of
the rail foot. Thus by slackening the bolt of one clip and
tightening the other, the gange of the line can be slightly altered.

The bearing-plates are fastened to the sleepers by three spikes,
tAvo on the outside, and one on the inside. The large size of the
bearing-plate gives a greater resistance to the tilting over of the
rail than is the case with the ordinary plate in II.

The weight of the ironwork of one rail-length of this road is : —

2 rails 29 feet 6 inches long . . . 1 ,309-54 lbs.

4 angle-joint plates 91-25 „

8 fish-bolts 10-68 „

8 washers 1-38 „

22 large rail bearing-plates . . . 247 • 34 „

44 bolts for „ ... 48-49 „

44 washers 1 - 99 „

66 spikes 55-34 „

44 holdfasts 81-57 „

Total 1,847-58 „

or ] 87 - 7 lbs. per lineal yard.

Bavarian State Eailways.
The lines may be divided into three classes : —

I. Main lines.
II. Secondary lines.
III. Local lines (of normal and narrow gauge).

I. Main lines : Greatest wheel-pressure 7 tons, and highest
speed 46 miles per hour.

(a) With steel rails and iron cross-sleepers (Heindl system) ;

(6) With steel, or steel-headed rails, and wood cross-sleepers.

The rails (flat-bottomed) are the same for both a and h.

There are eleven sleepers in the rail-length, spaced as follows : —
At the joint, 19-7 inches, centre to centre; next, 29*6 inches;
next two, 31* 5 inches ; four middle spaces, 35 "4 inches.

The angle fish-plates have the same cross-section for a and 6,
the length being 19" 7 inches for the outside plate in both cases,
and 26-2 inches and 29-5 inches for the inside plate in a and h
respectively. The fish-liolt holes are 2 inches and 7 inches from
the joint.

Papers.] WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. 311

The fish-bolts are 0*87 inch diameter, and weigh 1*3 lb.; the
foot-bolts which attach the rails to the iron-sleepers are 0 • 8 inch
diameter, and weigh 1 lb. ; the spikes for the wooden sleepers are
0 • 6 inch thick, 6 inches long, and weigh 0 • 6 lb.

The rail bed-plates on the iron sleepers are wedge-shaped, with
an inclination of 1 in 20 ; those on the wooden sleepers are 0 • 47
inch thick under the rails, and 0 • 7 inch at the edges, the 1 in 20
inclination being cut in the sleeper. The plates are 7 • 08 inches
X 5' 90 inches at the joint, and 5*9 inches x 5*59 inches at the
intermediate sleepers.

The wood sleepers are 8*2 feet long, 10 "23 inches wide below,
and at least 6 • 29 inches wide above, and 6 • 88 inches thick.

The weight of one rail-length of this road (29*5 feet) is : —

2 steel rails 1,238-10 lbs.

11 cross sleepers 1,527'80

2 outside fish-plates 39 • 24

2 iuside „ 52" 46

8 fish-bolts 10-14

22 bed-plates 47-61

44 foot-bolts aud fittiup-s . . . . 100-08

Total .... 3,015-48 „

or 306 lbs. per lineal yard.

II. Secondary lines : Greatest wheel-pressure, 6 tons ; greatest
speed, 15 miles per hour.

Commencing in 1888, these lines will be laid with material
similar in design to that used for main lines, but lighter.

III. Local lines : Greatest wheel-pressure, 5 tons ; greatest
speed, 15 miles per hour.

(a) Flat-bottomed steel rails on iron longitudinal sleepers.

The total weight of this permanent- way is 164*4 lbs. per yard
run.

(6) Flat-bottomed steel rails on iron cross-sleepers.

The total weight of this permanent-way is 195*86 lbs. per yard
run.

The rails are kept to gauge, and to their cant of 1 in 20, by cross-
ties (four in the 29 feet 6 inches length of the rail), 3|^ inches by
I inch, bolted to the web of the rail by two bolts.

The total weight of this permanent- way is 139*5 lbs. per yard
run.

In addition to the local lines laid on these three systems, there

312 WORTHIXGTON ON THE PERMANENT- WAY OF RAILWAYS. [Selected

are some narrow-gauge (1 metre) lines, laid witli a flat-bottomed
rail on light iron cross-sleejiers, the total weight of the permanent-
way being 123-58 lbs. per yard run.

State Eailways of Saxony,
These may be divided into three classes : —

I. Main and branch lines.
II. Local lines of normal gauge.
III. Local narrow-gauge lines.

I. The permauent-Avay of these, as of the local lines, consists of
flat-bottomed steel rails, laid ujDon wooden cross-sleepers. The
cant of the rail is at present 1 in 16, but it is intended to make
it 1 in 20.

The sleepers are of fir, impregnated with zinc chloride ; 6 feet
4 J inches to 8 feet 2^ inches long; 6*7 inches wide above, and
7*87 inches below, and 6-29 inches thick. At the rail-joint they
are 21^ inches apart (centres), the next pair 30*7 inches, and the
remainder 35 • 4 inches.

The angle fish-plates are 25' 19 inches long outside, 17*54 inches
inside; the former weighing 26*8 lbs., the latter 13*59 lbs.
The outside plate is prolonged upwards under and round the
top flange of the rail, so that the top of it is only about f inch
below the top of the rail. The fish-bolt holes nearest to the joint
are 3f inches from centre to centre, and the outer holes are 5*18
inches from these. The bolts are 0*97 inch in diameter, and with
the nut weigh 1*93 lb.

The rail bearing-plates, which are fixed on every sleeper, are
7-56 inches X 5*96 inches, 0*47 inch thick, and weigh 6*72 lbs.
On each side of the rail-foot they have a rim 0 • 23 inch high, and
on the under side have three pointed ribs, 0*12 inch high, to pre-
vent the plate from slipping on the sleeper.

The rail is fastened to the sleeper by three | inch square spikes,
5f inches long, two on the inside and one on the outside.

II. Local lines of normal gauge, with maximum wheel-pressure
of 5 tons.

The sleepers are the same as for main lines, and spaced in the
same way.

The outside angle fish-plate is 20 • 3 inches long ; the inside one
18 "10 inches. Their ends butt against the spikes which attach
the rails to the sleepers, and which are the same size, and arranged

Papers.] WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. 313

in the same way as those for the main lines. The fish-bolts are
the same as on main lines, and spaced in the same way.

The rail-hearing plates on each sleeper are 7 • 07 inches hy 5 • 89
inches, 0 • 43 inch thick, and weigh 4 • 84 lbs. They have no ribs
on the under side.

The cant of the rails is 1 in 1 6.

III. Local narrow (2 feet 5^ inches) gauge lines.

These are laid with flat-bottomed steel rails on wooden cross-
sleepers.

The sleepers are of fir, impregnated with zinc chloride, and are
about 5 feet long, 7 • 9 inches wide at the bottom, 5 • 5 inches at the
toj?, and 4 • 3 inches thick. There are twelve sleepers to the rail-
length, spaced 19" 7 inches apart (centres) at the joint, 30*4 inches
for the rest.

The varioxis fastenings are similar to those of the main lines
described above, but lighter.

Rhenish Bavarian (Palatinate) Eailways.
The permanent-way may be divided into : —

I. For main lines with iron cross-sleepers.
II. For main lines with wood cross-sleepers.
III. For secondary lines with wood cross-sleepers.

I. The angle fish-plates are 19-7 inches long, and weigh 17*6 lbs.
each. The fish-bolts on each side of the joint are 3 • 9 inches apart
from centre to centre, and the other two are 5 • 1 inches from these.
The bolts are 0-86 inch diameter, and weigh 1*2 lb. each. The
rail foot-bolts are 0 • 74 inch diameter, and weigh 0 • 66 lb. They
hold down the clips which press upon the foot of the rail, and
which have on the under side a projection which fits into the
oblong bolt-hole in the sleeper. These projections are of different
sizes, and by changing the clips the gauge of the line can be
regulated.

The sleepers are of varying section, and are of the pattern fully
described in the Minutes of Proceedings Inst. C.E., vol. xci. p. 492.
The varying thickness is obtained by rolling in eccentric rolls, and
the bending is done by hydraulic pressure while the metal is still
warm. The sleeper is deep and narroY^r in the middle, and widest
and thickest under the rail, where it has an inclination of 1 in 20.
It weighs 114-6 lbs.

314 WOBTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. [Selected

The nine sleepers are sp^aced in the 24 feet 3 inch rail-length
from centre to centre as follows : —

22-04 inches at the joint,
33-06 „ the next,
37-76 ,, the remainder.

The weight of one rail-length, 24 feet 3 inches, of this permanent

way IS : —

2 rails 1,199

4 anc(le fish-plates 70

8 fish-bolts 9

9 iron sleepers 1,031

36 rail foot-bolts 23

36 „ foot-clips 26

36 washers 1

Total . . . .2,362

31 lbs.

54 „

34 „

74 „

82 „

19 „

14 „

or 270 lbs. per lineal yard.

II. The permanent-way for main lines with wood sleepers is, as
regards rails and rail-joints, exactly similar to I. The sleepers
of oak in the natural state, or of fir treated with corrosive sub-
limate, creosote oil, or zinc chloride, are 8 feet 2^ inches long, Q\
inches thick, 10 "6 inches wide at the bottom, and at least 8*6
at the top. They are adzed to a slope of 1 in 20 to receive the
rail-bearing plates, which are 7*7 inches by 6"3 inches, and 0*4
inch thick, with a rim 1 • 8 inch x 0 • 3 inch along the outer edge
to hold the rail. The weight of the bearing-plate is 6 • 6 lbs. ; it
has one hole on the outer and two on the inner side of the rail for
the spikes, 6*5 inches long, and weighing 0*7 lb., which are
driven into the sleeper to hold the rail-foot.

The spacing of the sleepers is the same as that of the iron
sleepers in I.

Bearing-plates are used on every sleeper, whether in curves or
straight lines.

- III. For local lines a small flat-bottomed rail on wood cross-
sleepers is used.

The angle fish-plates of Bessemer steel are 15j inches long, and
weigh 9*1 and 9'5 lbs. inside and outside respectively^ They
project below the bottom of the rail to the extent of the thickness
of the rail-bearing plates, against the ends of which their ends rest.

The fish-bolts are 0 • 7 inch diameter, and weigh, together with
nut and washer, 0-7 lb. each. The rail-bearing plates are 6"3
inches X 5 • 9 inches X 0 • 3 inch, without any raised outer rim, and
weigh 2 • 8 lbs. each. The spikes (one on the outside and two on
the inside of the rail at each sleeper) are 5-9 inches long, and
weigh about ^ lb. each.

Papers.] WORTHINGTON ON THE PERMANENT- WAY OF RAILWAYS. 315

The sleepers are of fir, 7 feet 6^ inciies long, 5 • 9 inches thick,
7 • 9 inches wide at the bottom, and at least 5 • 9 at the top. The
seats for the hearing-plates are adzed to a slope of 1 in 20, and
hearing-plates are used on every sleeper both in straights as well
as curves.

The sleepers are spaced from centre to centre : —

20 "86 inches at the joint,

34-82 „ next,

37 '39 „ the remainder.

Hessian Ludwigs-Eisenbahn.

On this line two forms of permanent- way are now used —
T. Flat-hottomed steel rails with iron cross-sleepers on the lines

of great traffic.
II. riat-hottomed steel rails with wooden cross-sleepers on the

lines of small trafiBc.

The further use of the iron longitudinal sleeper permanent-way
(Hilf's system), which was laid on the lines from Frankfort-on-the-
Main to Limburg, from Wiesbaden to Niedernhausen, and part of
the line from Mainz to Worms, has been given up, the cost of
wages for maintenance of the 78 miles of line laid with longitudinal
iron sleepers having been found to be, for the years 1881-1886,
36 per cent, higher than in the case of road laid with cross-sleepers.

I. The angle fish-plates are 24 inches long ; the fish-bolt holes on
each side of the joint are 4 • 7 inches from centre to centre, and the
other two holes are 5 • 5 inches from these. The foot of the angle-
iron is cut away at each end so as to rest against the clip which
holds the foot of the rail down. These angles weigh 17*6 lbs,
each. The fish-bolts are 0-78 inch diameter, and weigh 1*1 lb.
each.

The rail foot-bolts, which are provided with an eccentric where
they pass through the sleepers, by means of which the gauge
(4 feet 8i inches) can be regulated, are 0-78 inch diameter, and
weigh 0-95 lb. each. The clips through which they pass, and
which hold the foot of the rail, weigh 0*55 lb. each. The iron
cross-sleepers are closed at the ends. The sleeper is bent to give
the 1 in 20 cant to the rails for a length of about 6 inches outside
and 10 inches inside the rail. The sleepers weigh 114*2 lbs. each,
and are spaced from centre to centre : —

24 '8 inches at the joint,

30-0 „ next,

35 '0 „ the remainder.

316 WORTHINGTON ON THE PERMANENT- WAY OF RAILWAYS. [Selected

The weight of one rail-length (24 feet 7 inches) of this permanent-
way is : —

2 rails 1,177

9 sleepers 1 , 027

4 angle fish-plates 70

8 fish-bolts 8

36 rail foot-bolts 34

36 clips 19

Total .... 2,338

25 lbs.
79 „
54 „
82 „
13 „
85 „

or 284 • 09 lbs. i^er lineal yard.

II. The rails and rail-joints are the same as for I.

The rail-bearing plates are 7 • 1 inches long, 6 • 6 inches wide,
with a rim 0 • 2 inch high and 1 • 6 inch wide on the outer edge,
and weigh 7 • 7 lbs. each. There are four holes punched in them,
through which the ^ inch square and 6^ inches long spikes are
driven in.

The wooden sleepers are of oak and fir, 8 feet 2J inches long,
8-83 inches wide at the bottom, and at least 4*72 inches at the top,
and 5 • 9 inches thick. The oak is used in its natural state, the fir
is treated with con'osive sublimate. The sleepers are spaced in the
same way as the iron sleepers (I). With the oak sleeper in straight
lengths, bearing-plates are only used for the sleeper on each side of
the rail-joint, while in curves of from 15 to 30 chains radius four
additional bearing-plates are used on the intermediate sleepers ; in
curves of from 30 to 60 chains radius only two additional plates are
used. Where, as is sometimes the case, oak and fir sleejiers are
used together, in straight lengths, five oak sleepers and four fir are
used in each rail-length, and in curves oak only. Main lines are
never laid with all the sleepers of fir.

As yet no special permanent-way is used for local lines.

Austrian State Eailways.

The present normal permanent-way is divided into

I. For first-class lines —

(a) Steel rails (system X) on iron cross-sleepers on Heindl's

system.
(h) Steel rails (system X) on wooden cross-sleepers.

II. For second class lines —

(a) Steel rails (system XI) on iron cross-sleepers on Heindl's

system.
(h) Steel rails (system XI) on wooden cross-sleepers.

Papers.] WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. 317

The rails and joints are similar in la and lb ; the sleepers and
fastenings in 16 are the same as those in II&, while the rails in
Ila are the same as in 116. It is therefore only necessary to
describe la and 116.

la. The outside angle fish-plate is 23 • 6 inches long, and weighs
17 '2 lbs., the inner 26 "25 inches long and weighs 23-5 lbs. The
fish-bolts nearest the joint are 4*08 inches from centre to centre,
and 4*91 inches from the outer bolts.

The wedge-shaped bearing-plates are 5*22 inches long, 2*63
inches wide, and varying from 0 • 23 to 0 • 52 inch thick, thus giving
a cant of 1 in 1 6 to the rail. They weigh 3 lbs. each. Along the
outer edge is a raised rim against which the outer edge of the rail-
foot rests.

The fish-bolts are 0 • 85 inch in diameter, and weigh 1 • 25 lb.
Grover's washers are used to prevent the nuts from working loose.
The rail is attached to the sleeper by two bolts 0*85 inch diameter,
with tee-heads, and weighing 1 • 1 lb. each. The bolt passes through
a clip about 2 inches square, and weighing about ^ lb., which rests
on the foot of the rail, and is separated from the sleeper by a
packing, on the lower face of which is a projection which fills the
hole in the sleeper through which the tee-head of the bolt has
passed. These packings are of four different patterns, so that the
gauge can be regulated by their means. Their average weight is
0-8 lb. Grover's washers are used with these bolts also.

The distance apart of the sleepers from centre to centre is : —
19-7 inches at the joint, 31*5 inches next, and 35*4 inches the
remainder.

The weight of one rail-length (24 feet 7 inches) of this per-
manent-way is : —

With Rail System X. With Rail System XI.

Lbs.

2 rails 1,167-35

9 sleepers 1,418-67

4 angle fish-plates . . . . 81-36

8 fish-bolts 10-00

18 beariug-platea 53-55

36 rail foot-bolts 40-00

18 outside clips 11*90

18 inside „ 8-84

36 packings 28-15

Something omitted in original^ 07. 7f;
? 44 Grover washers . . . /

Total .... 2,847-58

Lbs

1,049

1,418

2,729-23

or weight per yard run 347 - 20

332-30

318 -WOETHINCtTON on the permanent-way of railways. [Selected

II&. The angle fisli-plates on the inside of the rail are 21 • 6 inches
long, and weigh 16*7 lbs. ; on the outside they are 23 • 6 inches long,
and weigh 18 lbs. The foot of the angle-iron is cut out to take
the heads of the spikes by which the rail is attached to the
sleeper. The fish-bolts are 0 • 86 inch in diameter, and weigh
1 • 3 lb. each, and they are spaced as in la.

The rail-bearing plates are 7^ inches long, 5"1 inches wide,
0 • 35 inch thick, with a ^ inch rim at each side to hold the rail-
foot, and weigh 4i lbs. each. They are let into the sleejier to give
the rail cant of 1 in 1 6. To take the spikes they have two holes
on the inner, and one on the outer, side of the rail.

The spikes are 0 • 6 inch square, 6 inches long, and weigh 0*7 lb.

The sleepers are 6 feet 8j inches long, 6 inches thick, 8'8 inches
wide at the bottom, and at least 6 inches at the top. They are
either of oak, larch, or soft wood impregnated with chloride of
zinc. They are spaced in the same way as the iron sleepers in la.

In straight lengths and curves of more than ^ mile radius with
oak and larch sleepers, bearing-jDlates are used only on the sleepers
on each side of the rail-joint and the sleeper at the middle of the
rail. "With soft wood sleepers a bearing-plate is used on every
alternate sleeper. On curves of 15 chains radius and under,
bearing-plates are used on every sleeper for all kinds of wood.

Baden State Eailways.
These railways may be divided into two classes : —

I. Main lines with a permanent-way of steel rails upon iron

cross-sleepers.
II. Local lines with steel rails upon wood cross-sleepers.

The outer cover of the rail-joint is in the form of a channel iron
with the two legs bent outwards, the inner is a flat plate ; both are
21 J inches long, the outer weighing 22*6, the inner 11^ lbs. The
bolt-holes on each side of the joint are 4^ inches apart, centre to
centre, and the outer holes are 6 • 1 inches from these. In order to
prevent the creeping of the rail, the end of the channel iron cover
butts against the clip which holds the rail down to the adjoining
sleeper.

The fish-bolts are 0*8 inch diameter, and weigh 1 -14 lb. each.

The iron cross-sleepers are of the Hilf pattern, without the
middle rib. From a point about 10 inches inside, to a point about
5j inches outside the centre of the rail, the sleeper is bent to a
slope of 1 in 20 to give the rail its cant, and from this outside

Papers.] WORTHINGTON ON THE PERMANENT- WAY OF RAILWAYS. 319

point it is bent down again with a slope of about 1 in 17, the end
being closed (bent over). In the 29 feet 6 inches rail-length there
are eleven sleepers ; those at the joint are 22 • 4 inches apart from
centre to centre, the remainder being 33 • 2 inches apart. The rails

are fastened to the sleepers by bolts passing throiigh | 1 shaped

clips. The bolts are f inch diameter, and weigh 0 • 9 lb., and the
clips weigh 1 lb. each. In the hollow under the clip is fitted a
plate If inch sqiiare, and ^ inch thick, with a ^ inch hole for the
bolt, so placed that the circumference of the hole is 0*27, 0*4,
0"54, and 0*66 inch from the four sides of the plate respectively,
so that by turning this plate through an angle of 90° the gauge
can be altered.

Various kinds of washers are used to prevent the bolts from
working loose.

The weight of one rail-length (29 feet 6 inches) of this permanent-
way is : —

2 rails l,43G-53 lbs.

11 cross-sleei^ers 1,037 •94 „

2 channel fish-jjlates . . . . 45'19 ,,

2 flat fish-plates 22-93 „

8 fish-bolts 9-17 „

44 clips 4G-56 „

44 gauge-plates 15'52 „

44 rail-bolts 40-73 ,,

Total .... 2,654-57 „

or 269-72 lbs. per lineal yard.

II. The fish-plates are similar in design to those in I, but
smaller, being 16.^ inches long, and weighing, the outer 13^, the
inner 5^ lbs. The bolt-holes on each side of the joint are 3*8
inches from centre to centre, the other two being 4 • 7 inches from
these. The fish-bolts are f inch diameter, and weigh 0-9 lb.
The rail-bearing plates are 6*13 inches long, 4*72 inches wide,
and 0 • 3 inch thick, with an outer raised rim 0 • 3 inch high, and
weigh 2f lbs. Each has two rectangular holes through which pass
the spikes which hold the foot of the rail. These are 5 • 9 inches
long, 0 • 6 inch square, and are slightly widened oiit at the head to
enable them to be drawn out.

There are nine sleepers to each rail-length (24 feet 7j inches).
Of these the two at the joints and the middle one of each length
-are of oak, the remainder of red wood, both impregnated with
corrosive sublimate.

The sleepers are spaced from centre to centre; 21^ inches at the
joint ; 33 inches next space ; 34j inches the next two sjiaces ; and

320 WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. [Selected

35^ inches the middle two spaces. In ordinary cases rail-bearing
plates are used only on the three oak sleepers, the rail being
attached to the others by two spikes, one on each side. In sharp
curves bearing-plates are used on every sleeper.

The weight of the ironwork for one rail-length (2-i feet 6j inches)
of this permanent- way is : —

2 rails 876

2 channel fish-plates 2G

2 plain „ H

8 fish-bolts 7

6 bearing-plates IG

36 spikes 21

33 lbs.
46 „
13 „
06 „
41 „
43 „

Total . . . . 758-72 „

or 116 -87 lbs. per lineal yard.

Austrian Southern Eailway Company.

The permanent-way of this line is laid with Siemens-Martin
steel rails upon wood cross-sleepers.

The outer cover of the rail-joint is a channel iron with the
upper limb bent outwards, 23^ inches long, and weighing 17-8 lbs.;
the inner cover is flat, 21-65 inches long, and weighing 10 -35 lbs.
The l)olt-holes on each side of the joint are, from centre to centre,
4-16 inches, the other two being 5^ inches from these.

The lower limb of the outer cover is slotted near each end to
take the spike which attaches the rail-foot to the sleeper. The
fish-bolts are 0-86 inch diameter, and weigh 1^ lb. each. The
nuts are provided with washers.

The rail-bearing plates are 7-35 inches long, 5-17 inches wide,
0 • 4 inch thick, and have a raised rim 0 • 4 inch high along each
end to hold the foot of the rail. They weigh 5 lbs. each, and have
two holes in the inside, and one on the outside of the rail for the
spikes. These are 6^- inches long, 0-58 inch square, with T heads
and weigh 0*7 lb. each.

The wood cross-sleepers are 7 feet 10^ inches long, 6-4 inches
thick 10 inches wide at the bottom, and at least 5" 2 inches at the
top. Those which are of oak and larch are not treated with any
antiseptic, while those which are of beech are impregnated with
the fumes from gas tar oil (Paradis system). In the 32 feet 9 J inches
rail-length there are twelve sleepers spaced from centre to centre ;
20 inches at the joint; 30-9 inches the next space; 34-6 the
remainder. In curves up to 15 chains radius rail-bearers are used

Papers.] WOETHINGTON ON THE PERMANENT-WAY OF RAILWAYS. 321

on every sleeper; from 15 to 25 chains radius they are used on
eight out of the twelve including those at the joint, two spikes being
used on the inside, and one on the outside of the rail at the sleepers
without plates ; from 25 to 40 chains radius plates are used on
four only out of the twelve, the spikes on the other sleepers being
used as above. In curves of 40 chains radius and upwards, there
are plates on four out of the twelve, but the remaining sleepers
have one spike on each side of the rail.

The weight of the ironwork of one rail length (32 feet 9 j inches)
of the permanent-way is : —

2 rails 1,499-14 lbs.

2 outer joint covers 35'71 „

2 inner 20-72 „

8 fish-bolts 9-88 „

8 washers 0-35 „

8 rail-bearing plates 39-69 ,,

56 spikes 38-89 „

Total .... 1,644-38 „

or 150-4 lbs. per lineal yard.

Hungarian State Railways.

The permanent-way of modern Hungarian State Railways may
be divided into —

I. For main lines of the first rank.
II. For main lines of the second rank.
III. For lines of the third rank.

all of which are laid with flat-bottomed rails on wooden cross
sleepers with rail-bearing plates.

I. The outer fish-plate, which is an unsymmetrical channel iron,
is 24 '8 inches long, and weighs 21*6 lbs. The inner fish-plate is
plain, 22 inches long, and weighs 13 "9 lbs. The fish-bolts on each
side of the joints are 4 • 3 inches apart from centre to centre, and
5 • 9 inches from the next bolts. The fish-bolts of j-inch diameter
weigh 0-9 lb. each.

On the wood sleepers rest rail-bearing plates with an inclination
of 1 in 16. They are 7-08 inches long, 6-28 inches wide, 0*35 inch
thick, and weigh 4 lbs. They are plain plates without any outer
raised rim, and are punched for one spike on the outside, and two
on the inside of the rail. With a view to their durability these
plates are laid with the direction of the fibre at right angles to the
length of the rail.

[the INST. C.E. VOL. XCV.] Y ♦

322 WORTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. [Selected

In straight lengths and curves of 35 chains radius and over three
bearing plates are used in each rail length ; in curves of from 20
to 35 chains radius, four, and in curves of less than twenty chains,
six under the outer and four under the inner rail.

The rail spikes have T heads, are 6 j inches long, 0 • 62 inch by
0 • 70 inch in section (the long sides being at right angles to the
rail) and weigh ^ lb. each. There are three spikes to each bearing
plate. Where there are no bearing plates in straight lengths and
in curves of 50 chains radiiis or more, there are four spikes to each
sleeper, one on each side of each rail ; in curves of 35 to 50 chains
on two sleepers, there are six spikes, two on the outside, and one
on the inside of each rail, and on the remaining sleepers one on
each side of each rail. In curves of 20 to 35 chains radius, each
sleeper has two spikes ou the outside, and one on the inside of the
outer rail, and one on each side of the inner rail. In curves of
less than 20 chains radius the arrangement is the same as for 20-35
chains with the addition of an extra spike on the oiitside of the inner
on two sleepers. The classification above refers to rails of 8 metres
(26 feet 3 inches) lengths, the same proportions being adhered to
for shorter rails.

The cross sleepers are of oak and beech, the former occasionally,
the latter always impregnated with zinc chloride. They are
8 feet 2;^ inches long, 5-9 inches thick, 9-8 inches wide at the
bottom, and at least 6 • 7 inches at the top. They are spaced from
centre to centre 22 inches at the joint, and from 31 • 9 to 38 • 2 inches
the remainder.

The weight of one rail length (26 feet 3 inches) of the iron and
steel in the permanent-way is : —

2 rails 1,172-85 lbs.

2 inside fish-plates 27'82 ,,

2 outside „ 42-22 „

8 fish-bolts 7-19 „

6 rail-bearing plates . . . . 23-81 „

42 spikes 31-47 „

Total .... 1,306-37 „

or 149 '32 lbs. per lineal yard.

II. Main lines of the second rank.

The outer fish-plates (angles) a:re 20 • 1 inches long, and weigh
13-2 lbs., the inner, which are plain, are 22-4 inches long, and
weigh 7 • 1 lbs. The bolt holes nearest to the joint are 4 • 04 inches
apart, and the other two bolts are 5*7 inches from them, centre
to centre. The fish-l)olts are 0 • 62 inch diameter, and weigh 0 • 6 lb.

Papers.] WORTHINGTON ON THE PERMANENT-WAT OF RAILWAYS. 323

Some of the sleepers liave rail-bearing plates 4- 3 inches long,
5 • 9 inches wide, 0 • 3 inch thick, weighing 3 • 2 lbs. They have no
raised rim along the outer edge, and have two spike holes on the
inside, and one on the outside of the rail. The rail has a cant of
1 in 1 6. The rail spikes have T heads, are 5 ■ 9 inches long, and
0-6 inch x 0*55 inch in section and weigh ^-Ib. each. The
number of spikes used with each sleeper varies according to the
radius of the curve as in I. The wood sleepers are of oak, 7 feet
3 inches long, 5^ inches thick, 7*9 inches wide below, and at least
4 J inches above. They are spaced from centre to centre, 20*1
inches at the joint, and from 35 '1 to 37 inches the remainder.

The weight of one rail length (26 feet 3 inches) of the iron and
steel in this permanent-way is : —

2 rails 879

2 inside fisli-plates (plain) ... 14

2 outside ,, (angles) ... 26

8 fish-bolts 4

6 rail-bearing plates 19

42 spikes 21

Total . . . . 965-30

02 lbs.

or 110 '.34 lbs. per lineal yard.

III. The lines classed of the third rank are 1 metre gauge
(3-28 feet).

The fish-plates (plain) are 12 •35 inches long and weigh about
2\ lbs. each, the inner being a trifle thicker than the outer. Of
the four bolt holes the middle ones are 4'1 inches apart, centre to
centre, and the outer ones are 3 inches from these. The fish-bolts
are ^-inch diameter, and weigh 0 • 28.

The rail-bearing surfaces of the wood sleepers have an inclination
of 1 in 1 6, and are in part laid with bearing plates, 5 inches square
and 0"2 inch thick, weighing l£ lbs. These have on each side of
the rail a raised rim 1 inch wide, and 0 • 2 inch high, and have four
spike holes. In curves of 10 chains radius and flatter, two bearing
plates are used in each rail length ; in sharper curves four are used.

The rail spikes, which have a single-hooked head to hold the rail
foot, and two side lugs for drawing out by, are 5^- inches long,
0 • 46 inch square, and weigh 0 • 35 lb. each. There are four spikes
to each bearing plate. For sleepers without bearing plates, if the
radius of the curve is 10 chains or more, there is one spike on
each side of each rail ; if under 10 chains, there is one spike on
each side of the inner rail, one inside, and two outside the outer
rail. The wood cross sleepers are of oak, 5 feet 7 inches long,

Y 2

824 WOKTHINGTON ON THE PERMANENT-WAY OF RAILWAYS. [Selected

5^ inches thick, 7' 9 inches wide at the bottom, and at least 4*7
inches at the tojD. The rail joints are supported, not suspended.
There are eight sleepers to the rail length (19 feet 8^ inches wide)
spaced from 24*6 to 30 • 3 inches from centre to centre.

The weight of iron and steel in one rail length (19 feet 8^
inches) of this permanent-way is : —

2 rails 376-83 lbs.

4 fish-plates 10-05 „

8 fish-bolts 2-31 „

2 rail-bearing plates 3 - 47 „

36 spikes 12-38 „

Total . . . . 425-04 „

or 04-72 ll'S. per lineal yard.

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 325

(Students' Paper No. 243.)

" The Speed-Trials of the latest additions to the Admiral
Class of British War- Vessels." ^

By David Sing Capper, M.A., Stud. Inst. C.E.

The speed trials of H.M.SS. " Camperdown " and " Anson," in April,
1887, brought to a conchision the trials of the Admiral class of
British war-vessels.

The results show, that both in speed and economy, they siirpass
any of their predecessors except the "Howe"; and the perform-
ances of the " Anson," perhaps, are unequalled by those of any
heavily armoured vessel afloat. The " Camperdown " excelled the
"Howe" in speed, but was at light draught; while the "Howe"
was tried at load draught. This, being allowed for, places the
" Camperdown " second.

The " Camperdown " and the " Anson " are twin shijis, each
330 feet long between perpendiculars, 68 feet 6 inches in extreme
breadth, and with a depth of hold of 26 feet 2 inches. Their
displacement is 10,000 tons at load draught. The " Camperdown"
was built at Portsmouth dockyard, the engines being manu-
factured by Messrs. Maudslay, Sons, & Field, of Westminster ;
while the "Anson" was built at Pembroke dockyard, the engines
being manufactured by Messrs. Humphrys, Tennant & Co., of
Deptford.

These ships thus afford examples of two of the three types of
propelling machinery, recently described by Mr. S. H. Wells, Stud.
Inst. C.E.'^ It will therefore be needless to enter minutely into their
differences. A short summary of the dimensions of their leading
parts will, however, be necessary. Each shij) has twin screws driven
by two sets of engines of the three-cylinder compound inverted type.
Each set has one high-pressure cylinder, 52 inches in diameter,
and two low-pressure cylinders 74 inches in diameter. The stroke

* This communication was read and discussed at a meeting of the Students
on the 20th of AiH'il, 1888, and was awarded a Miller Prize in the Session
1887-88.

" Minutes of Proceedings lust. C.E., vol. xci. p. oG6.

326 CAPPER ON SPEED-TKIALS OF BRITISH WAR-VESSELS. [Selected

is 3 feet 9 inches in each case. The engines of the " Camperdown "
are in all leading particiilars identical with those of the "Benbow,"
supplied by the same firm. The cylinders are supported on four
cast-steel frames, to which the double guides for the cross-heads
are bolted. The condensers, one to each set of engines, are of
brass, vertical, containing eleven thousand five hundred and fifty
tubes apiece, giving a total cooling-surface of upwards of 17,000
square feet. The air-pumps, 30 inches in diameter, also of brass,
are worked by wrought-iron beams from the low-pressure cross-
heads. There is one air-pump to each low-jiressure cylinder.
The circulating water is set in motion by centrifugal pumps,
driven by separate engines with cylinders 12 inches in diameter.
The diameter of the impeller is 4 feet. The condensers can be
used as jet condensers should the centrifugal pumps break down.
All working parts are of steel. The crank-shafts, made of Whit-
worth compressed steel, are of annular section. The cranks are
placed at angles of 120^ to each other. The boilers, twelve in
number, in four stokeholds, separated by water-tight bulkheads,
are oval with flattened sides, 12 feet 4 inches wide by 14 feet
1 inch high and 9 feet 10 inches long. There are thirty -six
furnaces, each 3 feet 2 inches in diameter, with grates 7 feet
3 inches long, giving a total fire-grate area of 82 6i square feet.
The iron tubes are three thousand four hundred and thirty-two in
number, 2j inches in external diameter, and 7 feet long, having a
heating-surface of 17,000 square feet. The total heating-surface is
20,400 square feet. The working-pressure is 90 lbs. per square
inch. There are two funnels, oval, 10 feet by 6 feet, rising to a
height of 75 feet above the lower fire-bars. The air-pressure under
forced draught is maintained by eight fans, 5 feet in diameter,
two in each boiler room. These are driven at a high velocity by
small horizontal engines ; four fans 4 feet 6 inches in diameter are
fitted for ventilating purposes. There is the usual comi^lement of
auxiliary engines for donkey, feed, fire, bilge, and other services,
which, together with electric-lighting and other small engines,
exhaust into an auxiliary condenser.

The propellers are 16 feet in diameter, and 2 feet 8^ inches
long, with a pitch variable between 18 feet and 21 feet, and
struck at a mean of 19 feet 6 inches. The area of each blade
is 19*38 square feet, giving a total to each propeller of 77 •52
square feet. They are made after a pattern supplied by the
Admiralty, deduced from the experiments of Mr. Froude at Torquay,
known as the modified Grifiiths type. In this type of propeller the
boss is enlarged to 1 or j, or sometimes even a larger proportion of

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 327

the diameter of the propeller, and the i;seless portion at the tips is
reduced. In the present case the propellers are four-bladed.

The engines of the " Anson " are similar in design to those of
the " Rodney," " Collingwood," and " Howe," which were engined
by the same firm. Several modifications, however, have been
introduced.

The condensers, instead of being of brass, and placed separate
from the engines, are of cast-iron, and form the frames upon
which the low-pressure cylinders rest on the midship side.
By this arrangement much space is saved without increase of
weight. It is this firm's practice to fit air-pumps worked direct
from the main pistons, without the intervention of rocking levers.
Hitherto two pumps have been fitted to each condenser, to guard
against the destruction of the vacuum resulting from any injury
to a single pump. This by long experience has proved a totally
unnecessary precaution, and in the " Anson " only one brass air-
pump has been fitted to each condenser. It is placed behind the
low-pressure piston-rod guide (Plate 8). The aggregate cooling
surface in the two condensers is 17,000 square feet. The diameter
of the air-pumps is 15 inches. The crank-shafts are made of
Whitworth compressed steel in three interchangeable lengths.
The cranks are jilaced at somewhat uniisual angles, the low-
pressure cranks being at right-angles to each other, and the high-
pressure crank, bisecting the supplementary angle between them,
being at 135'^ to each low-pressure crank. The high-pressure
crank leads, and is followed by the forward and aft low-pressure
cranks in that order. The reason for this arrangement will appear
from the twisting-moment diagram (Fig. 5).

The valve-gear is Stephenson's solid bar-link with indirect action.
This gear certainly has disadvantages compared with the double-bar
direct-acting links fitted by Messrs. Maudslay. It requires a larger
eccentric, and consequently is more liable to cause heating in the
eccentric straps at high speeds. It is, moreover, found convenient
to hang it from the near eccentric-rod end. This gives a short
drag-link, and consequent large influence of drag-link ujion the
valve-motion. Yet with the very short valve-travel in use with
double-ported valves, these objections are more theoretical than
real ; and the advantages of greatly reduced first cost and solidity
of construction more than counterbalance the slight disturbing efi'ect
of the short drag-link, while a balance-cylinder relieves the weight
upon the eccentric straps.

The boilers, eight in number, constructed throughout of Siemens-
Martin steel, are 16 feet in diameter, and 14 feet 2 inches long.

328 CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. [Selected

They are of the high-cylindrical type. The thirty-two furnaces
(Fox's corrugated) have a mean width of 3 feet 7^ inches ; sixteen
of them are 7 feet long, and sixteen of them 6 feet 9 inches
long. The total fire-grate area is therefore 797*5 square feet.
They contain in all three thousand four hundred iron tubes,
2j inches in diameter, and 7 feet long between the tube-plates,
giving a heating surface through the tubes of 17,150 square
feet, and a total heating surface of 20,300 square feet. The
two funnels are oval, 9 feet by 5 feet 6 inches. Their height
above the lower fire-bars is 75 feet. The fans for forced draiight
are eight in number, driven at a velocity of 400 to 600 revolutions
per minute by Brotherhood's three-cylinder single-acting high-
speed engines. The other auxiliary engines and fittings are
similar to those of the " Camperdown."

The propellers are of gun-metal, 15 feet 6 inches in diameter,
with a pitch variable between 18 feet and 21 feet, struck at a mean
pitch of 19 feet 6 inches. The area of each blade is 18*14 square
feet, giving a total of 72 • 56 square feet.

The manner in which Admiralty official trials are conducted has
been already described by Mr. Wells ; but additional particulars
are required, for the proper understanding of the trials which
follow. The official trial consists of a four hours' run at fiill speed,
both under "natural draught" and "forced draught." These are
the terms in general use, although the trials would now be more
accurately described as "open" and "closed" stokehold trials;
for the stokeholds being so far below the deck, it is found
advisable even on the natural-draught trial to keep the fans
running at a moderate speed, althoiigh as the air-tight doors are
open, the pressure cannot rise much above that of the atmosphere.
During these trials several runs are made on the measured mile in
both directions. The influence of the tide is thus eliminated
by taking the mean of two runs, one with, the other against,
the tide. This constitutes the first mean speed. The means of a
number of such double runs, taken in pairs, then give second means.
If sufficient runs have been made, a third and a fourth mean are
taken, until finally the true mean speed is arrived at. The result
is thus rendered practically free from the varying tidal influence.

Every half-hour during the trial indicator diagTams are taken,
and the steam-pressures, vacuum, &c., recorded. The revolutions
are taken from mechanical counters, the mean revolutions per
minute for the four hours being used as the constant for working out
the indicated HP. This gives a fair mean result. During the
closed-stokehold trial, the pressure of air in the stokeholds on

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 329

the water-gauges is registered. The maximum limit allowed by
the Admiralty regulations is a pressure of 2 inches of water. In
torjDedo-boat practice this is largely exceeded ; a pressure of 4 and
5 inches being quite common in such craft, and some builders
permit as much as 7 inches of water. It is doubtful whether any
advantage is gained by so strong an air-blast. To supply too great
an amount of oxygen is apt to cool the burning fuel unnecessarily ;
while portions of unburnt and half-burnt coal are forced up the
funnel by the draught and wasted ; and the temperature of the
waste gases is raised, and heat by that means thrown away,
which, with a more moderate draught, would have been utilized.
Experiment proves that, even with a pressure of 2 inches of water,
this source of loss is serious. Moreover, the deterioration of
boilers and the burning of fire-bars are serious considerations.
Some attempts have been made to obviate the latter difficulty by
evaporating water in the ashpits, and these have proved very
successful ; yet with a pressure of 5 to 7 inches it is doubtful if
this arrangement would suffice. No doubt the Admiralty limit of
2 inches is therefore a wise one, and with such a moderate draught
and careful stoking no serious injury is done to the boilers.

It is to be regretted that complete data are not obtainable
for calculating the efficiencies of the engines and the boilers at
these trials. Some of the data, moreover, are almost worthless from
the roughness of the methods adopted for obtaining them. Such,
for instance, is the method by which the coal consumed is
measured. A certain number of buckets at the commencement of
the trial are weighed, and a mean is taken of the weight per
bucketful. This is multiplied by the number of bucketfuls used
during the trial. But no particular care is taken to fill the bucket
equally each time. No account is taken of the amount of coal in
the furnaces when the trial commences, this being assumed to be
equal to that which remains at the end of the trial, though no
special care is taken that it shall be so. A more accurate criterion,
of the economies of engines of different types, is obtained by
comparing the amount of feed-water used per HP. per hour. By
combining this with the amount of coal used, the true evaporative
efficiency of the boilers would be obtained. This would be by no
means difficult to accomplish, though it would undoubtedly entail
extra expense and trouble during the trial. All the boilers are
supplied with feed- water from a common tank, to which is returned
the condensed water from the hot-well. The amount wasted, in
evaporation and in condensation, is made up from a fresh water
tank; or, as is now contemplated, from double distillers. So that,

330 CAPPER OS SPEED-TRIALS OF BRITISH WAR-VESSELS, [Selected

by some form of water-meter, all the feed-water diiring the trial
could be automatically registered. The surplus water from the
overflow could be similarly measured, and its amount deducted
from the total feed-water. Care must then be taken that the water
in the boilers stood at about the same level at the end of the trial
as at the beginning ; the difference being estimated and the amount
of water it represented being calculated from the known capacity
of the boilers, or from an observation easily made when the boilers
were being filled. The auxiliary engines take steam from the
main boilers, and exhaust into an auxiliary condenser. The
amount of steam used by them could be measured ; and the HP.
developed by them estimated, and added to that of the main
engines.^ The}" generall}^ take steam throughout the stroke.

Experiments as to the internal resistance of the engines would
be exceedingly valuable ; but there is the difficulty of obtaining a
means of measuring the effective HP. imparted to the propellers.
The method, which most readily presents itself, is to measure
this quantity by the amount of torsion produced in the propeller
shaft. This would entail previous experiment to ascertain the
coefficient for each shaft, to which there is the objection of trouble
and cost. The only method of determining the internal resistance,
in the absence of special exj^eriment, is by the approximation
obtained from the tangent to the curve of indicated thrust in
the manner pointed out by the late Mr. AV. Froude, M. Inst. C.E.

It is certain that such experiments would amply repay their
cost; for by them an accurate comparison of the relative effi-
ciencies of various tyj)es of engine could be made, which could
not but result in increased care in design, and reduction of loss by
internal friction. At present, labour in this direction is only
carried on by surmise, and without definite data to go upon.

The trial of the " Camperdown " with open stokehold took place
at Portsmouth on the 14th of March, 1887 (Aj)pendix, Table I).
The ship was in light trim, drawing 22 feet 3 inches forward, and
24 feet 5 inches aft, the mean draiight therefore being 23 feet
4 inches, or 3 feet 5 inches under the designed load-draught. This
represents a displacement of 8,292 tons. The trial was prolonged for
six hours, and the results were very satisfactory. Full particulars
are given in Appendix, Table II, where the table of half-hourly
observations shows that the lowest collective HP. indicated was in
the second half-hour, namely, 7,931 • 6 indicated HP., while the

' The reason for this addition is to supply correct data for comparison with
engines, where the pumps are worked direct from the main engines by rockiug-
levers or otherwise.

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR- VESSELS. 331

highest was 9,151*6, or 1,651 indicated HP. above the contract.
The mean for the six hours was 8,622 indicated HP., or 1,122
above the contract. The fans were running, as above explained,
for ventilating purposes, at a mean speed of 403 revolutions
per minute, representing an air-pressure of about 0*3 inch of
water; but the pressure was not recorded. The mean boiler-
l^ressure for the twelve boilers was 83-3 lbs. per square inch.
The pressure in the main steam-pipe in the engine-room was
80-3 lbs., showing the very moderate loss of 3 lbs. pressure
due to friction and condensation. The high-pressure cylinder
was in these engines placed forward of the two low-pressure
cylinders, to shorten the steam-j^ipe ; and this, no doubt, consider-
ably helped towards this result. The revolutions reached a mean
of close upon 95 per minute for the two engines. The power
was very nearly equally divided between the high-pressure and
two low-pressure cylinders. The mean indicated HP., developed
by the high-pressure cylinder, was: starboard, 2,151*5, and port,
2,173; while for the two low-pressure cylinders together, the
collective power was : starboard, 2,222*8, and port, 2,074*9. The
coal consumed was, by the above method of measurement, 974 cwt.
86 lbs. during the four hours, or over 2 lbs. per indicated HP. per
hour. This would be reduced were the HP. of the auxiliary
engines taken into account. The coal used was Harris's Deep
Navigation, and the stokers employed were supplied by the dock-
yard at Portsmouth, The mean speed on the measured mile was
16*3 knots.

The closed-stokehold trial of the " Camperdown " took place on
Wednesday, the 16th of March. The draught of the ship had been
increased to 22 feet 4^ inches forward, and to 24 feet 4.^- inches aft,
or a mean of 23 feet 4^ inches. At this draught the displacement
is 8,313 tons. The sea was rougher than on the former trial,
tending to diminish the speed.

The mean indicated collective HP. was 11,742*16. The dis-
tribution of power was not as it had been in the former trial.
The three cylinders here developed approximately equal powers.
The high-pressure cylinder developed less than on the former trial,
the figures for the starboard being 1,885*5 indicated HP., and for
the port, 1,828*2; while the low-pressure cylinders combined
developed a mean of starboard, 3,948*9, and port, 4,079*6 indicated
HP. This was accomplished by opening communication through
a pass-valve direct from the main steam-pipe to the low-pressure
receiver. By this means the pressure in the receiver was raised
from 11-2 lbs. to 29 • 15 lbs. per square inch, and the mean pressure

332 CAPPER ox SPEED-TEIALS OF BRITISH •\VAK-VESSELS. [Selected

in the Ligh-pressure cylinder correspondingly lowered. The power
developed by the high-pressure cylinder during this trial was
13 per cent, less than during the open-stokehold trial, although the
toiler-pressure was about 5 lbs. per square inch higher, and the
number of revolutions was greater. The extra steam evaporated
was therefore utilized in the low-pressure cylinders, which greatly
increased the power, though the advantages of a high rate of
expansion were thereby impaired.

The weight of steam per HP. used must therefore have been
increased, and this is perhajis the cause of the much greater con-
sumption of coal per indicated HP. For the four hours during
which the trial lasted, the total consumption of coal was 1,368 cwt.
42 lbs., being a mean of more than 3^^ lbs. per indicated HP. per
hour, or an increase of 53 per cent, over the consumption during
the open-stokehold trial. The advantages of increased power by so
very simple a method, however, counterbalance the disadvantages,
where the increase is required only under special circumstances.

It is to meet this division of power, when the strains are a
maximum, that the cranks were placed at equal angles with one
another. To place them at the most desirable angle for their
maximum power, therefore, they are at a disadvantage when
working at lower powers.

During this trial the air-pressure somewhat exceeded the regu-
lation maximum, reaching the mean of 2*47 inches of water, the
maximum being 2 "87 inches, and the minimum 1*87 inch. The
fans were run at a mean velocity of 558 revolutions per minute.
The speed on the measured mile was 17 '14:4 knots per hour,
showing an increase of 0*85 knot for the additional 3,000 indicated
HP. over the sj)eed at the open-stokehold trial. The mean revo-
lutions were : port, 101-4; starboard, 101 -86 per minute. Details
of the circle-turning, and reversing-engine trials are suj)i3lied in
the Appendix, Table III.

The open-stokehold trial of the " Anson" took place on Monday,
the 4th of Ajjril, 1887. The weather was very favoiirable, the
mercurial barometer standing at 30 inches, and a light breeze
blowing with a force of 2. The draught on this trial was 22 feet
6 inches forward, and 24 feet 2 inches aft, the mean being 23 feet
4 inches, and the displacement 8,318 tons, or rather more than
that of the " Camperdown " had been. No preliminary trial
had been made, yet the machinery worked smoothly, with no
hot bearings, and the results obtained were highly satisfactory.
The fans were kept running, for ventilating purposes, at a mean
speed of 397 revolutions per minute. This, with the stokehold

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 333

doors open, produced a pressure of 0*2 inch of water in the
stokeholds. The average steam-jiressure in the boilers through-
out the trial vras 94*4 lbs. per square inch, vs^hile that in the
engine-room, close to the high-pressure slide-jacket, was 89 • 65 lbs.,
the loss being a little under 5 lbs. from friction and radiation.
This loss was somewhat greater than in the " Camperdown,"
the diiference being accounted for by the greater length of steam-
pipe entailed by placing the high-pressure cylinder in the middle
between the two low-pressure cylinders. The loss is, however,
slight in any case, and shows the absence of ground for the objec-
tions raised to the arrangement on this score.

The power developed was about halved between the high-
pressure cylinder and the two low-pressure cylinders combined.
The high-pressure developed 1,884-95 indicated HP., and 2,201-57
indicated HP. for starboard and port respectively, while the corre-
sponding collective powers for the two low-pressure cylinders were
1,995-73 and 2,179-63. It is to maintain a good balance with this
unequal division of power that the unusual angles of cranks above
referred to were adopted. The effect upon the indicator-diagrams
is noticeable ; for the high-pressure cylinder, exhausting just as the
aft low-pressure cylinder is full open to steam, produces a slight
bump aboiit mid-stroke in the aft low-pressure diagram, the receiver
pressure being raised at this moment. This has the effect of
reducing the variation in twisting moment for this cylinder, and at
the same time reduces the evils of fluctuating pressure in the
receivers, these being of small capacity. The back-pressure line on
the high-pressure diagram, therefore, shows very slight deviation
from a straight line.

The coal-consumption for the four hours was 699 cwt. 102 lbs.,
being a little over 2^- lbs. per indicated HP. per hour. The
power steadily increased during the trial from 7,624 indicated HP.
in the first half-hour to 9,700 collective HP. in the last. This
was due to the small and broken coal at the bottom of the bunkers,
which necessitated bucketful after bucketful having to be thrown
away at the beginning of the trial. It was not, therefore, till
some time after the trial commenced that the boilers evaporated
their full steam. After the large coal was reached, steam escaped
freely from the safety-valves, and no further difficulty was en-
countered. This probably also increased the apparent consumption
of coal.

The speed, from the mean of six runs on the measured mile, was
16-5 knots per hoiir. Details of the circle turning are contained
in the Appendix, Table IV.

834 CAPPER ON SPEED-TEIALS OF BRITISH WAR-VESSELS. [Selected

The official full-power trial with " closed stokeholds " was made
on Wednesday, the 6th of April. The results exceeded anything
hitherto accomplished by engines of a similar weight of the com-
pound type. There was a considerable breeze, so that the sea was
rough, making it necessary to keep to the inside of the Isle of
Wight. This, with the consequent frequent turning and extra
strains on the engines, somewhat reduced the speed by log.

The safety-valves were blowing off freely throughout the trial,
a proof of the ease with which the eight boilers generated the
reqiiired volume of steam. During the last half-hour it was
deemed advisable to ease down the fires somewhat. The average
air-pressure during the trial was 1-9 inch, being below the
maximum allowed. This pressure was maintained by the eight
fans with an average speed of 44,1^ revolutions per minute.

The distribution of power between the cylinders remained the
same as in the former trial. The means were : High-pressure, star-
board, 3,028 indicated HP. ; port, 3,070 indicated HP. ; while the
collective HP. for the two low-pressure cylinders was : starboard,
3,369; port, 3,122 indicated HP.

The economy was, if anything, increased by the use of forced
draught, as far as can be judged by the coal consumption. The
total for the four hours was 1,004 cwt. 85 lbs., the mean being a
little under 2^ lbs. per indicated HP. per hour, or rather under the
mean for the open-stokehold trial. The total mean indicated HP.
developed reached 12,584, or 3,084 indicated HP. over the contract
power. The speed, reckoned from the mean of five runs on the
measured mile, was 17,435 knots per hour, while the patent log
registered a mean of 17*6 knots. The ship had been somewhat
lightened since the open-stokehold trial, the mean draught having
been diminished to 23 feet 3i inches, giving a displacement of
8,277 tons. The reversing-engine trials are detailed in the
Appendix, Table IV.

The sjiecial conditions, which influence the design of the ma-
chinery of war-vessels, have been enumerated by Mr. Wells. ^ Of
these conditions, those upon which the most stress must be laid are
the keeping of the engines below the water-line, and the reduction
of weight to its minimum safe limit.

It is to reduce the weight that the piston-speed of war-vessels
has been gradually increased, until its mean value for vessels of
the class under consideration is now from 750 to 850 feet per
minute. The necessity for keeping the engines as low down as

' Minutes of Proceedings Inst. C.E., vol. xci. p. 366.

Tapers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 335

possible, and the consequent reduction of stroke, lias led to a gradual
increase in the number of revolutions to attain this piston-speed,
until they have reached 110 per minute. In some triple-expansion
engines, 130 to 1 50 have been attained for engines of about the same
power. The chief objections to so short a stroke, accompanied by a
small ratio of connecting-rod, are, the larger effect upon steam dis-
tribution produced by the angularity of the connecting-rod, the
much larger value of the normal thrust upon the guides, and the
consequent increase of the absolute value of the friction upon them.
The connecting-rods are rarely more than four times the length of
the crank, and sometimes less than that. The effect ujion the
twisting moments is shown by Figs. 4 and 5.

It will be instructive to examine briefly how far the two sets of
engines fulfil the conditions above referred to. The engines of
both ships are entirely below the water-line. The diameters of
the cylinders are the same ; they have the same length of stroke,
3 feet 9 inches, and the same length of connecting-rod, which is in
each case four times the length of the crank.

The total weight of the machinery of the " Camj)erdown "
exceeds 1,276^ tons; that of the "Anson" is 1,150.^ tons, while
the contract weight was 1,225 tons. Thus the engines of the
" Camperdown " exceed the contract weight by upwards of 50 tons,
while those of the " Anson " are over 74 tons below it. There is thus
a saving in weight of more than 125 tons in favour of the "Anson."
In comparing the weights per indicated HP. developed, this advan-
tage is further increased. With open stokeholds the weight per
indicated HP. per hour of the machinery of the " Camperdown " is
364 lbs. ; of the " Anson," 309 • 6 lbs. On the closed-stokehold trial
the corresponding figures were, for the " Camperdown," 267*3 lbs.
per indicated HP., and for the "Anson," 204*7 lbs. The weight
of the engines of the " Inflexible," built about eleven years ago by
Messrs. John Elder and Co., of Glasgow, was nearly the same as of
those of the " Camperdown"; while the maximum power developed
was only 8,483 indicated HP., or nearly 25 per cent. less. This
remarkable increase in power for a given weight is largely due to
a more lavish use of cast-steel and brass than was possible at that
time ; but still more is due to forced draught, and the consequent
reduction in weight of the boilers, and to the higher piston
speeds.

The adoption of triple-expansion engines, and a more extended
use of cast-steel, as the foundries become better able to cope with
the difficulties of casting, will probably give results surpassing
even those above quoted.

336 CAPPER ON SPEED-TFJALS OF BRITISH WAR-VESSELS. [Selected

It may be pointed out that triple-expansion engines are neces-
sarily heavier, power for power, than simple or compound engines
with a given boiler-pressure. The advantage in point of weight
lies in the possibility of using much higher steam-pressures
with economy. By this means the size and weight of the
cylinders is greatly reduced ; while the boilers may be fewer in
number.

The weight of the boilers, when full of water, always bears a
large ratio to the total weight of the engines. By computing the
indicated HP. developed per ton-weight of boilers, a fair idea of
the relative efficiencies of various sets of engines, and the advantage
of forced draught may be obtained. The method usually adopted
is to compare the ratio of indicated HP. per square foot of grate.
Biit, as pointed out by Mr. E. Sennett, M. Inst. C.E., in a Paper
read before the Institution of Naval Architects,^ this is by no
means a fair method of comparing boilers dissimilar in design and
construction. For reference, however, the indicated HP. per square
foot of grate has also been given in the accompanj^ing Table IX
in the Appendix. The total weight of the boilers of the " Cam-
perdown," with uptakes, funnel, water, and all fittings, is 662 tons.
With open stokeholds, therefore, the engines developed 12-4 indi-
cated HP. per ton of boiler; while with closed stokeholds they
developed 1 6 • 8 indicated HP. per ton, or above 35 per cent, more
with closed than with open stokeholds.

The total corresponding weight of the boilers of the "Anson" is
590 tons. With open stokeholds, therefore, the " Anson " developed
14-1 indicated HP. per ton, and with closed stokeholds 21*3
indicated HP., showing an increase of 50 per cent, by the use
of forced draught. The difference between the two vessels, by
grate areas, is not so marked; but as the boilers are of different
types, this, as above pointed out, is not so fair a way of comparing
them. The "Camperdown" has a total fire-grate area of 826 '5
square feet, and therefore developed 10*43 and 14-2 indicated HP.
per square foot for closed and for open-stokehold trials respectively.
The "Anson," with a grate area of 797 "5 square feet, developed
10 "43 and 15*78 indicated HP. for closed and open-stokehold trials
respectively. The "Anson" no doubt derived some advantage by
the reduction in the number of boilers to eight, partly due to the
increase of 10 lbs. per square inch in boiler-pressure, this being
100 lbs. per square inch to 90 lbs. in the " Camperdown." Yet this
was again counterbalanced by their extra weight and size, so that

' Transactions, vol. xsvii. p. 17C. 1886.

Papers.] CAPPER ON SPEED-TRIALS OP BRITISH WAR-VESSELS. 337

the boilers of the " Anson " were Init 20 tons lighter than those of
the " Howe," which had the same niiniher of boilers and of the
same type as the " Camperdown."

The slight difference in weight of the engines is chiefly account-
able to the difference in type. In the " Camperdown," double steel
frames and massive cross-head and double guides replace the single
frames, light columns, and single guides of the "Anson." The
engine-room is thereby rendered much less open and free of
encumbrance. The position of the condenser and pumps of the
" Camperdown," behind the engines on the wing side, also takes
away from the available platform space. The pumps, as already
stated, are worked by rocking-levers from the low-pressure cross-
heads. This, with the low horizontal condensers which obtain in
the merchant service, is no doubt a convenient method of working
them. But when the condenser is vertical, and separated from the
framing, as in the " Camperdown," these pumps are clumsy and
block up the passage-way to an unnecessary extent. Long-
continued experience has proved that the direct-acting pumps
of the " Anson " type give resiilts as good, if not better, than
those from pumps worked at a lower speed. A series of experi-
ments made with the pumps of H.M.S. " Collingwood " gave at
from 88 to 90 revolutions, and a piston-speed, and therefore
plunger-sj)eed, of 630 feet per minute, and a vacuum of 28 inches, a
maximum pressure in the barrel of only 5 lbs. above the atmo-
sphere. The speed of piston on the "Anson" reached at the closed-
stokehold trial a maximum of 820 feet per minute. This is
considerably greater. But experiments show that where there is a
short delivery, and a small volume of water to be set in motion
at each stroke, the maximum pressure in the pump-barrel does not
increase with the speed of plunger, but tends rather to diminish
with a well-designed pump ; while at higher speeds, where the
inlet and outlet are of good proportions and unobstructed, the
variation in pressure is much reduced and a much steadier diagram
obtained.

There is some advantage in the rocking-lever over the direct-
acting pump as regards the balancing of the weights of the recipro-
cating parts ; yet with a three-cylinder engine, with cranks placed
at the most suitable angles, and carefully designed parts, no
additional aid of this kind is needed. In horizontal engines, where
it is always more difficult to obtain a good vacuum, direct-acting
pumps are universally used.

The diagrams and tables which accompany this Paper need a
word of explanation. The midship section and displacement co-

[tHE INST. C.E. VOL. XCV.] Z

338 CAPPER ON SPEED-TRIALS OF BRITISH TVAR-VESSELS. [Selected

efficient curves are shown in Figs. 1 and 2 respectively. The
former is of little value except in a case like the present, where
ships similar in design are compared.

Fig. 1.

MIDSHIP SECTION COEFFICIENT.

•

-n

^--

•v

-■s

■"nA

.■■■k 1

B 9 10 II 12 13 /♦ IS le II Id
SPBEO IN KNOTS

Hcwc

ColLuigyvoocb

Alison

CojnpcTLwwn/

280
2S0
2W
220
200

tea

160

DISPLACEMENT

DOEFFIC

lENl

1. H P.

— -

•«t^

\ ^

IZ 13 J* IS 16 n IS

SPBEO IN KFIOTS

The ratios of indicated HP. to heating-surface and grate area
have also been calculated, and the results recorded in Table IX.
Fig. 3, which represents the curve for indicated thrust of the

propellers, is calculated by the formula - — ^ — ' — , where

P = Pitch of propeller,

N = Number of revolutions per minute.

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 339

As no j^rogressive trials were made of the " Camperdown " and
" Anson," the curves for the " Collingwood " and " Howe " have

THRUST
III TOMS

too

Fig. 3.

INDtCATED THRUST.

Sf€ED IN KNOTS

Howe

0)lLLn(jwoo(L

Anson.'

A«

l\-

fi";

—

CcLnipcrdx)wn,

been added for comparison. The above foruuila gives the thrust
exerted by the propeller in tons. The curves are obtained by

z 2

340 CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. [Selected

plotting this with vertical ordinates equal to the thrust and abscissas
equal to the ship's speed in knots. The late Mr. W. Froude,
who proposed this system of plotting the efficiencies of the
propeller, j^ointed out that such curves showed a persistent refusal
to cross the vertical asymptote at the zero of the scale, and
that the point where the curve did cross the asymptote showed the
amount of internal resistance in the engines. To obtain this, the
tangent must be drawn to the curve at the lowest calculated point
on the curve, which should correspond to a sjieed of not more than
3 to 5 knots per hour. The abscissa under this tangent being
divided in the ratios of 0-87 to 1 (the resistance being found
to vary for these speeds as the 1*87 power of the speed), and a

Fig. 4.

MEAN !<90 / V^ ,'...*> ...

TwiBting moment on crank-shaft H.M.S. " Camperdown " starboard engines. Full power.

Closed stokeholds.

vertical drawn through this point, a horizontal line through the
point where this vertical ordinate cuts the curve will cut the
vertical asymptote at a point which corresponds to the power
absorbed by internal friction in the engines. The lowest speed for
which data are obtainable, for the " Collingwood" and the " Howe,"
is 8 knots per hour. The curve for the " Anson " lies considerably
below the curves for the above-named ships ; while for the " Camper-
down " it nearly coincides with the upper part of that for the
" Collingwood."

The slip-ratios for the propellers are given in Table IX. In the
" Camperdown," on the open-stokehold trial, the ratio for the star-
board propeller was 11 per cent, and for the port 12 per cent. On the
closed-stokehold trial it was 12 per cent, for l)oth starboard and port.

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 341

For the " Anson," on the open-stokehold trial, the ratio for star-
board was 9 per cent., and port, 12 per cent. ; on the closed-stoke-
hold trial, for starboard, 16 per cent., and for port, 17 per cent.

The much greater value of the slip-ratio, for the propellers of the
" Anson " on the closed-stokehold trials, is partly accounted for by
the unexpectedly high number of revolutions at which they were
run, and for which they were not designed. The slip is calculated
from the mean speed of ship and mean number of revolutions. The
propellers of the " Camperdown " show little more slip for the
higher than for the lower speeds.

Fig. 5.
mjit.ikeo _

MEA N 2132.

/ -

Twisting moment on crank-shaft H.M.S. "Anson." Tort engines. Full power. Closed

stokeholds.
In these diagrams allowance has been made for weight and inertia of reciprocating parts.
Scale for vertical ordinates 1 Inch = 1,100 inch-tons.

In the curves of twisting moment on the crank-shaft in the
" Anson," Fig. 5, allowance has been made for weight and inertia
of the reciprocating parts. The moments have been calculated
from the ordinates taken from indicator diagrams, obtained during
the last half hour of the closed-stokehold trial. The method
adopted was as follows : —

The indicator diagrams were divided by vertical ordinates at
■^V part of the stroke apart. A true diagram of pressures was
constructed by subtracting from these ordinates the values of the

342 CAPPEE ON SPEED-TRIALS OF BRITISH WAR-VESSELS. [Selected

back-pressures, shown on the indicator card for the opposite end of
the cylinder. The curve, given by the inertia of the reciprocating
parts, was then constructed by the ixsual method, and algebraically
added to this diagram. The low-jiressure diagram was read off on
such a scale as would harmonize its ordinates with the scale of the
high-pressure diagram, so as to represent the moments from the two
cylinders on the same scale. A correction was made for the dead
weight of the reciprocating parts. The ordinates thus obtained
were plotted on a horizontal base, representing the circumference of
the crank circle at points corresponding (allowing for angularity of
connecting-rod) with the ten positions of the ordinates on the
indicator diagrams. The sum of the ordinates of the three
diagrams thus obtained, at any point, gives the true twisting
moment for that point.

The effect of the inertia of the reciprocating parts is to shift the
maximum moment for any crank, from the first and third to the
second and fourth quadrants of the crank circle ; and, in combina-
tion with a finite connecting-rod, it considerably affects the maxi-
mum and the minimum moments of the combined diagram. For
the diagram of twisting moment on the crank-shaft for the " Cam-
perdown," Fig. 4, the Author is indebted to Mr. S. H. Wells, Stud.
Inst. C.E.

The Paper is accompanied by several illustrations, from which
Plate 8 and the Figs, in the text have been prepared.

[ArrENDix.

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 343

APPENDIX.

Table I. — Abstract of Mean Results obtained

\t Trials of H.M.SS.

" Anson "

and " Campekdown," in 1887.

H.M.S. " Camperdown."

H.M.S. "Anson."

Open

Closed

Open

Closed

Stokehold.

Date of trial

14 March. 16 March.

4 April.

6 April.

Where tried

Portsmouth.

Inside Isle of Wight.

Draught of water {^J™^

22 ft. 3 ins. |22 ft. 4^ ins.
24 ft. 5 ins. :24 ft. 4| ins.

22 ft. 6 ins. 22 ft. 4 ins.
24 ft. 2 ins. 24 ft. 3 ins.

Area of midship section

1,342 sq.ft.

1,345 sq.ft.

1,339 sq. ft.

1,330 sq.ft.

Displacement ....

8,292 tons.

8,313 tons.

8,298 tons.

8,277 tons.

Load on safety valves .

( 90 lbs. per|
\ sq. inch /

|90 lbs. perj
\ sq. inch j

flOOlbs.perj
\ sq. inch /

1100 lbs. per
\ sq. inch.

Air pressure (inches of water)

2-47

0-2

1-91

Steam in boilers (mean pres- 1
sure /

83-3 lbs.

87-5 lbs.

94-4 lbs.

101-0 lbs.

Ford. Aft.

Vacuum (Starboard engines
\Port engines . .

28-3 ins.

26-9 ins.

29-3 27-928-2 26-8

28-3 ins.

27-4 ins.

28-2 27-627-8 26-8

Steam pressure in receiver .

11-2 lbs.

29 -15 lbs.

3 -53 lbs.

11-96 lbs.

1 Starboard .

94-4

101-4

95-2

108-6

Revolutions < Port .

95-4

101-9

98-7

108-9

Mean . . .

94-9

101-7

96-9

108-8

Starb. Port.

Mean pressure in Jhp. .

47-7 46-738-5 37-240-9 47-457-8 58-4

11-2 11-919-9 20-510-7 11-315-8 147

StarboardJM-^^Hip^'
( Total .

2,172-9

1,885-5

1,884-9 3,028-2

2,074-9

3,948-9

1,995-7 3,363-8

4,247-8

5,834-4

3,880-6 1 6,392-0

LHP.

' '

Port, .j^'^-'^'^fli?'
1 Total .

2,151-5

1,828-1

2,261-6

3,070-8

2,222-8

4,079-7

2,179-6

3,122-1

4,374-3

5,907-8

4,441-2 1 6,192-8

Collective HP

8,622-1

11,742-2

8,321-9 12,584-8

Fan engines, mean revolutions

403

558

397-5

441-3

(Joal consumption, lbs. perl
LHP. per hour . . . /

2-11

3-26

2-35

coal verv small.

2-23

Description of coal used

Harris's Deep Navigation.

Time at full speed without)
stopping /

6 hours.

4 hours.

Stopping and starting —

Starboard.

Port.

Starboard.

Port.

Stopped from full speed

6 seconds.

5 seconds.

18 seconds.

14 seconds.

Being stopped started astern

10 „

13 „

From astern full speed tol
ahead full speed . . . /

14 „

Speed, If/ l-^g ■ ■ ■ ■
(Measurcil mile .

16-3

17-06
17-14

16'-52

17-6
17-44

344 CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. [Selected

Table I — continued.

ClRCLE-TuENING.

j H.M.S. " Camperdown.'

Starboard

Circle.

Port
Circle.

H.M.S. " Anson."

Starboard
Circle.

Port
Circle.

Budder |

Helm to starboard or port . ' aport

Angle of rudder . . . . ' 34°

Time taken to put helm to this) k- ,

1 -ii i • • Wo seconds

angle with steering engine f

Turns of wheel from amid-i

ships position of helm

Number of men at wheel

Half circle made in .
Full „ „
Diameter of circle, yards
Revolutions of engines after "I
helm was put up, jjer circle/

astarboard
34°

11 seconds

2min. 10 sec. 2miu. 20 sec.
4min. 538ec. 4min. 42 sec.

630

650

Area = 190 square feet,
aport I astarboard
341° I 34 J°
18 seconds 18 seconds

4 4

2 2

2min. 46 sec. 2min. 28sec.

5min. 47 sec. 5min. ISsec.

652 I 632
Starb. Port. Starb. Port.
492 455 496 516

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 345

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Papers.] CAPPEB ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 347

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Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 349

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Tapers.] CAPPEE ON SPEED-TKIALS OF BRITISH WAR- VESSELS. 351

Table VIII. — Particulars of Machinery : (I).

H.II.S. " Camperdown."

H.M.S. " Anson.''

Number of cylinders

Diameter of „ < , ^

Length of stroke
Number of boilers
Diameter of „
Length of ,,
Number of furnaces
Width of

Length of fire-grate
Total area of „
Heating surface in tubes

Total
Number of funnels .
Dimensions of ,,
Height above fire-bara
Propellers, Type of .

,, Number of blades

„ Diameter

Pitch.

,, Area of each blade

Cooling surface condensers

Diameter of circulating pumps,
four (centrifugal) .

Water discharged per hour by
two pumps, each working
separately

Do. by all four together

G (2 hp. and 4 Ip.) 6 (2 hp. and 4 Ip.)

52 inches.
74 „

3 feet 9 inches.

( 14 ft. 1 in. X 12 ft.
\ 4 ins. (oval)

9 feet 10 inches.

36
3 feet 2 inches.
7 „ 3 „
826-5 square feet.
17,000
20,400

52 inches.
74 „

3 feet 9 inches.

16 feet.
10 „
32

3 ft. 7J in. (mean width)

("16 furnaces 7 feet, and
\16 furnaces 6 ft. 9 ins.

797 • 5 square feet.
17,150
20,300

10 feet X 6 feet (oval) 9 ft. X 5 ft. 6 ins. (oval)

75 feet

Modified Griffiths'.

16 feet.

19 feet 6 inches.

19 '38 square feet.

17,000

4 feet.

75 feet.
Modified Griffiths'.
4
15 feet 6 inches.
19 „ 6 „
18 • 14 square feet.
17,000

3 feet 10 inches.

2,205 tons.
3,465 „

352 CAPPEE ON SPEED-TRIALS OF BRITISH WAR-VESSELS. [Selected

Table IX. — Particitlars of Machinery : (II).
Eatios and Coefficients.

H.M.S. "Camperdown."

H.M.S. '

'Anson."

Open
Stokehold.

Closed
Stokehold.

Open
Stokehold.

Closed
Stokehold.

Heating surface (tubes)

Heating surface (total)

Heating surface (tubes)
Fire-grate area

20-5

Heating surface (total
Fire-gi-ate area

1
25-3

Propellers: ^r: ....

Diameter

LHP. per sq. foot fire-grate . .

10-43

14-2

10-43

15-78

„ „ heating surface .

0-42

0-57

0-40

0-62

„ ton displacement ' .

1-04

1-4

1-0

1-52

„ „ machinery . . .]
(total) . . ./

6-75

9-2

7-2

10-9

„ „ boilers ....

12-4

16-8

14-1

21-3

Cooling sm-face per I.HP. sq. feet

1-44

2-03

1-3

Coal consumed ,, ,, lbs.

211

3-26

2-35

2-23

,, „ ,, sq. foot fire-grate

220

46-3

24-5

35-2

CT . c Starboard .
Slip, per cent.;

IPort

12
12

9
12

16
17

Displacement coeflEicient , „p .

207-7

176-0

222-0

172-9

A V^
Midship section „ frr-p-

680-3

576-8

725-4

631-3

( Starboard

708 -Oft.

751 -5 ft.

714-0 ft.

814-5 ft.

Piston speed per minute <

(Port . .

715-5 „

764-3 „

740-3 „

814-8 „

' In trim as at trial.

Papers.] CAPPER ON SPEED-TRIALS OF BRITISH WAR-VESSELS. 353
Table X. — Compakative Table of Weights of Engines and Boilers.

Weight of engines

,, of water in condensers .

„ Screw propellers and shafting

„ Boilera

„ Water in boilers ....

i Engine-rooms .
Boiler-rooms .
Screw-tunnels
i Engine-rooms .
Boiler-rooms .
Screw-tunnels

Total weight .

H.M.S.

" Camperdown."

Tons. cwt.

403 12

24 6

100 13

488 1

174 0

14 9

21 19

5 19

9 19

11 9

21 19

qrs. lbs.
0 8

1,276 12 1 15 1,150 10 2

H.M.S.

"Anson."

Tons. cwt. qrs. lbs.

377 1

22 17

98
446
144

40 1 0 24

21 14 2 13

Total contract weight 1,225 tons.

H.M.S. "Camperdown,"

H.M.S. "Anson."

Open-Stoke- Closed-Stoke-
hold Trial, i hold Trial.

Open-Stoke-
hold Trial.

Closed-Stoke-
hold Trial.

Weight of enginee (complete)!

per indicated HP. developed/
Weight of Ixiilers (water, &c.)\

per indicated HP. developed/
Total weight of machinery per \

indicated HP. developed . f

Ll)s.
150-9

213 1

364-0

Lbs.
110-8

156-5

267-3

Lbs.
150-7

158-9

309-6

Lbs.
99-6

105-1

204-7

Indicated HP.developed per ton j
weight of boilers, including >
uptakes, water, and all fittings )

12-4

16-8

14-1

21-3

Table XI.— Data for Twisting-Moment Diagrams. Closed-Stokehold Trials.

Port or starboard engines ....
Half hour during which cards were taken

Boiler-pressure

Revolutions

Vacuum

Mean pressure per sq. inch . hp. cyl.

No. 1 Ip.

No. 2 Ip.

Indicated HP hp.

No. 1 Ip.

No. 2 Ip.

Total collective indicated HP. .

Maximum moment

" Camperdown."

Minimum

Starboard
7th half hour
84 lbs.
103
27 inches
39-0 lbs.
18-2 „
22-6 „
1,940-1 „
1,832-4 „
2,275-4 „
6,047-8 „
Forward stroke 1,760
Backward „ 2,010
Forward „ 1,320
Backward „ 1,190

'Anson.

Port

8th half hour

lOOi lbs.

110
26i inches

58
14
15
3,064
1,472
1,694
6,230

•6 lbs.

•7 „

■0 „

•0 „

•4 „

•2 „

•0 ,.

2,980
1,090

[the INST. C.E. VOL. XCV.]

2 A

354 SANDBERG ON THE USE OF HEAVIER RAILS [Selected

(Paper No. 2366.)

On tlie of Use Heavier Eails for Safety and Economy in
Eailway Traffic."

By Christkk Peter Sandberg, Assoc. M. Inst. C.E.

(Abstract.)

The following is an abridgment of a communication which should
be considered as a sequel to the Pajier written three years ago
on " Eail-Joints and Steel Eails." ^

In that Paper the Author gave a design for a 100-lb. flange
rail, which has been called the Goliath rail, and recommended its
adoption for railways with heavy traffic and high speed. The
Author has since devoted considerable time to persuading railway
authorities, both in America and on the Continent of Europe, to
make a trial of this heavy rail. The Paper now presented gives
the result of his labours, and further suggests the adoption of
steel base-plates in order to secure a longer duration for the wooden
sleeper, and to permit of the use of a harder steel in the rails, with
safety against fractures.

The Belgian State Railway was the first to adopt the idea, and
after a trial of a lOo-lb. rail for an order in 1886 of about 300
tons, a second trial order of 1,000 tons was given in 1887, and
in 1888 it was adopted for the whole of the replacements, about
10,000 tons having been ordered for that purpose. These figures
show the satisfaction given by this heavy rail, as regards both
safety and economy in the maintenance of the road and rolling-
stock, as well as comfort in running at high speeds.

Other countries are working in the same direction ; on some of
the French railways the weight of rails has been increased from
60 lbs. to 86 lbs., and on the German railways to 80 lbs. per yard.
But considering the high sjDeed run on some of the continental
main lines, there is still room for a further increase in weight of
rails. In America, the proposal has met with much favour, and the
60-lb. rail which had been generally used there has been supplanted
by rails of 70 lbs. and 80 lbs., and even 90 lbs. per yard on some of

' Miimtcs of Pi'0('e(?ding8 lust. C.E., vol. Ix xiv. ]). 3C5.

Papers.] FOR SAFETY AND ECONOMY IN RAILWAY TRAFFIC. 355

the heavier worked lines. But in America, however, the heavy-
rails of modern section have not given as good wearing results as
the former light rails. The Author would explain this by the fact
that the heavy sections are designed with a wide thin rail-flange,
which necessitates the employment of softer steel than was the case
in the former sections with narrow thick flanges. Eail-makers
must guard against fractures of rails, and the harder the rail and
the wider the flange, the greater is the risk ; consequently, not-
withstanding the desire of the engineer to obtain a harder steel, in
order to resist the wear as well as the crushing from the increasing
weight of the rolling-stock, manufacturers have been obliged to
make the heavy sections softer than the light rails used in former
times ; and engineers, so far as experience goes, have not had the
economically good results from the heavy rails that they expected.
Makers have done all they could to obtain safety with these wide
and thin rail-flanges, by curving the rails when hot, so as to avoid
cold straightening, which much deteriorates the strength of the
rail. It would be well for rail-makers in Europe to adopt the same
process when meeting the demand for harder rail steel, in order to
secure safety against fractures. In Europe there is a general
demand for harder rails. That this hardness must be carefully
dealt with, the Author proved by experinients made during the
summer and winter of last year upon an extensive scale, at the
Domnarfvet Works, in Sweden, where it was desired to increase
the proportion of carbon from 0'3 to 0*4 per cent. The rails
were cut in halves ; and the one half was tested in the winter at a
temperature of — 30^ Centigrade = — 22° Fahrenheit ; the corre-
sponding half being tested in the summer at a temperature of 4- 30^
Centigrade = -f- 90° Fahrenheit. The result was, that out of the
twenty-one rails tested, nearly all broke in the winter, and all
stood in the summer with a specified drop-test of 1 ton falling
15 feet for a 63-lb. rail. It was consequently thought unsafe to
increase the proportion of carbon to 0'4 per cent. ; but that it was
better to go back to 0 • 3, which had given satisfaction as regards
safety ever since the introduction of steel rails, notwithstanding
the excessively cold climate of that country.

The rail-section has a good deal to do with the determination of
hardness. For instance, a bull-headed rail or a flange rail with a
narrow, thick flange, can be made much harder than a rail with a
wide thin flange, such as that which has been adoj^ted in America.
The danger of copying specifications as to the constituents for
different sections of rail is therefore evident. However, as where
flange-rail sections have been adopted, harder rails are neces-

2 A 2

356 SANDBERG ON THE USE OF HEAVIER RAILS [Selected

sary, and it is at the same time desirable to have rails with
wide flanges to lessen the damage to the sleepers, a problem
is presented which does not exist with the rail of bull-headed
section fixed to a cast-iron chair, or when metal sleepers are
used, namely, how to obtain good wearing-results combined with
safety in a rail with a wide flange. The engineer demands a
hard and at the same time safe rail, while the manufacturer
prefers a rail with thick flange, to enable him to make it of hard
steel without risk of fracture. Thus, the wide flange must either
be made thick, or the narrow flange must be provided with a
steel base-plate fixed on to wooden sleepers. Several railways in
Eurojie have already been provided with steel base-jjlates, but
these have not yet reached the dimensions of the cast-iron chairs
used on the English roads. The Author suggests the adoption of a
wider base-plate, the conversion of the light flange rail into a
heavier one, by giving greater thickness, both to the head and to the
flange, and by using a base-plate at least 10 inches long, as shown
by Plate 9. The Swedish 63-lb. section is proposed to be increased
to 80 lbs., and 10 lbs. additional weight given to the base-plate ;
this is instead of making the flange wider and thinner, as has been
the case with the American roads. Thus a hard and safe rail could
be obtained that should satisfy both producer and consumer,
besides providing a much broader base, which would prolong the
duration of the wooden sleej^er to an extent impossible with a
flange rail.

The English roads are the best in existence, and a proof of that
is given by last year's experience in the run from London to Edin-
burgh in eight hours (which means over 50 miles per hour) without
accident ; but this should not tempt the managers of continental
roads of weaker construction to imitate such sjieed until these have
been strengthened. High speed requires heavier rails for safety
and economy, both of road and rolling-stock. High speed is
dangerous on light rails, producing fractures, widening the gauge,
and thereby causing accidents. The rails used on the continental
lines are generally too light for the speed actually run upon them.
The price of steel rails is now much less than formerly, and as at
least 50 per cent, is recouped by the value of the old rails, there is
no excuse for delaying the change to heavier rails for all main
lines. The cost and qiiality of sleepers should decide what system
should be adopted, either steel sleepers, or steel base-plates, or rails
with wide flanges laid upon sleepers of hard wood; but thin-
flanged rails should be avoided, as incompatible with hardness com-
bined with safety.

Papers.] FOR SAFETY AND ECONOMY IN RAILWAY TRAFFIC. 357

In Plate 9 is shown the English permanent way with 80-lb. or
90-lb. bull-headed rails fixed to cast-iron chairs attached to wooden
sleepers ; also steel sleepers of different designs ; and Irish, Scotch,
and Welsh rails applied to wooden sleepers. The second row of
Figs, shows the 100-lb. flange-rail section with angle fishplates on
wooden sleepers, according to the Author's design as published in the
former Paj^er ; also the 105-lb. Belgian Goliath, as it is called, with
but slight alterations from the Author's designs. Dutch, Danish,
Swedish, French, German, Eussian, and American sections of rails,
of the heaviest weights used in those countries, are also shown ; and,
finally, the Author's design for converting a light weak road into a
strong road, by increasing the rail head and the thickness of the
flange, and by the application of steel base-plates.

Here may be given the approximate cost of the different types of
road. Metal sleepers being dearer, but lasting longer, could not
be compared with the other systems ; and as fishplates, bolts,
spikes, wood screws, or fang-bolts, are used for local reasons, or fcr
reasons arising from climatic conditions, their cost may be left out.

English Permanent Way, 1 mile, Single Line.

£. s. £. i-.
For SO-lb. bull-headed rails, 1251 tons at £4 per ton . . 50.3 0
3,625 chairs, 40 lbs. each, at £2 10s. per ton . . . 162 0

Total cost jjer miJe . . £665 0

Goliath Flange Eails, 100 lbs. per yard.
156 tons at £4 per ton. Total cost per mile . . . £624 0

Flange Rails, 80 lbs. per yard.

1251 tons at £4 per ton 503 0

2,921 base-plates (two for every sleeper), at 10 lbs. [x-r) r-a ^^
plate, at £6 per ton /

Total £581 12

These calculations show that there is ample room for increasing
the weight of the flange-rail system before it comes up to the
cost of the biill-headed rail with cast-iron chairs, and that even a
100-lb. rail would be cheajier than an 80-lb. bull-headed rail with
chair.

To balance economy with safety and all other conditions, an
international discussion, not only between English and continental
engineers, but also between them and their American brethren
would be highly valuable. The Author having shown his designs,

358

SANDBERG ON THE USE OF HEAVIER RAILS

[Selected

in comparison with others, has no other object in view than an
improvement in safety and economy in railway traffic, and hopes
that some practical good may result from this communication.

The Paper is accompanied l)y a tracing and sketch, from which
Plate 9 and the cut have been engraved.

SUPPLEMENT.

On the 29th of October, 1888, the Author handed the above com-
munication to the Secretary of the Institution, and on the same
day, almost the same hour, the accident took place to the Czar's
train near Borki station, on the Kursk-CharkofiT-Asov Eailway in
the south of Eussia. The coincidence is singular, as the main cause
of this most disastrous accident lay in the rails being too weak for
the heavy Imperial train, run at a comparatively high speed, pre-
cisely the danger which the Author warns against in this Paper.

The following Pig. shows the effect of the accident in displacing
the carriasces : —

a O

ACCIDENT TO THE CzAR's TRAIN AT BORKI.

Here Nos. 1 to 4 represent two heavy engines and tenders ; No. 5,
the luggage van ; No. 6, brake-van ; No. 7, the minister's carriage
(the first to run off) ; No. 8, the cook's carriage ; No. 9, the
kitchen; No. 10, the servants' carriage (where most were killed);
No. 11, the dining-saloon (in which the Czar and the Court were

Papers.] FOR SAFETY AND ECONOMY IN RAILWAY TRAFFIC. 359

travelling at the time of the accident); No. 12, the Imperial
children's carriage; No. 13, the Czar's sleeping carriage; No. 14,
the Czarevitch's carriage, followed by others.

The lesson, technically speaking, to be drawn from this ought
to be invaluable, not only to Eussia, but also to other countries on
the Continent of Europe, namely, not to attemjjt to exceed the
speed which the condition of the road will permit with perfect
safety. Taking into consideration how slowly a change can be
brought about in strengthening the road, a commencement should
be made without delay on all main lines where it is desired to
increase the speed, and to use heavier rolling-stock than was
originally contemplated.

300 CHARLES SHAW-LEFEVEE. [(Obituary.

OBITUARY

The Right Hon. CHARLES SHAW-LEFEVRE, Viscount
EVERSLEY, was Lorn in London, on the 22nd of February, 1794.
He was descended from one Pierre Lefevre, a French Huguenot
who settled in England after the Revocation of the Edict of
Nantes, and whose descendants became the possessors of estates and
dignities sufficient to secure their enrolment among the untitled
aristocracy of England.

The larger part of Lord Eversley's celebrity having been
achieved in connection with a political career, abundantly recorded
elsewhere, it is not necessary in these pages to do more than give
an outline of a life remarkable alike for its success and for its long
continuance. He was the eldest son of Mr. Charles Shaw, who
subsequently took the additional surname of Lefevre, himself a
considerable figure in the politics of a century ago, and whose
imposing and somewhat pompous manner provoked the remark of
Canning : " There are only two great men in the world — Shah
Abbas and Shaw-Lefevre." The younger Shaw-Lefevre, on leaving
Cambridge, commenced life as a barrister of Lincoln's Inn; but
while pursuing his studies with all diligence and success, he proved
himself so keen a sportsman that his serious mother, slow to discern
the greater qualities of her firstborn son, sorrowfully observed:
" As for Charles, he is only fit to be a gamekeeper." But whatever
her estimate of his intellect, she had reason to be proud of his
person, for he grew to be one of the tallest and handsomest men of
his generation. On the death of his father in 1823, he settled in
Hampshire on the family estate, and soon acquired an important
position in the county, as an able magistrate, an influential member
of the Court of Quarter Sessions, and a zealous officer of Yeomanry.
In 1830 he entered the unreformed Parliament as Member for
Downton, in Wiltshire, which, though one of the oldest boroughs
in the United Kingdom, was, two years later, disfranchised by the
passing of the Great Reform Bill. He was subsequently elected
one of the representatives of North Hants, and retained his seat
until he was made a Viscount in 1857. In less than ten years from
his first entry into the House of Commons he was elected Speaker,
and, when after eighteen^years of service he retired with the usual

Obituary.J CHARLES SHAW-LEFEVRE. 361

title and pension, he left behind him the reputation of having been
the best Speaker that ever ruled debate. On resigning his dignified
office, he was raised to the peerage as Viscount Eversley of Heck-
field, in the county of Southampton, and there, on the 28th of
December, 1888, he died at the patriarchal age of ninety-four.
The thirty-two years of his life after retiring from the Speakership
were mostly devoted to the avocations of a country gentleman ; for
though he was pretty constant m his attendance at the House of
Lords, he took no great part in its affairs, the Upper Chamber
being too cold and listless for one who had spent his best days in
the exciting atmosphere of the popular assembly. In his own
county Lord Eversley was an active and zealous public man, serving
at different times as Chairman of Quarter Sessions, High Steward of
Winchester, Hon. Lieut-Col. of the Hants Yeomanry, and Aide-de-
Camp to the Queen ; Governer and Captain-General of the Isle of
Wight, and Church-Estate Commissioner, which post he resigned
on his acceptance of that of Ecclesiastical Commissioner. He was
also a Trustee of the British Museum, and in 1885 was made a
G.C.B.

As a relief to his public duties he devoted himself to practical
farming and gardening, and it was in connection with the former
pursuit that he was, on the 20th of June 18-12, elected an Honorary
Member of this Institution; his qualification setting forth the
" encouragement he has given to the application of mechanics to
Agriculture, and his general attachment to Scientific pursuits."

Lord Eversley, alike by the gifts of fortune and b}' their limita-
tions, was the type of what a modern English gentleman should
be ; and, in the opinion of those who knew him best, he fulfilled
that ideal in every relation of life.

JOHN BROWN died on the 24th of August, 1888, in his sixty-fifth
year, having been born at Stafford in 1823. He began his technical
education as a clerk in the office of Mr. John T. Woodhouse of
Ashby-de-la-Zouche, and became an articled pupil in this office in
1848, subsequently acting as Mr. Woodhouse's principal assistant.
After serving in this capacity for a few years, he commenced business
on his own account in Barnsley about 1854. He had been engaged
along with Mr. Howel in a difficult investigation regarding Lord
Granville's collieries in Staffordshire, and his extensive information
and accurate and cautious reports soon gained for him the con-
fidence of a large clientele. For about ten years he resided at

362 JOHN BKOWX. [Obituary.

Harbro' House, Barnsley, and while there was entrusted with
many important arbitration cases. He was appointed Engineer to
the Lundh.ill Colliery Company after the occurrence of a disastrous
explosion in that pit in 1857, when the bodies of eighty victims
of the explosion were recovered under his superintendence. He
here introduced the " Dumb Drift," a device whereby the gases
coming with the ventilation-current from the workings were
delivered into the upcast shaft at a higher level than, and without
coming in contact with, the furnace. Xo"n' that furnace-ventilation
has almost ceased to be used, this improvement may have lost
interest ; but it was a novelty at the time in this district, and in
spite of its evident advantages, Mr. Brown incurred much hostile
criticism in introducing it. From the management of this pit he
retired, assured of the respect and good wishes of the officials and
workmen of the place, which were testified to by the presentation
of a handsome silver-gilt cup. Mr. Brown and Mr. T. W. Jetfcock
now became partners, the firm having offices both in Barnsley and
Sheffield. While still at Barnsley an exciting episode of Mr.
Brown's life was the explosion at Oaks Colliery in 1866. He had
previously been the Viewer of this colliery, and this knowledge of
it enabled him to recover the bodies of many of those killed on this
occasion.

Mr. Brown's consulting practice was not confined to this country.
While at Barnsley he was called upon to report on mining pro-
jects in Denmark, and on others in Eussia, the latter in 1868, and
again in 1874 on other jirojects in Portugal. In 1869 he became
Engineer to the Cannock Chase Colliery Company, having been
at an earlier date the late Marquis of Anglesea's adviser in the
enterprise that has led to the development of this important
coal-field. As early as 1852 he had made the plans from which
No. 2 pit of this field was constructed. It was called the " Fly "
on account of the high speed of winding adopted, and it is still
in work. In the Hednesford pit Mr. Brown designed the apparatus
for closing the mouth of the upcast shaft when winding ; and
throughout the colliery he made gTeat use of compressed-air
engines for underground haulage, and winding from a lower seam
to the foot of the main winding-shaft. His stay here, however,
was also short, and the same sort of difficulties as those at Lundhill
led to his retiring from his post in 1873. He now removed to
Hednesford, and was appointed Engineer to the South Staffordshire
Mines Drainage Commission. He had also a large private business,
and from 1874 to 1879 acted as Consulting Engineer to the Mid-
Cannock Colliery Company.- In 1880 he shifted his head-quarters

Obituary.] JOHN BROWN. 3G3

to Birmingham, where he continued and extended his consulting
and arbitration business. He worked with Sir Eobert Clifton in
developing the Clifton Colliery near Nottingham, and acted as
Consulting Engineer also for the Duke of Portland, Lord Wharn-
cliffe and others. One of his important arbitrations was the North
Staffordshire Coal and Ironstone Trade Arbitration in 1875. Mr.
Brown was elected a Member of The Institution of Civil Engineers
in 1858. He was also a Fellow of the Geological Society, and a
Member of the Iron and Steel Institute ; the North of England
Institute of Mining Engineers ; the Cleveland Institute of Mining
Engineers ; the Chesterfield and Derbyshire Institute of Mining
Engineers ; the Midland Institute of Mining Engineers ; and the
South Staffordshire and North Staffordshire Mining Institute, of
which last he was for a period the President. On the institu-
tion of the Professorship of Mining in the Mason Science College,
Birmingham, he was appointed to fill the chair, which he held for
one year.

He had a very extensive knowledge of the mining characteristics
and conditions of the Midland district. This, combined with
a retentive memory, a strictly methodical system of working,
a markedly judicial habit of mind in criticising the cases laid
before him, and a frank and kindly manner, led to his being
widely trusted in arbitration cases, and to his advice in private
enterprises being highly valued. Unfortunately a certain quick-
ness of temper led to his frequent premature abandonment of posts
where his more permanent service would have been desirable.
His pupils describe him as a kind and considerate master, and his
generosity towards his personal friends, not only in money matters,
but also in imi^arting professional information, was lavish to a
high decree.

WILLIAM ARMITAGE BROWN was born at Plymouth on the
8th of August, 1830. His father was a surgeon, and young Brown
studied for a few years with the intention of following the same
])rofession, passing some examination for the pxirjiose. He, however,
abandoned the idea, and became pupil and apprentice to Mr. J. E.
Hodgkin, of Suffolk Works, Birmingham, in January 1855. In 1858,
Mr. Hodgkin retired from business, and Messrs. Charles and Walter
May, and George Mountain became his successors, with whom
Mr. Brown went through the ordinary routine of the shops and
drawing-ofiice. After this he spent some time in the London

364 WILLIAM AEMITAGE BROWN. [Obituary

office as drauglitsman. Thence, in 1860, he went to Pernambuco,
Brazil, for Mr. (now Sir) Charles Hutton Gregory, and was engaged
on bridgework for the Eecife and Sao Francisco Eailway Company.
Mr. Brown spent nearly two years in Brazil, and on his return to
England, he in 1862 entered the service of the London, Chatham
and Dover Eailway under Mr. William Mills, the Engineer to
the Company. Mr. Brown served first as draughtsman, and subse-
quently as Chief Office Assistant. He continued in that position
until the early part of 1879, when he was appointed Inspecting
Engineer for the permanent-way materials for the same line, which
post he held until his death. In 1863 Mr. Brown took out a
patent for a train-speed indicator, and in the same year he, conjointly
with the late Mr. Eichard Lionel Jones, patented a single-handed
signal-lamp. He was engaged on a patent for steel sleepers at
the time of his death, which occurred on the 28th of August, 1888.
Mr. Brown was elected an Associate of the Institution on the 3rd
of February, 187-i, and was transferred to Member on the loth of
December, 1886.

HENEY CAEE was born in Derby, on the 24th of November, 1817.
On the death of his father, when he was only six weeks old, his
mother with her two children, the subject of this memoir and his
sister, went to Holbrook, near Derby, to reside with her father-
in-law, the Eev. John Carr, and here Henry Carr remained sixteen
years, until the death of his grandfather, when the family removed
to Duffield. The intention was to educate him for Holy Orders.
He was sent to Oakham Grammar School, as well as several other
schools. He, however, evinced no inclination or taste for classical
studies, but took the greatest interest and delight in carpentry,
and indeed in any kind of mechanical work. Before he was nine
years old he had saved up his money to buy a lathe, and all his
spare time was spent at his lathe or carpenter's bench. It was
then that the wise decision was come to of allowing him to choose
a profession in accordance with his own inclinations and taste, and
in January 1837 he was articled as a civil engineer to Mr. (after-
wards Sir William) Cubitt, and started work in Mr. Cubitt's
London office.

Mr. Carr's first expedition was with Mr. Cubitt to the North of
Ireland, a trip he always looked back upon with the greatest
pleasure as having afforded him the advantage of close contact with
Mr. Cubitt during the time the latter was examining various

Obituary.] HENRY CARR. 365

engineering works and projects ; a note-lDook, still preserved, evinces
the interest Mr. Carr took in all these engineering works. He then
went to Tunbridge for three months, at the time the South Eastern
Railway was under construction, and had his first railway experi -
ence ; but so little work was doing there that Mr. Culiitt placed him
under Mr. John Wright, then Resident Engineer on the line from
Folkestone to Dover, and he had almost the entire supervision
during the construction of the Shakespear Tunnel. While at
Folkestone he devised an instrument for setting out the slopes of
cuttings. He was about eighteen months at Dover, when a very
severe attack of typhoid fever necessitated his return to Derby-
shire, and left him an invalid during the remainder of his
])upilage. In the spring of 1841, three months after his articles
had expired, his health was so far recovered that Mr. Cubitt
recommended him to Mr. George Turnbull, then Engineer in
charge of the important works at Middlesbrough Docks. The
following extract from a letter to Mr. Turnbull shows the high
opinion Mr. Cubitt had formed of him : — " He is highly talented,
and if his health gets re-established will make a very good
engineer, his inventive talent being great and his judgment good."
He remained at the Middlesl)rough Docks about two years, and
while there made a survey of the town and docks for the late Mr.
Pease, for which he received his first pay.

His next work was building a weir across the River Trent,
near Trent Junction, of which he had sole charge under the late
Mr. Peter Barlow, during the spring and summer of 1843. He
was at Folkestone for a short time the year following on harbour
work, and afterwards on the London and Croydon Railway, then
under construction as an atmospheric railway. He was next
apjiointed Resident Engineer on the extension to Epsom, and as all
road-crossings had to be by over- or under-bridges, he had great
scope for his love of bridge-designing in the thirty-two bridges be-
tween Croydon and Epsom. Before this extension was completed,
the difficulties experienced in working the atmospheric system from
Croydon towards London decided the Directors to abandon it, and
the Croydon and Epsom line was laid for the ordinary locomotive.
While at Epsom Mr. Carr preioared plans, working-drawings, &c.,
for the bridges on the proposed extension to Dorking.

On the completion of the work at Epsom, Mr. Carr removed to
London to prepare drawings for the Great Northern Railway, and
to Doncaster in September 1847, on being appointed Resident
Engineer on the section of that railway between Askern and
Retford. While at Doncaster he designed and superintended

366 HENKY CAER. [Obituary.

the Imilding of t-svo bridges at Sprotbro', over the Eiver Don and
canal, for the late Sir Joseph Copley, Bart. On their completion
he furnished a Paper on the work to The Institution of Civil
Engineers, for which he received a Council premium. In September
1850 Mr. Carr went to Eetford as Resident Engineer on the 18 miles
from Eetford to Xewark, which included two bridges over the
Eiver Trent and the Newark Dyke. He also superintended the
building of the extensive machine- and locomotive-shops at Don-
caster. In August 1853 Mr. Carr moved to Peterborough, when for
some time he had charge, as Resident Engineer, of the whole of
the Great Northern main line from London to Doncaster. About
this time he designed and built a bridge across the Eiver Trent at
Kelham for Mr. Manners-Sutton. Previous to going to Peter-
borough Mr. Carr had designed and patented a crossing to resist
the crushing of the rail-flange in the ordinary crossing. This
brought him in contact with Mr. Wild, of points and crossing
fame ; and in 1855 he resigned his position on the Great Northern
Eailway, and took offices in Victoria Street, Westminster, com-
mencing practice on his own account. During the first two years
he was engaged on Mutford Sluice, near Lowestoft, and on several
small engineering works, and from this time he also took great
interest in architecture, preparing plans and specifications for
several country residences, two being parsonages at Hartington
and near Carlisle, as well as making additions and alterations to a
number of large houses.

He had also business relations with Mr. Barrow, of the Staveley
Ironworks, and in 1861 he commenced preparing the elaborate
plans for the large engine-erecting and repair ing-shops at Long-
hedge, Battersea, for the London, Chatham and Dover Eailwa}'',
which occupied nearly three years in execution. At this time
Mr. Carr, in conjunction with the late Mr. Joseph Cubitt,
designed the new bridge over the Thames at Blackfriars, and
although his name did not appear with Mr. Cubitt's as Joint
Engineer, it is well known that the drawings were prepared in
]\Ir. Carr's office under his immediate superintendence, and that
all the calculations and a great deal of the drawing were done
by Mr. Carr himself. The temporary timber Ijridge, which carried
the traffic during the building of the new bridge, and which was
very favourably noticed at the time, was entirely the work of
Mr. Carr. Blackfriars Bridge was in hand for the seven years
1862-69, and during this time Mr. Carr, under Mr. Cubitt's direc-
tions, prepared the drawings for the bridge which carries the
London, Chatham and Dover Eailwa}' over the Eiver Thames,

Obituary.] HENRY CARR. 367

niakinp; all the calculations of strains and scantlins^s himself.
In 1869 Mr. Carr reported to the Bridge House Estates Com-
mittee of the City of London on the Metropolitan connnunications
between the north and south sides of the Eiver Thames. He
prepared schemes for improving the gradients of Southwark Bridge
(it was mainly by his eiforts the bridge was eventiially thrown
open to the pul)lic), and also for widening the footpaths of London
Bridge. In 1872 Mr. Carr read a Paper at the Eoyal Institute
of British Architects on " The Bridges of London."

Not having good health, Mr. Carr was obliged in later years to
decline undertaking work which would involve nu;ch exposure.
Having no family, and being possessed of some private means, he
was able to a certain extent to choose his work. His great forte
was designing, and the rapidity with which he worked was
astonishing to those with whom he came in contact. It was 'his
habit to get all his drawings out in pencil, passing them over
to others to " ink in," colour and finish, and it was wonderful to
note the accuracy and care with which they were drawn ; there
was seldom a line to alter, and they were neatness itself. It has
been said of some engineers that they were made by their staff; of
Mr. Carr it may be said that he made his staff.

Soon after the completion of Blackfriars Bridge Mr. Carr retired
from the active duties of his profession, but he was never idle ; his
carpenter's shop and lathe kept him much occupied, as many of
his friends can testify by the number of useful as well as orna-
mental things he made and presented to them. Occasional tables
for the drawing-room, in walnut and oak, he was fond of making,
and the work and finish was so good that no cabinet-maker need
have been ashamed of them. He also interested himself in several
other matters. Amongst the first was the subject of canvassing
for admission to charitable institutions ; some specially distressing
cases that came under his notice first drew his attention to the
subject. As a result of his efforts the Charity Voting Reform
Association was formed under the presidency of the Duke of
Northumberland, with many influential noblemen, clergymen and
others as vice-presidents, the Eev. E. J. Simpson of St. Clement's
Danes, and Mr. Carr being honorary secretaries.

During the last ten years of his life Mr. Carr took up the sul)ject
of the use of arsenic in domestic fabrics, more especially in wall-
papers. He wrote a pamphlet, " Our Domestic Poisons," which
had a very wide circulation ; also a Paper read before the Society
of Arts, and he delivered a lecture on the subject at the Health
Exhibition in 188-1. He was supported by man}" of the leading

368 HENRY CARR. i[Obituary.

medical men in London, some amongst them having themselves and
their families suffered from the effect of arsenic in wall-papers, &c.
He tested hundreds of papers for manufacturers and private indivi-
duals, using both the Eeinsch and the Marsh processes, and largely
in consequence of his efforts the use of arsenic has been to a great
extent abandoned. Mr. Carr, as an engineer, had great courage in
the pursuit of his profession, amounting at times to what would
almost appear rashness. He was rapid in judgment, and accepted
responsibility without hesitation, not only for his own work, but
for the actions of his trusted assistants, to whom he was very loyal
when satisfied they were doing their best, never forgetting any one
who had worked faithfully for him, and it always gave him great
pleasure to be of any help or assistance to his old hands by advice,
encouragement, or even in a pecuniary way. In private life Mr.
Carr was known for his scrupulously high tone of honour, com-
bined with extreme kindness and sympathy with trouble and mis-
fortune ; no one with any claim upon him ever sought his assistance
in vain, and many without any claim have benefited largely by his
generosity and goodness, and now mourn the loss of a true friend
and liberal benefactor.

Mr. Carr's name was borne on the roll of this Institution for
more than half a century. He was elected a Graduate on the 6th
of February, 1838, transferred to Associate on the loth of June,
1847, and to full Member on the 2nd of March, 1852. He died
on the 21st of August, 1888. He was assiduous in his attendance
at the meetings, and took great interest in the proceedings, as will
be seen by the following list of Papers, &c., contributed by him to
the Minutes of Proceedings.

*' Description of an Instrument for setting out the width of Cuttings and

Embankments of Railways, Canals, or Eoads, as particularly applicable to

falling or side-lying ground." Vol. i., 1839, p. 52.
*' Description of a Dynamometer, or an Instrument for Measuring the Friction

on Eoads, Railways, Canals, etc." Vol. i., 1840, p. 52.
*' Description of an Instrument for describing the Profile of Eoads." Vol. i.,

1810, p. 56.
•" Description of two Bridges over the Eiver Don and the Canal, with the Lodge

and Approaches, on the Estate of Sir Josejjh Copley, Bart., at Sprotbro',

near Doncaster." Vol. x., pp. 302-306.

A model of Carr's Eailway-Crossing was exhibited after the meeting of the
2ud of May, 1854.

Mr. Carr also freqiiently took part in discussions, especially on
questions referring to railways, in which branch of the profession
lie was an expert.

Obituary] HENRY CARR. 869

The following works by him are in the Library of the
Institution : —

Cubitt, J., and Carr, H. — " Blackfriars Bridge. Contract for removal of existing
bridge and for building the projxjsed new bridge, and other work connected
therewith." Folio. Atlas of drawings. ISQi. (Reprinted in 1869.)

" Metropolitan Street TrafBc. Suggested improvements." Tract 8vo. Vol.
234. Plate. London, 1871.

" The Bridges of Loudon." Tract 4to. Vol.68. Plates. London, 1871. Ex-
cerpt Ti-ansactions of the Royal Institute of British Architects.

" Our Domestic Poisons ; or, the Poisonous Effects of certain Dyes and Colours
used in Domestic Fabrics." 2nd and 3rd editions. Paper read before the
Society of Arts. 8vo. London, 1879-80-83.

ROBERT DENNY, the fifth son of the late Rev. Henry Denny,
Rector of Churchill, Diocese of Ardport, of Churchill, in the
County of Kerry, was born on the 5th of June, 1843. He was
educated at Beaumont College, co. Cork, and in 1862 was articled
for three years to Mr. W. R. Le Fanu, by whom he was employed
on part of the Nenagh extension of the Great Southern and
Western Railway, as assistant in charge of the works, and after-
wards on the same line, under Messrs. Cotton and Flemyng, when
Mr. Le Fanu had retired from the engineering profession. From
these gentlemen he received the most flattering testimonials. He
subsequently worked with Mr. J. C. Biirke, of Westminster, and
in the year 1870 started engineering business independently in
Tralee. Thenceforward, until a short time previous to his death,
he was associated in all the principal works carried out in Kerry,
his native county. These works were of a varied nature, and
comprised : The Castleisland Railway (a branch of the Great
Southern and Western) ; the Tralee Waterworks ; the Limerick
and Kerry Railway (in which work he was associated with Mr.
W. Barrington ; the Fenit Railway, and the Tralee and Fenit Pier
and Harbour works, of which Mr. Benjamin Baker was Engineer-in-
Chief. The last work which Mr. Denny carried out was a scheme
for providing a water-supply to the town of Killarney. All these
works were successfully completed, and their success was in a great
measure due to the local supervision exercised by Mr. Denny.

His genial and sociable manner caused him to be a universal
favourite, while his attention to business and his integrity gained
him the respect and esteem of his professional brethren. He died
on the 25th of July, 1888, regretted by all who knew him.

Mr. Denny was elected a Member of the Institution on the 4th
of December, 1883.

[the INST. C.K. VOL. XCV.] 2 B

370 JAMES EASTOX. [OLituary.

JAMES EASTOX, bom in Stamford Street, Southwark, on the
1-ith of September, 1830, was the second son of James Easton, the
founder of the firm, of which the subject of this notice became
subsequently the head. Mr. Easton's education commenced at a
private school in Eamsgate, and was completed at King's College
School, London. In his father's Avorks he obtained a desultory
engineering training, until called uj^on, in 1851, to assume the
management of the Wandsworth Paper Mills, now in the occupa-
tion of Mr. McMurray. The business was not found to answer;
he therefore joined his maternal grandfather, Mr. Shaw, in a large
stationer's business, which comprised the manufacture of cheques
and bank-notes; but resigned the occupation in 1856, in order to
enter his father's ofBce in the room of his elder brother, who had
become incapacitated from work by a severe accident.

The firm of Easton and Amos, which Mr. Easton joined in 1858,
was at that time largely engaged in the manufacture of centrifugal
pumps, on the system introduced by Mr, Appold, and Mr. Easton
devoted himself very much to the business, especially in the larger
sizes used for drainage purposes, his strong common-sense and
large views rendering him a very eificient adviser to the various
Drainage Boards in Somersetshire, and in the Fen counties. The
drainage of Whittlesea Mere by a centrifugal pump in 1852 —
a bold and thoroughly successful application of a comparatively
new system — was followed by many equally important enterprises
both at home and abroad, among which were the reclamation
works at Wexford, the great pumping establishments erected, under
Sir John Hawkshaw, for the Witham drainage at Lade Bank, near
Boston, and on the Amsterdam Canal.

The experience which he had acquired as a paper-maker proved
very useful in extending that branch of the business. His firm,
in 1861, erected the Ettric Forest Paper-Mills on Dartford Creek,
since become the property of the Daily Telegraph, the Stowmarket
Paper-Mills, in 1865, and large mills in Egjq^t, Portugal, and Japan,
besides imj^roving and adding to many existing establishments.

The Franco-German war in 1870-1 prevented Messrs. Call, of
Paris, from completing some large contracts for cane-sugar factories
which they had entered into with Ismail Pasha, the then Viceroy
of Egypt ; that astute riiler, who had made Mr. Easton's acquain-
tance during the construction of the Boulac Paper-Mill and the
large pumping establishment of Gizeh, and who had already
entrusted one large sugar-mill to him, judged rightly that he
would be best qualified to complete, at short notice, the work

Obituary.] JAMES EASTON. 371

which the French firm was unable to carry out, and so prevent a
ruinous loss of cane. Two more mills, each, like the first, capable
of making 120 tons of white sugar per day, and having the largest
cane-crushing rolls in the world, were ordered, and two out of the
three were finished in the sti2:)ulated time, thus saving the crop
which had actually been planted before the machinery was ordered.
The third factory, though delivered in good time, was never com-
pletely erected.

In the waterworks branch of the business, Mr. Easton's talents
were chiefly devoted to the financial arrangements and negotiations
necessary to carry out great undertakings abroad. He conceived
the idea, in the case of such towns as Antwerp and Seville, of
completing the works from his own resources and from those of
many friends, whose confidence he enjoyed, and of disposing of the
finished undertakings in complete working order to properly con-
stituted companies. The case of Antwerp was surrounded with
extraordinary difiiculties ; the concession had been revoked and
renewed more than once, and in addition there were several pre-
tenders to a share in the prospective benefits to arise from the
enterprise. The difficulty of disentangling the complicated busi-
ness was very great, and this was intensified by the objectionable
nature of the only available source of supply, which, although it
would have yielded a sufficiently good water for municipal pur-
poses, could never have commanded a ready sale for domestic use ;
he had, therefore, to take the bold step of introducing the iron
process of purification on a far larger scale than had ever been
attempted before, and did so with complete success. The case of
Seville was less difficult ; but much skill and patience were needed
to complete the negotiations with the authorities and with the
Government.

Mr. Easton's health, never very robust, began to fail sensibly in
the early part of 1888 ; his strength gave way gradually, and he died
on the 28th of August in that year at Westgate, in Kent, and was
buried in the old churchyard of St. Peter's, where many of his
wife's relations lie at rest.

He married in 1855 Miss Annie Devonshire Sackette, daughter
of Mr. S. Sackette, Deputy-Mayor of Eamsgate. The four daughters,
the fruit of this marriage, all survive him.

JOHN FOWLEE was born in the year 1824 at Rubislaw, near
Aberdeen. He was educated at the Aberdeen Grammar School,
which he left at the age of fifteen- He does not at this time

2 B 2

372 JOHN FOWLER. [Obituary.

appear to have had anj' clear idea what vocation he should follow,
and has left no information as to his tastes or inclinations beyond
the fact of his great love of Botany. His family at this day hold a
rather valuable collection of specimens gathered on the Aberdeen-
shire hills ; and in his later life, his great interest in this science was
evinced by the tenderness with which he would pluck flowers,
fruit or ferns, and the care with which he examined the same.
Probably influenced by his love of this subject, after leaving school,
he was appointed as a gardener to Sir Thomas Gladstone, of Forgue,
in Forfarshire ; but, after a month or two, he went to London for
the purpose of getting employed on some of the great engineering
works of the Metropolis. He did not stay there long, as at the age
of eighteen he visited his half brother, Mr. James Johnson, then
Superintendent to the Tees Navigation Company, Stockton, who
persuaded him to stay in that town as his assistant. On the death
of Mr. Johnson, Mr. Fowler succeeded to the position of Superin-
dent; and in the year 1854, on the transference of the interests of
the Navigation Company — a private company — to the Corporation
of the Tees Conservancy Commission, he was appointed Chief
Engineer. In this year a start was made with the series of works,
which have converted the Eiver Tees from a shallow unimportant
stream into a river easy of navigation, and capable of accommo-
dating vessels of over 4,000 tons burthen ; and which reflects credit
on Mr, Fowler as furnishing one of the most striking instances of
river improvement, both with respect to economy and the per-
manent benefits secured. The varioiis improvements designed and
carried out by him have been described in Papers entitled
" Dredgers, and Dredging in the Tees," and " Eiver Tees Improve-
ments," contributed to the Institution.^ It may not, however, be
out of place to say that, thirty-five years ago, the channel from
Middlesbro' to the bar — a distance of 7 miles — was beset with shift-
ing sand-banks and shoals, and sj^lit up, sometimes into four, and
always into two. In the 3 miles of river from the bar upwards,
forty-two buoys, besides beacons, were needed to mark out the
channel, and required changing, more or less, every spring-tide. The
available depth at low-water was 1 foot 10 inches in two places;
and the channel crooked. Ships that would now be considered very
small ran many times into the sand-banks, before getting through.
During the thirty-three years that have elapsed since the commence-
ment of the works, the channel has been gradually improved, so
that, at the present time, there is an available depth of 15 feet at

• Minutes of Proceedings Inst. C.E., vol. Ixxv. p. 239 ; ibid., vol. xc. p. 344.

Obituary.] JOHN FOWLER. 373

low-water up to Middlesbro', a width of channel at that place of
170 yards, increasing to 350 yards at the fifth buoy-light. Ships
of 3,000 tons are built and engined at Stockton, and vessels carry-
ing 1,700 tons trade there. At Middlesbro' vessels carrying over
4,000 tons, and drawing 24 feet of water, are not unusual. The
estuary has also been made into a safe harbour of refuge, and a
gi'aving-dock, capable of accommodating the largest vessels, has
been constructed by the Commissioners. To accomplish this, more
than 20 miles of low- water training- walls, and 15 miles of high-
water walls have been constructed; 21,000,000 tons of material
have been dredged, and 120,000 cubic yards of rock removed.
The breakwater on the south side was completed about two years
ago. The northern one is in course of construction. On the
25th of October, 1888, the First Lord of the Treasury, Mr. W. H.
Smith, M.P., formally opened the south breakwater in the presence
of a large and influential company, and dedicated it as a " national
work for ever." But Mr. FoAvler, the completion of whose hard
and honest labour of thirty-five years was thus celebrated, was not
spared to see the consummation of his task ; for a fortnight earlier,
on the 11th of October, he was called to his rest.

In his position as Engineer to the Commission, Mr. Fowler had
not opportunity of getting information and experience in any but
his own branch of his profession, nor did he attempt or wish to do
so. His whole professional life was devoted to the action of waves,
tides, currents, and other matters contingent on his duties as a
harbour-engineer. With application, he made himself so conver-
sant with this subject that the value of his opinion was in a short
time recognized. In few instances of improvements to our inland
navigations was he not consulted ; his knowledge in these matters
being so complete that he was in great demand as a parliamentary
witness, being retained on every scheme of importance connected
with waterways brought before the Parliamentary Committees.
His evidence was always tendered in a straightforward, ready way,
giving the impression of truth and conviction, and without
equivocation in cross-examination.

He was a leading witness in all the parliamentary fights in cod-
nection with the Manchester Ship Canal, and among the many
rivers respecting which he was consulted were the Humber, Ouse,
Trent, Mersey, Eibble, Eden, Clyde and Carron, and in Ireland,
the Forth, Liffey, Boyne and Shannon.

In 1868, he was offered the appointment of Engineer to the
Clyde Trustees, and it speaks greatly to his credit that his
employers were unanimoiis in doing all in their power to induce

374 JOHN FOWLER. [ObituaiT.

him to remain with them, which, after some consideration, he
decided to do, although at some pecuniary sacrifice. In 1885, he
was consulted in reference to the improvements for the Port of
Havre, but his engagements prevented him from entertaining the
flattering proposal then made to him. He was also consulted
some years ago on the harbour of Pobena, in Spain, At the
time of his death, he was Engineer to the Trustees of the Ouse
Navigation, who are carrjT.ng out improvements between York
and Goole. The last work completed by him was the Naburn
New Lock, 6 miles below York, opened by Prince Albert Victor
on the 27th of July, 1888. He was also Engineer to the Pier
and Harbour Commissioners of Whitby.

There are men who make a favourable impression at first, but
are found, on more intimate acquaintance, to fall short of the
estimate which has been formed concerning them. It was not so
with Mr. Fowler. A natural reser\'e made it somewhat difficult
to know him intimately ; but those who were privileged to get
within the fence of this reserve, discovered the sterling excel-
lences of his character, the deep true worth of the man. To knoAv
him was to respect him ; to know him well was to love him much.
He was an upright, honest and unselfish man, leal-hearted and
true, in whose death all who knew him have to mourn the loss of
a faithful friend ; those associated with him in work of any kind,
that of a trusted colleague and ever ready helper ; while those more
closely related to him by ties of blood, sorrow most of all for the
removal of a kind and loving husband and father.

Mr. Eowler was elected a Member of the Institiition on the 4th
of February, 1873.

WILLIAM FRANCIS was the eldest son of William Francis
of Whitehall, Kenwin, Cornwall, and was born on the 2oth of
September, 1831. He was educated at Plymouth Grammar School,
and was afterwards articled to Mr. Nicholas Wliitley, Engineer and
Surveyor of Truro.

In 1850-6, Mr. Francis was engaged on the Cornwall Eailway,
first under Mr. Glenny in the preparation of the working plans, &c.,
subsequently acting as Assistant Engineer when the works were
commenced, and latterly as Resident in charge of about 10 miles of
that line, between Grampound Road and Liskeard. In 1856-7,
he was employed as general Assistant in the Engineers' Office of
the Great Eastern Railway, and subsequently became Resident
Engineer on tlie Ipswich and Woudliridge Raihvay, under Mr.

Obituary.] WILLIAM FRANCIS. 375

Peter Bruff, the Chief Engineer. In 1800, Mr. Francis re-
moved to Hamjishire, and under Messrs. Collister and Galbraith,
superintended (1860-5) as Eesident Engineer, the construction
of the Andover and Eedbridge Railway, now the property of the
London and South Western Eailway Company. He was subse-
quently engaged in the preparation of the Parliamentary surveys
of the Northampton and Banbury Railways, and after the Act
was obtained, took charge of a section of the works until
the same were suspended during the financial crisis in 1866.
Mr. Francis afterwards entered into business on his own account,
and was extensively employed in arbitration work, the preparation
of parliamentary plans, &c. During the latter portion of his
life, Mr. Francis turned his attention to contracting, and super-
intended the construction of the Ascot and Aldershot branch of the
London and South Western Railway, for Mr. James Taylor. He
also superintended for Messrs. Curry, Reeve and Co., the execution
of the railway from Corfe to Swanage, now forming part of the
London and South Western, and the Gravesend Extension of the
London, Chatham and Dover Railway, for Mr. (now Sir George)
Barclay Bruce. Mr. Francis was likewise interested in the con-
tract for the first section of the North Cornwall Railway, from
Halwill to Launceston. He was thoroughly conversant with tlie
details of railway construction, which he had mastered both tlieo-
retically and practically ; and from his genial disposition and good
business habits, he was respected and esteemed by all who knew
him.

For the last twelve or fifteen months Mr. Francis had been in
failing health, and he died at Ealing on the 8th of November, at
the age of fifty- seven years. He was elected an Associate of
the Institution on the 5th of February 1867, and was transferred
to Member on the 18th of February 1873.

FRANK ALEXANDER BROWN GENESTE, of Huguenot
descent, was a son of the late Rev. Maximilian Geneste, Incumbent
of Holy Trinity Church, West Cowes, Isle of Wight, and was born
on the 28th of July, 1842.

Frank Geneste was educated at Winchester College, and was
placed as a pupil with Mr. Habershon, architect, with whom he
served a two years' pupilage, commencing in 1860. He was sub-
sequently with Mr. H. C. Wilson, Civil Engineer, as jjupil, on the
works of the Newport-Pagnell Railway. After this, he was em-

376 FRANK ALEXANDER BROWN GENESTE. [Obituary.

ployed on the following works : For nearly five years in India, on
the construction of the Delhi Railway, for Messrs. Brassey, Wythes
and Henfrey, the contractors for that line. He then went out as
District Engineer for Messrs. Waring, Brothers, contractors, on
the East Hungarian Railway, and was next engaged on railway
surveys in the United States of Colombia for the Public Works
Construction Company, first as Chief Assistant, and then as Chief
Engineer.

The Government of Venezuela, requiring a survey to be made
for a railway from La Guaira to Caracas, Mr. Geneste was
appointed as the Chief Engineer. This survey was conducted
by him, and the line has been constrvicted. He again was called
upon to go to the United States of Colombia, this time for the
Government of that country, as Chief Assistant Engineer. On
returning to England, he entered into practice as a Civil Engineer
in Westminster, on Parliamentary work, and on investigation of
claims for compensation, &c. In September, 1877, he was nominated
by Sir Charles Hutton Gregory, K.C.M.G., and appointed by the
Crown Agents for the Colonies, as an Assistant Engineer on the
Cape Government Railways, where he was chiefly engaged on the
construction of the Beaufort West Extension of those railways ;
first as an Assistant, then as Acting District, and finally as District
Engineer. This included the erection of some large wroxaght-iron
bridges, besides other works of importance, the work being carried
out departmentally, without the intervention of a contractor.

On his return from the Cape of Good Hope, at the termination
of his engagement, he, in Kovember 1880, undertook the con-
struction of the Malta Railway, which he carried out with com-
plete success. This work included a tunnel f mile long, under the
lines of fortification ; also various military defence works. He
was then appointed Engineer and General Manager by the Malta
Railway Company, Limited, maintaining and working the line in
a masterly fashion, as will be seen by any one who can read the
local accounts of the different Festas, involving sudden and large
traffic ; his greatest care having been to avoid peril to life or
limb, and his pride being a clean bill. In November, 1887, he
resigned his appointment at Malta, in order to take up the position
of Resident Engineer and General Manager of the Santa Matia
Railway, United States of Colombia, and left England in December
of that year; but less than four months later, on the 1st of April,
1 888, he died of typhus fever.

His career makes it manifest that he was a capable engineer, of
large experience. An accomplished artist, he rarely lost an oppor-

Obituary.] FRANK ALEXANDER BROWN GENESTE. 377

tunity of using this power ; and while always placing work before
pleasure, his love of nature gave him that change of labour which
to such minds is recreation. Comprehensive in his tastes ; able
with all the aids at his command, especially pen and pencil, he
was ever ready to amuse or instruct even a child ; and duty being
always paramount, his genial character served him in making the
way of life pleasant as well as consistent.

He was elected an Associate on the 7 th of April, 1871, and was
transferred to the class of Member on the 13th of December, 1887.

CHARLES MAEKHAMi was the son of Mr. Charles Markham,
Solicitor and Clerk of the Peace for the County of NortJiampton,
and was born on the 1st of March, 1823. He was educated at Oundle
School, and subsequently at Edinburgh University. It had been
intended that he should follow an agricultural career, but his bent
being towards mechanics, he went to France, and became Manager
of the Marquise Rolling Mills, between Calais and Boulogne. The
Revolution of 1848 destroyed this industry, and Mr. Markham
returned to England and studied chemistry for twelve months under
Professor Scoffern. He then served a pupilage under Mr. John
Hunter, on the Eastern Counties Railway, and in 1852 entered the
service of the Midland Railway Company, as an Assistant in the
Locomotive Department at Derby. Here he rapidly rose, becoming
Assistant Locomotive Superintendent under Mr. Matthew Kirtley.
While occupying this position, Mr. Markham conducted a series of
exjjeriments on the use of coal in locomotive-engines, that led to
the total disuse of coke in the engines of the Midland Company,
whereby that undertaking was saved nearly £50,000 a-year. Other
workers in the same field shared with him the honour of this great
advance ; but Mr. Markham's part in it was acknowledged to be a
leading one, and his Paper, read before the Institution of Mechanical
Engineers,^ marked a new era in locomotive practice.

In 1863 the Staveley Coal and Iron Works, which had been
extensively developed by Mr. Richard Barrow, were transferred to
a Limited Company. Mr. Markham accepted the post of Managing
Director, and left Belper, where he had lived for some years, to
take up his residence at Brimington Hall. No better choice for
such a post could have been made. Mr. Markham was gifted

' The substance of this notice is taken from the Derbyshire local press of
August and September, 1888.
^ lustilutiuu uf Mechanical Engineers. Procccdiugs, 18GU, p. 117.

378 CHARLES MABKHAM. [Oljituaiy.

"svitli a tlioroug'h business capacity; he had had a wide and
far-reaching experience, and he worked with an energj^ and zeal
which coukl hardly have been surpassed had the concern been his
own. At the same time, under his superintendence, and the direc-
tion of competent officials who had the immediate oversight of the
various departments, nothing but work of the best quality — both
as to material and execution — was turned out. The result was
that a connection was built up which sustained the Company
through the trying and prolonged period of commercial depression,
which proved disastrous to so many undertakings of a similar
character, and enabled it to pay its shareholders, in the worst of
times, a fair interest for the money they had invested. Shortly
after the formation of the Company, an ojiportunity was afforded to
those of the shareholders who desired to avail themselves of it, of
inspecting their newly-acquired property. An interesting gathering
assembled, and after the visitors had been conducted over the works,
and had examined the surface managements at several of the prin-
cipal collieries, they were entertained to dinner in the Workmen's
Hall at Barrow Hill. Mr. Barrow himself presided, and Mr.
Markham was one of the speakers. Mr. Barrow referred in terms
of pardonable pride to the growth of the works under his manage-
ment, pointing out that the output had increased from 50,000 tons
of coal and 15,000 tons of castings in 1844, to 700,000 tons of coal
and 20,000 tons of castings in 1864. During Mr. Markham's
management the development continued, though the ratio of
increase, in consequence of the exigencies of keen and constantly-
extending competition, had hardly been the same, the output at
the time of his death being over 850,000 tons of coal, and 40,000 tons
of castings. Mr. Markham's devotion to business prevented him
taking a very active part in public affairs in the district, but when
once he undertook a duty, he always performed it with assiduity
and thoroughness. He was made a County Magistrate in 1869, and
while health permitted he attended the Quarter Sessions for the
county, and the local petty sessions, with exemplaiy regularity,
and always manifested the utmost anxiety to administer even-
handed justice.

Mr. Markham took a deep interest in the welfare of the Chester-
field and North Derbyshire Hospital, of which he was one of the
Vice Presidents. It was chiefly through his instrumentality that
the area covered by tlie operations of this institution was divided
into districts, each returning a working man to act ujion the
Board of Management. He was one of the leading members of
the Iron and Steel Institute ; he however disa2iproved of the forma-

Obituary.] CHARLES MAKKHAM. 379

tion of local institutes, believing that the necessities of the case
were met by institutes of a national character, and hence he took
no part in connection with the Chesterfield and Derbyshire Insti-
tute of Mining Engineers. The erection of the Stephenson Memorial
Hall was also in opposition to his views, and he declined to assist
it by a contribution ; but on the day when the building was opened,
he forwarded a cheque for £100, for the purpose of providing a
supply of books for the Free Library of the borough, which was
located in a portion of the building.

The poor always found a warm friend in Mr. Markham, and
for several years he forwarded donations to provide Christmas
treats for the inmates of the Chesterfield Union Workhouse,
and the children in the Industrial Schools. In 1880 he gave
a donation of £1,000 to his native town of Northampton, to
found a "Markham Memorial" in memory of his parents. By
Mr. Markham's wish, the money was devoted to providing prizes
for Board and other Schools in Northampton, and to adding to the
Free Library. Mr. Markham became some years ago the purchaser
of Tapton House — where the last days of George Stephenson were
spent — and he then removed from Brimingion Hall to Tapton
House, where he afterwards resided.

Towards the end of 1887, Mr. Markham's health began to fail;
and the death, shortly afterwards, of a son to whom he was much
attached was a blew from which he did not seem to rally. He
died on the 30th of August, 1888, in his sixty-sixth year.

Mr. Markham was elected a Member of the Institution on the
6thof April, 1864.

JULIUS PAZZANI was born on the 16th of June, 1841, at
Brunn, Austria, where his father, who was a Greek by birth, had
settled on becoming a naturalized Austrian subject. The younger
Pazzani was educated at the Imperial Polytechnickum of Vienna,
and in due time passed the principal examinations. In 1861, he
entered the service of the Imperial Continental Gas Association as
junior assistant at their Erdberg works, Vienna. In 1868, he
became Engineer of the Belvedere works of the same company,
also in Vienna, which he entirely reconstructed, and greatly
extended, insomuch that of what he found there, nothing remained
in a few years. In 1880, Mr. Pazzani was transferred to the
Rotterdam station of the Association as Chief Engineer. Here he
rebuilt the Delfshaven works, and generally reorganized the
business of the company. Four years later, in 1884, he was

380 JULIUS PAZZANI. [Obituary.

removed to Amsterclam, also as Chief Engineer, with the special
mission to construct two new gasworks, and to lay new mains
and services all over the town. In this capacity Mr, Pazzani
successfully carried out all the difficult and delicate negotiations
involved in repijDing a city of 400,000 inhabitants, being exposed,
moreover, to the hostility of the old gas interest, which it was his
business to supersede. Mr. Pazzani just lived long enough to
complete this undertaking, the first station being put into operation
in September 1885, and the second or Amstel works in the course
of 1887.

Mr. Pazzani's death was very sudden. On the evening of the
20th of October, 1888, he visited a friend, and on returning home
complained of feeling unwell. He rapidly became unconscious,
and died at seven o'clock the next morning — the immediate cause
being a paralytic stroke.

Mr. Pazzani was elected a Member of the Institution on the 11th
of January, 1887, and was also connected with the Gas Institute
and the cognate bodies in Germany and Holland. In addition to
being a notable engineer, Mr. Pazzani was a most amiable and
accomplished man. He was a specially-skilled ling-uist, speaking
Avith facility German, English, French, Italian, and Dutch.

WILLIAM EOGEES was the eldest son of the late Ebenezer
Eogers, of Abercarne Vach, Abercarne, Monmouthshire, and was
born on the 5th of February, 1843. At the age of sixteen, he
entered the Ebbw Vale Ironworks, and went through the various
shops, being afterwards engaged as an assistant in the engineering
department.

Leaving these works in 1863, he was engaged for eighteen
months as Assistant Manager under the late Mr. S. H. Blackwell, at
the Eussell Hall and Corbyn Ironworks in Staffordshire, and ujjon
the branch railways connected therewith. Having by this time
acquired a considerable knowledge of the manufacture of iron,
and an amount of useful experience in the construction of iron-
work generally, which proved invaluable to him in the varied
works which he had subsequently to carry out in foreign countries,
he, in 1865, went to Australia. For a period of six years from
this time he found employment uj)on the railways, waterworks,
and other public works in the Government of South Australia,
first as an Assistant Engineer, then as Eesident Engineer in
charge of the surveys and construction of the Port Wakefield and

Obituary.] WILLIAM ROGERS. 381

Hayles riain Eailway, and of tlie Dry Creek Loop Line, under
Mr. William Hanson, Eugineer-in-chief, and Mr. J. England, and
subsequently as Chief Engineer to the contractors of the Northern
Extension Eailway. In these various positions throughout this
period, Mr. Rogers proved a thoroughly trustworthy surveyor, and
showed that he possessed great natural capacity as an engineer.

Returning to this coimtry in 1871, he spent but a short time at
home, for the same year he obtained an appointment as assistant
on the staff of the Imperial Government Railways of Japan.
During the next five years he filled in succession the posts of
Resident Engineer during the constriiction of the Central Section
of the Osaka-Kioto line, and Resident Engineer in charge of the
open Yokohama- Yedo line, under Mr. R. Vicars-Boyle, C.S.I., the
Engineer-in-chiefti' Owing to the abandonment at this time of
further extensions b}' the Japanese Government, and the con-
sequent reductions in their English staff, Mr. Rogers, in 1870,
found himself out of employment, and came home.

After a few months in England, he accepted a post as Assistant
Engineer on the East London and Queenstown Railway, under
Mr. James Fforde, Chief Engineer for the Cape Colony, and was
engaged on that railway until its completion, and on other minor
works until his return in 1881.

The next field in which Mr. Rogers worked was Brazil ; as Chief
District Engineer, he was engaged in the construction of the
Alagoas Railway, and afterwards as Chief Engineer of the surveys,
and preparing the plans and estimates of the Sergipe Railway,
115 miles in length, for Messrs. Hugh Wilson and Sons. Respect-
ing his work on this latter line, the Consulting Engineers, Messrs.
Hawkshaw, Son, and Hayter, write : " This line has been laid out
with skill and jiidgment, and complete information obtained, and
we have never known a work of the kind more rapidly, and at
the same time more effectually done." The commencement of the
const]*uction of the Sergipe Railway appearing to be postponed
for some time, Mr. Rogers returned to England in 1885, and being
unwilling to wait an indefinite time for the resiimption of active
work in this district of Brazil, he accepted the post of Engineer-
in-chief of the West Australian Railway then projected from
Albany to Perth, and started for that colony in August, 1886.
For a period of eighteen months, he carried out the multifarious
duties of locating and inaugurating the construction of the line in
a sparsely populated and almost unexplored country, throughout
its length of upwards of 240 miles, when, on the 20th of February,
whilst at his rooms at Albany, he was suddenly struck

382 WILLIAM KOGERS. [Obituary.

down with an attack of apoplexy, and expired in a few minutes.
Thus, at the early age of forty-five years, ended a hright career,
marked by hard and energetic work, and an amount of varied ex-
perience in foreign lands that falls to the lot of few engineers.

Mr. Eogers was elected an Associate of the Institution on the
6th of February, 1877, and was transferred to the class of Member
on the 1st of April, 1879.

GEOEGE HEXXET EOSS, the eldest son of the late Commander
C. H. Eoss, E.X., was born on the 19th of March, 1843. At the age
of- seventeen he was placed with Mr. E. Bagot as a pupil for three
years, and was then employed for two years iu?. that gentleman's
drawing-office, and on surveys for railways, waterworks, and town
sewerao-e. In 1865 he entered the service of Mr. (now Sir
Alexander) Eendel, and was employed for four years as a draughts-
man in his London office, and in making surveys at Llanelly, the
Victoria Docks, and elsewhere. Then Mr. Eendel appointed him
Eesident Engineer on the Workington Harbour Improvements,
where he had charge for three years of considerable marine surveys,
the cutting of a new channel for the Eiver Derwent, the erection
of a timber jetty, and the building of a breakwater in Portland-
cement concrete, besides other minor works. In March, 1872, Mr.
Eoss proceeded to Trinidad as Engineer and Surveyor for the
Colonial Company, and was occupied in surveying large sugar-
estates, and in laying out railways. "While in that colony he
passed the Government examination as a Sworn Surveyor. He
returned to England in December, 1873, and for six months of the
following year was again in Mr. Eendel's drawing-office. In
November, 187-4, he was appointed, on the nomination of Sir
Charles Hutton Gregory, K.C.M.G., an Assistant Engineer on the
Cape Government Eailway Surveys. Two years later he was
placed in charge, under the District Engineer, Mr. G. D. Ather-
stone, of No. 1 Section of District 2 of the Grahamstown Branch
of the Midland and North-Eastern (Cape) Eailways. The survey
and construction of this section, which included some heavy earth-
works, such as cuttings in hard rock, an embankment nearly 70
feet high, and several retaining walls, a short tunnel through
very treacherous strata of rock on clay beds, a temix)rary terminal
station, with the necessary sidings and accommodation for goods, all
such works as culverts, platelaj-ing, ballasting, and the telegraj^h,
"were completed by Mr. Eoss, in the most careful and accurate

Obituary.] GEORGE HENNET ROSS. 383

manner. From September, 1879, to August, 1880, he took charge,
for Mr. Faviell, the Contractor, of the construction of 10^ miles of
the Midland System of the Cape Government Eailways, which
included a tunnel, and some heavy cuttings and embankments
about 30 miles south of Cradock. In August, 1881, Mr. Eoss
was appointed District Engineer on the Survey Staff, under Mr.
William Willcox, and placed in charge of survey camps on the
Cradock and Colesberg Extension, and on proposed junction lines
between the Midland and Eastern Railway Systems. This appoint-
ment Mr. Eoss held until September, 1883, when he returned to
England. In August, 1884, he was engaged by Mr. John Brunton
and Mr. T. Claxton Fidler, Joint Engineers for the East India
Tramways Company, as Eesident Engineer on the construction of
the Karachi Steam Tramways, which work he carried out to their
entire satisfaction, performing the duties of his position there with
zeal, energy and ability. When the works were completed, and
handed over by the contractors to the Company in September, 1885,
Mr. Eoss returned to England. In the following November he
obtained, again on the nomination of Sir Charles Hutton Gregory,
the appointment of Colonial Engineer and Surveyor at Lagos.
This post he held until his death, which occurred on the 16th of
August, 1888, from fever.

Mr. Eoss was much regretted. A member of the Institution,
under whom he served on the Cape Government Eailways writing
after his death, said : — " He was a cheery bright fellow, was, I
know, most hospitable and popular, and I am sure was thoroughly
straightforward in all respects. His untimely death will be
greatly regretted by all the members of the Cape Eailways who
knew him, and by many others in the Colony, as he had a
wide circle of friends, and, to the best of my belief, no enemies."

He was elected an Associate of the Institution on the 9th of
April, 1872, was jilaced in the group of Associate Members on its
creation in December, 1878, and transferred to the class of Members
on the 14th of April, 1885.

EANSON COLECOME BATTEEBEE, eldest son of the late
Joseph Batterbee, of Eeigate, was born on the 10th of March, 1838.
In 1859 he was articled for three years to Mr. Eobert Sinclair,
then Engineer-in-Chief of the Eastern Counties (now Great Eastern)
Eailway. On the completion of his pupilage, Mr. Batterbee re-
mained with Mr. Sinclair, and with his successor, Mr. H. W.

38-1 RANSON COLECOME BATTERBEE. i [Obituary.

Davis, for ten years. He left the Great Eastern Company in
1872 to become manager of the Brazilian Street Eailway Com-
pany's line of tramway from Eecife to Caxanga. This under-
taking, which was of a peculiar nature, had fallen into disrepute,
and it required considerable tact and firmness to reinstate it.
Mr. Batterbee gave great satisfaction in a very difficult jDosition,
his management being distingiiished by sound good sense, attention
to the interests both of the Company and the public, and strict
integrity. About 1876 Mr. Batterbee returned to England, and
did not resume professional employment until 1883, when he went
to Parahyba de Xorte, also in Brazil, as Eesident Engineer of the
Conde d'Eu Eailway. Here, again, a difficult task was imjiosed
upon him, owing to disputes between the Company and the Con-
tractors for the line. The worry and responsibility predisposed
him to sickness, and an attack of heat apoplexy intervening, he
was obliged to come home eighteen months later completely
prostrated. Eecovering his health, he returned to Brazil in
October 1884, and remained in charge of the line till April 1885,
when, his health again giving way, he was compelled to resign his
appointment. From that time till his death, on the 15th of July,
1888, Mr. Batterbee, though unable to engage in active work,
took part in the settlement of the contract accounts, and performed
other duties for the Company in London up to the end of 1887.

Mr. Batterbee was intelligent, courteous, and amiable, zealous
in the discharge of his duties, and honourable in all his proceedings,
and was much and deservedly esteemed by those with whom he
came in contact. He was elected an Associate Member on the
oth of December, 1882.

JAMES JOHN ALEXANDEE FLOWEE was born at the Baptist
Parsonage, Chobham, Surrey, on the 21st of April, 1847. After
being educated by private tutors, he served a pupilage to Messrs.
A. and J. Inglis, Marine Engineers, Glasgow. He then proceeded
to the Cape, and after Ijeing for a short time in private practice he
was appointed Acting Engineer of Cape Town. During his tenure
of that post he carried out an extension of the water-supply from
Table Moiintain through Platte Klip, and constructed a small
reservoir and filtering-beds. About a year after the return of the
City Engineer, the latter Avas pensioned, and Mr. Flower was
appointed his successor. During Mr. Flower's absence in England
the duties of the office were fulfilled hy his father, and in the

Obituary.] JAMES JOHN ALEXANDER FLOWER. 385

result lie never personally took np the appointment, preferring to
remain at home as the London rejiresentative of the firm in which
he was a partner, namely, Messrs. James Flower and Sons, Mechan-
ical Engineers, largely occupied in the construction and importation
of machinery for gold-mining. He was thus occupied until the
spring of 1888, when, owing to some misunderstanding with the
Cape banks, the firm were obliged temporarily to suspend payment,
being at the time in the full swing of business. This untoward
event caused a shock from which Mr. Flower never recovered, and
he died broken-hearted on the 12th of April, 1888.

Mr. Flower was elected an Associate of the Institution on the
2nd of December, 1873, and was transferred to the class of
Associate Members on the separation of the former grade into two
divisions.

SAMUEL HAEPUR was born at Derby on the 1st of March,
1820. At the age of seventeen he was articled to Mr. Samuel Henry
Oakes, a civil engineer, whose daughter he subsequently married.

In 1841, shortly after completing his pupilage, he was appointed
Borough Surveyor of Derby, where he carried out some important
engineering works, amongst them the construction of the Flood-
sewers and Main-drainage of the town, also the erection of a bridge
across the Derwent. In 1846, while at Derby, he invented and
first used the transverse invert-bricks, now so generally employed
in the construction of sewers.

In 1851 he resigned his appointment at Derloy, in order to become
Managing Partner in the firm of Thomlinson, Harpur and Harpur,
Contractors. Among the works carried out by him in that capacity
were : The main drainage and waterworks at Ashby-de-la-Zouch ;
the Thornton Reservoir of the Leicester waterworks ; the main
drainage and sewage-disposal works of the City of Coventry ;
sewerage works at Burslem, and sewerage and sewage-disposal
works at Cheltenham. These contracts occupied him until the
year 1859, when he removed to Merthyr Tydfil, his firm having
taken the contract for the construction of the filter-beds, depositing-
tanks, pure-water reservoirs, engine-house, and erection of pumj^ing-
machinery, as a portion of the scheme for sujiplying the district of
Merthyr with water. With that contract began Mr. Harpur's
connection with Merthyr Tydfil, and it became the means of the firm
acquiring other work in the neighbourhood. On the failure of the
original contractors for the construction of the storage-reservoir at
Pentwyn, also in connection with the Merthyr waterworks, the

[the IMST. C.E. VOL. XCV.] 2 C

386 SAMUEL HARPUR. [Obituary.

contract was given to Mr. Harpnr, who carried it to completion in
a satisfactory manner. The whole of the foregoing works were
executed under the personal supervision and instructions of Mr.
Harpur, his two partners seldom visiting the works.

In consequence of serious difficulties encountered in the con-
struction of the Pentwyn Eeservoir, Mr. Harpur sustained heavy
pecuniary losses, and as a result, on the completion of his contracts
for these works in 1862, he severed his connection with the firm
of Thomlinson, Harpur and Harpur, and resumed the profession of
a civil engineer. About this time the appointment of Engineer
and Surveyor to the Merthjn: Tydfil Local Board became vacant,
and Mr. Harpur applied for the post, to which he was unanimously
elected. The district of the Board was at that time in a lamentably
unsanitary condition, the registered death-rate being upwards of
30 per 1,000. Mr. Harpur immediately set to work with a deter-
mination to improve the health of the locality. Under his direc-
tions the water-supply was at once extended to the outlying
districts, and as the water came to be used by the inhabitants
generally, the necessity for a proper system of drainage became
more and more apparent. Mr. Harjjur thereupon prepared a scheme
of sewerage for the district, and for disposing of the sewage by
irrigation. The Board, however, after lengthy discussions, decided
to carry out the sewerage scheme only, leaving the matter of the
ultimate disposal of the sewage for further consideration, and in
the meantime to discharge the sewage into the Taff". The contract
for the complete sewerage of the district was let, and the Avork
carried out in 1868-9. Scarcely, however, had the sewers been
completed, when a Chancery injunction was obtained against the
Board, restraining them from discharging sewage into the river.
The Board were now forced to face the question of properly
deodorizing and disposing of the sewage, and ultimately decided to
adopt Mr. Harpur' s amended scheme of irrigation. Some of the
lands selected for irrigation purposes were situated at a distance
of 10 or 11 miles from Merthyr, and the line of the outfall sewer
lay in places through very precipitous ground, crossed in numerous
instances by deep ravines. In surmounting these, Mr. Harpur
introduced a new feature in sewer-construction. Instead of follow-
ing the contour of the ground, or siphoning under the depressions,
he carried the sewer over by means of timber tubes supported on
stone piers, the tubes being formed in segmental sections, banded
together by iron straps. This mode of construction has proved
highly satisfactory, and the traveller on the Taif Vale Eailway
cannot but be struck by the novel features presented in numerous

Obituary.] SAMUEL HARPUR. 387

places by these tubes. Subsequently to the completion of the
Merthyr Outfall Sewer, and when the lands of the Merthyr Local
Board were being prepared for the reception of the sewage, the
Merthyr Board arranged with the neighbouring Local Boards of
Aberdare and Mountain Ash to treat the sewage of those districts
on their land, and Mr. Harpur was engaged by those Boards as
Consulting Engineer to carry out the work. The lands for
irrigating the sewage of these three districts (some 400 acres
in extent) were ultimately laid out by Mr. Harpur, and are
now accomplishing all the objects which were sought to be
attained, and are yielding a profit on working expenses. Upon
the delivery of sewage from Aberdare and Mountain Ash on to
the farm, the three Local Boards became joint-owners, and the
farms were invested in a Committee representative of the three
Boards, entitled the " Merthy and Aberdare Joint Sewage-Farms
Committee." To this body Mr. Harpur continued to act as Engi-
neer up to the time of his death.

In 1885, failing health compelled Mr. Harpui to resign his
appointment under the Merthyr Local Board, but latterly his health
had to outward appearance very much improved, and his death
came at last very suddenly, on the 10th of November, 1888. after
an illness of only five days' duration.

He was elected an Associate of the Institution on the 6th of
May, 1873, and was transferred to the class of Associate Members
on the formation of the latter grade.

Mr. Harpur was a man of great reserve ; he was earnest,
conscientious, and upright in his dealings with all men, and
scrupulously straightforward and impartial in the conduct of his
business ; he was, moreover, very unpretentious in his manner,
would never push himself forward in any way, and a marked
trait in his character was a want of ambition. From his long
experience in sanitary engineering, his advice and assistance was
frequently sought, and he was often engaged as a witness in
Parliament and elsewhere upon sanitary matters, though seldom
seeking such engagements.

EENEST FEEDERIC MOEANT, son of Mr. John Edward
Morant-Gale, was born on the 29 th of July, 1849, at Upham, in
Hampshire. He was educated for the Indian Civil Service, but on
reaching full age he resolved to try the more adventurous life of a
sheep-farmer in Uruguay. Like many others, he was unfortunate.

388 ERNEST FEEDERIC MORANT. [Obituary.

and in 1873 found Mmself without capital or employment. Under
the secirciimstances he joined the North Western of Uruguay Eailway
as an assistant under Mr. W. G. Ferrar, by whom he was afforded
every opportunity of acquiring engineering knowledge. Possessed
of a keen intellect, he was, within two years, fully competent to
undertake the ordinary duties of an assistant engineer, the practical
knowledge gained in his uphill experience making his services of
far more than ordinary value. From the North Western of
Uruguay Company, Mr. Morant passed to the Buenos Ayres and
Campana Eailway in the Argentine Eepublic. Owing to the
completion of this line, he was for some time without regular
emplo}Tnent, but proceeding to Brazil he was engaged by Mr. John
Dixon, on the Eio de Janeiro Waterworks, and subsequently
became one of Messrs. AVaring's agents on the Minas and Eio
Eailway. While in Brazil he married a daughter of Mr. John
Morritt, a prominent merchant of Eio, and joined him in several
business undertakings, reorganizing a cotton-mill, and also aiding
in the working of steam-navigation on the great Brazilian rivers.
Having made a moderate fortune he returned to London, and
entered into business as a contractor. In conjunction with another
gentleman, Mr. Morant, in 1886, tendered for the construction of
the great sewage-collecting tank at Barking. He was also much
interested in the adoption of shale and other mineral oils for fuel
purposes, under the form of gas. Mr. Morant was a director of the
Amazon Steam Navigation Company, where his intimate knowledge
of the river was of considerable service to his colleagues. Mr.
Morant was an excellent business man, seeing at once the points of
anything presented to him, and was able to go to the root of a
matter.

Mr. Morant was elected an Associate Member of the Institution on
the 2nd of February, 1886. His death, on the 26th of August, 1888,
was the result of being thrown from a dog-cart.

EOBEET PINCHIN was born in the year 1821. In 1842 he was
articled to Mr. W. J. Lord, formerly of the Eoyal Engineers, and
on the expiration of his pupilage he was employed by Mr. (now
Sir Joseph) Bazalgette, who was surveying a proposed railway
from Birmingham to Stratford-on-Avon. On the completion of
this work Mr. Pinchin, in 1846, had entire charge of the survey
of the Parish of Moncton Combes, in Somersetshire, In the same
year he sailed for India.- In taking his passage, however, provision

Obituary.] EGBERT PINCHIN. 389

was made to give Cape Town a call, and if professional prospects
were at all bright, he proposed making the Cape Colony his future
home. This was all the more desirable, as India was then univer-
sally denounced as an unhealthy country for residence.

On arriving in Cape Town Mr. Pinchin called upon the several
Government officers in charge of public works. The result was
disappointing. Civil engineering at that date was confined to the
construction of a few main lines of road and simple bridges,
the erection of prisons, and other Government buildings, works
which held out very little encouragement for gaining either pro-
fessional experience or a suitable livelihood. When on the eve of
continuing his journey to India, he was advised to call upon the
late Mr. Charles Bell, the then Surveyor-General for the Colony,
and at this visit Mr. Pinchin's professional future was decided.
Mr. Bell pointed out that the only lucrative or permanent profes-
sional employment in the Colony for some years would be Govern-
ment land surveying, and advised Mr. Pinchin to devote his
attention to this branch of his profession, and remain in Cape
Colony. Through Mr. Bell's kindly advice and assistance he
passed the necessary Government examination, and was licensed
to practice as a land surveyor in the Cape Colony. No favourable
opening offered itself in the Cape districts, which were at that
time overstocked with surveyors, so Mr. Pinchin proceeded to the
eastern province.

Port Elizabeth, in 1846, was insignificant compared -with its
present influential standing, but was even then rapidly rising in
mercantile importance. Mr. Pinchin's advent was, therefore,
professionally propitious, and subsequently most advantageous
from a financial point of view. The laying out of this " Liverpool
of South Africa," Port Elizabeth and suburbs, may be said to
have been Mr. Pinchin's lifework. For, though enjoying a wide-
spread professional connection, he made his headquarters at Port
Elizabeth, where he was an authority upon local land questions
to the time of his death. About 1863 he was for a brief time in
partnership with Mr. G. W. Smith, the Government Engineer and
Surveyor now his successor, but depression in trade led to its
termination, and Mr. Pinchin enjoyed for many years almost a
monopoly of practice. The enlargement of the town and municipal
improvements gave Mr. Pinchin opportunity for the exercise of
his attainments as a civil engineer. Prize designs were invited
by the Corporation for supplying Port Elizabeth with water, and
Mr. Pinchin's scheme was many years afterwards adopted, and
construction carried out, by the late Mr. J. H. Wicksteed, at an

390 ROBERT PINCHIN. [Obituary.

outlay of about £150,000. The works for a water-supply to
Uitenhage were entrusted to Mr. Pinchin, but his extensive and
lucrative land survey practice left him scant time to pursue other
branches of the profession.

In 1872, when the Colonial Government entered upon the con-
struction of railways, Mr. Pinchin's services were in constant
demand for valuing, defining, and dividing town-lands for the
various works and expropriations naturally attending the intro-
duction of railways. About this time he became acquainted
with Mr. H. L. Spindler, assistant to the Chief Eesident Eailway
Engineer. Mr. Pinchin, on the part of the public, and Mr. Sjiindler
on the part of Government, carried out the settlement of the
many and varied land questions involved in the compulsory expro-
priation of property. The professional ability and integrity dis-
played by Mr. Pinchin averted any recourse to law, and his services
were appreciated both by the Government and his clients. When
Mr. Spindler retired from the railway service in 1879, and entered
upon private practice, Mr. Pinchin became his professional associate,
and remained so to the day of his death.

Mr. Pinchin enjoyed a well-deserved reputation as a geologist,
and was for many years a member of the geological societies of
London and Vienna. On several occasions his knowledge of the
eastern province of the Colony saved prospectors and others fruitless
search for coal, gold, &c. ; and his services were freely, and in
most cases gratuitously, oifered to surrounding farmers to encourage
search for precious stones, minerals, and in well-sinking. One of
the last of many benefits conferred by him ujion Port Elizabeth
was the careful arrangement of geological specimens acquired
by the Eastern Province Naturalist Society.

From his scientific tastes and education he was not a man to
attract many friends in a town of commercial men. He took no
part in politics, nor did he seek municipal distinction, being
out of touch with what may be termed strife for office. Upright,
straightforward, and accurate in his business affairs, he made
many friends among the Dutch farmers. Few enjoyed the privilege
of his confidence, and though to most he would appear unusually
reserved in manner, yet the young surveyor would find him
animated and enthusiastic upon professional subjects. On his
death-bed he sat up to write out, in Mr. Spindler's memorandum-
book, a trigonometrical formula which he greatly admired for its
simplicity. He had jiassed the crisis of a dangerous disorder, and
had just returned to his office in a weakened condition, when a
chilly south-east wind brought on an attack of inflammation of the

Obituary.] ROBERT PINCHIN. 391

lungs, to which he succumbed on the 9th of May, 1888. Mr.
Pinchin was elected an Associate of the Institution on the 3rd
of February, 1874, and was subsequently included among the

Associate Members.

CHAELES THOMAS SPENCER was born on the 12th of May,
1856. At the age of sixteen he was articled to Sir James Ramsden,
of Barrow-in-Furness, for four years, and on the expiration of
his pupilage, in 1876, he continued in the service of the Furness
Railway until 1882. During that period he was engaged, as
Assistant Engineer, in surveying and levelling, making plans,
sections and drawings, superintending various works in connection
with the railway and the Barrow Docks. In 1883-4, he was
employed in the office of Mr. Stileman, as Assistant Engineer,
in jDreparing contract and Parliamentary plans and sections. In
January, 1884, he entered the service of the East Indian Rail-
way Company, and was appointed as Assistant to Mr, Graham
Peddie, District Engineer of the Jubbulpore Extension, and
placed in charge of 140 miles of line. In 1885 he was, during
the absence of the incumbent, placed in temporary charge of the
next division of 83 miles. While thus engaged he carried out
the Katni-Umaria (State) Railway Junction works with the East
Indian Railway, and subsequently the junction of the Indian
Midland Railway at Manikpur, with the East Indian system.
While thus engaged, he died very suddenly of cholera, at Moghal
Sarai, on the 7th of July, 1888.

Mr. Spencer was an exceptionally able man, thoroughly well up
in his work, and very energetic. His death deprived the East
Indian Railway Company of one of the most promising of its
younger officers. In private life he was a universal favourite,
being an eminently social and accomplished all-round man. He
could dance, sing, play cricket and lawn-tennis, fight, preach, and
play the organ in church, and was recognised as a type of true
English manhood, kind, considerate, and fair. He was elected an
Associate Member of the Institution on the 24th of May, 1887.

392 JOHN TRICKETT. [Obituary.

JOHN TRICKETT commenced his apprenticeship to engineering
at the age of sixteen years, at the Butterley Ironworks, Derbyshire ;
four years later he entered the Deptford works of the General
Steam Navigation Company, then one of the largest enterprises of
the kind in the country, as Assistant to the Managing Engineer,
During the ten years he was with that Company he designed and
constructed twelve pairs of marine engines and boilers, and super-
intended the working of most of them on their first voyage. He also
designed several land engines, constructed at the Company's works,
as well as all the boilers for replacements in the ships, and
supervised the new work in the shops, and repairs on board the
ships.

Subsequently Mr. Trickett entered the works of Messrs. John
Penn and Sons, at Greenwich, where he held a good appointment.
In 1846 he was recommended by Messrs. Penn to the Admiralty,
in answer to an invitation to submit the name of any one in their
establishment suitable for employment in the public service. In
July of that year he was appointed to the Steam Factory at
Woolwich, and while there, as Assistant to the Chief Engineer, he
carried out a series of elaborate screw experiments in the "Minx,"
" Teazer," " Eifleman," and " Sharpshooter."

In April, 1854, Mr. Trickett was appointed Chief Engineer and
Inspector of Steam Machinery at Devonport and Keyham. Among
the labour-saving arrangements made by him at those yards,
were the multi-spindled machines for drilling six holes at one
time in angle-iron, and for cutting four holes at once in tube-plates
for boilers, which were then the first tools of the kind made for
boiler-work. In 1855 he designed and fitted a rope-driving arrange-
ment to all the travelling cranes in the workshops, driving them
from the running shafting which is now generally adopted in
private shops. He also designed and fitted the post-cranes in
the foundry with steam-power for working them. In 1855-6 Mr.
Trickett made and erected the first iron sheer-legs put up in the
dockyards, and fitted them with steam-power. He also fitted steam-
power to the 40-ton crane erected by Fairbairn at the north basin,
and subsequently to the other cranes at Keyham, and to some
at Devonport. In July, 1862, Mr. Trickett was transferred, at his
own request, to Woolwich Yard, on the retirement of the late
Chief Engineer Mr. Charles Atherton, where he remained until the
closing of the yard at the end of September, 1869, when he
returned to Keyham.

Obituary.] JOHN TIIICKETT. 393

Mr. Trickett gave much attention to the manufacture of yarn
and rope, and made many improvements in the machinery, in all
the details of manufacture, which resulted in much better and
stronger cordage being produced, and the cost of manufacture
lessened. He vras a member of the Boiler Committee formed in
June, 1874, and was present in taking nearly all the evidence of
persons examined by the Committee.

He retired from the post of Chief Engineer of H.M. Dockyard,
Devonport, in December, 1879, and his long and able services
were recognized by the Admiralty awarding him a special pension,
which he enjoyed till his death, on the 9th of November, 1888.

Mr. Trickett was elected an Associate of the Institution on the
1st of February, 1853, and when the division into professional
and non-professional Associates was made, he was graded Associate
Member.

JOHN WAKEFOED was born on the 17th of December, 1833
He served a pupilage under the late Mr. E. Allen Stickney,
Surveyor to the Public Health Commissioners of Brighton, who was
employed at that time on trigonometrical surveys and in drainage
and sea-defence works. Mr. Wakeford was then engaged by the
Brighton, Hove and Preston Waterworks Company to prepare plans
of the mains, hydrants, &c., belonging to the Company. In 1854
he became assistant to Mr. J. G. Poole, Surveyor to the Local
Board of Health, Southampton, when he revised the Board's copy of
the Ordnance Survey of the town. From 1854 to 1857 Mr. Wakeford
was Assistant Borough Surveyor of Leicester, having the superin-
tendence of extensive drainage operations, street- works, and surveys.
During 1857-8 he was engaged temporarily with Mr. J. Gr. Poole,
and also Mr. C. E. Bernard, of Cardiff. In 1858-9 he was Clerk
of the Works and assistant to Mr. Edward Gibbs, Surveyor to the
Local Board of Stratford-upon-Avon, in charge of the main-drainage
works. In 1859-60 he was engaged by Messrs. Flint and Shenton,
surveying extensions of the Borough of Leicester and in making a
copy of the plans of that borough. In 1860 he was appointed
Assistant Borough Surveyor of Wolverhampton, engaged in pre-
paring a scheme of main drainage for that town, which was
approved by the Local Government Board. He held this appoint-
ment until 1865, when he became assistant to Mr. E. A. Marillier,
Engineer to the Hull Docks. From 1866 to 1867 he was

394 JOHN WAKEFORD. [Obituary.

Surveyor to the Beverley and Barmstone Drainage Commis-
sioners. The experience gained in these very varied engagements
prepared him for the post in which he was destined to pass the
remainder of his life. In 1868 he was engaged by the late Mr.
J. J. Montgomery, Borough Surveyor of Belfast, as an assistant,
and on that gentleman's death in 1884, Mr. Wakeford became
Chief Assistant Borough Surveyor under his successor, Mr. J. C.
Bretland. Mr. Wakeford held this oifice until his death on the
6th of June, 1888. Mr. Wakeford was elected an Associate
Member on the 6th of May, 1886. He was a very careful and
painstaking engineer of the second rank, and although not des-
tined to attain an independent position, he left a considerable
reputation for good and thorough work.

EEEBEET FEAXCIS WAEING, second son of Mr. Thomas
Waring, of Cardiff, was born at that place on the 2nd of October,
1859. He was educated chiefly at Cheltenham College, where he
took a good position in Physics and Mathematics. He entered his
father's oflSce in 1875, and making rapid progress in the profes-
sion, was elected an Associate Member of the Institution on the 4th
of March, 1884. He soon took charge of the engineering portion
of the business, and carried out a scheme of waterworks for the
Borough of Aberavon ; a filtration system of sewerage for the City
of Llandaff ; sewerage and sanitary works for various estates, and,
up to the day before his death, was engaged in completing a scheme
of drainage for the Cardiff Union Sanitary Authority.

Mr. Herbert Waring became a partner in the firm of T. Waring
and Sons, Civil Engineers and Land Agents, in 1885. Being of a
quiet and retiring disposition, he took no active part in the pro-
ceedings of the Institution. His death, on the 12th of August,
1888, from a fit of apoplexy after a few hours' illness, was a great
shock to his family and to a numerous circle of personal friends.

JOHN ASHWOETH was born on the 3rd of August, 1826. From
his earliest youth he evinced an aptitude for mechanics, and was
constantly making models of small pieces of machinery. When
quite a boy he constructed several miniature water-wheels,
which he fixed in small streams near his father's house. As he

obituary.] JOHN ASHWORTH. 395

advanced in years lie gave much attention to improvements in
the steam-engine, and was one of the first, if not the first, in Bolton
to see the advantages of iising steam at very high pressure. He
spent some time in experimenting with a new railway-chair, and
some specimens of the pattern he invented were laid on the Lanca-
shire and Yorkshire Railway near Bolton. He afterwards brought
this invention under the notice of Sir Edward Watkin, hut being at
the time greatly occupied with other matters, he failed to follow it up.
In due course Mr. Ashworth joined his father, who was in business
as a cotton-spinner at Bolton, and turned his attention to the im-
provement of spinning machinery, taking out several patents for
that purpose. One related to what is called a lap-machine, used
for making laps for combing-machines. The selvedges made from
the machines then in use were not satisfactory, and after a con-
siderable time in experimenting, he introduced a revolving plate
in lieu of the stationary or fixed one. This was a great success
and was adopted by many machine-makers, who paid Mr. Ashworth
a considerable amount for royalties ; he also invented an improved
cam for lifting conical valves, which was applied by several other
engineers in Bolton.

About the year 1862 Mr. Ashworth left his father's mill, and
built a large one for himself at Astley Bridge, near Bolton. This
was a model structure in every respect, both as regarded the building
and the engines, and machinery. Here he had a pair of engines
of 500 or 600 indicated HP., working with an initial pressure
of 100 lbs. to the square inch, and burning less fuel in proportion
than any engines in the neighbourhood. In the necks of the steel
crank-shafts of these engines, he cut elliptical grooves which
caused the lubricating oil to pass along the necks in such a way as
to be suifused equally over the whole surface, and so prevent
heating.

Several other inventions also proceeded from his prolific brain,
amongst them an improved cheese-toaster, which is a great
favourite, all of the inventions being of a practical nature, and
such as commended themselves to his associates in the spinning
trade. Mr. Ashworth's motto was " thorough."

Mr. Ashworth was elected an Associate of the Institution on the
12th of May, 1874. He died on the 18th of September, 1888.

396 MAJOR AUGUSTUS SAMUEL WILLIAM CONNOR. [Obituary

MAJOR AUGUSTUS SAMUEL WILLIAM CONNOR, Bombay
Staff Corps, son of the late William Connor, Honorary Magistrate
of Alignrli, in the North- West Provinces of India, was born
on the 18th of June, 184-i. He was ediicated at Mnssoori under
the Rev. Dr. Lnoni, and afterwards at the Thomason Civil En-
gineering College, Roorkee. From thence he was appointed to the
Indian Trignometrical Survey, and did good work in it for some
little time. In 1864, he entered the Public Works Department as
an assistant engineer, and was employed on the Agra and Bombay
road, and afterwards at Gwalior under Lieutenant (now Lieut. -
Colonel) J. B. Sparks, Executive Engineer. Here he had the
supervision of the construction of barracks, as also the defences
of the fortress of Gwalior. His services were so highly esteemed,
that although he had meanwhile been appointed to an ensigncy
in the Ceylon rifle regiment, he was retained by the Govern-
ment of India for eighteen months. He joined his regiment
in Ceylon, but soon after exchanged into the 7th Royal Fusileers,
and returned to India. The want of occupation during the peaceful
period that now intervened in India proved irksome to his busy
mind ; he therefore applied for re-employment in the Public Works
Department, and was appointed a Second Grade Assistant Engineer
on the railway branch, on the 1st of February, 1871, and was pro-
moted to First Grade Assistant Engineer on the 1st of March, 1872.
He Avas employed on the Indus Valley Railway for some time, but
was sent to siiperintend famine operations on the Northern Bengal
Railway, when he officiated as Executive Engineer from Janiiary
1874. These duties undermined his health, and he was sent to
England on sick leave from March 1876 to September 1877. On
returning he was jjosted to the Western Rajj)utana State Railway ;
but on the Mysore famine breaking out shortly after, his previous
similar services pointed to him as a valuable man, and he was sent
there as an officiating Executive Engineer. In May, 1878, he was
permanently promoted to executive rank. He returned to the
Western Rajputana Railway in December, 1878 ; but again suffer-
ing from exposure during the famine works, he was obliged to
proceed to England on eighteen months sick leave in March, 1879.
He was promoted to Third Grade Executive Engineer during his
absence on leave. He received the thanks of the Government for
his services during both these famines. His health was perma-
nently affected by exposure during this trying time, and he
never perfectly recovered. While in England on leave. Captain

Obituary.] MAJOR AUGUSTUS SAMUEL WILLIAM CONNOR. 397

Connor attended the Eoyal Engineer extra courses of study at
Chatham, in electricity, telegraphy, army signalling, &c. ; also
musketry at Hythe, and on his return to India in January, 1881,
he was posted to Burma, where he remained two years, and while
there he organized and commanded a company of Eailway Volun-
teers. In August, 1883, he was transferred to the Madras Eail-
way Surveys. In January, 1885, he was promoted Second Grade
Executive Engineer, and transferred to the Sind Pishin State
Eailway, where he was employed for over two years. For his
services on this frontier line, he was specially commended by the
Secretary of State and the Government of India. On the comple-
tion of work here, his services were temporarily lent to the Central
India Administration in February, 1888, and during an epidemic
of smallpox at Mhow, in May, 1888, he caught the infection, and
there died, on the 26 th of May.

Major Connor was appointed Ensign in the Ceylon Eifle Eegiment
on the 13th February, 1867, he exchanged into the 7th Fusileers
in 1869, and was promoted Lieutenant on August 31st, 1870; he
then was transferred to the Bombay Staff Corps on April 30th,
1872; promoted to Captain February 13th, 1879, and Major,
February 13th, 1887. He was elected an Associate of the Institu-
tion on the 7th of December, 1875.

Major Connor was a most painstaking and hardworking officer ;
and the conscientious performance of his duties under unfavourable
climatic influences, was the indirect cause of his regretted death
when yet in his prime.

GEOEGE HAWKINS was born at Daventry, in Northampton-
shire, in 1815, and was left an orphan at three years of age.

He commenced his railway career on the Liverpool and Man-
chester line under Mr. Braithwaite Poole, and in 1843, joined the
London and Brighton Eailway as Goods Manager, at that Company's
southern terminus. He was appointed Traffic Manager of the
whole system in 1849, which position he held for twenty years.
Amongst the able men who, in those days, thronged the Com-
mittee Eooms of the Houses of Parliament fighting for and against
the schemes of railway extension, Mr. Hawkins was for years a
well-known figure ; and wherever crowds of passengers had to be
accommodated at races, reviews, and similar gatherings in his

o98 GEOPlGE HAWKINS. [Obituary.

company's district in the South of England, he was alwaj's to be
found superintending the arrangements in person. He was elected
an Associate of the Institution on the 7th of December, 1858, and
to the last he retained a strong interest in the success and develop-
ment of the Institution. He had been member of various Lodges
of Freemasons for over forty years, holding office in all. At the
time of his decease, he was the oldest Past-Master of the
Britannia. He died on the 1st of November, 1888, and was buried
in the Brighton Cemetery on the 5th of that month. A large
number of his old colleagues and employees attended the funeral,
notwithstanding that nearly twenty years had elapsed since his
retirement from active life.

GEAHAM HEWETT HILLS, Staff Commander, Eoyal Navy,
was born on the 5th of July, 1826, at St. Lawrence's, near
Eamsgate, his father, the late Captain John Hills, E.N., being
then a lieutenant attached to H.M.S. " Eamilies," 74, stationed at
Pegwell Bay. He received an education in mathematics and classics
under a graduate of Cambridge, at Lancing, in Sussex, till April,
1842, when he embarked as a midshipman in one of Messrs.
Soames's vessels then employed as a transport in the service of the
Admiralty. This ship, during the first war with China, was sent to
Hong Kong, where Mr. Hills contracted the illness which well
nigh decimated the troops engaged in the expedition. But through
the almost parental care of his captain, he was brought home
alive. On his restoration, he embarked again in another transport
of the same owners, engaged as a troopship for the service in the
West Indies. Eeturning to England in December, 1844, he was
soon after entered by the Admiralty as Master's Assistant, and joined
H.M.S. " Victory," at Portsmouth, on February 20th, 1845 ; being
thus settled in the navigating branch of the royal navy. On the
18th of March, 1845, he was transferred to H.M.S. "Vindictive,"
50, carrying the flag of Vice-Admiral Sir F. W. Austen, and com-
manded by Captain Sir Michael Seymour, with an old shipmate
of his father. Lieutenant Franklyn, as First Lieutenant. In this
ship he served till the 16th of June, 1848. By his log-book he
can be traced as employed occasionally on surveying service, and
drawing and copying charts. Particularly, he was several times
engaged in buoying the outer shoals at Halifax. On the 19th of

Obituary] GRAHAM HEWETT HILLS. 399

June, 1848, Mr. Hills was again appointed to tlie old "Victory," tlie
flagship at Portsmouth, and on the 28th of June, he received his
commission for the rank of Second Master. On the 19th of Septem-
ber following, he was removed into H.M. steam vessel "Dwarf,"
Lieutenant Sherard Osborne commanding. In company with
another steamship, the " Dwarf " started the next day for Ireland,
being destined to intercept the communications of the disaifected
followers of Mr. Smith O'Brien, in the Eiver Suir, and to encourage
and support the loyal. In this service the vessel was frequently
patrolling the river from Waterford to Carrick-on-Suir, often with
much doubt where her old-fashioned and nearly worn-out
machinery and frame would land her. Mr. Hills utilized his
opportunities to make a survey of the river, and drew up sailing-
instructions for it which were published by the Admiralty. The
collapse of the armed movement of Mr. Smith O'Brien enabled the
services of the " Dwarf" to be dispensed with in the Suir, and on the
19th of January, 1849, the "Dwarf" proceeded to Haulbowline,
in Cork harbour, for a complete refit. In June, the vessel returned
to the Suir, and made one trip up the river, and was at Queens-
town again in August, assisting in the honours of the visit of the
Queen and Prince Consort. On the 15th of November, 1849,
Lieutenant Sherard Osborne retired on half-pay, and for the
remainder of the commission, Mr. Hills was commander.

This insight into coast service in Ireland, led to Mr. Hills being
commissioned on the 13th of April, 1850, on the Irish coast survey.
Accordingly, on the 15th of that month, he joined H.M.S. " Sparrow,"
at Waterford, on surveying service under Captain Eraser, E.N. ;
under whom he took command of the ship whilst the survey was
completed from Carnsore Point to Cork. Mr. Hills went to Ports-
mouth in February, 1851, and on the 11th, passed at the Naval
College for the rank of Master, with full numbers on the college
sheet. The work of Captain Fraser being brought to an end, the
" Sparrow " was paid off at Cork, on the 24th of January, 1852, upon
which occasion the ship's company presented Mr. Hills with a
regulation sword. His next commission, January 28th, 1852, was
to H.M.S. "Neptune," 80, guardship at Portsmouth, which he joined
on the 5th of February. The monotony of harbour duty brought
his regularly kept log-book to an end at the end of April. On the
11th of September, Mr. Hills was glad to be "lent" from the
"Neptune" for second-master's duty in H.M.S. " Tyne," carrying
troops to and from Ascension, and visiting Rio de Janeiro. A
fortnight after returning to Woolwich, on the 3rd of February,

400 GRAHAM HEWETT HILLS. [Obituary.

1853, he rejoined the "Neptune" at Portsmouth ; and on the 25th
of April, he was again lent to take charge of H.M.S. " Illustrious,"
appointed as a hospital ship on account of an outbreak of sickness
in the crew of the "Agamemnon." On the 19th of July, 1853,
Mr. Hills was sent in the " Ehadamanthus," under the orders of the
master attendant of Portsmouth dockyard, to assist in fitting out
and bringing round the "Caesar," expected to he found launched at
Pembroke dockyard. But the first attempts to launch that vessel
failed, and it was not till the 9th of September that the " C^sar "
was navigated into Portsmouth harbour, and Mr. Hills rejoined
the " Neptune."

As the year 1854 opened, the probabilities of war with Russia
were strong. In preparation for the despatch of a fleet to the
Baltic, the Admiralty assigned the " Hecla " (s.v.) for special service
to embark several scientific officers and specialists to ascertain par-
ticulars of the navigation and of the fitness of certain ports for
the reception of the fleet. Mr. Hills was one of the officers ordered
to join the " Hecla " on this duty, and he sailed from Sheerness,
on the llth of February. But on the 16th he was commissioned
to H.M.S. "St. Yincent," and he was so borne whilst absent
in the "Hecla." That ship proceeded to Hull, and embarked a
number of Baltic and North Sea pilots for the common instruc-
tion of all concerned. The first attempt to use photography for
warlike purposes was made by Captain E. A. Scott, E.N., in the
examination now made of the coasts of Norway and Sweden ; but
the draughtsmen (chief of them Mr. Hills), were held to be more
successful in carrying away likenesses of the coast, than the
photographic apparatus, owing to the minute size of its repre-
sentations. The process used was instantaneous. They recon-
noitered the coast of Pomerania, crossed over to Copenhagen,
embarked various Swedish and Danish pilots for information, and
returned to the Downs on the 12th of March, where Captain
"Washington, E.N., of the Admiralty hydrographic department
boarded the ship and gniided them to the fleet under Sir Charles
Napier. The "Hecla" proceeded to Portsmouth, where Mr. Hills
was ordered to join the " James Watt," 91, fitting out for the
Baltic at Devonport, which he did on the 25th of March. It
became necessary to secure a handy anchorage for the fleet away
from the enemy's to-^vns or fortresses; this was found in Baro-
sund, on the north side of the Gulf of Finland, nearly opposite
Eevel, and was surveyed, Mr. Hills being one of the officers
employed. Shortly afterwards, Mr. Hills was employed on survey-

Obituary.] GRAHAM HEWETT HILLS. 401

ing for the attack on Bomarsiind, biat having been promoted Master
for his services at Barosund, he was ordered home at once. Mr.
Hills was next commissioned as Master to H.M.S. " Geyser," which
lie joined on the 15th of December, under Captain Towers. In
April, 1855, this vessel was sent as an advance ship to the Baltic,
and on the 2nd of May, found Faro Sound frozen across ; never-
theless, the fleet arriving, picked up several prizes, and on the
17th the "Geyser" was ordered to convoy them to England and
reached Sheerness on the 30th. By the 20th of June, the " Geyser "
had got back to Copenhagen, and soon after was with the fleet
off Cronstadt, and took part in sundry contests with bodies of
Russian troops employed to harass the fleet from the shore. In
August he was engaged at the attack on and the destruction of
the great fortress of Swealjorg. On the 11th of November, the
fleets took their departure from the Gulf of Finland for England,
leaving only frigates and cruisers to bring up the rear, and on
the 18th, the "Geyser" had reached Faro Sound on the home-
ward voyage.

During the winter of 1855-6, a number of gunboats were built
;it Birkenhead for the Government. The "Geyser" was sent to the
l\rersey about the end of April, 1856, to superintend their fitting
r»ut, and to bring them to Portsmouth ; but certain of them being
found incomplete, Mr. Hills was left to superintend the completion
of the " Blossom " and the " Gadfly." This delay led to his be-
coming, on the 6th of May, a candidate for the post of Assistant
Marine Surveyor for the port of Liverpool. Shortly he had to
rejoin the " Geyser," and at Portsmouth he learned that the Liver-
pool Dock Board had selected him for the post, and had applied
to the Admiralty on the 28th of May for leave for him to accept the
appointment. The leave was granted, and thus began his twenty-
nine years' service under the board, now entitled the Mersey Docks
and Harbour Board. At the commencement of his service, the
superior authority was known as the Liverpool Dock Board, but
upon taking over the control of the Birkenhead Docks by Act
of Parliament in 1857, the title was extended to embrace both
sides of the river.

On the 15th of November, 1866, Mr. Hills was promoted to
Marine Surveyor, and became head of the department. The
service extended from the Mersey Bridge at Warrington, to the
whole of Liverpool Bay, and to the whole north coast of Wales,
requiring in its chief an accurate knowledge of the shoals and
channels always shifting, and a constant alertness to keep the sea-

[tIIE INST. C.E. VOL. XCV.] 2 D

402 GRAHAM HEWETT HILLS. [Obituary.

marks in serviceable positions. It included tlie control of the
lighting of the coasts and signal stations, and of the lightships in
the bay ; and constant readiness in all weathers, by night and by
day, to proceed with steam-power, and often with gunpowder and
dynamite, to the removal of wrecks and accidental obstructions
occurring in the navigable channels ; and the organization of a
portion of the life-boat service.

In 1867 Mr. Hills, with the whole of the naval officers of his
grade, passed from the old fashioned title of Master, to the newly
invented one of Navigating Lieutenant ; some time before his name
had been placed on the Naval Eeserved List. On the 1st of
August, 1869, he succeeded by seniority to the rank of Staff Com-
mander with the courtesy title of Captain.

Early in his service at Liverpool, it was proposed to him to ask
the leave of the " Dock Board " to give his assistance in selecting the
landing-places for the Atlantic Cable. He objected to any attempt
at " serving many masters," and declined to make the proposal.
A matter in which he accepted emplojnnent, extra to his service
with the Dock Board, was on the occasion of the construction of
the Euncorn Bridge across the Mersey, by the London and North
Western Railway. It was necessary in 1861, to have an exact
record of the state of the bed of the river, before the construction
of the bridge in reference to the widening of the water-way re-
quired by the Admiralty of about 100 feet at Euncorn, and the
effect afterwards of that widening, and of the construction of the
bridge upon the river-bed, some 5 miles along the river. Captain
Hills was applied to by the parties interested, and made the record
required ; two or three copies of the chart being made in London
from his instructions for deposit in the interested quarters.

A system of regular surveys of the Mersey had been set on foot
by his predecessors in office. Captain Denham, E.N., and Lieutenant
Lord, E.N. As a permanent basis for such surveys, Captain Hills,
in 1860, made a complete survey, with a 100-foot chain, of
both sides of the Mersey, from Warrington Bridge to the sea; he
also levelled and fixed bench-marks on both banks of the river, and
with the theodolite fixed by triangulation the position of all
prominent objects near the Lancashire and Cheshire shores. This
has been the basis for the periodical surveys and observation of the
navigation of the river ever since. In 1861 Captain Hills made
the first survey of the river-bed founded on that basis. A point
which he very early took in hand was the form and construction
of buoys. He found the variety, in form, in colours, and in

Obituary] GRAHAM HEWETT HILLS, 403

numbering confusing, tliougli intended to distinguish tlie buoys
as sea-marks. The first necessity was to fix on a form which
would not be run under water and lost to sight, as many were
when most needed in view, by the strength of the currents and the
violence of the sea. Another necessity was, that a buoy when
sighted by a navigator, should tell him at once that he was inside
the channel (where he wished to be), or was outside of it and in
peril. The system established by Captain Hills for Liverpool,
founded on that introduced by the first Marine Surveyor of Liver-
pool, Admiral Denham, was ultimately adopted by the Corporation
of Trinity House, when in 1882 a universal system was established
for the kingdom.

The attention of Captain Hills wasearnestly directed to that part
of the Manchester Ship Canal, which proposed to continue the cut from
its union with the Mersey above Kuncorn down the tidal estuary
by a deep low-water channel, as far down as a point near the
middle of the river-bed, between the opposite towns of Frodsham
and Garston. By his little book on the Hydrography of the Mersey,
published in May 1858, it can be seen how early he began to study
the causes of the formation of the water-channels of the river, and
the changes in them, and that, like his predecessors in office, he
then objected to any interference with their natural formation.
He now strongly felt that such a low-water channel as was pro-
posed to be formed in the estuary would certainly, in the course
of years, entirely change the character of the inner estuary, and
adversely afi'ect and impede, by the deposits it would occasion, the
navigation of the outer estuary. The result of the canalization,
viz., the silting up of the whole estuary of the Dee, had already
been matter of observation with him.

The year 1883 saw the scheme of Mr. Leader Williams intro-
duced into Parliament, and after a protracted examination at thirty-
nine sittings of the Committee, the House of Commons passed the
measure ; but in the House of Lords, the Committee, after ten
sittings, decided, on the 10th of August, "that it is not expedient
to proceed with this Bill in the present session of Parliament."
Captain Hills was examined at great length before the House of
Commons.

In 1884 the Parliamentary campaign was entered upon, with a
much better knowledge on each side of the opposing views, and of
the facts relied upon. The inquiry began in the House of Lords on
the 12th of March. The opponents to the measure commenced their
case on the 25th of April, opening with the case of the Mersey Docks
and Harbour Board ; after the Solicitor to the Board had given evi-

2 D 2

404 GRAHAM HEWETT HILLS. [Obituary.

dence on legal matters, Captain Graham Hills was called, on the
26th of April, and was three days under examination. After forty
sittings the Lords' Committee, by a narrow majority, passed the Bill,
with some modifications of a monetary character. On the 7th of July
the Bill came before the Hoi;se of Commons' Committee, and on the
18th of July Captain Graham Hills was again the second witness
called for the opposition by the Mersey Docks and Harbour Board,
and was for three daj's under examination. He pointed oiat how
the instances of an artificial channel in the Tees, the Tyne, and
the Clyde, had no analogy with the case of the Mersey, and that
each of these cases, nevertheless, showed that silting up and the
reclamation of land followed. This, and the circumstances of the
Dee and the Seine, which were analogous to those of the Mersey,
proved that the proposed low- water channel in the bed of the river
must lead to silting up, to the contraction of the anchorages in the
river, and loss of the scouring power of the water. As a practical
seaman, Captain Hills pointed out some of the difficulties which
must occiir in the navigation of the distance from Liverpool Bar
to Manchester in a single tide. Powerful engineering evidence
supported Captain Hills' scientific views, and on the 1st of
Augiist the Committee unanimously threw out the Bill.

In 1885 the indefatigable promoters of the canal came to Parlia-
ment a third time, but with almost a new scheme. The land
course of the canal was much modified, and the canal between
training-walls in the bed of the estuary, beginning a mile above
Eimcorn and going down some 9 miles, was abandoned. In lieu
of it, accepting the suggestion of the engineers called by the former
opponents, Mr. Eads, Mr. Lyster, Mr. Law, and Mr. Stephenson,
the canal was proposed to be carried from Euncorn to Eastham,
along the Cheshire shore of the Mersey, terminating with locks
there in deep water, and entering at once a large anchorage called
the Sloyne. Again on the 23rd and 2-ith of March Captain Hills was
in the witness chair before the House of Lords' Committee, con-
tending for the least possible infringement on the area of the
estuary, and against establishing an unnatural channel along the
Cheshire shore. On the 7th of May the Lords' Committee reported
in favour of the Bill. On the 15th of June it appeared before the
House of Commons' Committee. On the 6th and 7 th of July Captain
Hills was called to give evidence ; but the dangers of the present
scheme were admittedly far less and more remote than those of its
predecessors, and on the 5th of August the Bill was read a third
time, thus terminating one of the most remarkable scientific con-
troversies dealt with by Parliament.

Obituary.]

GRAHAM HEWETT HILLS.

405

Before this great question had reached its solution, Captain
Hills' health had shown signs of weakness, which he had been
warned would imperil his life, if he continued night service afloat
another winter. In fact, in the year 1883, in the month of January,
the wreck of the " City of Brussels," in one of the channels in the
bay, about 10 miles outside of the Eock Lighthouse, had brought
upon him such exertions and exposure during forty-eight hours, in
the pressing necessity to remove the wreck, that a state of collapse
followed, which left a permanent physical weakness behind.
Before the third hearing of the Manchester Canal Bill, the Mersey
Dock Board had consented to his retirement from office with a
pension, and with a retaining fee to secure his consultative services.
In the quiet of his retirement at Beckenham, Kent, he lived a
little over three years, and then succumbed suddenly whilst on a
visit to Folkestone, on the 16th of August, 1888. He was elected
an Associate of the Institution on the 6th of March, 1866.

*^* The following deaths have occurred, or been made known,
since the 3rd of September last, in addition to some of those
included in the fores'oino; notices : —

Members

Bateman, Frederic Foster ; born 22

July, 1853 ; died February, 1889.
Bell, Wilson ; died 27 November, 1888,

aged 49.
DiBBLEE, Frederick Lewis; died 28

September, 1888, aged 50.
Hamand, Arthur Samtjel ; died

September, 1888, aged 51.
Lastarria, Victorino Aurelio ; born

22 November, 1813; died 27 July,

1888.
Leslie, Frederick ; died 20 February,

1889, aged 61.
Miller, Daniel; born January 1826;

died 28 September, 1888.
MuiR, James; born 31 May, 1817;

died 4 January, 1889.

Associate
Batten, "William ; died 18 July, 1888,

aged 65.
Boothby, Alexander Cunningham ;

born 26 February, 1857; died 17

December, 1888.
Crowley, Jonathan Sparrow; died

13 September, 1888, aged 62.

Murton, Frederic ; died 17 January

1889, aged 71.
Parkes, William ; died 5 February,

1889, aged 66.
Phipps, George Henry ; bm-n 27 March,

1807; died 11 December, 1888.
PuRDON, Wellington; died 14 Feb-
ruary, 1889, aged 73.
Salter, Frank, B.Sc, Wh. Sc. ; born

19 October, 1848 ; died 31 December,

1888.
Schmidt, Bernhard ; died 6 February,

1889, aged 60.
Stephens, Frederick Cook; born 21

September, 1829; died 3 January,

1889.

Members.
Phillips, Alfred; died 8 February,

1889, aged 44.
Roberts, Peter ; born 3 April, 1846 ;

died 25 February, 1888.
Tyndall, George Reaveley ; born 17

October, 1856; died 17 November,

1888.

406

GRAHAM HEWETT HILLS.

[Obituary.

Associates.

Hunt, Sir Henry AflTHrR, C.B. ; died
13 January, 1889, aged 78.

KoE, John Phentel ; died 8 Septem-
ber, 1888, aged 73.

ViCKERS, George Naylor ; born 14
November, 1830 ; died 20 January,
1889.

Wakefoed, William ; died 9 Novem-
ber, 1888, aged 64.

WiLLOCK, Captain Harry Borlase.
R.E. ; born 6 March, 1854; died 7
February, 1889.

Wilson, Hugh; died 25 September,
1888, aged 60.

Information resiDecting the life and works, the career and
leading characteristics, of any of the above, is solicited, to aid
in the preparation of future Obituary Notices. — Sec. Inst. C.E.,
22 February, 1889.

Abstracts.] NEW THEOEY OF FRICTION. 407

Sect. III.

ABSTEACTS OF PAPERS IN FOEEIGN TRANSACTIONS
AND PERIODICALS.

Neiv Theory of Friction. By N. Pktroff.

(Neue Theorie der Reibung, von N. Petroff, niit Genehinigung des Verfiissers aus dcui
russischeu iibersetzt vou L. Wurzel, &c. 8vo. Leipzig, 1887.')

The naphtha industry of Russia has attained enormous pro-
portions. American crude oil yields 70 per cent, of petrolexxm ;
the Russian only 30 per cent. Therefore it was early apparent
to Russian manufacturers that they must find some use for the
residue, and from it they made lubricants.

A lubricant, itself good, may be applied in unfavourable con-
ditions. Numberless experiments have been made to determine
coefficients of friction, but there is still wanted a thorough
appreciation of the qualities and behaviour of lubricants. These
contribute to the sum of friction their own internal fluid resistance ;
also a superficial resistance to the relative motion of the opposed
surfaces with which they are in contact. The Author recites the
following propositions. For rigid bodies friction : —

(1) is approximately proportional to the normal pressure;
(2) bears some proportion to the pressure per square inch of
surface, and is greater for very light, or for very heavy loads,
than for some intermediate load ; (3) diminishes as the velocity
increases ; (4) depends on the quality of the materials in contact ;
(5) depends on the surface condition of the materials in contact,
the smoother the surfaces, the smaller the friction ; (6) dej^ends
on some factor of importance as yet undetermined, which requires
to be known.

Friction in fluids^ (1) is proportional to the relative velocities ;
(2) is proportional to the wetted surfaces along which the relative
motion occurs ; (3) is dependent on natural properties of the fluid ;
(4) is independent of the pressure.

To these, recent observations require to be added : —

(5) An increase of temperature lessens friction.

(6) Friction varies with the remoteness of the flviid surfaces,
and the coefficient of surface friction may be greater or less than
that of friction within the fluid.

The second and third propositions are accepted by everybody.

• The original is in the Library of the Inst. C.E.
' The Author does not always discriminate fluids.

408 NEW THEORY OF FRICTION. [Foreign

The first, thougli generally accepted, is disputed. The Author
examines in chronological sequence the data of research, criticises
methods and deductions, and ela'.jorates equations. He finds
nothing irreconcilahle with the statement that friction in fluids
is proportional to the first power of the relative velocities, and
concludes thus : —

(1) Newton's hypothesis is very nearly correct for water; there-
fore probably for other fluids, unless they are dense.

(2) The internal friction of fluids is proportional to the tem-
perature.

(3) The relation of the coefficient of friction to the temperature
can be ascertained experimentally, and at dift'erent velocities, but
the conditions should be such as to afford data to prove the results
by integrating Navier's equations.

(4) Using Poiseuille's method : —

(a) The surface of the tubes must be even ; (b) and one of the
factors vaiiable, either the diameter or the length of the tubes;
and the velocity of discharge under varying heads, must be
carefully noted.

(5) Equation (9) would probably then enable the inner, and
perhaps the superficial friction to be determined, providing the
direction of flow is sufficiently straight.

The Author supposes two vertical cylinders of infinite length,
having the same axis of revolution, and the annular space between
them filled with a homogeneous fluid, which adheres to the opposed
faces in greater or less degree. It is convenient to consider the
outer cylinder as stationary, and that the inner revolves always in
one direction. However narrow the annular space may be, the
liquid filling it has two surfaces and a thickness. He supposes
that motion is communicated from the inner rigid surface to a
concentric inner sheath of the fluid enveloping it ; from that to a
next outer sheath, and finally to the opposite surface. The fluid
particles, and the forces acting on them, will be sjnumetrically
arranged about the common axis of revolution, and the jiarticles in
each imaginary sheath will have a uniform velocity always less
than that of the adjoining particles in the next inner cylindrical
sheath, and always greater than the velocity of those in the next
outer sheath. With these assumptions, and accepting Newton's
hypothesis, the ratio of the flixid friction of adhesion and cohesion
to the torsional moments on the inner cylinder can be worked out.
If the annular thickness of the fluid is very small compared to the
radii r^ r.^ of the concentric cylinders, he obtains equation (19).

Experiments should be made with cylinders having different
circumferential velocity, and especially of difl^erent diameter, and
they should be paired so that no eddies or currents are set up.
The Author adverts to details in which the experimental apparatus
would not represent the actual conditions of engineering practice,
and points oiit that the thickness of the lubricant, and the ratios of
the whole group of factors he has introduced, must be experi-
mentally determined.

AbstractH.] NEW THEORY OF FRICTION. 409

Equations — q = volumo of li(iiu(l flowing thrnugli in

.74. A \ \ uuit time ; temperature coustaut.

^ TTl^nr / 4. ^-^ ) ] r = radius of tube.

S ixl \ Xr I A = weiglit uf a cubic liquid unit.

, {. I = uuits leugtli.

' "^^ Ahr'^ / 4 u\ ( h = head, units length.

V = J- ( 1 4" T~ )\ V = mean velocity of flow.

o fj. I \ Ar/j ^_ yjj j^ Qf surface-friction.

SUi

/x = unit of internal friction.
F = sum of frictional resistance.

(19) F = / = coefficient of frictional resistance.

1^ /^i j^ A^-i /i = coefficient of resiutance at special pres-

^ A A^ sure.

1 ^ S = effective surface of inner cylinder.

TT U, = surface-velocity of inner cylinder.

(21) / = — ^1 = coefficient of surface-friction at inner

/ /Xj /Aj \ cylinder.

( « + r^ ~\~ ^ Jp X., = coefficient of surface-friction at outer

'^i ^2 ' cylinder.

TT (U, = coefficient of internal friction.

(2\a) f — ix -^ € = mean thickness of lubricant.

ep p — load on square unit of surface-bearing.

p^ — special pressure on square uuit of

/■orw f -e ^ / Pi surface-bearing.

M,U,

/Qo^f _ l^2^2 / P\ U2 and U3 = special circumferential-velocities.

(3-) ~7~ = Y\~ '\/ ^ /"2 and jUj = values of coefficient of internal

/i /^3 ^3 P friction.

Summary. — Equation (21) is justified, and other results brought
in accord with equations (21rt), (30), and (32); the Author finds
no instance of disagreement with equation (21a). Apparent
differences are, no doubt, due to variation of temperature and want
of adjustment in the bearings. Equation (30) is correct for rape
oil under a load not exceeding S-i, and for W. Virginia oil 51
atmospheric pressures. The Author asserts that the coefficient of
friction, for parts of machinery which are nicely adjusted and
copiously lubricated, is —

(1) to the coefficients of internal friction of the fluid lubricant
at the tem})erature of the film; (2) to the relative velocities of
the rubbing parts directly measured ; (3) to the average thickness
of the layer of lubricant interposed between the surfaces ; (4) in
inverse proportion to the pressure exerted on a superficial unit of
the bearing surfaces. (5) At a constant tenqierature the thickness
of the couch of lubricant is inversely proportional to the square
root of the relative load on the bearing surfaces.

(6) Therefore (4) and (5) : at a constant temperature the
coefficient of friction is inversely proportional to the square root of
the load on a superficial unit of the bearing surface.

(7) The temperature of the couch of lubricant depends on the
character of the lubricant, on the velocity, on the load, on the
conducting power of the surrounding bodies, and the temperature
of the atmosphere at the time.

For parts of machines which are improperly or insufficiently

410 NEW THEORY OF FRICTION. [Foreign

lubricated, in wMcli the accuracy of adjustment is not greater, the
coefficient of friction will he larger than in the foregoing cases, and
on the whole larger as the influx of lubricant is less, and the want
of adjustment greater, that is, if the surfaces are rough, or the
shape distorted by external pressure. If the Author's coefficients
are correct, his deductions elucidate some hitherto obscure pheno-
mena ; but the incompleteness of available data makes new experi-
ments indispensable. The Author indicates the direction which, in
his opinion, such further experiments should take. . -p

On the Critical Extension of Bodies strained simultaneously in
several directions. By — Wehage.

(Mittheilun£:9n aus den Koniglichen technischen Versuchsanstalten zu Berlin,
1888, p. 89.)

In investigating the strength of the walls of vessels and other
bodies which are subject to stress in several directions simul-
taneously, it is usual to take the greatest extension or com-
pression in any one direction as a measiire of the stress on the
body at any given point and to take no notice of the extension
or compression parallel with the two remaining principal axes.
According to the view represented by this method of treatment,
the stress on a plate subject to tension in one direction woiald be
reduced if it were, in addition, put under tension in a direction at
right angles to the former, and would be increased by compression
in this direction.

Experience, however, shows that in drawing wire a prismatic
body can endure a much greater extension longitudinally without
diminution of its strength, if it is sinniltaneously under compression
transversely, than when the latter is not the case.

To obtain further insight into the subject, the Author was
permitted, by the Eoyal Commission managing the Technical Ex-
perimental Institute, to carry out bending tests with circular
wrought-iron plates, and to determine, radially as well as tan-
gentially, the extensions corresponding respectively to the limit of
elasticity and the breaking stress ; this was done directly with the
microscope.

For ascertaining the permanent extension on fracture it was
found sufficient to draw small rectangles or squares with sides of
from 1 to 1 • 5 millimetre and observe the alteration of these with
the microscope by the help of an ocular micrometer. In order to
measure the extension at the elastic limit, the method was finally
adopted of drawing wdth a double scriber on the loaded plate a pair
of parallel lines, and when the load was removed a second pair
parallel with the first and so close to these that the corre-
sponding lines with and without a load were well within the
microscopic field.

As test-pieces three circular plates 420 millimetres (16 '54 inches)
diameter of Kruj^p steel were employed cut out of the middle of

Abstracts.] EXTENSION OF BODIES UNDER COMPOUND STRAIN. 411

square plates about 10 millimetres (0-39 inch) thick. From the
outer jjarts of each," of these plates, four test-pieces for tensile and
bending tests were prepared. Two pieces out of the four were
tested by tension to fracture, in order to be able to compare the
extensions resulting from simple tension with those produced by
compound stresses ; the remaining two were subjected to bending
tests chiefly, to ascertain if the extensions were the same as under
tension ; the material was, however, so good that when bent
through 180'^ no fracture could be produced.

Two of the circular plates or disks were tested by being sup-
ported against a concentric ring on one side and pressed in the
centre by a die on the other side, in the Werder testing-machine ;
the supporting ring had an inside diameter of 323 millimetres
(12 '72 inches). The disks were jwlished on both sides. Each
measurement was taken four times and the mean result of the four
observations adopted. The dies employed had spherical surfaces of
different radii.

From the results of his experiments, as far as they go, the
Author draws the following conclusions: — (1) The extension at
the elastic limit of a plate bent in the manner described is only
about half that occurring with simple tension ; (2) when a wrought-
iron disk is subject to equal stress simultaneously in two directions
at right angles to each other, rupture takes place with an extension
which is only about half that due to simple tension.

According to these results, the tensile stress to which a cylin-
drical shell is subject, in a tangential direction, from the internal
pressure of a fluid, is increased (not diminished) by the addition
of a simultaneous axial tension. n -n -o

ijr. ±C. ±>.

Landslip at Zug, Switzerland, Jtdy 5th, 1887.

(Die Catastrophe von Zug, 5 Juli, 1887, &c., &c.' 8vo. Zurich, 1888.)

This Paper is an abstract of a pamphlet of sixty pages, published
at Zurich in the early part of this year, containing : —

1. The opinions of a committee of experts, consisting of Pro-
fessor Dr. A. Heim ; Chief-Engineer E. Moser ; and Dr. A. Biirkli-
Ziegler.

2. Historical notes of the disasters at Zug in 1435 and 1887, by
Anton Wickart.

3. Abstract from the registers, regarding the distribution of
charity to the sufferers from the recent catastrophe, by Albert
Keiser, Secretary.

From the above it would appear that, in past times, breaches
and subsidence of the banks of the Lake of Zug have frequently
taken place, and notably on the 4th March, 1435, when twenty-six
houses, with about sixty inhabitants, were submerged ; and on the
7th March, 1594, when nine houses sunk into the lake. It is further

The original is in the Library of the Inst. G.E.

412 LANDSLIP AT ZUG, SAA1TZERLAND. [Foreign

stated that similar settlements or subsidences have occiirred in
other parts of Switzerland, even in recent times, causing the
destruction of a row of houses at Morcote, on Lake Lugano, in
1863, and of the quay at Vevey in 1877.

In view of the possible recurrence of such a disaster at Zug,
every precaution was taken before commencing the building of the
new quay wall in 1868, to ensure the stability of the site selected ;
and the professional gentlemen who were called in to advise in the
matter, after having made preliminary trial-borings, sunk shafts,
driven in test-piles, &c., reported favourably on the site, and recom-
mended a concrete foundation on a piled jilatform, the piles to be
from 8 to 10 inches in diameter, and about 20 feet long; but it
would appear that the piles were driven to a greater depth than
this, which indicated a loose soil below a moderate depth of firm
ground, of itself clearly an element of danger, which was, however,
rendered more evident by the fact that the vil)ration caused by
driving the piles j^roduced such serious cracks and openings in the
walls of a hoiise in the immediate neighbourhood, that it had to be
pulled down. It is also stated that in laying the foundation of
the present steamer landing-stage there was great subsidence of
the soil ; consequently, in order to prevent a recurrence of such
settlement, a new method was adopted in the new quay j^roject.

This project comprised the construction of a strand road, about
50 feet wide, along the edge of the lake, and the allotting of the
space between this and the Cham road (150 feet) for building
purposes.

The work was commenced by driving in two rows of piles,
2^ feet apart, the piles themselves being at intervals of 5 feet.
They were driven down to 12 inches below lowest water-level, and
at intervals of about 20 feet they were tied to the bank and kept
vertical. The space between the rows of piles was filled with
ballasting uj) to within 6 inches of the pile-heads, then came a
layer of concrete on which the wall was built.

In 1884, after some 260 yards of wall had been built, cracks
were observed ; and as about the same length of wall had still to
be constructed, a further examination of the nature of the soil
was made, and it was decided to build the foundation on a layer
of hurdles and fascines, which would settle down in the bed
of the lake, the whole to be protected by piling ; the wall to have
a slight batter in front, and to be biiilt up to an average of about
2^ feet above high-water level ; and the w^ork was carried out in
accordance with this plan in the winter of 1885-86, and at the
time of the disaster the whole length of quay was nearly completed.

The first warning of danger was noted at 3.20 p.m., when cracks
were observed in the quay-wall, which rapidly increased, and
within a quarter of an hour brought about the destruction of a
portion of the wall and the sinking of some adjoining huts, with a
loss of seven lives. Gradually the disaster extended until about
7 P.M., when it was found ^that many buildings near the Lake had
sunk vertically to a depth of about 25 feet.

Abstracts.] LANDSLIP AT ZUG, SWITZERLAND. 413

The general opinion then formed — which was confirmed by sub-
sequent investigation — was that the subsidence was caused by the
squeezing out of the soft muddy stratum lying below the top soil,
by the weight of the new quay-wall and the buildings adjoining ;
and this mud-stream was pushed out from 200 to 300 yards into
the Lake, carrying with it the foundation-piles of the wall, and
which, when free again, stood up vertically out of the water, as
testifi.ed by an eye-witness (Mr. Henggeler), who also observed a
remarkable rise and fall of the Lake in front of the area affected.
Measures were at once taken to protect the neighbouring houses,
and by midnight of the 6th Jiily all hoiises within a fixed distance
from the centre of disturbance were evacuated without accident
of any kind. Small cracks were plastered up, and surveyors were
stationed at certain points with levelling instruments, in order to
note if further movements of the ground occurred.

After the panic had ceased, a thorough investigation of the
disaster was made by Engineer Miiller, by means of trial shafts
and borings, and a section of the Lake-bed was taken with extreme
accuracy of detail by Engineers Hornlimann and Suter.

The result of these investigations is very clearly shown by
sections to scale, and from these it is seen that the top layer of earth,
sand, and gravel is only from 5 to 23 feet in depth, and then muddy
quicksand is met with, for depths varying from 65 to 100 feet,
of almost uniform consistency, being composed of mud and sand in
nearly equal volumes.

At one or two points the borings showed chalk, and as similar
slips of the bank had occurred at the Lakes of Zurich, Bret, &c.,
which were entirely caused by the washing out of the chalk, it was
at first assumed that this was the cause of the Zug disaster ; but
closer examination showed this to be a false assumption, and that
the squeezing out of the stratum of muddy sand was the sole and
true cause of the catastrophe.

On analysis this stratum yielded 38 per cent, of clean grey
quartzose sand of angular grains, with limestone, mica, a little
felspar and hornblende, and traces of organic remains ; the remain-
ing 62 per cent, being composed of fine sand and stone-dust, without
organic remains, and from this character the stratum is supposed
to have been an alluvial deposit of the Lorze delta, the whole area
from Baar to the Lake of Zug being, geologically speaking, a recent
alluvium of the Lorze river.

The examination of the sub-soil water showed that it had fallen
but very little, even in the immediate neighbourhood of the disturbed
area, and stood everywhere from 6^ to 10 feet above lake level.

The survey of the bed of the lake (for which three thousand two
hundred depths or soundings were taken) shows that the slip or
subsidence of the bank caused a tearing-up of the bed, and the
formation of a trench about 100 yards wide, gradually diminishing
in depth till, at about 300 yards distant from the shore, it was on
a level with the lake bottom, and from thence onwards, for nearly
800 yards more, there was a deposit of muddy sand, varying from

414 LANDSLIP AT ZUG, STSaTZERLAND. [Foreign

160 to 270 yards in width. The direction of this trench and
deposit was not in a straight line perpendicular to the bank, but in
an irregular curve trending to the left. The survey of the lake
bed also shows that the first deposit (consequent on the first sub-
sidence at 3.30 P.M.), commenced at about 135 yards, and terminated
at 460 yards from the bank, is egg-shaped, and has an extreme
breadth of 270 yards ; while the second deposit (caused by the
subsidence at 6.50 p.m.) passed over this for a distance of about
1,100 yards from the shore, to a point where the lake was about
150 feet deep.

After having satisfied themselves that the primary caiise of the
disaster on the 5th July, 1887, was the existence of a very deep
layer of muddy quicksand under a comparatively thin stratum of
earth and gravel soil, the qiiestion of the safety of the neighbour-
hood was considered by the experts, for borings showed that the
same formation underlies the whole Vorstadt or Strand, extends
for a great distance towards Cham, and, in fact, is met with in all
directions. The experts recommend that the destroyed houses should
not be rebuilt, but the space utilized as a park or garden, and an
efficient drainage of the soil should be carried out ; and for this
purpose they advise masonry drains, 2 feet 7 inches wide, and
about 5 feet high, or cement pipes, 1 foot in diameter, perforated
in the upper half, and furnished with the necessary man-holes at
the bends or jimctions ; such pipes not to be laid directly in the
quicksand, but on a plank platform 2j inches thick, to prevent
unequal settlement.

In the project proposed there are three main drains, each dividing
into two branches, the total length being about 820 yards, and
the cost estimated at £1,600. In addition to the above proposals
for the safety of the place, it is recommended that all the houses
between the Vorstadt road and the lake — from the Government
buildings to the tannerj^ a distance of nearly 450 yards — should
be pulled down, and that a protecting dam should be built along
the base of the bank, on a foundation of trees and brushwood well
embedded in the lake bottom, the crown of the dam to be about
33 feet wide, and 36 feet below mean level of the lake. The cost
of this work is given at £28,000.

The proposed new plan of Zug provides in the first place for the
restoration of the road to Cham, and as the project assumes the
entire removal of the houses in the area above specified, this road
will be correspondingly widened. Two new streets will also be
laid out; one commencing at the junction of the railway-station
and Cham roads, and terminating in the Baar road, at a point mid-
way between the Post-office and the railway-station; the other
crossing this at about the centre of its length, and extending from
the railway-station to the jimction with the Cham road. The inter-
sections of these roads furnishes four blocks for building-sites,
but it is proposed to lay one block out as a public garden.

A new landing-stage for steamers will be built, about 30 yards
from the site of the old one.

Abstracts.] LANDSLIP AT ZUG, SWITZERLAND. 415

As compensation to sufferers from the disaster, the sum of
£27,630 was received, and £24,675 disbursed ; the balance of
£2,955 being retained by the town of Zng for payment to the
owners of houses which in the future may have to be pulled down
as a measure of safety.

The pamphlet contains a plan of Zug and neighbourhood,
showing the area disturbed ; longitudinal and cross-sections of the
bed of the lake along the line of the mud and sand deposit ; the
proi)osed new plan of Zug, and a photograph of the ruins.

W. H. E.

A Folding Levelling -Staff, By H. Bentabol.

(Revista Minera, Metalurgica y de Ingenieria, 1888, p. 310.)

By the aid of five illustrations, the Author describes a new form
of staff adapted either for levelling or for tacheometry. The staff
is 4 metres (13 feet 1;V inch) in length, and is divided into four
sections, joined to each other by means of metal hinges. These
lengths fold up in a zigzag manner, so that any required number
may be used. When folded up, the staff is packed between a pair
of boards that serve to protect the graduations. The boards are
united by means of a pair of straps passing through metal guards,
and one of the boards is provided with a strap, like that of a rifle,
which the staff-holder can place over his shoulder, and in this
way carry the staff with his hands free. The graduations of the
staff are painted on a white ground, whilst the edges and the
encasing boards are painted grey. The portions of the hinges
visible when the staff is unfolded are painted grey at the edges
and white at the face. At the side of the first length of the staff
is suspended a plumb-line, which is held in its place by a hori-
zontal ring that does not allow more movement than is absolutely
necessary. For holding the staff, two handles project from the
sides of the second length.

For short distances, the staff is graduated in centimetres with
inverted figures, lines, and dots, in black throughout its entire
length, each metre being numbered from 1 to 9. The second
metre is distinguished by a black dot, the third by two dots, and
the fourth by three. For great distances, the staff is graduated in
double centimetres, the figures and dots being black in the lower
half of the staff, and red in the upper.

B. H. B.

The Alignment of a Tunnel at Stuttgart. By — Widmann.

(Zeitschrift fiir Vermessungswesen, 1888, p. 520.)

In the summer of 1887, in connection with the Stuttgart water-
works, a tunnel, 471 yards in length, and averaging 32 feet in
depth, was driven from the Pfaffensee through compact sandstone.

416 ALIGNMENT OF A TUNNEL AT STUTTGART. [Foreign

When lined with water-tight masonry, the tunnel was 3-28 feet
wide, and 63 feet high, from invert to crown, the section cut being
8 V feet high and o.y feet wide. The axis of the tunnel was not a
straight line, bi;t altered its direction at three points, the transition
from one direction to another being efiected by short curves 32 feet
in radius and 13 to 32 feet in length. Along the tunnel axis shafts
were sunk, 54 yards apart ; they had a depth of 30 to 40 feet ; a
breadth, perpendicular to the centre line, of 6 feet, and a length of
10 feet. Of this length, 4 feet was taken up by timber and
ladders, leaving only 6 feet as a base-line for setting out the
tunnel. Nevertheless, with the aid of a simple instrument em-
ployed by the Author, the subterranean alignment was effected
with such accuracy that, on piercing through, the differences
obtained, within a section 50 yards in length, never exceeded
0-19 inch.

Eanging-frames were erected, 6 yards apart, on both sides of
each shaft, at right angles to the centre line of the tunnel. At
some distance from the shaft, a theodolite was set up accurately in
the line, and this was established on the frame by means of a fine
cut with a saw. A string, 0 • 04 inch in diameter, was then strained
in the cuts, and after it was found, b}" repeated observation, to he
accTirately in the centre line, two })lummets of the Author's design
were suspended, at some distance apart, from the stretched string
down the shaft. The plumb-lines are attached to l)road hooks that
enable them to slide along the string and to be xised for shafts of
any length. Above the hook is fixed a sight, resembling that of
the miner's dial. These sights are useful as a check in determining
whether the plumb-line hangs accurately in the centre line, as the
plumb-line is hidden by the string stretched across the ranging
frame, and consequently cannot be directly sighted. The weight
of the plummets attached to the lines causes the horizontal string
to be drawn down vertically, but as this takes place in the direction
of the vertical plane, it has no influence on the accuracy of the
alignment.

B. H. B.

Methods of Testing the Resistance of Stones, Cements, and other
Building Materials. By LtON Durand-Clayk.

(Annales des Fonts et Chaussees, 6th series, vol. xvi. 1888, p. 173, 1 plate and
20 woodcuts.)

Three methods are employed in these tests, namely, compression
or crushing, tension or tearing asunder, and flexion. In the first
method, the test-blocks are cubes or rectangular prisms with square
ends, which are placed between two plates, to which the compres-
sion is applied by a lever or hydraulic press. Tensional strains
are aj^plied by gripping the two T-shaped ends of the test-block
in jaws which are pulled in opposite directions, by means generally
of levers. Lastly, flexional tests are made on prismatic bars, whose

Abstracts.] TESTING THE RESISTANCE OF STONES, CEMENTS, ETC. 417

ends rest on knife-edges, and have a strain imposed at the centre,
either by loading- a plate suspended on a knife-edge, or by means
of levers. Compression is mainly used in testing stones, and
tension for limes, cements, and mortars ; whilst it is not usual to
test by flexion in a regular manner. These three methods of
testing do not give at all identical coefficients of resistance ; and
the results by any one method vary according to the form of the
test-blocks.

Compression. — The crushing pressure, P, under which a material
under compression gives way, divided by the sectional area S of
the block, gives the resistance to compression per unit of bearing
surface. The block, however, is not wholly crushed ; but it fails
by the formation of cracks, and the occuiTcnce of slidings in the
plane of these cracks. When a i:)rism with a square base is
employed, having a height more than double the length of a side
of the base, a single crack is generally produced, with its plane
following a slope of about ^ to 1, which accords with theory.
The compression test, therefore, measures the resistance to shear-
ing, which approximates to a quarter of the mean compressional
breaking strain, in the materials under consideration. When the
uiatei;ial is homogeneous, and the pressure is very uniformly distri-
buted, the symmetry of the arrangement leads to the formation of
two cracks, starting from the sides at the top, and converging
towards the centre of the block, leaving a central wedge-shaped
mass which tends to split down the lower part of the block into
two parts, with a central vertical crack. In other cases, the two
upper cracks extend down, forming a second wedge below pointing
upwards, and dislocating the sides ; or, if the uniformity of the
material and pressure is perfect, the wedges become prisms. When
the blocks are cubes, the cracks, starting from top and bottom,
sometimes form two truncated pyramids separated by a central
horizontal crack ; but more often one crack follows the diagonal,
and the two cracks from the two remaining corners, meeting it,
divide the block into four triangular fragments. In the case of
homogeneous material and uniformly distributed pressure, frag-
ments fall off from the sides ; and the two oblique pyramids freed
by the cracks slide along the diagonal crack. From the above

observations, it is evident that the resistance to crushing, -, varies

with the form given to the blocks, and that the results of experi-
ments with different materials are not comparable unless the forms
of the test-blocks are the same. The cube is the simplest and
most easily pre^mred form.

Tension. — In the earlier experiments at the Ecole des Ponts et
Chaussees, the T-shaped briquettes had their inner angles rounded
off by curves, and a central section of 2^ square inches; but this
was modified, about 1876, by substituting straight lines across the
angles for the curves, increasing the solidity at this part, but
retaining the same central section. At the present day, all operators
in Europe adopt the German form of l)riquette. or similar types,

[the ixst. c.k. vol. xcv.] 2 E

418 TESTING THE RESISTANCE OF STONES, CEMENTS, ETC. [Foreign

widening ont to a rounded form at each end, and with a narrow
contraction in the centre, having a sectional area of f square inch.

The ratio 77 is only the average tensional breaking strain, and not

the limit of resistance of the material ; for rupture occurs when
the limit of resistance is reached at any one point of the section.
The strain, indeed, is greater at the outside than in the centre of
the section, as indicated experimentally in the laboratory of the
Ecole des Fonts et Chaussees. Briquettes of india-rubber, with
lines drawn on them perpendicular to the axis, were stretched ;
and the curves assiimed by the lines showed plainly the greater
strain towards the outside. Two series of similar briquettes were
next made with the same mixture of cement, one set having a hole
left in the centre of the section, and the other set with the hole at
the side; and the breaking-strain averaged 570 lbs. per square inch
in the first case, and 485 lbs. in the second. Lastly, briquettes
were made 1*57 inch wide; and in one set, the central portion,
0 • 78 inch in width, was made of mortar, and the other portions of
neat cement ; whilst in another set, the materials were reversed.
Thus the sectional areas of the mortar and cement were eqiial in
both cases, but their positions altered ; and the average breaking-
strain of the first set was 301 lbs. per square inch, and of the second
set 261 lbs. It is proved, analytically, that the larger briquettes
have a smaller proportionate breaking-strain — a well-known fact,
but not previously explained. The distribxition of the tensions
also depends on the form of the briquette, as is readily perceived
from an inspection of the different curves assumed by the lines on
the india-rubber models under the same tension. The difiereuce in
the curves of the same india-rubber model, when different jaws
were used, shows that the form of the jaws also has some influence
on the distrilmtion of pressures. It is clear, therefore, that com-
parable results can only be obtained with briquettes of the same
section and shape, clasped by similar jaws, which explains the
frequent apparent discrepancies in results of experiments. The
advantages of the German form of briquette are, that its small size
enables several to be made with the same mixture of cement, and
that rupture can only occiir in the contracted central portion ;
whereas, in the other forms, rupture does not always take place in
the minimum central section, in which case the conditions are
somewhat modified.

Flexion. — Tests by flexion are rarely resorted to, though the
materials are often subjected to such strains. This is due to the
necessity of interpreting the results by help of calculations, instead
of obtaining them by simple observation as in the preceding
methods. With a rectangiilar prism of height h, breadth h, and
length/ between its siipports, loaded with a weight W at its centre,
and having a weight w per unit of length, the maxima tension and
compression on the bottom and top fibres respectively, are repre-
sented l)y the formula, R =.— 7 r-f — '. This formula is, however,

Ahstracts.] TESTING THE RESISTANCE OF STONES, CEMENTS, ETC. 419

only applicable for materials which elongate proportionally to the
tensions up to the moment of rupture. This is true for the top
fibres in compression of the materials under consideration ; but the
bottom fibres, being in tension, give way first ; and for some of
these fibres, which have passed the limit of elasticity at the moment
of rupture, the formula is no longer applicable. The modulus of
elasticity of various building materials, subjected to compression,
has been determined in the laboratory of the Ecole des Fonts et
Chaussees ; but the tensional breaking-weight is so small that it is
impossible to ascertain directly the corresponding elongations.
Diagrams, however, are given, showing the results of the measure-
ment of the deflection of prisms of the materials under increasing
loads, where the loads are taken as the abscissas, and the deflections
as the ordinates. As long as the limit of elasticity is not passed,
the locus is a straight line, but becomes a curve concave upwards
beyond this limit ; and it is evident from the diagrams that, for the
materials under consideration, the limit is reached considerably
before the breaking-strain. It follows that the resistance deduced
from the formula at the moment of rupture is greater than the real
limit of resistance, so that the results derived by the ordinary
formula of elasticity from the flexional tests are too high. The
coefficient for deducing the real limit of resistance from the calcu-
lated limit, can be found by investigating the curves of flexion ;
but the calculations are complicated, and the operations and
measurements are delicate. Nevertheless, by reducing the dimen-
sions of the test-bars, and merely measuring the breaking-load,
comparable results are obtained with bars of exactly the same
form ; and this method of testing is as reliable as tension-tests, and
more simple, owing to the greater simplicity of the manufacture of
the test-bars, and of the machinery employed for testing. The
Author has made a large number of experiments with bars, 0*78
inch square, of varioiis cements, placed on supports 3 • 94 inches
apart, which gave as regular results as briquettes subject to tension.
Any one of the three methods may be employed for comparing the
resistances of the several materials ; but none of the methods give
the absolute resistance of the materials. In experimenting upon
moulded materials, such as limes, cements, and mortars, it is essen-
tial that the specimens should be prepared under identical con-
ditions in respect of proportion of water, duration and extent of
mixing, temperature, compression in the moulds, &c. ; so that
really few experiments are comparable, except those made in the
same laboratory, by the same persons, and with the same precau-
tions. Tabulated results of the Author's experiments by the three
methods are appended to the article, together with further calcula-
tions and investigations with reference to flexional strains.

L. V. H.

2 K 2

420 THE TESTING OF PAPER. [Foreign

On the Testing of Paper. By N. Haselkoos.

(Znjiisky Iinperatorskavo Russkaro Teclmitchezskavo Obstchestva, 1888, No. 11, p. IG.)

After making mention of the investigations of Professors Hart-
ing and Goier, and of the establishment of a series of standards
(Xormalien) by Mr. Martens, at the Berlin testing-oiEce, the
Aiithor enumerates the tests now employed : 1st, for the strength
and stretching power ; 2nd, for the resistance to softening and
crumpling ; 3rd, for the measurement of the thickness of paper ;
4th, for the determination of ash ; 5th, microscopical investigation ;
Gth, determination of free chlorine and acid ; 7th, determination of
the kind and qiiality of sizes.

1. The absolute strength of a paper is measured by its resistance
to tearing. In machine-made paper the strength and stretching
power vary according as the force acts lengthways or across ; in
hand-made paper there is little difference. The Author found that
in the former the diflerence was in the projiortion of 2 : 3 accord-
ing to the direction of the tearing force. The stretching-power
acts inversely to the strength, i.e., is greater across than length-
ways. The Author gives a description of Horak's and the Harting-
Resch testing-machines, the latter giving in his opinion the best

results. He proposes the formula a; = — Q, where T = the length

of the test-paper, P = its Aveight, and Q = the tearing-weight, for
finding the absolute strength of a paper.

2. In order to test the resistance of a paper to the most varied
mechanical wear, it is crumpled and kneaded between the hands.
After siich treatment a weak paper will be full of holes, a strong
paper will assume a leathery texture. This test also gives a rough
insight into the comj^osition of a paper, much dust showing the
presence of earthy impurities, while breaking up of the paper
shows over-bleaching.

3. The thickness of a paper is ascertained either by measuring
the thickness of a certain number of sheets, or by taking that of
a single sheet by means of a micrometer or " piknometer," where
the paper is placed between two rules, one fixed and the other
movable, acting on a pointer showing the thickness of the paper on
a dial.

4. Over 3 per cent, of ash shows the presence of clay, kaolin,
heavy spar, gypsum, &c.

5. Microscopical investigation of paper aims at determining the
kind and equality of fibre. For this a magnifying power of 150 to
300 diameters suffices, when, by colouring the paper with a solution
of iodine, a yellow coloration shows the presence of wood fibre ;
a brown coloration that of linen, cotton, or flax ; and no coloration
that of cellulose.

6. The test for free chlorine and acid is rarely necessary.

7. The determination af the kind and quality of size may be

Abstracts.] THE TESTING OF PAPER. 421

made by boiling in distilled water and adding a concentrated
solution of tannic acid, when a flocculent precipitate shows the
presence of animal size, and by heating in absolute alcohol and
adding distilled water, when a precipitate shows the presence of
vegetable size. If well sized a drop of Fe2Cly on one side and a
drop of tannin on the other will not permeate through the paper and
form ink. The amount of moisture ought also to be determined.
The Paper is fully illustrated by drawings and diagrams.

G. K.

Yield of Hydraulic Mortars. By — Bonnami.

(Annales des Pouts et Chaussdes, Gth series, vol. xvi. 1888, p. 99.)

The yield of a lime in jiowder is defined as the volume of paste
obtained with 1,000 kilograms of powder. The yield of a lime or
cement varies with the proportion of water used in mixing, which
may be expressed in a formula, such as R4gf| = 0*84, indicating
that 1,000 kilograms of the substance, treated with 460 litres of
water, gave 840 litres of paste. The yield is obtained by treating
1 kilogram of the substance with water in a graduated vessel and
multiplying the volume by 1,000. When water is gradually
added in measured quantities, the moistened powder swells at first ;
it next contracts on the addition of more water, the volume of
paste reaching a minimum, called the minimum yield ; after
which the increase in volume is equal to the volume of water
added. The paste attains a firm consistency, representing its
maximum strength, only slightly before the minimum yield is
reached. Accordingly, by finding the minimum yield, the value of
the paste for mortar is ascertained. If e is the percentage of water
corresponding to the minimum yield, and E, in respect of the
weight of the ])owder, the j^ercentage of water in the paste of a
mortar, the inferiority of this paste will increase with the difi'erence
E — e ; and for the same substance R„ — e = a constant which is
the absolute volume of the powder minus the volume of water
absorbed during the trial. The yield of a lime or cement, to fill
the interstices in the sand, is the foundation of all important
mortar making ; for the impermeability and compactness of a
mortar is at least as important for durability as its strength. The
consistency of a mortar, made with a given sand, depends upon the
quantity of the paste and its fluidity. With little paste, great
fluidity is necessary to give the mortar proper consistency, and
cohesion is rapidly reduced by increasing the fluidity of the paste ;
whilst, for a given consistency of mortar, the fliiidity of the paste
is reduced by increasing the amount of powder. Thus, a lime
requiring less water than another, even though the strongest of the
two in a pure state, may form the weaker mortar, owing to the
greater excess of water required to be added to it to give diie
consistency to the mortar. For a given substance, the suitable

422 YIELD OF HYDRAULIC MORTARS. [Foreign

proportion of water increases with the fineness of the powder, and,
therefore, with the amount of free lime, which is always in very
fine powder. Beyond a certain fineness, the ultimate resistance of
neat Portland cement does not augment with the fineness of the
grinding, whereas, with the mortars made from the cement, it
augments very perceptibly. Inert matters in the lime should be
excluded from the yield, and regarded as merely acting like sand ;
and their presence explains Avhy some j^owders give good results
when used neat, and only furnish moderate mortars with the best
sand. The yield of hydraulic mortars varies between 0 • 50 and
1-10.

L. V. H.

Pulverization of Claij and its Application at the Works of the
Societe Arnaud Etienne and Co. By C. Bidois.

(Bulletin de la Societe Suientifique Industrielle de Marseille, 1888, p. 38.)

In the manufacture of ordinary terra-cotta, bricks, tiles, &c.,
the first operation is preparation of the raw material. The clay
should be freed from all foreign matter which would be injurious
to the production of the finished articles. The subject of this
Pajier, the pulverization of clay, is not quite novel ; it has long been
employed in the preparation of the materials used in the finer
kinds of pottery, porcelain, Dutch tiles, and similar manufactures.
But in these cases, the quantity of material dealt with is compara-
tively small, the process here described is in use where very large
quantities of material are used. In late years of keen competition
many means have been used to cheapen the cost of production, such
as the use of inferior clays, and the pushing to the utmost of the
machines used in producing the finished articles. But the i^rocess
in use at the above-mentioned company's works, admits of the use
of clays hitherto held as unfit for the production of good sound
finished articles, and thus lowers the cost of production by enabling
cheaper raw material to be used, and in addition to this imjDortant
point, it also reduces the quantity of faulty articles turned out.
In the branch of the ceramic art which has for its object the pro-
duction of bricks, tiles, terra-cotta, and other artificial building
materials, the low cost of production necessary renders it impera-
tive that all processes be as simple as possible. The regularity of
the chemical composition of the clay does not seem to be of great
importance, for although all clays are very similar in chemical
composition, they do not always appear alike, perhaps the differ-
ence is molecular. It is very important for the clay to be worked
up into a perfectly homogeneous paste, otherwise it is impossible to
turn out sound finished products. With respect to clay prej^ared
for the manul'acture of liricks, &c., plasticity and homogeneity may
be considered as equivalent terms. The object of the Paper here
quoted is to show that by pulverizing the clay in a dry state, an

Abstracts.] PULVERIZATION OF CLAY, 423

almost perfectly homogeneous paste can be made. If the moulded
articles become defective in drying, it shows that in the piece there
are parts of different density, which cause unequal contraction.
Failures in burning show the presence of empty spaces or cavities
in the piece. A method is then described of preparing the clay by
passing it well moistened through a series of rollers ; this machine
has seven rollers, three pairs placed vertically over each other, and
the remaining roller engaging with one of the lower pair ; the rolls
are 19f inches long and 11^ inches in diameter. The upper pair
revolve at sixty revolutions per minute, and their surfaces are
about y\v inch apart ; the second pair revolve at from eighty to
eighty-five revolutions per minute ; their siirfaces are about j\v inch
apart ; the other three rolls receive the clay and force it through a
perforated steel plate ; it is stated that the action of this machine
is to give the worked up clay a laminated structure. With clay
prepared by exposure to frost during the winter, and then passed
through this machine, fairly good results have been obtained ; but
the process is slow and costly. The idea which led to the use of
dry pulverization was to utilize beds of clay containing stones,
chalk, &c. The effect of chalk is not deleterious if the quantity in
the clay does not exceed 13 to 15 per cent. Such clay, thoroughly
pulverized so as to disseminate the chalk equally through the mass,
yields good results. The pulverization is effected very successfully
by edge-runners ; the pressure must not be too heavy, as clay is
always slightly unctuous. The edge-runners weigh 2,204 lbs. each,
and run equidistant on both sides of a vertical spindle ; the pan in.
which they revolve has rectangular holes in the bottom, in which
perforated plates are fitted, and scrapers are provided to turn the
clay into the track of the rollers ; the powder, as it falls through the
plates, is taken by a screw conveyor to a polygonal reel covered
with No. 40 wire cloth, and the overtails are returned to the pan
by an elevator ; the pulverized clay is then damped by an automatic
arrangement, and joasses on to a kneading machine, from which it
passes out ready for use.

Some of the principal advantages of pulverization are stated to
be as follows : —

Eaw material of less value can be successfully used.

The bricks, tiles, &c., made from pulverized clay are stronger
than those made in the ordinary way ; experiment shows the total
resistance to rupture of ordinary plain tiles to be from 210 to
280 lbs. when made in the usual way, and 343 lbs. when made from
pulverized clay ; by reason of the extra strength fewer tiles are
broken in transport.

The appearance of the tiles, &c., from pulverized clay is better
than those made in the ordinary way.

Owing to the uniformity of the prepared clay by pulverization,
especially when pure, the ground product may be passed through
comparatively coarse sieves, so that the purer the clay the larger
the yield of the grinding machinery. Some remarks are made on
the cracking of terra-cotta by frost. The Union Ceramique ap-

424 PULVERIZATION OF CLAY. fForeign

pointed a committee in 1886 to determine the causes of frost-cracks
in terra-cotta ; they came to the conclusion that terra-cotta does not
crack by the action of frost, if the burning is jDushed just to the
point of fusion or vitrification, pores may be formed, but they are
then impenetrable to water. Again, it Avill not crack by frost if
the pores have communication with the surface by sufficient
channels. Granular structure is favoiirable, but laminated structure
is not. For these reasons fabrics made by comjjression are best,
and pulverization of the clay favours the granular structure.

H. H. P. P.

Stone-cutting and Quarrying hij Wire.

(L'Inhistrie Moderue, 1S88, i)p. 203, 218.)

Al)out ten years ago a Belgian company was formed to work the
old Eoman marble quarries of Schemton in Tunis. Though the
marble, of various colours and structure, was estimated at more than
253,165,800 cubic feet, working was discontinued on account of the
expense. Lately the comjiany has been reorganized to work the
quarry by the " Helicoidal-wire " system, by which not only can
the blocks be subdivided, but also the marble extracted from the
mountain side.

Power from a 60-HP. engine is transmitted by teledynamic
cable to the highest point of the quarry, whence it is distributed
to the sevei'al working jilaces by three helicoidal cords, each com-
posed of three ^iteel wires, twisted spirally, and running at the rate
of 14 feet 9 inches per minute. The cord cuts the marble into
slabs by penetrating into the rock at the rate of from 5 to 5^ inches
per hour for hard marble, sand and water being allowed to flow
constantly into the groove. By changing the direction of the cord,
by means of pulleys with adjustable axes, their bearings being
fed down as the stone is penetrated, the same cord can be made to
serve several working places. The marble, cut to the required
dimensions, without being touched by the chisel, is brought down
in tramways to a workshop, where the blocks may be still further
subdivided by the helicoidal wire so as to be reduced to the required
dimensions. The Avorkshops are connected with the Bona-Guelma
Railway by a tramway 2.V miles long made by the comjiany.

The installation of the Societe Anon^aue Internationale du Fil
Heliq'oidal in the grounds of the Brussels Exhibition of 1888,
exemplifies the principal applications of this new method of work-
ing quarries. The endless wire cord is sent by the driving pulley
to a tension truck at the end of the yard, and, guided by pulleys
with universal joints, is diverted at given points for sawing a
mass of concrete and a block of marble, while there are also
the following appliances : — A frame, in which the usual blades are
rejdaced by cords i'or sawing slabs ; a finishing ajjparatus ; and a
drill, driven ly teledynamic rojic, for sinking the shafts by which

Abstracts.] STONE-CUTTING AND QUARRYING BY WIRE. 425

the cord carriers are introduced, the whole being driven by a
14-HP. engine.

In most quarries, especially those of marble, it is less important to
exti'act the greatest quantity of stone, than to obtain blocks of the
form and size desired with as little waste as possible ; and this is ac-
complished in a high degree by the helicoidal cord ; while, manual
labour being superseded by a regular mechanical operation, there is
no need for skilled workmen, but only a few boys to tend the appa-
ratus. A still further saving of lalwur is effected by the mass
being subdivided into blocks of the desired size on the spot where
it is quarried.

The rapidity of the operation naturally depends on the hardness
of the stone ; but it may be put roughly at ten times as great as
that by old methods, while concrete, and such rocks as cannot
otherwise be worked, yield to the helicoidal cords. At the Exhi-
bition, the same cord which sawed a block of marble also cut
simultaneously a mass of concrete composed of quartz and flint
peljbles.

Quarries in France, Algeria, Tunis, Italy, Spain, Germany,
Eiissia, and Finland, have been provided with the new apparatus,
while it is exclusively used in the marble qi;arry of Traigneaiix,
near Philippeville, Belgium. Here the trench 60 centimetres, or
nearly 2 feet, wide, which was formerly, as it is still generally
in other quarries, made by hand, is superseded by vertical cuts
with the helicoidal cord on all faces not detached, and a horizontal
cut underneath the mass to be extracted. If the mass be not
detached on any side, it is necessary to run two cuts 2 feet apart
along one of the faces.

In order to permit the cord to descend, it is also necessary to
sink shafts at all the angles of the mass where not detached, in
order to receive the pulley carriers ; and this work is now per-
formed mechanically by the drill invented by Mr. Thonar, at the
same time preserving the cores for use as columns. It is usual to
make three contiguous shafts, and break down the intervening
angles ; but the number and size of the shafts may be made
subservient to the diameter of columns most in demand. The drill,
driven by teledynamic cable, requires from 3 to 3\ HP., and
descends at the rate of about 10 centimetres (4 inches) per hour in
Belgian marble.

The endless helicoidal cord, composed of three steel wires, varies
from 100 to 300 metres in length, and receives its longitudinal
motion from a fixed engine, the requisite tension being preserved
by a weighted truck on an incline. The downward feed is given
by screws in the pulley carriers, turned either automatically or by
hand ; and the helical twist of the cord causes the rotary motion,
which is demonstrated by the even wear of the wires. The cord
serves as a vehicle for conveying the sand and water, the former
of which is the real agent in cutting the stone.

The diameter of cord found most suitable for quarrying is 5\ to
6 millimetres, or less than a ([luirter of an inch, running at a speed

420 STONE-CUTTING AND QUARRYING BY WIRE. [Foreign

of 4 metres a second, while smaller diameters and quicker speeds
are adopted for siiLdividing the masses. A cut of 10 to 12 centi-
metres, or more than 4 inches per hour, is obtained for lengths of
3 or 4 metres in Belgian marble. In Quenast porphyry, which it
had not before been found possible to saw, a cut of ci or 4 centi-
metres, or from 1 to 1 .V inch per hour, is obtained.

For quarrying, 2 HP. is found sufficient. If the cord should
break, it is readily spliced; and a cord of average (150 metres)
length will produce -from 40 to 50 square metres of sawn surface,
before wearing out, when it may be used for fencing. The sawn
surface, plane if not smooth, is readily finished by the application
of an amalgam of emery with lead, tin and antimony, used in a
machine like that for polishing glass.

The latter of the original articles is fully illustrated, and further
Papers relating to the system have been presented to the Institution,
and can be consulted in the Library\

J. W. P.

The Theory of Jointed Bow-Girders. By E. A. Werner.

(Journal of the Franklin Institute, 1888, ]\Iay to October, pp. 387 et seq.)

Under this title the Author presents a series of mathematical
Papers, having for their object a complete investigation of that
class of structure which is commonly known as the jointed arch or
jointed arched rib ; and throughout the Paj^er the terminology
employed is often different from that which is familiar to English
engineers.

However, the conditions assumed are, practically, that the
structure shall be hinged at the two abutments A and B, and also
at some intermediate point C, which may be conceived to have any
position between A and B, but is assumed by the Author to be
situated at the centre of the span. Under such conditions a
siispended system might be included as well as an upright arch ;
but the Paper deals only with the upright form, in which the
height of the central hinge C above the chord line A B is denoted

A certain curve passing through the three jioints A, C, and B, is
designated the "line of thrust," and is defined as the geometrical
locus of the points of application of thrust in the structure. In the
Paj^er it is treated as the curve about which moments are reckoned ;
and the position of any j^oint m in the curve is defined by the
rectangular co-oi-dinates a:,,, and y„„ the point A being taken as the
origin of co-ordinates.

At the joints A, C, and B, the bending moment is always zero ;
but between the points A and C, the moment may have any value
between -|- a and — a, according as the curve is raised high
above or sagged deeply below the chord line. If v/ = -j- a , then
M = — a, and vice versa. -

Abstracts.] THE THEORY OF JOINTED BOW-GIRDERS. 427

Continuing the cliord line BC until it intersects, a vertical
line AD erected at A, the triangle ADC is called the " deciding
triangle," and it is shown that whatever may be the manner of
loading, the bending moment can only be zero when the curve lies
within the deciding triangle. It is also shown that, under the dead
load, the moment reaches its maximiim at the point where the
curve runs parallel to the chord AC ; and the point may be found
by drawing a tangent to the curve parallel to AC.

By the aid of these and similar theorems, the Author examines
the effect of varying the form of the rib, or of the " line of thrust,"
and illustrates it by hypothetical examples, in which the curve is
supposed to have various imaginable shapes.

Another branch of the enquiry relates to the effects produced by
varying the position of the load ; and in discussing the moments
and stresses in the half-rib AC, the deciding triangle again comes
into requisition ; the ordinates of the line AC being denoted by p,
and those of the line DC by p'.

The load is divided into three portions, of which

G^ = the load between the points A and m,
G-2 = „ „ „ m „ C,

while (/,, f/2 and ^3 represent the abscissae to the points of applica-
tion of Gi, G2 and G3 resj^ectively, and I rejjresents the total
span AB.

Then, by analytical methods, it is shown that the moment at
the j)oint m will be —

M,.= G,j7,(^'

p - y

2/
+ G3 G - 173) (^)^^ (i«)

The second term is positive or negative according to the value
of rt,, and it becomes zero when q., = n,,, = ^ ^ — ^ .
The moment can be expressed by —

M^ =

1 X

— {g,n - x) Gi g, + G2 {g,n - g.,) — +

_y»i Urn

2 g,„ — l\ X

+ Gs(l- Os) i^-^'f^)

fjoij

(Ih)

and the expressions (la) and (16) are regarded as the pivot
equations of the whole theory.

In structures whose " lines of thrust " lie outside of the deciding
triangle, or coincide with either side of that triangle, the maximum
moment occurs when the whole structure is loaded. But when the
line of thrust lies inside the triangle ADC, the maximum positive

428 THE THEORY OF JOINTED BOW-GIRDERS. [Foreigu

moment is attained by applying the whole of Gj and a portion of
G., extending up to a certain point where (/., = g,„ ; while the
gTcatest negative moment is obtained by removing these loads and
applying all the load that can come upon the remainder of the span.
The critical point is found by drawing a straight line through A
and m, which being continued will intersect the line DC at the
point in question.

The method pursued is analytical throughout, and the geometrical
ex]iression of each conclusion arrived at comes out as an incidental
corollary.

By similar methods it is shown that the greatest shearing force
occurs when the load extends to a certain point whose abscissa is
(J., = r/s ; and gs may be found by drawing through A a line
})arallel to the tangent of the curve at the point x,„ «/„„ which line
will intersect DC at a point whose abscissa is rj^.

The theory is applied to arched ribs consisting of an upper and
lower member converging together at the joints A and C, and
united by diagonal bracing. The horizontal and vertical reactions
of the abutments are determined in the usual form, and the stresses
in the principal chords and in the bracing are worked out in
detail for certain examples.

T. C. F.

Experiments on a Neiv Form of Strut.
By C. L. Strobel, M. Am. Soc. C.E.

(Transactions of the American Society of Civil Engineers, vol. xviii., 1888, p. 103.)

In the new railway bridge over the Mississippi at Kansas city, a
length of 1,545 feet consists of a double track carried on iron
trestlework, at an average height of 45 feet ; and for all the
columns and struts in this part of the structure, the Author
designed a new form of cross-section which is believed to combine
many practical advantages. The strut may be described as consist-
ing of two flanges, or legs, united by a single central web of lattice
bracing ; while each flange consists of a pair of Z irons riveted foot
to foot with the lattice bars sandwiched between them.

To ascertain experimentally the strength of this form of con-
struction, fifteen columns were tested at the joint expense of the
Eailway Company and the Keystone Bridge Company, by means
of the hydraulic testing-machine at the works of the latter
company, and under independent supervision.

The Z irons employed in the structure were 3 inches by 5 inches
by 3 inches, with a thickness of -}! inch ; but the tests were made
with columns of smaller dimensions, the Z irons being 2 '; inches
by 3 inches by 2.^ inches with a thickness of -{^^ inch. The
columns were placed horizontally in the testing-machine, with the
lattice bars in a vertical jjlane, and the weight of the column was
counterbalanced by an upward pull applied at the centre. In

Abstracts.] EXPERIMENTS ON A NEW FORM OF STRUT.

420

every case, however, the strut gave way by flexure in the lateral
direction, which was theoretically the plane of easiest flexure. In
this direction the radius of gyration is said to he 2 • 05, the sectional
area varying, however, from 9'IG to 10*10 square inches in the
several struts tested.

The breaking weight per square inch, as shown by the tests in
the case of the longer columns, is greater than that given by

Itaukme s lormula, viz., }) = —

1 +

and to express it, the

46,000 - 125 -, as

36,000 r-

Anthor proposes the empirical formula p

applicable to struts whose length is more than ninety times the
radiiis of gyration ; while for all shorter lengths he takes a con-
stant strength of 35,000 lbs. per square inch.

Taking the average of the two or three experiments made with
square-ended columns of each length, the results were as follows : —

Breaking Weight in Pounds per Square Inch.

Length.

By Experiment.

By Rankine'i
Formula.

By Author's
Formula,.

Feet Ins.

10 Hi

35,700

32,300

15 0

35,600

29,600

35,000

19 Of

112

33,750

26,700

32,200

22 0

i 129

30,300

24,600

29,900

25 0

t 146

28,170

22,600

27,750

28 0

■ 164

27,770

20,600

25,500

The Author considers that the customary factor of safety, in
bridge compression-members, is on the average about 4*35; and
adopting a slightly higher factor, he proposes the following ex-
pression for the allowed stress in square-ended Z-iron columns, viz.,

10,600—30 - , for lengths exceeding 90 radii; and 8,000 lbs. per

square inch for struts whose length is equal to or less than
90 radii.

As compared with a strut composed of two channels with two
planes of lattice bracing, the new form of construction has the
advantage of saving half of the lattice bars and half of the riveting,
while the lattice, being in a more protected position, is less liable
to damage in handling, and the form of cross-section offers very
great facilities for connection with other members of the structure.
In addition to this, the strut is not weakened by rivet-holes at the
outer edges, where the material is most serviceable for resisting
flexure.

When this form of section was first adopted by the Author, Z
irons were not rolled in the country, and it was necessary to

430 EXPEKEMENTS ON A NEW FORM OF STRUT. [Foreign

prepare rolls specially for the purpose. The section was rolled
without any dilficnlty in the same way as an ordinary angle-iron,
the line of rolling contact being diagonal to the section ; and,
notwithstanding the cost of preparing the rolls, the section was
furnished by the makers at a lower rate per ton than channel iron.
The material was manufactured by Brown, Bonnell and Co., of
Youngstown, Ohio.

T. C. F.

Sighivay Bridges of Iron and Steel.

(Journal of the Association of Engineering Societies (U.S.) 1888, p. 451.)

The manner in which highway bridges, of iron or steel, are
designed and contracted for in America, formed the principal
subject of a discussion which was held by the members of the
Engineers' Club of Kansas City ; and which followed upon a Paper
by Mr. J. A. L. Waddell, Assoc. M. Inst. C.E., of which an abstract
only is given in the Journal.

The members were unanimously in accord with the writer of
the Paper as to the urgent need of reform in the present methods
of designing highway bridges ; whose frequent imperfections were
attributed, in great measure, to the system under which bridges
are let to competing manufacturers, and contracts taken upon their
own designs.

Under the system which, by law, is comiDulsory^ in the State of
Missouri, the construction of a new county bridge is let by public
auction, or " outcry," to the lowest bidder ; the purchasers being
represented by certain highway officials, who are not supposed to
have any technical knowledge of bridge designs, and are unassisted
in general by any engineering adviser.

The abuses of such a system, and the mutually opposed intrigues
of buyer and seller, are adverted to in detail ; while the inadequacy
of the means which are supposed to guarantee the safety of the
bridge, is demonstrated by reference to the actual results of the
system. Numerous failures of highway bridges are quoted (and
they are said to occur every month), while it is also stated that
the iron bridges built to-day, in the West, are often more unsafe
than those built five years ago.

Under the stress of a competition, stimulated on both sides, the
strength of the bridge sufiers in many ways. The design is
prepared with a theoretical strength lower than it ought to be —
the scantlings of all members that do not appear in the strain-
sheet are cut down to the lowest possible figure — and when the
design has been accepted in this faulty form, the strength is
further reduced in execution by paring down those portions of the
ironwork which are not exposed to view.

For the evil results of the system, the Paper suggests the
following alternative remedies : —

Abstracts.] HIGHWAY BRIDGES OF IRON AND STEEL. 431

1. State inspection.

2. The formation of an association of highway bridge-builders
pledged to the adoption of a standard specification.

3. The employment of a bridge engineer to decide l)etween
competing designs, and to inspect the bridge after completion.

4. The employment of a bridge engineer to prepare the design.
The second alternative is examined at considerable length and

elaborated in detail ; and the Paper contains a complete set of
specifications, which are intended to cover the whole gronnd of
highway bridge designing, and are suggested as forming the
standard that is required for the object in view.

The salient points of the specification, as described, refer chiefly
to those questions which commonly form the main subject of
American bridge specifications, the first being the live load which
the bridge shall be designed to carry.

For this purpose highway bridges are divided into four classes,
according to the locality and the kind of traffic that is expected ;
the floor load varying from 65 lbs. to 100 lbs. per square foot of
area, while the load on each truss is never to be taken at less than
a certain figure, varying from 800 lbs. to 1,800 lbs. per lineal foot in
the different classes. Certain concentrated wheel-loads are also
specified as affecting the joists.

The working stress per unit of sectional area is next treated, and
is made to vary, not according to any general formula, Ijut according
to a specified list of members, which appears to have been drawn
with special reference to those types of girder-bridge that are most
commonly used in America, and comprises such members as " hip
verticals," "beam-hangers," &c.

The discussion evinced a general approval of the proposed
specifications, qualified by some criticism directed to the small
details above mentioned, but was chiefly concerned with the
broader question of finding some means by which the general
safety of highway bridges might be adequately guaranteed. The
highway commissioners were powerless to obtain the requisite
guarantee, for they would probably be satisfied with a factor of
safety of two, if it were explained to mean that the bridge would
be strong enough to carry a load twice as great as any that would
come upon it.

The discussion, however, did not evince any general confidence
in the proposed association of bridge-builders, the preference being
given either for the employment of an independent engineer, or
for State intervention ; and it was urged that whatever measures
were taken, they should apply to railway bridges also, which stood
equally in need of a thorough inspection ; while it was further
stated that the question had recently been widely discussed among
the engineering societies of the several States, and that a memorial
to the Legislature would be generally supported.

Incidentally it was pointed out that the question of danger is
sometimes only a comparative one ; for among the sparse com-
munities of the West, the choice sometimes lies between having a

432 HIGHWAY BRIDGES OF IRON AND STEEL. [Toroigii

very cheap l)ri(l(2;e, and having none at all ; and in siich cases it is
only a question I'ctween the danger of crossing a weak structure,
and the danger of fording the stream.

T. C. F.

InsjJedion and Maintenance of Railway Structures.

(Transactions of the Aniericnn Society of Civil Engineers, vol. xvii., 1887, p. 259.)

At the request of a number of niemhers of the above Society, a
disciission upon the Inspection and Maintenance of Eaihvay Struc-
tures was announced, and a circular embodying seme leading points
that had been suggested was issued to the members, with a request
for discussion.

The questions suggested were as follows : —

1 . What measures, legal or other, can be taken to insure a proper
inspection of railway-bridges ?

2. What is a j^roper bridge-inspection ?

3. Should there not be a standard sj^ecified rolling load, much
heavier than as now generally used, and a siiecified engine wheel-
base for rolling loads ?

4. Is it not expedient to adopt a standard bridge-floor?

5. Should not bridges of small span lie made strong enough for a
buckle-plate floor and a continuous coat of ballast on the bridge?
and if so, up to what span should this apply ?

6. Should not a safety-giiard (Latimer) be iised at all openings
over a certain width?

7. Should there not be required either overhead crossings, or,
in their place, interlocking ajiparatus with derailing switches ?

8. Is legislation as to any of these points, or as to any other
you may suggest, expedient ? and if so, what sort of legislation ?

In reply to these questions, wi-itten communications were
received from fifteen members, including many well-known bridge-
engineers, in addition to an oral discussion by some others.

In regard to the first and eighth questions, it was the general
opinion that an inspection of all existing railway-bridges is de-
sirable, with the object of ascertaining whether the bridge is
adapted to the purpose for which it is being used, and esjiecially
for the continually-increasing rolling load, and whether it is being
properly maintained. It was also repeatedly urged, and on no
part contravened, that the inspection, to be efiective, must be made
by a skilled engineer who is an expert or specialist in bridge-con-
struction, and that a periodical inspection by practical foremen
unskilled in the principles of design, is insufficient ; one member
stating that the Ashtabula Bridge was habitually inspected in
such a manner, and uniformly reported to be " all right," up to the
date of its collapse, although any bridge-specialist would have at
once detected that it was " all wrong."

There was, however, some difference of opinion as to the authority
under which the inspection should be made. Of the fifteen cor-

Abstracts.] INSPECTION OF KAILWAY STRUCTUEES. 433

respondents, eight were in favonr of invoking legislative control in
one form or another; some recommending a Government Com-
mission to deal with the whole question, while others advised that
the inspection should be compelled by legislative authority, but
not undertaken by it. Two or three of the remaining members
assumed that the insi^ection would be taken in hand by the railway
companies, one of them being prepared to recommend Government
interference in the event of their failing to do so. Three cor-
respondents were expressly opposed to any legislative interference,
chiefly on the ground that it would entail a divided responsibility,
and that the companies should be made directly and solely re-
sponsible for all bridge accidents. One member was of opinion
that the desired object might be attained by the united action of
the engineering societies.

It was suggested that the inspection should include all designs of
bridges about to be erected, and highway- as well as railway-bridges.

As touching upon the second question, it was repeatedly urged
that the detailed plans, calculations, and strain-sheets for every
bridge should be filed on record, and mamerous suggestions were made
as to the particulars and form of the official inspector's report.

Upon the third question, it was generally admitted that the
prevailing tendency is to increase the weight of engines and rolling-
stock ; while it was generally recognized that a standard which
would be applicable to trunk lines, would be considerably beyond
the present requirements of many branch lines. In view of this
difficulty, the balance of expressed opinion was in favour of adopting
several different standards for different classes of road, some members
recommending that each line should be licensed only to carry
certain defined loads corresponding with the safe capacity of its
bridges. There were, however, one or two opinions in favour of
applying a universal standard, and one or two against apjilying any
fixed standard at all ; while one member would apply it only to
trunk lines of railway.

As regards the fourth question, there was much diversity of
opinion, some advocating a uniform type and standard of floor-
system, while others would admit several types, and some were
opposed to any standard at all.

A greater unanimity prevailed in regard to the employment of
a buckle-plate floor and covering of ballast, eight or nine members
being distinctly opposed to it, while only two or three favoured its
adoption in small bridges ; some, however, being of opinion that
the dead-weight of the ballast is useful in small bridges, but that
it is better to carry it upon a planked and creosoted platform.

In conclusion, there was an entire concurrence of opinion as to
the necessity of using rail-guards on all excejDt small-span bridges ;
some members preferring an inside guard-rail brought to a point
at each end of the Ijridge, while others preferred a high timber
guard outside the track, and some advised the employment of both
methods. The only objection to a high guard was that, if placed
within 18 inches of the rail, it would be fouled by the snow-])lough,

[the INST. C.E. VOL. XCV.] 2 F

434 INSPECTION OF RAILWAY STRUCTURES, [Foreign

and if placed at a wider distance it would be comparatively
ineffective. To meet this, it was suggested that the plough might
he provided with an aiitomatic lifting apparatus, so as to clear the
rail-gaiards on bridges.

The remaining questions and remarks had reference to matters
lying outside the scope of the main enquiry.

T. C F,

The Garahit Viaduct} By G Eiffel.

(Compte rendu de la Society des Ingenieurs Civils, July 1888, p. 55.)

This is an account of the calculations of strains, and of the
sections of the principal parts of the structure. Beginning at the
Marvejols side, and ending at the Neussargiies side, the dimensions
are as follows : —

ahcdefgC
70-09 I 51-80 I 55-50 | 55-50 | 55-50 | 51-80 | 24-64 ] 12-32;

C h i h I

: 12-32 I 24-64 | 51-80 | 51-80 | 45-91 metres.

To the left of a, and to the right of /, there are masonry viaducts ;
h, c . . . .k are iron piers. Between a and / is a continuous girder
of five spans ; between / and i a continuous girder of three spans ;
and between i and I a continuous girder of two spans. Between
e and /i is a moon-shaped parabolic arch, of 165 metres (541 feet)
span, and 56-850 metres (186-5 feet) rise in the neutral fibre, so
that the piers, /, g, h, i, stand on the arch, C being its centre ; piers
g and h are therefore very short, / and i a little higher, and e and
k are 60-736 metres (200 feet) high. The platform is for a single
line of railway, and the width of the arch at the crown is 6 • 28 metres
(10-6 feet), at the base, however, it is 20-00 metres (65-6 feet),
and it is anchored down to the masonry by two bolts of 90 milli-
metres (3i inches) diameter at each of the four supports. The
calculation of strains is divided into four parts, viz., 1, the calcula-
tion of the continuous girders ; 2, the calculation of the piers ;
3, the calculation of the arch under the vertical loads, and under
the change of temperature ; and 4, the calculation of the arch
under the wind-pressure.

1. Calculation of the Continuous Girders. — For the calculation of
the bending-moments, and therefore also of the strains in the
flanges, the moving load is applied as one unbroken train of the
length of either one span or of two spans, the weight of the
train being assumed as evenly distributed, viz., 4,800 kilogTams
per lineal metre = 1-44 ton per lineal foot. Clapeyron's formula
is used for the calculation of the moments over the piers, and

* A general account of the Garabit Viaduct will be found in tLe Minutes of
Proceedings, vol. Ixxvii. p. 398r

Abstracts.] THE GARABIT VIADUCT. 435

diagrams show the parabolas of moments derived from them under
the assumptions as stated. The increase of the moments occurring
over the piers and in the middle of the spans, when more than one
train of the stated length is applied, is not mentioned, as also the
increase occurring between the pier and the middle of the S2:)an
when these trains are broken up in parts. The eifect of the change
of height of the tall piers upon the moments is also not stated. In
the calculation of strains in the trellis-web, the actual train on
wheels has served for the construction of the polygon of maximum
shearing-forces, assuming at first that the girder is not continuous,
and the correction for the continuity is then made by adding a
uniform quantity derived in the well-known manner from the
moments over the piers, which, however, were calculated with
the evenly distributed load. It is mentioned that this is not
mathematically correct.

Each flange of a girder is composed of a vertical plate 600 x 15
millimetres,^ two angle-irons 100 x 100 X 12 millimetres, and
several flange-plates 500 millimetres wide ; the depth of the girder
between the angle-irons is 5*16 metres. In the case, for example,
of an aggregate thickness of flange-plates of 42 millimetres, the
moment of resistance of the section of the girder (without having
regard to rivet-holes) is stated to be 0-224126 metre^ and the
corresponding bending moments calculated as above, 1,296,478
metre-kilogram. This gives, as stated, a strain of 5 '77 kilo-
grams per square millimetre (3*66 tons per square inch). A panel
of the web consists of two diagonals. The strain in each diagonal
is stated, for example, to be 82,500 kilograms, the gross section of
the tie, consisting of a web-plate, two angle-irons, and a flange-
plate, to be 15,200, the nett section 14,257 sqiiare millimetres, and
the strain in the tie accordingly 5*78 kilograms per square milli-
metre (3*68 tons per square inch). The gross section of the striat
is, in the same panel, 14,168 square millimetres, and the strain
accordingly 5 • 85 kilograms per square millimetre (3 • 72 tons per
square inch).

In the end verticals of the girders it is noticeable that liners are
calculated as parts of the sectional area. In this way one end-
vertical has a gross sectional area of 47,960 square millimetres.
The stated pressure is 255,390 kilograms, and the strain 5 • 32 kilo-
grams per square millimetre (3*39 tons per square inch). The
admissible strain is stated to be 6 kilograms per square millimetre
(3 • 82 tons per square inch).

The cross-girders, which have a support in the centre by means
of a cross-bracing between the main girders, are strained to 4-08
kilograms per square millimetre (2*53 tons per square inch), the
moment of resistance of the gross section, inclusive of the web,
being taken; the rail-bearers, which are also plate-girders, have
in the same way a strain of 5*76 kilograms per square millimetre
(3 '66 tons per square inch).

> The millimetre = 0-039 mch.

2 F 2

436 THE GAKABIT VIADUCT. [Foreign

2. Tlie Calculation of the Piers. — The height of the tallest piers is
about 60 metres, and their width transversely 5 metres at the top,
and 18 -SI metres at the hottom. The wind-pressure is taken at
150 kilograms per superficial metre on the structure with the
train, and 270 kilogi'ams withoiit the train. The surface of the
girders exjiosed to the wind is calcialated according to Nordling's
method, by taking one top and bottom flange and two webs, the
wind blowing horizontally ; to this is added the thickness of the
platform structure, and so much of the body of the carriages as is
not protected by the top flanges, the spaces between the carriages,
however, being ignored ; this gives for the train 2-20 — 0* 60 = 1-60
square metre per lineal metre; 3 '70 square metres per lineal
metre being the surface of the girders and platform. The surface
of the piers is calculated by taking the surface shown in the
elevation of the bridge twice.

The calciilation of the strains from these forces is too simple to
be referred to here. The gross sectional area of the four inclined
posts, having a tubular section, varies between 33,000 and 49,200
square millimetres each ; the greatest corresponding pressures are
182,373 and 288,153 kilograms. This gives the strain jier square
millimetre, viz., 5 • 53 and 5 • 85 kilograms (3 "52 to 3 • 72 tons per
square inch). The strains in the diagonals are, in the same way,
4 • 84 and 3 • 08 kilograms per square millimetre (3*08 to 1 • 89 tons
per square inch). The posts terminate at the bottom in a bed-
plate one metre square, and 15 millimetres thick, resting on a
stone 1 • 60 metre square, and 0 • 5 metre thick. The compressive
strain for the maximum pressure between bed-jDlate and stone is

288 742
therefore ' = 29 kilograms per square centimetre (26*49

tons per square foot), and that between stone and masonry beneath
11 kilograms per square centimetre (10-09 tons per square foot).

3. TJie Calculation of tlie Arch under the vertical Loads. — Four cases
are calculated, viz., 1, when there is no train-load on the arch ;
2, when the load extends between the piers e and h ; 3, when it
extends between / and i ; and 4, when it extends between e and
the centre. The pressures on these joiers are taken from the
previous calculation of the continuous girders, and the loads thus
applied to the arch in the four points, /", g, h, i, are stated in a
Table.

The arch has thirteen verticals (thirteen and a half panels),
between abutment and crown, and its dead weight is considered as
acting in those thirteen verticals. Then the theory of the arch is
explained. As it is pivoted at each springing one eqiiation suffices
for the calculation of the horizontal strain ; one of the pivots is
imagined to move freely horizontally under the loads when there is,
of course, no horizontal strain ; the movement Ax of the pivot is cal-
culated ; then the horizontal strain Q is considered as acting alone,
withoiit the loads, the corresjionding movement A.r is then calculated
and added to the former As?, and the total is put equal to nil, because,
in fact, there is no movement. From this equation Q is found. The

Abstracts.] THE GARABIT VIADUCT. 437

members in the equation constituting the portions of which Ace is
composed, are of the usual form, and consist of three kinds, viz.,
1, horizontal movements due to forces acting in the neutral axis of
the arch ; 2, the same due to forces acting at right-angles there-
with ; these forces prodxice the strains in the diagonals, and the
expressions therefore contain, besides the angle of the tangent on
the neutral axis with the horizon, a, also functions of the angle of
the diagonals with the neutral axis, /3 ; 3, the same due to the bending
moments. The first and the second kind of members contain the
sectional areas of the booms and the diagonals respectively, while
the third kind contains the moments of inertia of sections through
the whole arch.

In the calculation of the strains from a change of temperature
(30 CentigTades above and below the mean), the sum of the members
with Q is simply put equal to the elongation of a bar as long as
the chord of the arch. The strains in the booms on this account
vary between 0 and 0 • 7-1: kilogram per square millimetre (0 • 47 ton
per square inch).

4. The Calculation of the Arch under the Wind-pressure. — The acting
forces are here computed in the same manner as they are in the
calculation of the high piers, but with regard to those acting on
the arch itself, it is assumed that the leeward booms are protected
by the windward booms, while both trellis-webs are exposed. In
this way the forces acting upon the thirteen and a half jDanels
of the half arch vary between 22*30 and 35*38 square metres,
multiplied with 150 or 270 kilograms, as the case may be.

In the case of the symmetrical distribution of the loads and the
wind-pressure upon the structure — the only case considered — there
is at the crown no torsional moment, but only a bending moment,
i.e., one acting in a horizontal j^lane at right-angles with the
sectional plane through the crown, m being this moment. The arch
can now be cut at the crown, and one half can be removed if this
moment and a horizontal force is put in its place. In all sections
between the springing and the crown act moments in the plane of
the sections as well as at right angles with them ; they are derived
from the acting forces which have been ascertained before, but
have to be supplemented by the moment m at the crown. The
various moments produce elastic rotations of the sectional planes,
which can be resolved into those round a horizontal axis and those
round a vertical axis. As the sectional plane at the crown is the
free end of the half arch, the rotation of -that plane will be the
sum of all rotations between the springing and the crown. The
rotation of the section through the crown round a vertical axis
is nil, on account of the symmetrical position of the forces ; conse-
quently the corresponding sum of rotation can be put = 0. This
equation only contains one unknown quantity, viz. m, and this
can therefore be determined ; with it all moments acting in the
various sections can be found, as also the rotations round the
horizontal axes, but the latter are not required for the calculation
of strains.

438 THE GARABIT VIADUCT. [Foreign

The results of the calculations of the arch are stated in twenty-
two Tables, and it can be seen that the strains in the booms of the
arch from all causes, excepting the change of temperature, do not
exceed 6 kilogTams per square millimetre (3 • 81 tons per square
inch) of the gross sectional area, and those in the parts of the web
do not exceed 5 kilograms per square millimetre (3-17 tons per
square inch).

M. A. E.

The Bridge over the Po at Casalmaggiore for the
Parma-Brescia Bailway.

(L'Ingegneria Civile e le Arti Industriali, 1888, p. 129.)

This bridge consists of seventeen spans, of which those at each
end are 180 feet, and the other fifteen are 213 feet, the total length
between the abutments being 3,560 feet. The j^iers and abutments
were founded by means of compressed air at dejiths varying from
65 to 85 feet.

The bridge is for a single line of way, the load being on the
bottom flange. It is formed of two parallel continuous lattice
girders fixed upon the eighth pier, and supported on rollers on the
other piers and abutments. The river, when not in flood, is 1,312
feet wide, and a temporary bridge of timber was built over this
vridth for the carriage of materials. Near one of the abutments
shops were erected for the engines, air-compressors, pumps, dynamos,
repairs, smithies, stores and offices. After the first ten supports
had been b^^ilt, these shops and their contents were transferred to
the other side of the river. The air-compressors were driven by
two semi-fixed engines of 35 nominal HP. each, and one of 10 HP.,
the latter being used for shallow depths.

The whole of the compressed-air foundations were completed in
fourteen months, during two of which work was susjiended on
account of the cold. The material excavated, which was almost
entirely of a sandy nature, was thrown by the workmen into a
chest about 1 foot 8 inches sqaiare, and 2 feet 8 inches high, into
which water was pumj^ed through a pipe so as to mix with the
sand. The mixture was then forced out through another pipe, in
an almost continuous stream, by the pressure of the compressed-air
in the chamber. By this means a volume of aljout 130 cubic yards,
in the j^roportion of one-third of sand and two-thirds of water, was
forced out in twenty-four hours. The working chambers were
lighted by electric lamps continuously, and during the night the
temporary bridge and the whole of the shops were also lighted,
there being in all fifty Edison lamps of 6-candle power each, driven
by a 4-HP. (nominal) portable engine. The total depth of founda-
tion amounted to 1,312 feet, and was executed in three hundred

Abstracts.] BRIDGE OVER THE PO AT CASALMAGGIORE. 439

and eighty-three working days of twenty-four hours. There was
no considerable flood in the river during this period.

The calculations for expansion and contraction were based on
the assumption that the temperature would range from 14° to lO-i'^
Fahrenheit, and that the difference in temperature between the
top and bottom flanges, owing to the top being in sun and the
bottom in shade might amount to 22^. This difference might be
disregarded in a single-span bridge, but in the case of eight or
nine continuous spans it must be considered, owing to the fact that
it will have a tendency to throw the uprights out of the vertical, and
strains will be brought upon the flanges in resisting this. In the
present case, the elongation of the upper over the lower flange,
between the eighth pier and the abutment, would amount to 2'8
inches, or to 0"36 inch in one span. The upper flange would
therefore be compressed to the extent of 0*18 inch, and the lower
flange extended to the same amount, and the force necessary to
produce these alterations in length was allowed for in the calcula-
tions for the flanges. The permanent load was taken at 2,460, and
the moving load at 4,000 kilograms per lineal metre of bridge
(j ton and 1} ton per lineal foot respectively). In calculating the
wind-bracing the wind-j^ressure was taken at 51^ lbs. per square
foot (250 kilograms per square metre). The working loads were
taken at 6 kilograms per square millimetre (3 "SI tons per square
inch) for plates, 5 kilograms (3-175 tons per square inch) for
lattice-bars, and 3-5 kilograms (2 "222 tons per square inch) for
parts subject to crushing over the supports. The tests for the iron
were : — 1st, to bear a tensile strain of 15 kilograms per square
millimetre (9-22 tons per square inch), without the least i:)ermanent
set ; 2nd, to show no sign of ruptiire with a less strain than
35 kilograms per square millimetre (22 • 22 tons per square inch),
and to show an extension of not less than 8 per cent, if intended to
bear tensile strain in the work ; 3rd, to show no sign of rupture
with a less strain than 32 kilograms (20*32 tons per square inch),
with elongation not less than 8 per cent, if the iron is to be subject
to compression in the work. There were three hundred pieces
tested, and they all satisfied the first test, and the breaking-load
varied from 36*6 to 38*98 kilograms per square millimetre (23*24
to 25 * 4 tons per square inch).

The work was commenced in March 1885, and finished in
March 1887. The bridge was tested first by allowing five engines
and three tenders to stand on each of the seventeen spans suc-
cessively, then by allowing ten engines and six tenders to stand
on each pair of girders. A train consisting of six engines and
tenders was then run over the bridge at 30 miles an hour, and
afterwards two engines and tenders. The gTcatest deflection, both
with stationary and moving loads, was 1*18 inch, the calculated
deflection being 1 * 30 inch. The greatest lateral deflection was
0 * 088 inch. The maximum strain on the iron (taken by Castigliano's
multiplying micrometer) was 2 * 80 tons per square inch on the
flanges, and 2 * 54 tons on the lattice bars. The tests of the various

440 BKIDGE OVER THE PO AT CASALMAGGIOEE. [Foreign

spans gave very uniform results, showing that the material was
homogeneous, and the workmanship accurate.

W. H. T.

Note. — There is a mucli fuller description of this bridge, giving in detail the
preliminary calculations and the j-esults of the proof-loads, in the " Giomale
del Genio Civile" for February, March, and April 1888. — W. H. T.

Erection of the Large Girders of the Machinery Hall at the
Paris Exhibition of 1889.^ By Eugene Henard.

(Le G^nie Civil, vol. xiii. 1888, pj). 211 and 321, 2 plates and 7 woodcuts.)

A detailed description of ithe work of erection is given on the
eve of its completion, with several drawings in ilhistration, sup-
plementing the summary description previously given shortly
after the commencement of the work.^ The huge iron structure,
1,378 feet long, and 337 feet wide, was to be completed in
September 1888, six months only after its commencement. The
method adopted by the Fives-Lille Company, of riveting together
the portions of the four sections of each rib on the ground, and
then lifting the four sections into place by aid of scaffoldings and
w^inches, so as to leave very little riveting to be done on the
scaffolding, is first described in detail. The lifting of the large
central portion requires about five hours. The weight of each of
the ordinary ribs is about 193 tons, and of the end rib 236 tons;
and the total w^eight of the ribs, with their purlins and framework,
for half the building, is about 3,640 tons. Out of 32,000 rivets in
each ordinary rib, 19,600 were riveted up at the shops, 10,300 on
the gToiind at the works, and only 2,100 on the scaflbldings. The
first rib, with its accessories, was erected in twenty-three days,
the second in sixteen days, the third in twelve days, and the
remaining ribs, on an average, in aboiit 10 days each.

The second portion of the article describes in detail the method
of erection, for the other half of the ribs of the biiilding, adopted
by the Anciens Etablissement Cail Company, consisting in raising
the pieces of the ribs separately, not exceeding 3 tons each, and
riveting them together on a single scaffolding following as nearly
as practicable the intrados of the arch. The scaffolding consists of
five large upright stagings 52 j, 59, and 65 1 feet long, and 26 j feet
wide, connected together at a height of 33 feet above the ground
by braces, and at the top l)y two timlier platforms, one in steps
following the curve of the arched rib which it is made to support,
16 jf feet wide, and the other running horizontally at a height of
115 feet alongside the first, and touching it in two i:)oints where
they are at the same level. Two cranes run along this latter plat-
form, on a line of 8.1 feet gauge, for erecting the girders. Each

' Minutes of Proceedings lust. C.E., vol. xciv. p. 372.

Abstracts.] MACHINEBY HALL, PARIS EXHIBITION, 1889. 441

crane consists of a braced iron staging, 39. \ feet high, supporting
at the top a wronght-iron double-webbed girder, 32t feet long,
overhanging the stage on each side, carrying a movable winch for
lifting the several pieces. The scaffolding, which is borne on twelve
rollers under each of the upright stagings resting on rails running
lengthways along the building, can be shifted, after the erection of
one rib, to the site of the next, a distance of 70\ feet, in 1^ hour at
most, by the aid of ropes, pulleys, and winches, though the total
length of the scaffolding is SS-ij. Special precautions "were taken
in adjusting the rails, and in equalising the rate of progress of the
five stagings. The piers at each side are erected first by means of
the large travelling cranes on the ground, and then these proceed
to the next rib ; whilst the scaffolding and its travelling cranes
are employed for the erection of the remainder. In this case, out
of the 32,000 rivets in each rib, only 4,000 were put in at the
workshops, 8,000 on the site, and 20,000 from the scaffolding. The
number of men employed on this half of the work was 215 i)er day,
as compared with 250 men for the other system of erection. The
first rib was completed on the 2-ith of May, together with its
intermediate parts, the second and third were finished in thirteen
days each, the fourth and fifth in twelve days each, and the
remainder in ten days each.

L. V. H.

Reports of the French Delegates on the Proceedings of the Second
International Inland Navigation Congress, held at Vienna
in 1886.

(Annales des Pouts et Chaussues, 6th series, vol. xv. 1888, p. 85(3, 2 plates.)

After giving a brief summary of the origin of these international
inland navigation congresses, and of the questions submitted, and
resolutions adopted at the first of these congresses, held at Brussels
in 1885, the programme of the second congress, held at Vienna in
1886, is given, followed by a short reference to the proceedings of
the congress drawn up by Mr. Voisin Bey, the President of the
French delegation. Eeports of the proceedings of the four sections,
into which the subjects to be considered by the congress at Vienna
were divided, are then given. The study of navigable waterways
from the economic point of view formed the subject allotted for the
deliberations of the first section, reported on by two of the French
delegates, Messrs. Boule and Hirsch. The congress arrived at the
resolution, on this point, that the economic importance of artificial
navigable waterways for trade is so great, that it is advantageous
to construct them in suitable localities, even where there are
railways, and to equip them with the appliances for working
requisite for modern traffic ; whilst acces-iory advantages, such
especially as drainage and irrigation, would often facilitate their
construction. It was considered that a more complete and practical
collection of statistics is very necessary, to enable the economic

442 INTERNATIONAL INLAND NAVIGATION CONGRESS. [Foreign

vahie of navigable inland "n'aterAvays to be fully determined. Tlie
question submitted to the second section was the normal sections of
canals, and the dimensions of works of construction relating to
artificial navigable inland waterways ; and the proceedings of this
section were reported on by Messrs. Holtz and Carlier. The pre-
liminary consideration of this subject had been entrusted to one of
the French delegates, Mr. Holtz, and to a German professor, Mr.
Schlichting ; and their reports formed the basis for the delibera-
tions of the congress. Mr. Holtz proposed that the minimum
dimensions adopted for the principal French waterways, under the
law of 1879, namely, a depth of 6 feet 7 inches of water, width of
locks 17 feet, available length 126_^ feet, and a clear height of
12i^ feet under bridges, should be extended to all the waterways in
direct communication with the French watero^ays. Mr. Schlichting,
however, whilst recommending the same depth of 6 feet 7 inches
as on the French canals, proposed wider sections and larger locks.
Thus he proposed that the wetted section of the canal should be
four times the immersed section of the boats, instead of only three
times as on French canals ; that the minimum width of the locks
should be 23 feet, and their available length 1 885 feet ; and a clear
height of 14j feet under the bridges, and in tunnels, above the
water-level. Owing to the superior number of German members,
the proposals of Mr. Schlichting were adopted by the majority.
The congress also expressed the opinion that the existing canals,
where directly in communication with the canals of adjoining
countries having larger dimensions, should be as soon as possible
enlarged. The third section of the congress devoted their attention
to the methods of working the navigable waterways ; and a rejiort
of the proposals brought forward, the discussion, and the resolu-
tions arrived at, is given by Mr. Denys of Epinal. The congress
decided that a regular service of traction should be organised on
canals ; that on rivers, it is neither necessary or desirable to
impose any restrictions on the liberty of towage as actually exist-
ing ; that it appears expedient to establish on all waterways, by
side of public traction and private navigation, associations of
boatmen for the transjwrt of goods, which are not generally sent in
large quantities, but nevertheless for long distances ; that a rapid
extension of warehouses and sheds is very important for the
progress of inland navigation, provided with the best mechanical
appliances for handling the goods ; that a uniform classification of
grains would greatly facilitate inland navigation, and enable
European agTiculturists to compete more advantageously with the
markets of the world ; and, lastly, that the formation of public
havens of refuge for vessels in the winter is an absolute necessity
for inland navigation. The labours of this section of the congress,
bear the marks of being influenced by local considerations, for the
three first resolutions are only strictly applicable to a system of
navigable waterways of very large size, and very large traffic, such
as Northern Germany is constructing; whilst the three other
resolutions relate particularly to the special conditions and needs

Abstracts.] INTEENATIONAL INLAND NAVIGATION CONGRESS. 443

of the Danube navigation. The fourth section had to discuss
the constrixction and utility of ship-canals ; hut the conclusions
arrived at by the members of this section were too general for the
congress to adopt any definite conclusions, and the subject was
referred to the Frankfort Congress of 1888. The report of the
proceedings of this section was drawn up by Mr. Barlatier de Mas.

The French delegates have added to their reports of the proceed-
ings at the Vienna Congress, notices of navigations and works
visited by them on their way to the congress, and after its
termination. Mr. Barlatier de Mas, in his notice on the navigation
of the Ehine in 1885, gives particulars with reference to the
navigability of the river in that year, as compared with 1882,
which is affected by the lowness of the water, by floods, and by
ice, and therefore varies from year to year, so that the actual benefits
from the important works in jirogress cannot be precisely deter-
mined. Statistics are next given of the tonnage of goods conveyed
along the Ehine in 1885, which amounted to over 12 million tons,
an increase of 21 per cent, on the tonnage in 1882, which was
mainly due to the increase at the German ports, as the tonnage at
the Dutch and Belgian ports showed an advance of less than 5 per
cent. The port of Mannheim-Ludwigshafen is the real terminus of
the Ehine navigation, for the traffic is quite small beyond.
Between 1876 and 1885, the traffic of this port had trebled in
tonnage ; whilst the port of Duisburg had doubled its tonnage,
and the port of Euhrort had increased its tonnage by one half.
Tables are given showing the cost of transport between Eotterdam
and the several German ports. The notice concludes with some
references to the boats employed, and traction. The ample supply
of means of transport on the Ehine, and the active competition,
have produced a constant reduction in the freightage ; and the
reduction in the price of towage has been considerable, having
amounted, for one company, to 20 per cent, between 1882 and 1885.
A regular direct service was started between Cologne and London by
the BadenNavigationCompany in 1885, with one steamer; and the
results were so satisfactory that a second steamer was put on in 1886.

A detailed account of the works for the canalization of the river
between Frankfort and Mainz, which were in progress when
visited by the French delegates in 1886, is given by Mr. Boule ;
a description of them, subsequent to their completion, will appear
in a Paper on " Some Canal, Eiver, and other Works, in France,
Belgium, and Germany" to be published in the Minutes of Pro-
ceedings, vol. xcvi.

The last notice ajipended to the reports is an account of the
excursion made by the members of the congress down the Danube,
from Eegensburg to Turnseverin, by Mr. Hirsch. A summary
description is given in this notice of the portion of the Danube
traversed, and of the works being carried out for the improvement
of the navigation. L. V. H.

444 MEASUREMENTS OF THE FLOW OF THE ELBE IN SAXONY. [Foreign

Measurements of the FIoiv of the Elbe in Saxony, 1886 and 1887.
By A. EixGEL.

(Civilingenieur, vol. sxxiv. 1888, p. 505.)

The measiirements of the flow of the Elbe forming the subject of
this commnnication were undertaken by the Author in conjunction
with the Engineers, Messrs. M. Eingel and F. Lindig, in the year
1886, at the instance of the Eoyal Hydraulic Department (Koenig-
lichen Wasserbau Direction).

In Saxony there are three points on the Elbe arranged for taking
measurements. For about 500 metres both above and below these
points the sections of the stream previously taken are indicated by
blocks of sandstone, the tops of which are furnished with bolts.

Current meters were employed for measuring the velocity of the
water, which were made to slide up or down on vertical rods firmly
secured in the bed of the river. Every revolution of the screw was
transmitted by electricity to a counter or chronograph placed above
water. The current-meters were supported by wire ropes wound
upon drums attached to the rods before referred to.

In addition to the usual method of measuring by current-meters,
Professor Harlacher's system of so-called integration was employed.
The observations were conducted from a floating platform carried
by two strong barges connected with each other in siich a way
that between the barges there was a clear space of 6 metres (19 feet
8-22 inches).

The rod on which the current-meter slides was supported at the
upper end by an iron fork carried on a tripod, at the top of which
was a roller over which the rope passed for hoisting up the rod
and meter. This tripod was hinged at one of its legs so that it
could be laid down flat on the platform.

The allocation of the apparatus at a previously determined
point of the section in which a series of observations at various
depths were to be made, was effected by means of a wire rope
stretched across the stream, on which the points were indicated by
small bands tied on.

Every observation lasted two minutes, and in each position at
least three measurements were taken.

Professor Harlacher's method of so-called integration is carried
out as follows : — The current-meter is hoisted by means of the
drum about 0 • 5 metre above the surface of the water, and then
allowed to slide slowly down the rod by its own weight until the
screw touches the bottom ; at the moment when the axis of the
meter passes below the surface, all the recording instruments in
connection with it are put into gear, and as soon as the bottom is
reached thrown out again. The recording instruments consist of a
stop clock, a counter, and three styles belonging to the chrono-
graph.

Abstracts.] MEASUREMENT OF THE FLOW OF THE ELBE IN SAXONY. 445

On the moving paper band driven by the chronograph are
recorded : —

l) The number of revohitions of the meter.

[2) The depth of the axis of the meter below water.

(3) The time in quarter seconds.

By taking into account these three quantities the mean velocity
can be approximately arrived at.

In order subsequently to obtain some mathematical connection
between the surface gradient and the other observed quantities,
the levels of the surface were observed twice each day in that
portion of the river where the measurements were carried out,
piles having been previously driven in and graduated for this
purpose.

After reviewing the varioiis theories as to the distribution of the
velocity of flow according to the depth, the Axithor states that he
and his colleagues arrived at the conclusion that the experi-
mental results agreed best with the assumption that the maximum
velocity was at the surface and the minimum velocity at the
bottom, and that the variations of the velocity with the depth
were most accurately represented by a parabolic curve of the wth
order, of the form ?/" = p x, where x is the height of any point
above the bottom, and y proportional to the velocity of flow at that
point ; the curve has its apex at the bottom and the axis of abscissa
coincides with the axis of the curve which is vertical.

The value of n varied at difierent points of the section from 3 • 53
to 5*65 in one case, from 3*43 to 8* 01 in another, and from 2-69
to 4-58 in a third. The original is accompanied by diagrams in
the text.

G. E. B.

Begulation of the Isar according to Wolfs method.
By E. IszKOwsKi.

(Wochcnschrift des osterreichischen Ingenieur- und Architekten Vereines,
1888, pp. 74 et seq.)

The Author states the advantages of Wolfs method over the
systems hitherto employed to be, not only that it is a more speedy
and effective method of regulating rivers, but much more eco-
nomical, and he grounds his statement on the results obtained on
a section of the Eiver Isar, 44 miles in length, extending from the
boundary between Upper and Lower Bavaria (7^ miles above
Landshut) down to the village of Plattling.

The Isar, throughout its course of 170 miles from its source in
the Karwiindel moimtains to its junction with the Danube, has the
character of a mountain stream, and has a drainage area or catch-
ment basin of 3,416 square miles. The average fall at low- water
level, in its coitrse of 111 miles through Upper Bavaria, is 1 in

446 KEGHLATION OF THE ISAE. [Foreign

600, and for the remaining 58 miles 1 in 1000, bnt owing to large
deposits of gravel and boulders here and there, the fall varies in
places from 1 in 200 to 1 in 1,500.

Its discharge in ordinary floods may he taken at 900 cubic yards
per second.

The dejith varies very considerably, and at mean-water level is
as follows :

At Mittenwald (near the soui-ce) . . . 1-65 foot per second.

At Tolz 3-28 feet „

From Municli downwards 6"56 „ „ „

but in places where the concave banks are specially exposed to the
current, the depths vary' from 1 3 to 23 feet.

The normal breadth in the lower section of the river is about
75 yards.

Wolf's system aims at leading a river at the smallest possible
cost in a normal channel ; that is, with breadth and depth con-
sistent with its proper regimen or stability ; it also effects a
uniformity of fall, the reclamation of old channels, the stopping of
branches, and the proper maintenance of the regulated section of
the river. This is attained by the employment of floating spurs
(^Gelidnge) or layers of fascines (attached to piles driven in the bed
of the river), the action of which increases the velocity of the water
in the parts of the river to be improved or deepened, and reduces it
in the part to be reclaimed, causing respectively an erosion in the
former case, and a dej^osit in the latter, and this much more quickly
and completely than by the works usually constructed.

The piles are from 8 to 10 inches in diameter, and are driven in
a line parallel to the regulation trace to a depth of from 10 to 16 feet
below the river-bed, and at distances of about 8 feet apart. To
these the fascines are attached with their thick ends towards the
stream, that is, with their brush-like ends towards the line of
bank to be formed, and the distance of the row of piles from this
bank is dependent on the depth of the water. At places where
specially strong currents are met \\ith, a second row of piles is
driven in behind the first row, and both are secured by cross stays
oblique to the axis of the river. When the deposit of gTavel or
boulders behind the fascines has settled down to its natural slope,
the fascines are sunk so as to cover this slope, and are weighted
down with stones so as to form a complete revetment ; the top of
the bank is protected in a similar manner.

According to Mr. Wolfs experience a river can be trained or
regulated in this way in a remarkably short time, but the speed
is dependent in great measiire on the nature of the water-levels.
Strong continuous mean average levels accomplish more in a week
in this respect than low water-levels in twenty times that period.

As a result of the success of this method, it is stated that in a
section of the Isar, about 15 miles long, regulated by this method,
no place was found were the action of the floating spurs did not
produce a deepening of the" channel in front of them, and the re-

Abstracts.] REGULATION OF THE ISAR. 447

quired deposit of gravel behind extending tip to the surface of the
water or even above it. The cost of these works is as follows per
lineal yard : One row of piles 6i to 8 feet apart, including fas-
cines, &c., 2s. 9f/. to 3s. 8d. ; two rows of piles, front row 8 feet
apart and back row 6i to 13 feet apart, distance between the rows
6 J to 10 feet, inclusive of fascines, cross-stays, &c., from 4s. Id. to
6s. bd. ; and in exceptional cases, where an unusually strong current
is met with, the price may be taken at from 6s. bd. to 7s. 4(i. per
lineal yard. The Paper is illustrated by twelve examples, showing
the arrangement of the piles and floating spurs to meet particular
cases during the regulation of the Isar.

W. H. E.

On the Imi^rovement of the River Moldau at Prague, and the
Construction of a Port there.

(Wochenschrift des osterreichischen Ingenieur- und Architekten Vereines,
1888, p. 2U2.)

The general project prepared by the Government engineers was
referred to a Sub-Committee, and by it again referred to a Technical
Committee for report.

This report, drawn up by Mr. Kaftan, is divided into two parts.
The first part treats of the economic importance of waterways
in general, and of the great benefit accruing to Prague (and
Bohemia generally) by making the Moldau navigable there, and
the shipment and trans-shipment of goods.

The second part is of a purely technical character, and lays down
a programme for carrying out the details of the scheme. This
programme was strongly opposed by Messrs. Olwein and Umrath,
on the ground that the fixed weirs, which it was proposed to
retain, should be removed and replaced by movable weirs with a
view to lower the existing flood-levels, and thus prevent the con-
tinually recurring inundation of the low-lying parts of the city,
and to admit of its proper drainage and sewerage.

The lowering of the water surface in floods being of the greatest
economic importance, as then all the quay- and wharf-walls might
be built at least 1 metre less in height, and the drainage and
sewerage of the city being matters of great urgency, the proposal
of the Technical Committee to retain the fixed weirs was re-
jected by the Sub-Committee ; but the project for the Holesovic
harbour and wharf for trans-shipment of goods, 3j miles distant
from Prague, was accepted and highly approved.

This scheme provides for the berthing of about three hundred
boats, and of a convenient approach for the Austro-Hungarian
Government Eailways and the Buschtehrad Railway. The Techni-
cal Committee also recommended an enlargement of the Carolinenthal
harbour, where at present there is only accommodation for thirty
boats ; biit as it was feared that this work might interfere with

448 IMPROVEMENT OF THE RIVER MOLDAU AT PRAGUE. [Foreign

the immediate execution of the Holesovic harbour works, which
were urgently necessary, it was declined by the Sub-Committee on
that ground.

A proposal by Chief Inspector Olwein to include in the scheme
a goods wharf and landing-stage on the right bank of the Moldau,
between Lieben and Carolinenthal, on the ground of its easy and
cheap connection with the railways on that bank of the river, as
well as with the Holesovic harbour, was accepted by the Sub-
Committee on condition that they did not prevent the Holesovic
harbour works being first taken in hand, together with the drainage
of Prague, and that they did not interrupt the free navigation of
the river.

At a subseqiient meeting of the Sub-Committee the scheme for
the enlargement of the Carolinenthal harbour was again considered,
and a proposal to carry oiit this work before any of the other works
was passed by a majority of the members.

W. H. E.

Special Plant for Blasting binder Water at the Panama Canal
Works. By Max de Naxsouty.

(Le Geuie Civil, vol. xiii, 1888, p. 324, 1 woodcut.)

A wooden raft, 82 feet by 46 feet, kept above water by forty-
eight floats, and covered with planking, in which holes 8 inches
square and 8i feet apart have been made, serves as a stage, from
which the blasting of boulders under water on the site of the canal
at Mindi, near Colon, can be carried on across the whole bottom
width of the canal. Tubes 1-38 inch in diameter, and 16| feet
long, which can be screwed together, j^rovide bars of variable length,
by which blasting holes can be driven to a depth of 29.5 feet without
too great toil. These bars are passed through the holes in the
planking, and are kept vertical by passing them through the
meshes of a sort of trellis roof erected over the raft. An iron pipe,
about 3 2 inches in diameter, resting on the bottom, and passing at
the top through one of the holes in the planking, prevents the
blasting hole being lost when the bar is removed, or in charging
the hole ; and it also serves for guiding the bar. The pipe is raised,
when the charge is in place, by tackle from the superstructure.
The explosive is inserted through a tube of 2\ inches inside
diameter. The several charges are connected by wires, so that
35 to 40 mines can be fired simultaneously by electricity.

L. V. H.

Abstracts.] THE EMBANKMENT OF THE PO AT TURIN. 449

The Emhankment of the Po at Turin. By Tommaso Prinetti.

(Gioriiale del Genio Civile, June 1888, p. 314.)

In prolonging the embankment of the Po, it was decided, instead
of constructing an ordinary retaining-wall, to adopt the system of
forming a series of chambers with a roadway over them. The
principal reasons for this decision were, first, that the height from
water-level to ground-surface was so great that it would take a
long time for the earth filling behind the wall to consolidate;
secondly, it was considered advantageous to have a number of
underground chambers which could be used for stores, workshops,
laundries, boat-houses, and so on ; thirdly, that the additional cost
would be compensated by the rents ; fourthly, that as houses would
be built along the roadway on the further side from the river, and
these houses would have certainly one and probably two stories of
cellars, the height of the earth pressing against the back of the
wall would be reduced by the height of these cellars.

Several types of wall were adopted, and drawings of one of
them are given. In this case there is next to the river a towing-
path wall founded on piles and concrete, and built of rubble faced
with ashlar. Its height is 8 feet 6 inches above water-level.
The towing-path is 26 feet 3 inches wide, and slopes 1 in 20
towards the river. At the side of the path is the fa9ade to the
chambers, which is 29 feet high to top of cornice, and 33 feet
3 inches to top of parapet. It is 3 feet thick, and consists of a
series of piers 8 feet 10 inches wide, and openings 6 feet 10 inches
wide, 11 feet 6 inches high to springing, with semi-circular arches
over them. Above each of these openings is a square window.
The face of the wall is hammer-dressed coursed rubble with rusti-
cated quoins. The underground chambers are behind this wall,
their width being 37 feet 9 inches. At the back is a solid wall
3 feet thick carried up to road-level, and forming the foundation of
the front wall of the houses facing the road. The span of the vaults
is 13 feet, and the walls separating them are formed of a central
pier 3;^ feet wide, and two arched openings of 15 feet 6 inches with
semicircular arches. Flights of stairs are formed at intervals,
leading from the roadway to the towing-path and from the latter
to the water. The vaulting ai )hes are 1 feet 7 inches thick at the
springing and 1 foot 3 inches at the crown; they and the spandrel
wall are covered with a layer of hydraulic cement and another of
asphalte. As chimneys will be required in some of the chambers,
they have been provided. Where houses are to be built along the
roadway the chimneys will be carried up the cross walls, and
where this is not the case they will be left in the face-wall and
ornamental iron columns will be provided as chimneys.

The cost of the wall as described above was about £68 per lineal
metre. A simple retaining-wall would have cost about £48. Some

[the INST. C.E. VOL. XCV.] 2 U

450 THE EMBANKMENT OF THE PO AT TTTEIN. [Foreign

of the chambers are retained bj^ the Municipality, others have been
made over to owners of frontage, others are let at a rental of Is. 9f^
per square metre, or about £l Is. per lineal metre.

W. H. T.

Jandin's Compressed- Air Dredger. By M. Boulle.

(Annales des Fonts et Chaussees, 6th series, vol. xv. 1888, p. 1034, 1 woodcut.)

This dredger accomplishes the removal of sand or silt by an
injection of comj^ressed air, instead of the well-known method
of suction. It consists of a tube going down under water to the
bottom to be dredged, and a compressed-air injector placed at the
bottom of another pipe at right angles to it, and surrounding the
main tube, into which the compressed air from the pipe is
injected from a great number of little mouthpieces directing the
current upwards. This injection caixses the w-ater to rise in the
tube, drawing in water from outside, which eflects the dredging
at the bottom ; and a mixture of water, silt, and air, flows up the
tube. This dredger has been tried in the Loire at Saumur, and on
the Seine at Havre. At Saumur the tube, 4 inches in diameter,
dredged pure sand at a depth of 13 feet, w'hich was lifted 5 J feet
above the water-level, and transported to a distance of 50 feet. A
compressor of 15 HP., drawing in 3*53 cubic feet of air per second,
enabled the dredger to raise 130 cubic yards of water -per hour charged
with sand, which composed three to four-tenths of the whole
volume. In the Eure Dock at Havre the silt w^as dredged, in a
depth of 26 to 30 feet, by a tube 9 inches in diameter; it w^as
lifted 5 feet above the water-level, and discharged into a barge.
Using a compressor of the same power as at Saumur, 390 to 520
cubic yards of silt and water were lifted per hour, the silt forming
one quarter of the whole volume. This dredger is most efficient
in soft silt, sand, or gravel ; but, nevertheless, at the foundations
of the Palma Bridge, stones weighing 22 lbs. w-ere removed with a
tube 9 inches in diameter. This machine might be advantageoiisly
used for pumping out water charged with gravel, sand, or debris.

L. V. H.

Renewal of the Water in the Hague Canals. By M. E. v. Pichler.

(Woctienschrift des Osterreichische Ingenieur- und Architeckten Yereines, 1888,

p. 118.)

In this Paper the Author first gives a sketch of the special
physical feature of Holland, namely, that a great j^art of the
country lies many feet below sea-level, and requires for its pro-
tection from the sea and from rivers, the construction of strong
dykes and embankments ;- and as regards the neighbourhood of the

Abstracts.] RENEWAL OF THE WATER IN THE HAGUE CANALS. 45l

Hagiie, it is pointed out that between tlie years 1713 and 1863, the
natural bulwarks of the coast (the Dunes or chains of quartzose-
sand hills), had been so washed away by the action of the waves
that the shore bad advanced in some places from 580 to 020 yards,
which necessitated the construction of massive stone dykes, the so-
called Delft Iwofde.

An account is also given of the formation of the Zuyder See in
the year 1300 by the bursting of the natural dam connecting
North Holland with Friesland, and of the disastrous inundations
in South Holland in the fifteenth century by the breaching of a
dyke. This locality is now an archipelago called Biesbosch.

The drainage of the Haarlem Lake (commenced in 1840, finished
in 1853) is also noticed, and a description given of the pumping-
engines emjiloyed which are in use to this day.

A large portion of the Paper is devoted to a detailed account of
the river systems of Holland, the Rhine, the Maas and their
tributaries, and an account is given of the locks at Katwyk at the
mouth of the Rhine, constructed in 1808 with a view of giving it
a free outlet into the sea, and of the pumping-engines that were
erected there in 1880.

The chief feature of the drainage system of Holland is the high-
level canal or reservoir called the Boezem, the level of which is
carefully regulated by pumping water up from the low-lying parts
when that level is too low, and by leading it off into other canals and
thence into the sea, or by utilizing it for working water-wheels in
times of flood. The particular canal which affects the Hague and
Delft districts is the Schie Boezem, so called from the River Schie, and
the ratio of its water-surface to that of the land draining into it
is given as 1 : 73*2, which is said to be much too small from the
fact that to this day a large extent of country is under water in
wet seasons because the Boezem cannot carry it off. It is pointed
out in the Paper that while cities like Amsterdam and Rotterdam,
situated on rivers subject to tidal influences, can easily have their
canals renewed and flushed, Hague is under the disadvantage of
being only indirectly connected with the sea by its high-level
canal or Boezem, and the consequence is that in summer the
canals (^gradden) which intersect the town in every direction, are
most insalubrious and offensive. The town archives show that
such has been their condition for centuries, and that although from
time to time suggestions have been made for the renewal of the
water in them, nothing was really done till 1883, when Chief
Engineer J. Van der Vegt submitted to the district council a plan
and estimate of cost of the works.

Under this scheme 88,000 gallons of water per minute were to be
taken from the Schie Boezem and led to the Hague through the
Trekvaart, and after passing through the town canals woiild be
lifted or pumped into a higher canal furnished with flood gates,
and thence led into the sea. This project was opposed by the
Delft district authorities because it did not favour their interests
sufficiently, and Mr. Van der Vegt (in conjunction with Messrs.

2 G 2

452 EENEWAL OF THE WATER IN THE HAGUE CANALS. [Foreign

Malsen and Siccama) prepared anotlier scheme, in which the water
was also to be taken from the Vaart and pumped into a high-level
canal with sill 6^ feet above the standard gauge, and discharged into
the sea at the " dunes " by means of three siphons each 5 feet in
diameter. This project was approved, and work was commenced in
1886, but the working expenses were so high and the season so un-
favourable owing to floods, that the first project was again taken up,
and being subsidized by a gTant of £14,500, was accepted by the
council. The carrying out of the entire scheme was entrusted to
Chief Engineer J. Van der Vegt.

The site for the outlet of the canal into the sea was fixed at a
point 1^ mile south of the celebrated bathing place Scheveningen,
so as not to injuriously affect that station, and it was decided that
a velocity of only about 8 inches per second could be allowed
during the day, so as not to render navigation, and especially towage
or haulage, difficult ; but at night when there was no traffic a
higher velocity was permissible.

Taking the experience of Amsterdam as a guide, it was calcu-
lated that nothing less than 44,000,000 g-allons should be supplied
daily for the renewal of the water in the Hague Canals alone, biit
for the irrigation of the " polders " in the whole of the Delft
district, and the maintenance of the i)roper level of its Boezem
canal, twice that volume would be necessary.

The water would be taken from the River Maas at Vyfsluizen,
then along the Schie and through the " polders " to Delft, and
thence through the Trekvaart to the Hague, and 10 hours a day
was the period fixed for admitting the water.

As regards the fall to be given, this was fixed at 15^ inches in
the 1 0-mile section from Vyfsluizen to the Hague, or about 1 inch
in a mile.

From the Hague to the sea the canal is divided into two
sections, viz., from the gas-works to the pumping-station and lock
adjoining, and from thence to the sea. The length of canal or
reservoir between the lock near the pumping-station and sea-lock
near the canal mouth, is about 1 mile, and the pumps have to deliver
88,000 gallons per minute into this reservoir. The lock adjoining
the pumping-station is provided with double gates, which are made
to slide or turn, and to act as flood-gates in the event of the sea-lock-
gates failing to act when reqiiired.

This sea-lock is built on concrete, and has two openings, each
about 13 feet wide, instead of one large one, in order the more
efiectually to resist the occasional terrible attacks of the sea, for
which purpose also wave-breakers or fenders formed of strong
baulks, are fixed in proper positions. The cost of the project
complete is given as £79,000.

Plans and cross-sections of the locks and longitudinal section of
the country adjoining them, as well as a plan of the Hague and
the canals referred to, accompany the Paper.

W. H. E.

Abstracts.] NEW YORK AND BROOKLYN BRIDGE. 453

The Cable Bailwaij on the Neiv York and Broohlyn Bridge.
By G. Leverich,

(Transactions of the American Society of Civil Engineers, vol. xviii., 1888, p. 67.)

The New York and Brooklyn Bridge is 601 7 '33 feet in length.
The railway is double line, laid to the 4 feet 8.V inches gauge, with
steel rails weighing 52 lbs. per yard. The inclines vary from level
to over 3j per cent., or 1 in 26.V. The total length of cable within
the rails, for actual train service, amounts to 2^ miles. It is
driven continuously in one direction, by one of two stationary
steam-engines at the Brooklyn terminus. The cars are each
connected to the cable by a roller-grip, and they are run singly
or in trains as may be required. They are moved and placed by
locomotives at each terminus. The cable is driven by means of
winding-drums and their accessories.

Steam is generated in six water-tube boilers, each of which has
fifty-four water-tubes, 4 inches in diameter, 18 feet long, with a
3-foot drum overhead. Each fire-grate is 3 feet 10 inches wide,
7 feet long, and consists of revolving self-stoking fire-bars. The
chimney is 129 feet 4 inches high, 5^ feet square at the top. Steam
is supplied for three electric-lighting engines besides the cable
service.

The two steam-engines are horizontal, having each a 26-inch
cylinder, with a stroke of 4 feet. They are connected to the outer
ends of the main driving-shaft by clutches, working one at a time,
making fifty-seven revolutions, or 456 feet of piston per minute.

The rope passes over two large drums, 12 feet in diameter, on
axes nearly horizontal, in each of which there are four semi-cir-
cular grooves for the rope, j inch deep. The drums are 17 feet
apart, slightly inclined to each other, the shafts making angles of
1 in 128 with the horizontal, so that the several rope-grooves of one
drum may be directly opposite to those of the other. The drums
are placed one at each side of the main-shaft, 5 feet clear of each
other. A smaller drum 5 feet in diameter, occupies this interval,
and runs loose on the shaft. Beside it, a toothed wheel 5 feet in
diameter is keyed on the shaft, and gears into a 12 feet toothed
wheel keyed on the shaft of the driving drum. Thus the drums
are kept exactly at the proper distance apart, and are driven by the
engine through reducing sjiTir-gear, making 23^ revolutions per
minute ; and moving the rope at a speed of 895 "35 feet per minute,
or 10*17 miles per hoTir. Allowing for wear and tear of grooves
and slipping, the speed is usually taken as 880 feet per minute, or
10 miles per hour. The cable is of crucible-steel, 11,500 feet in
length. It is, when new, 1^ inch in diameter, and it consists of
114 wires, nearly -/j^- inch thick, laid in six strands around a central
strand of hemp. It weighs 3i lbs. per foot of length. Tension-
cars are employed to prevent the cable from slipping, and to take
up slack. Between the rails, the cable is supported on pulleys

454 NEW YORK AND BROOKLYN BRIDGE. fForeign

placed 30 feet apart, in which the groove is packed with leather
and india-rubber beltings laid radially.

The cars are 48 feet 10 inches long over all ; the body is 39^ feet
long, 9 feet 7 inches wide, and 13 feet 8 inches high above the
level of the rails ; on a four-wheel bogie at each end. The wheels
are of paper, steel-tired, 30 inches in diameter. The car, without
load, weighs 16^ tons. The entrances at the ends, are 3 feet
5 inches wide, with double sliding-doors ; and at the middle of
each side, a 2 feet 8 inches opening, with a single sliding-door. Forty
barred seats are placed in line along each side, with an aisle 4 feet
8 inches wide. When fully occupied — seats and standing room —
the car has carried 150 persons. The car is lighted by eight
argand lamps, burning mineral oil. In cold weather, the car is
heated by a hot-water heater with ten lines of Ij-inch wrought-
iron pipes under each line of seats.

The grip is so devised as to maintain automatically the relative
positions of the pieces subject to wear. It is fully described in the
Paper. The brakes are applied to every car-wheel, by hand or by
vacuum. Five locomotives are employed on the terminal service,
having cylinders 11 inches and 12 inches in diameter, with a
16-inch stroke. Four are in constant use. The automatic car-
coupler is applied to the whole of the wheeled stock.

The indicator power exerted by the driving engine was observed
during the entire working day, 19^ hours, April 26, 1886. The
power ranged from 303 • 1 HP. to 12-9 HP. minimum and negative ;
the average for the whole day was 96*2 HP. ; for five hours of the
busiest time, the average was 150-5 HP. To drive the plant
without trains, the power was 47 • 7 HP.

The steel wire of which the cable is constructed has a breaking
stress of from 140,000 lbs. to 190,000 lbs. per square inch. The
first cable was in use 3 years 43 days ; during which time it
hauled 226,273 miles, 837,895 cars, and 48,960,000 passengers,
making a total weight of above 12,000,000 tons ; of which
9,000,000 tons of cars were hauled -j^ mile, and 3,000,000 tons
of passengers were hauled 1 ^V mile ; making a total service of
nearly 22,000,000 ton-miles (exactly 21,777,710 ton-miles). The
Paper is illustrated by twenty-seven plates. D. K. C.

The Neiv Harbour Worlis at La Bochelle.

Keport of Committee commisBioned by the Italian Government to inspect
the works.

(Giornale del Genio Civile, June 1888, p. 281.)

The port of Eochelle is protected from Atlantic storms by the
islands of Oleron and Ee, which form two great natural break-
waters, between which and the mainland shij^s can at all times ride
in safety. The tidal range is 9 feet 6 inches at neaps, 16 feet
9 inches at springs, and 21,^ feet 6 inches at equinoctial springs. The

Abstracta.] NEW HARBOUK WORKS AT LA ROCHELLE. 455

highest seas (the maximum wave height being about 13 feet) are pro-
duced by west and south-west winds. The present harbour being
deficient both in area and depth, new works are now being constructed
at a point about three miles west of the town (Porto della Pallice),
it having been found impracticable to enlarge the existing port.

The position of Pallice is very favourable ; the five-metre line
(below equinoctial low water) runs parallel with the shore at a
distance of 1,150 feet, so that by running out piers of moderate
length a sufficient depth can be obtained to enable small vessels to
enter at all times, while at high water there will be a depth
of 33 feet ; there is no danger of silting up, and there is close by an
area of low-lying land which can, with advantage, be filled up from
the excavations. The ground consists of oolitic limestone in
horizontal layers alternating with dry beds of clayey marl.

The works now being carried out consist of a tidal harbour with
a depth of 10^ feet at low water of ecpiinoctials, two locks available
for the largest vessels, and an inner basin having a minimum depth
of 26 feet. The area occupied, exclusive of the tidal harbour,
is 1 48 acres, of which the water area of the inner basin is about
30 acres. This basin is 700 metres long; the first length of
400 metres is 200 metres wide, the remaining 300 being 120 metres
wide. The northern side is straight, the reduction in width being
obtained by an ofifeett on the south side. The total length of quay
is 1,800 metres ; but of this, only 1,650 metres is available for ships
to lie alongside. It is calculated that with a proper equipment of
cranes and sheds, 700,00iJ tons of shipping per annum can be
accommodated in the basin. The excavation for this basin amounts
to 1,200,000 cubic metres, of which a large portion consists of rock
requiring blasting. The plant includes 9 locomotives, 250 wagons,
about 10 miles of railway, and 3 centrifugal pumps driven by a
40 HP. engine, and capable of discharging 300 cubic feet per
minute. Owing to the character of the ground, the walls consist
simply of a lining of masonry 1 metre thick with counterforts
2 metres deep at intervals of 15 metres. Bollards and mooring-
rings are provided alternately at each counterfort. The face of the
wall has a batter of 1 in 10.

There are two graving-docks, which are placed at an angle of 35^
with the basin to facilitate the entry of vessels. The larger is
541 feet long, 72 feet wide at entrance, and has a depth on the
side of 32 feet at spring tides, and 28 V feet at neaps. The smaller
dock is 328 feet long, 49 feet wide at entrance, and the same depth
as the larger. The larger dock is sufficient for any merchant
steamer now afloat, except the "Great Eastern" and the "City of
Eome." The quay space round the basin will be 100 metres wide,
and can be extended to 200. There will be a railway station
on the northern quay, and lines of rails will be laid round the
basin. The corners will be tiarned liy means of curves, turn-tables
not being permitted. The basin will be entered from the tidal
harbour by two locks, each having a depth of 16', feet at the
harbour end, and 13 feet at the basin end, at equinoctial low water,

456 NEW HARBOUR WORKS AT LA ROCHELLE. [Foreign

their lengtlis being 541 and 475 feet, and breadth 72 and 49 feet
respectively. There are intermediate gates in each, so as to save
water in passing through small vessels. At neap tides vessels
of 23 feet draught can enter at all times. There will be a swing-
bridge across each lock.

In designing the tidal harbour, it was decided that sufficient
funds were not available for a construction which would admit
large vessels at all times, but that during rough weather these
must remain in the roads, which they could do with perfect safety,
while smaller vessels would be able to enter at all times. The
depth was fixed at 16^ feet below equinoctial low- water, which
would admit ships of 31^ feet draught at high-water neap tides,
and 35i feet at ordinar\^ springs. The harbour is formed by two
breakwaters. The direction of the shore-line is north-north-east.
The soiithern breakwater runs from the shore in a west-north-
westerly direction, and the northern breakwater runs from the
shore towards the south-west, the distance between the two at the
entrance being 295 feet. The depth of water at the end of the
southern breakwater is 16^ feet at equinoctial low-water. The
harbour forms approximately a trapezium, the lesser base of which
(at the entrance) is 295 feet ; the larger base (at the shore) 1,475
feet, and the height (distance from shore to entrance) 1,640 feet.
Means have been adopted to insure the tranquillity of the water in
the harliour, so as to facilitate the entrance into the locks leading
to the inner basin, but these means cannot well be described
without reference to a plan. A very large amount of excavation
(about 850,000 cubic metres) was necessary to obtain the required
depth. In order to excavate the bulk of this in the drv% the greater
part of the area was enclosed by a temporary masonry dam, about
300 metres long, built across the harbour from breakwater to break-
water, and foimded at mean low-water. The excavation was
carried on at the rate of 1,800 to 2,000 cubic metres per day.

The breakwaters are biiilt of concrete, faced above low-water with
masonry. The work, both excavation and wall below low-water, is
executed by compressed air in caissons, of construction similar to
those described in the Minutes of Proceedings Inst. C.E., vol. xciii.
p. 522. The walls are built in a series of piers, each pier built in
the caisson, which is 72 feet long and 33 feet wide. Arches are
turned over the spaces between the piers, and later on the spaces
are also filled with concrete, which is executed by siDCcial means
described in the Paper. When the breakwaters are finished, a
temporary masonrj- dam will be built across the entrance to the
harbour, and the remaining excavation wall then be completed in
the dry. The cost of the compressed-air plant is given as : —

£.
Two large caissons, 72 feet by 33 feet, of wrought iron, at £4,800 9,600
„ small „ 33 „ 26 „ „ £iOO 800

Four steam engines (total HP. 90) 4,000

Air-compressors, pipes, sheds, repairing-shop 17,600

Total 32,000

Abstracts.] NEW HAKBOUR WORKS AT LA ROCHELLE. 457

There are four air-compressors, capable of furnishing in all
2,400 cubic metres of air at the pressure of 1 atmosphere, and one
giving a pressure of 4 atmospheres, for driving a machine for
raising and lowering materials in the caissons.

The work to be done by this installation comprises about 23,000
cubic metres of walling, and 5,500 cubic metres of excavation in
rock ; the total value of this work being about £120,000.

In front of the entrance to the harbour some rock has to be
excavated under water. This is to be done partly with compressed-
air caissons, partly by means of drills worked from a pontoon,
which, by means of adjustable legs, can be fixed in any required
position. In both cases the blasting-agent will be dynamite. The
broken rock will be brought to the surface by a Priestman dredger.

It should be noted that the caissons used for the foundations
have frequently been exposed to storms of considerable violence
(waves of 3 or 4 metres in height), and though it is not safe for
men to "work in them under such circumstances, the caissons with-
stand the force of the waves, and completely protect the work
inside them.

The cost of the works is : —

£.

Inner basin 230,000

Tidal liarboiu- 352,000

Land and accessories 198,000

Railway and sheds 220,000

Total 1,000,000

In conclusion, the Commissioners speak in very high terms of
the design and execution of the works, and especially in regard
to the Messrs. Zschokke and Terrier's compressed-air system.

W. H. T.

Tlie Qualities of Potable Waters.

(Les Annales des Travaiix Publics, 1888, p. 2156.)

Water should be fresh, aerated, free from smell, having a faint
but agreeable taste, and a residue not exceeding 42 grains per
gallon on analysis ; and the health of the popiilation drinking it
affords a test of its quality. The Consulting Committee of Hygiene
in France classes water according to its degTee of hardness after
boiling from two to over twenty minutes ; but the quality of water
cannot be determined merely by the extent of its hardness, though
where water contains more than 1 grain of lime per gallon it must
be regarded as tin wholesome. The hygienic committee also classes
water according to the chlorine it contains, regarding as potable
those waters containing less than 3j grains per gallon, and as bad
where the amount exceeds 7 grains per gallon. The same body
states that potable waters should not contain more than 2 grains

458 THE QUALITIES OF POTABLE WATERS. [Foreign

of sulpliiiric acid per gallon ; whilst waters are bad which contain
over 7 grains. The estimation of organic matters in water has
hitherto been very imperfectly effected, for these matters are
estimated all together ; whereas some kinds are far more injurious
than others, and a regular classification is needed in this respect.
The municipal laboratory of Paris has fixed 0-35 grain of organic
matter per gallon as the proper limit, which none of the waters
consumed in Paris comply with ; and the hygienic committee lays
down 1 grain of organic matter per gallon as allowable for potable
water, with a limit of 1 • 6 grain ; whilst water containing over
2 • 8 gTains must be absolutely rejected. The gas contained in the
water should be 3 j per cent, by volume, of whi(3h one-tenth should
be carbonic acid, and three-tenths oxj^gen. Water charged with
microbes loses its oxygen rapidly, whilst water charged -wdth algce
absorbs oxygen. Navigation and wind, by stirring up the lower
layers of water, and bringing them into contact with the oxygen
of the air, which oxidises the organic matter, improve the quality
of the water. Potable water should not contain any sulphuretted
hydrogen, or carburetted hydrogen, and not more than traces of
ammonia and other nitrogen compounds ; and the amount of iron
should be limited to -1- gTain per gallon. Microscopical investiga-
tion supplements chemical analysis ; but the two methods often
lead to discordant results. It is possible, however, that the
innocuous microbes destroy the hiirtful ones to a great extent.
There are four sources of water-supply available for Paris and its
neighbourhood, namely, spring water, such as the Dhuys and the
Vanne, near their sources ; the waters of the Seine, the Oise, and
the Marne ; artesian wells, and shallow wells. The spring waters
are the best, but costly to obtain owing to the distance of convey-
ance. The waters of the Seine, Oise, and the Marne are about
equally good. The water from artesian wells is small in quantity,
and, if drawn from a gTeat dejith, is too warm and little aerated.
The water from shallow private wells is still largely used ; but it
is gradiially being abandoned, owing to its liability to contamination.
A Table gives the degree of hardness, the residixe, and the organic
matter resulting from analyses of the waters supplied to the
princiiial towns of Europe, affording an idea of their quality.

L. V. H.

Water-Supply in the Kingdom of Wurtemherg. By J. R.

(Wochenschrift des osterreichischen Ingenieur- und Architekten Vereines,
1888, pp. 210-211.)

The paper opens with a description of the physical features of the
country referred to, viz., the Eauhe Alb, an elevated, bleak, and
sterile plateau north of the Danube. The works have been in
progress for the last twenty years, and have recently been com-
pleted. The general project consists iu the formation of nine

Abstracts.] WATEE-SUPPLY IN THE KINGDOM OF WURTEMBERG. 459

independent water-supply " groups " or districts, embracing an
area of 700 square miles and a population of 40,000 inhabitants.
The requirements are estimated at 16 j gallons per head per diem;
but provision is made for supplying nearly twice this amoixnt, if
necessary.

From the nine pumping stations, 1,100,000 gallons of water are
lifted daily and discharged into sixty-two reservoirs, which are
situated on heights not too far distant from the stations, and which
contain from 65,000 to 308,000 gallons, and have a storage capacity
equal to from six to ten days' supply.

The cost of the Eauhe Alb water-sujiply, inclusive of all charges,
amounts to about £280,000, and the cost of individual "grou})s"
varies from £6,750 to £60,000, according to population supplied,
and the share per head ranges accordingly from £-1 10s. to £10.

The benefits of the scheme, it is stated, are already evident in
the better sanitation of the houses, the less frequent occurrence of
cattle disease, and in the provision for extinguishing fires ; in short
(it is added), that the Alb water-supply in the kingdom of
Wurtemberg may be generally regarded as a model for imitation
under similar conditions.

W. H. E.

Facts in Relation to Friction, Waste and Loss of Water in Mains.
By C. B. Brush, M. Am. Soc. C.E.

(Transactions of the American Society of Civil Engineers, vol. xix., 1888, p. 89.)

The first part of this Paper contains some experiments on the
loss of head at different velocities in the main, supplying the City
of Hoboken. The main on which the observations were made is
20 inches diameter, 75,000 feet long. The quantity flowing appears
to have been obtained by noting the number of pump-strokes,
and allowing 5 per cent, for slip. The heads were determined
by pressure gauges. The friction at velocities of 2 to 3 feet per
second is a good deal less than that given by some ordinary formulae.
The results agree best with the following —

« = 203-3 ro-ea^gi-sss . . (Lampe)
V = 111-0 ^(rs) . . . (Darcy).

In 1882, Hoboken had a population of thirty- three thoiisand, and
the water consumption was 4,000,000 gallons per day. The Author
was convinced that half this was wasted. By prompt action, partly
by extending the use of meters, partly by inspections, about
750,000 gallons per day were saved by preventing waste in the
mains, and 750,000 gallons by preventing waste by consumers.
Since the waste was checked, a pressure 25 per cent, higher has
been maintained in the mains. In 1886, the Water Company was
obliged to establish a low minimum rate of charge depending ou

460 FRICTION IN WATER-MAINS. [Foreign

the size of meter attached to the service pipe, in order to check a
tendency to extreme economy on the part of some consumers.
Experience shows that the meter system is advantageous both to
the consumer and the Company. Also that the true policy of a
Water Board is to furnish meters and keep them in repair free of
expense to the consumer, except in the case of misuse or freezing.

Some data of measurement of the waste in mains are given. The
following is specially interesting: — A new 24-inch main, 11 miles
long, was laid by the Hackensack Company. At the time of test
it was supplied with gates, air-cocks, and blow-offs, but no hydrants.
The main had been carefully examined, and there was no evidence
of leakage ; about midway it was connected to an iron tank at the
summit of the whole system. The test was made by opening the
gates and filling the tank under a pressure of 107 lbs. per square
inch ; the gates were then closed. The loss was found by tank
measurement in several trials to be 70,000 gallons per day. The
main had good lead joints, well caulked and laid by experienced
men under careful inspection.

w. c. u.

Tlie East Orange Sewage- Works.

(Scientific American, 17 Nov. 1888, p. 307.)

The townshijD of East Orange, a typical suburban community of
New York, has recently been provided with sewage-works, designed
by Mr. C. P. Bassett, associated with Mr. E. Hering, M. Inst. C.E.
The pipes run from 8 to 2-i inches in diameter, and the sewer-
gradients vary from 1 in 30 to 1 in 800. Many difficulties were
encountered in laj-ing the sewer-jiipes, owing to the presence of
quicksands and rock, which latter necessitated tunnelling. The
outfall works provide for a chemical treatment combined with
intermittent filtration.

The precipitants employed are lime and sulphate of alumina,
which are mixed with the sewage-water in a trench 100 feet in
length, furnished with baffle-plates. The sewage is received in
tanks, where the suspended matter subsides, and the effluent is
clarified by intermittent downward filtration, being drawn oif from
the sludge by a floating swing-pipe. The sludge is conveyed into
vacuum-pans, and forced from thence into filter-presses, where it is
formed into cakes in the usual way. The works have been five
months in operation. No details are given of the cost, or of the
amount of the sewage-flow, nor is the area of the farm stated.
The article is accompanied by illustrations showing the works
and plant.

G. E. E.

Abstracts.] DISINFECTING ACTION OF SUPEKHEATED STEAM. 461

On the Disinfecting Action of a Current of Suiierlieated Steam.
By Professor Max Gruber.

(Gesiuidheits-Ingenieur, Oct. 15, 1888, p. 674.)

The Author alhides to his previous observations on this subject,
and to the conditions laid down for successful disinfection, namely,
that the steam must be as nearly pure as possible, that is, free
from admixture with atmospheric air ; and, second, that the steam
must become condensed upon the object under treatment by means
of dripping water, if the germs are to be rapidly destroyed. He
also calls attention to a statement in the ' Zentralblatt fiir Bak-
teriologie und Parasitenkunde,'^ that " The xase of moist steam is
preferable to dry superheated steam for purposes of disinfection."
A simple form of apparatus devised by Dr. Von Esmarch for testing
the action of steam is described, and the results of experiments
with steam at 100^ Centigrade, and with steam superheated to
110°, from 120^ to 123°, and lastly from 140° to 150°, are described.
With moist steam at 100°, the spores of anthrax were killed,
without any exception, in from five to ten minutes. In super-
heated steam at 110°, complete sterilization of the spores was not
attained in less than twenty miniites ; and as much as half an hoiir's
exposure was required when the temperature of the steam rose to
120° to 123°. Even under the action of steam at 150°, ten minutes
failed to suffice for the destruction of the spores, and complete
success was only attained by still further prolonging the ex]ieri-
ments. Similar tests with the spores of the garden-mould bacillus
gave corresponding results. The drier the steam, the less energetic
was it in its action. Steam superheated to from 120° to 130° acts
more slowly than steam at 110°, and it is not until a temperature
of from 140^ to 150' is reached that a destructive action, due to
the high temperature, is set up, similar to that produced by
hot air.

For the purpose of these trials, the test-objects were merely
enclosed in an envelope of filter-paper, and it was to be expected
that, in the case of trials upon a large scale with test-spores con-
tained in clothing, &c., the results would be more favourable to
superheated steam, as the amount of steam which would penetrate
to the centre of the bundles would be small, and moreover, it
woTxld be cooled down to condensation-point. This was found in
actual practice to be the case, and the results of three trials made
by Dr. v. Esmarch with a Henneberg's disinfecting apparatiis are
given. The spores were enclosed in rolls of blankets, which had
been provided with a signal thermometer adapted to give an alarm
as soon as a temperature of 100° Centigrade was attained in the
centre of the roll. In each case the germs were sterilized, though,
similar test-objects on the outside of the bundles were only in part

> Vol. iii., p. 638.

462 DISINFECTING ACTION OF SUPERHEATED STEAM. [Foreign

deprived of vitality. The Author draws attention, also, to Yon
Esmarch's statement respecting the necessity for a strong current
or jet of steam, as simple steaming had a less destructive effect on
the spores.

G. E. E.

Elucidation of the Bisinfecting-Pou-er of Steam.
By A. Walz, of Dusseldorf.

(Gesundheits-Ingenieur, Nov. 1st, 1888, p. 697.)

In the case of some previous experiments conducted by the
Author, which led him to form an opinion that the disinfecting
action of the steam was not due to its jiropulsion as a jet, but to
the extent to which it was generated under 2:)ressure, his views
were called in question by Professor Gruber. He now draws atten-
tion to the impossibility of caiising a jet of steam to jiass through
a bundle of clothing in a disinfecting chamber, unless the chamber
is filled with steam under pressure ; the matter to be decided is
whether the steam passes into, or out of, the space to be disinfected
as a jet at 100^ Centigrade. He examines the statements of Pro-
fessor Gruber in the ' Gesundheits-Ingenieur,' No. 20,' and shows
that the results of the experiments of Dr. von Esmarch, on which
Professor Gruber relies, might with miich probability be referred
to the action of steam under pressure ; and he states that the
steam, moreover, was in each case mixed with atmospheric air.

G. E. E.

Comparative Trials of various Gas-Burners. By S. Lamaxsky.

(Journal fiir Gasbeleuchtung und Wasserversorgung, 1888, p. 629.)

During the exhibition of gas-lighting apparatus held in St.
Petersburg by the Eussian Technical Society, an extensive investi-
gation of various gas-burners was made. All the tests were made
with the same gas and by the same observers, thus rendering it
possible to compare the different types of burners with each other
and also the burners of different makers ; the illuminating-powers
were also determined with varying rates of consumption to ascer-
tain the most favourable conditions for each. Batswing, argand,
incandescent, and inverted regenerative burners were tested, a
Bunsen photometer being employed with a standard argand burner,
the illuminating-power of which was verified every evening with
English standard candles. The illuminating-power of the argand
burner, with a consumption of 5-29 cubic feet per hour varied
between 14-5 and 14*75 standard candles. An angle photometer

' Ante, p. 461.

Abstracts.] COMPARATIVE TRIALS OF VARIOUS GAS-BURNERS. 463

was Tised for determining the illuminating-powers of the inverted
regenerative burners.

The batswing burners tried were the so-called " hollow-top "
burners, the surfaces of the flames being parallel to the photometer
disk ; with five descriptions of batswing-burners, and consumptions
varying between 5 '07 and 11*29 cubic feet per hour, the highest
results were obtained with Bray's 80-candle-power burner, con-
suming 9 • 32 cubic feet per hour, when it gave 2 • 25 candles
illuminating power per cubic foot of gas consumed, while the
lowest was the ordinary hollow-top 7 cubic feet per hour burner,
which gave 1 "81 candle per cubic foot per hour.

Eighteen varieties of argand burners were tried, the highest
results being obtained with the Rotsiper burner with heated-air
supply, consuming 8-34 cubic feet per hour, which yielded 3*75
candles illuminating- power per cubic foot of gas per hour ; and the
lowest was the Parisian union burner, consuming 7*37 cubic feet
per hour, with a duty of only 1 • 15 candle per cubic foot per hour.

Of incandescent biirners only two, the Sellon-Lewis and the
Welsbach, were exi:)erimented with. Of these, the Welsbach, con-
siiming 3 • 28 cubic feet per hour, gave the best result, namely,
2 • 93 candles per cubic foot, the light from it being whiter and
more agreeable than that obtained from the Sellon-Lewis burner.
Tliese incandescent burners are, however, not much more eco-
nomical than argand burners, and require more careful treatment.

The inverted regenerative burners, of which nine descriptions
were tested, were all, with the exception of the small Cromartie
Ijurner, tried at angles of 30'^, 45^, 60^, and 75', the best results
l)eing obtained with the No. 11 Siemens burner, which, with a
consumption of 42 '95 cubic feet per hour, gave 6*72 candles per
cnl)ic foot, while the lowest was the Butzke lamp, consuming
15*17 cubic feet per hour and yielding only 3* 18 candles per cubic
foot, these results being the average of the observations at the four
angles.

Comparing the lowest consumption of gas per candle of illumi-
nating power for the various ty2:)es of biirners, it appears that the
batswing, argand, and regenerative burners stand in the relation
of 3 : 2*1 : 1, or that the regenerative burners are three times
more economical than batswing,^ and nearly twice as economical as
argand burners ; to determine their absolute economical value the
cost of fitting and maintaining must however be considered.

CO.

' This comparison between the Argand and incandescent burners does not
agi-ee with the preceding figures. With the Argand giving 3-75 candles
illuminating-power pev cubic foot, and the incandescent burner 6 "72 candles
per cubic foot, the proportion would be 1 '79 : 1 instead of 2 : 1, but the figures
given are those in the original. — C. G.

464 WILMSMANN*S SMOKE- CONSUMING FURNACE. [Foreign

Wilmsmanns Smohe-Consuming Furnace.

By — SeilER, of Mannheim.

(Journal fiir Gasbeleuchtung und Wasserversorgung, 1888, p. 135.)

The progress ruade in various industries has attracted considerable
attention to the question of smoke-consumption, and numerous
suggestions have been made for its accomplishment by many who
have not realized the difficulties which surround the problem.
Although generator firing has been extensively applied in gas
manufacture, smoke-consuming furnaces are rarely used for steam
boilers, on account of the costly nature of the arrangements
required, and the difficulty of applying them to existing boiler
settings. A simple and cheap smoke-consuming and fuel economis-
ing arrangement is to be found in the furnace of Mr. Wilmsmann
(Mining-Director of Hagen, Westphalia), which can be easily
applied to all descriptions of boiler and other furnaces. The arrange-
ment consists, mainly, in converting the front part of the furnace
into a generator chamber, by forming a fire-brick shield and
division wall above the fire-bars, near to the bridge of the
furnace, to keep the gases and smoke from going direct into the
flues ; the fuel being put into the furnace so that it slopes up
against the shield, and the gases and smoke being compelled to
pass through a red hot layer of fuel, thus ensuring their perfect
combustion. In starting the furnace, the fuel is at first burnt for
three-quarters of an hour in the same manner as with an ordinary
furnace, but with the difference that, the incandescent layer of
fuel is gradually increased in depth until there is sufficient to
form an inclined heap against the baffle, and thus close the
combustion-chamber from the fire-space. As the coal burns,
carburetted-hydrogen is liberated, and combines with the air
entering through the fire-bars, while the coal, partly converted,
into coke, burns off with a further supply of air. The gases formed
on the upper surface of the red-hot coals in the combustion chamber
are conveyed through channels at the top of the furnace into the
back chamber, where they require a secondary air-supply for
complete combustion, for which heated air is supplied through air-
channels regulated by dampers.

The formation of smoke, which occurs with ordinary furnaces
after supplying fresh fuel, is entirely avoided with the Wilmsmann
furnace, if the gas-chamber is separated from the fire-space and
the flues, by the glowing layer of fuel. The principle of this
system of firing is similar to generator furnaces for gas-retorts in
which the hydro-carbons from the fresh coal have to pass a glowing
layer of coke. In both cases carbonic acid is formed at the com-
mencement of the combustion, Avhich, by passing through the
o-lowing coke, takes up a further quantity of carbon, and is reduced
to carbonic oxide, and this, if sufficient air is present, is burnt to
carbonic acid.

^ta

Abstracts.] WILMSMANn's SMOKE-CONSUMING FURNACE. 465

Many unsuccessful attempts have been made to apply generator
firing to steam-boilers, partly on account of the cost and partly
from other difficulties, and also because, although, with inter-
mittent working, the smoke could be consumed, there were other
pecuniary disadvantages connected with it, but with the present
extremely simple system smoke consumption must succeed ; in fact,
about 600 Wilmsmann furnaces have been put to work within the
last few years for steam-boilers, smelting, puddling, and other
furnaces in the Ehenish provinces, Westphalia, and the South
German States, and most favourable testimonials have been received,
not only with regard to the prevention of smoke, but also as to
economy of fuel, varying from 15 to 30 and even 40 per cent, as
compared with ordinary furnaces.

Experiments as to steam-production have been made with a
horizontal Cornish boiler, fired with an ordinary and also with a
Wilmsmann furnace. With an ordinary furnace a trial of eleven
hours was made, during which the consumption of coal was 1,109
lbs., and the water evaporated 7,0-45 lbs., the average feed-water
temperature being 104° Fahrenheit, and the average steam-pressure
4^ atmospheres. This gives 6 • 35 lbs. of water evaporated per lb.
of coal.

With the Wilmsmann furnace, fitted to the same boiler, a trial
was made for seven days of eleven hours per day. The total coal
consumed was 4,916 lbs., and the water evaporated 46,751 lbs. ; the
average temperature of the feed-water was 140° Fahrenheit, and
the average pressure of steam 4^ atmospheres, which gives 9 • 5 lbs.
of water evaporated per lb. of coal. The coal used in both cases
was Ruhr nut coal.

Mr. Vogt, Chief Engineer of the Berg Steam Boiler Examination
Society, has also spoken very favourably of the Wilmsmann furnaces
as being sound in principle, of great simplicity, and small in cost
for fitting.

C. G.

Raising the Steamer " Ferndale," sunk in the Entrance Channel
of the Port of St. Nazaire.

By Messrs. Kerviler and Preverez,

(Annales des Fonts et Chaussees, 6th series, vol. sv. 1888, p. 1030, 1 plate.)

On the 4th of February, 1888, the English steamer "Ferndale,"
of 604 tons, loaded with coal and tar refuse, was run down by the
English steamer "Dowlais," and sunk almost immediately, only
giving time to draw it alongside the northern jetty before its bow
plunged into the silt. The hinder part was readily unloaded, as it
remained afloat for two days ; but the front part of the hold was
only out of water just at low-tide. The rent caused by the bow
of the "Dowlais" was about 13 feet long, and, at 6i feet below the
water-line, it suddenly enlarged from a width of 4.V inches to 2 feet

[the INST. C.E. vol. XCV.] 2 II

466 RAISING THE STEAMER " FEKNDALE." [Foreign

for a height of about 5 feet, having been torn open by the anchor of
the " Dowlais " which hung across its bow. The narrow parts
were closed by poplar wedges with packing. A large wrought-
iron plate, ^ inch thick, lined round its edges with two large tresses
of greased cotton, was placed over the large hole, and was fixed in
place by being bolted to two very strong T irons put across the
opening inside. Eolls of tow were interposed where the plate was
not close to the torn plate-iron skin, and the whole was covered with
a large felted sheet. Two rotary pumps, capable of discharging
000 tons of water each per hour, were placed upon pontoons along-
side the sunken vessel. One of the pumps discharging water from
the front hold enabled the unloading from it to proceed for two or
three hours each tide. On the 13th, the two pumps pumped the
water out of the holds and engine-room, so that the stern soon rose
slightly; and at half-tide the bow was raised from the bottom.
The vessel, accompanied by the pontoons, was then taken into the
dock ; the cargo was further removed from the front hold, and on
the 14th, the vessel was placed in the graving-dock, which was
pumped dry the next day.

L. V. H.

Consolidation of Earthworks on the Railway from Gien to Auxerre.
By Messrs. Lethier and Joyan.

(Annales des Fonts et Chaussdes, 6th series, vol. xvi. 1888, p. 5, 2 plates.)

The portion of the Gien- Auxerre Eailway between the Toucy-
Moulins station and the Auxerre junction with the line from
Laroche to Nevers has a length of about 18^ miles, and passes
almost entirely over the clayey greensands and eocene strata.
Seventeen cuttings were excavated in treacherous clays, having a
total length of about b\ miles, with slopes of 3 to 2, except in
four cases, where the slopes were made 2 to 1. The slopes were
covered with moiild, drained, sown and planted ; and trenches were
carried along the foot of the slopes, lined with dry pitching, or
occasionally laid in mortar. Water-channels with a sharp fall
were formed on the top of the cuttings. The wet clayey portions
of the formation were drained by longitudinal and transverse
rubble drains. Bad slips occurred at only three places, owing to the
presence of springs ; and the rej^airs of the slips increased the cost
of the consolidation works from the original price of 25s. 3^cZ. per
lineal yard for the works described above, up to 27s. for the repairs
of the slips as well. Nine of the embankments experienced serious
slips directly after their completion, which necessitated large and
costly works of consolidation ; and the Fritton's embankment has
been selected for description as being the most seriously damaged,
and giving rise to the most complete works of reparation. This
embankment, about 550 yards long, crosses a small valley about
36 feet deep; it was constructed in 1880-81, with a top width of

Abstracts.] CONSOLIDATION OF EAKTHWORKS. 467

19| feet and slopes of 3 to 2. Slips soon occurred in the middle, and
towards the base of the slopes. In order to drain oif the water inside
the embankment, which caused the slips, rubble-drains were made in
the slopes parallel to the railway, restin^^ uj^on the solid ground, about
10 feet high and from 2 to 2| feet wide, and propped up on the
outer side by a bank of punned earthwork, having a benching
8j feet wide at the top. The water collected by the rubble-drain
on each slope was discharged beyond the embankment by trans-
verse rubble-drains 50 feet apart. A sum of £800 had been spent
on these repairs when the constant rains of the summer and autumn
of 1882 disintegrated all the higher parts of the embankment,
causing a settlement of over 2 feet at the top, and slips which,
commencing at the top, reduced the formation-width to 10 feet in
some places. The previous repairs stood well for the most part ;
but the large slips over the bench threatened to carry it away.
The consolidation and drainage was effected by spurs of rubble-
stone, perpendicular to the line of railway, 6 ^ feet wide and 39. \ feet
apart, cutting into the embankment from top to bottom, right up
the slopes, and into the formation width on each side to the extent
of the slij)s, nearly vertical on the inner face, and following the
line of the slope on the outer face. The spur rests at the ground-
level on a watertight layer of concrete ; and a passage, 1 foot by
8 inches, formed through its base, serves to discharge the water and
to supply air to the interior of the mass, which is very favourable
to its drainage. To repair and prevent slips between the spurs,
transverse rubble walls of an inverted V shape, 3j feet wide, were
formed from spur to spur near the top of the slopes ; they were
founded upon laj^ers of concrete carried down at least 2 feet below
the base of the slip, and passages formed through the base of these
walls or drains convey the water collected by them to the adjacent
spurs. These works were completed by the beginning of 1884 ; they
absorbed 11,120 cubic yards of rubble and broken stone, and cost
£6,720 on a length of 262 yards repaired, or £25 10s. per lineal yard,
the high price being due to the extent of the work and the dearness
of materials. Including the earlier repairs, the cost amounts to
£28 10s. per lineal yard, and 2s. O^d. per cubic yard of earthwork.
Details are also given of the cost of the repairs of the eight other
embankments which experienced serious slips. The sj)urs and the
top of the embankments settled gradually till the end of 1 885, the
greatest amount of settlement at the highest embankment of Fritton's
being 17 inches. This was made up with rocky excavations before
the opening of the line on 30th December, 1885, since which period
the spurs have not shown any further signs of settlement ; and
though the embankment between the spurs has settled a little, no
further work has been necessary beyond the ordinary maintenance
of the road.

The practical conclusions to be drawn from the experience on
these embankments, as well as from those on the Yonne and Cher
lines, are as follows: (1) In treacherous clay embankments, con-
solidations by benches at the top, with longitudinal and transverse

2 11 2

468 CONSOLIDATION OF EAKTHWOEKS. [Foreign

drains, are unable generally to stop slips ; (2) The best plan
consists of nibble-spurs about 33 to 40 feet apart, resting on an
impermeable floor, supplemented, where necessary, by inverted
V-shaped rubble-walls carried down into the undisturbed portion
of the embankment ; (3) It is expedient to make these spurs
6^ feet wide when the embankments exceed 20 feet in height and
the slips are large ; (4) It is always possible to construct these
rubble-spurs and trenches, like those at Fritton's, in an embank-
ment which has slipped, with safety, and without excessive
expense ; (5) It is assumed in this method of consolidation, that
the injured embankment rests upon a fairly solid soil ; but it is
nevertheless wise to provide against possible settlement, by giving
the top of the consolidated embankment an excess of width of one-
twentieth to one-tenth of the height of the embankment.

L. V. H.

The Laon Steep-Gh'adient Raihvay. By A. Braxcher.

(Le Genie Civil, vol. xiii. 1888, pp. 75 and 169, 4 woodcuts.)

The tramway laid down along the high road to connect Laon
with the station of the Northern Railway Company, has a gauge
of 1 foot 11§ inches; its rails are of steel, weighing 19i lbs. per
lineal yard, carried on steel sleepers, 3 feet 3^ inches long, hollow
underneath, and closed at the ends on Captain Pechot's system.
The line, which surmounts a difference of level of over 328 feet in
about l;j mile, has necessarily steep gradients, reaching to 1 in
15 "4, with curves having a minimiim radius of 1^ chain. The
traction is effected by a compound locomotive, on the Mallet
system, weighing 8f tons when empty, and lOf tons when loaded.
This engine has four axles, to make the load borne by each as
little as practicable ; all its wheels are driving-wheels, to utilise
the whole weight of adhesion ; and the front set of wheels are
made convergent, so that the engine can go readily round curves
of 1 chain. The heating-surface is 254 square feet ; the hinder,
high pressure, cylinders have a diameter of 6j inches, and
10 J inches stroke; whilst the front cylinders, low pressure, have
a diameter of 10 inches, and the same stroke ; and the wheels
are 1 foot llf inches in diameter. The total wheel-base is 9 feet
2 inches ; but the distance apart of each pair of axles is only
2 feet Qh inches. The locomotive has a tractive-force of 1"43 ton
at the tires of the wheels when running compound, but by the
admission of live steam into the four cylinders, this force can
be raised to 2 "07 tons. This latter method of working, however,
is only exceptionally used, to overcome excessive temporary resis-
tances. The carriages are on bogies, and have seats for twenty-
four passengers, and standing-room for eight more ; so that the
ordinary train of three carriages can convey ninety-six passengers,
amounting, when filled, -to a load of 12 to 13 tons. The laying of

Abstracts.] THE LAON STEEP-GRADIENT RAILWAY, 469

the line was effected by fifty workmen in three days with satis-
factory results. The locomotive, designed by Mr. A. Mallet, is of a
quite novel type, and is able to go up a gradient of 1 in 14-3, on a
curve of 1^ chain, at a speed of 19 J miles an hour, drawing a load
of 10 tons. The first locomotive manufactured with this object, by
Messrs. Decauville at their Petit-Bourg works, was the " Lilliput "
locomotive of 1 ton weight, exhibited at Compiegne in 1877, where
it drew sixty passengers at a time over a portable line of 2-foot
gauge and 11-lb. rails. Subsequently, the same firm constructed
locomotives of 2i, 3, 5 and 6 tons, before manufacturing the
locomotive described al)ove, which appears destined to prove very
useful in extending traffic on railways where heavy rolling-stock
is unsuitable.

L. V. H.

Cost Prices on Railways.^ By G. Eicour.

(Annales des Fonts et Chaussees, 6th series, vol. xv. 1888, p. 534, 2 diagrams.)

The present article is an extension of the Author's previous
article, and contains a discussion of the objections raised by Mr.
Noblemaire,^ manager of the Paris, Lyons and Mediterranean
Eailway, against the principles laid down by the Author in his
first article. The relations between the cost price of the unit of
traffic, the amount of traffic, and the gradients, are first considered,
the unit of traffic being taken as one passenger, or 1 ton of goods,
carried 1 kilometre. The cost price per unit of traffic of various
systems of railways can be no more compared directly than their
coefficients of working. After obtaining the amount of traffic for
each system, the corresponding normal cost price must be deter-
mined, either by the Author's diagram or formula ; and then this
normal cost price must be compared with the real cost price. It is
the ratio of these prices, which the Author terms the typical ratio,
which is the measure of the economy effected in working. The
following Table gives the respective results of the working, in 1884,
for the large railway companies, and the State railways.

Large Railway State

Companies. Railways.

Average traffic 712 252

£. s. d. £. s. d.

Normal cost of 1,000 units of traffic, per tou-mile 2 10 7 2 19 3

Real cost „ 1 18 3 2 10 5

Typical ratios 0-98 0-85

Coefficients of working 0 • 53 0 • 80

In comparing the two systems of railways according to their
coefficients of working, instead of by their typical ratios, the

Minutes of Proceedings Inst. C.E., vol. xci. p. 501.
Ihid., vol. xciii. p. 517.

470

COST PRICES ON RAILWAYS.

[Foreign

important iBfluence of traffic is entirely neglected ; and, in this
way, the State railways were sui^posed to be worked expensively ;
whereas, in reality, they manifest a notable economy over the large
private lines.

When it is desired to limit the comparison to the cost prices of
the rolling stock and traction, it must be based on the cost price of
the ton per kilometre of the gross load of goods trains or passenger
trains. These cost prices, determined carefully by taking into
account the changes in price of the materials consumed, cannot be
compared together directly ; but the characteristic gradient must
be found for each system of railways ; and then the normal cost
price of the ton per kilometre of the gross load, corresponding to
this gradient, must be ascertained, either from the Author's diagram
or table. It is this normal cost price, for each system of railways,
with which the real cost price must be compared. The ratio
between these two prices, which is termed the typical ratio, affords
the measure of the economy in respect of the working of the rolling
stock and traction. A comparison of these various data for the
Paris, Lyons and Mediterranean Eailways on the one hand, and for
the State railways on the other, as gathered from the results of
working in 1884 and 1885, are given in the following Table.

Paris, Lyons and Jledi-
terranean Kailways.

State Railways.

Characteristic gi'adients .

Normal cost of 1,000 ton-miles ofl
gross load of goods trains . . /

Real cost of 1,000 ton-miles ofl
gross load of goods trains . . /

Typical ratios

152-67 155-04

d.
11

s. d.
4 8

2 1

0-92

1 19 9

0-89

96-43

£. s. d.
3 0 7

2 9 2

0-81

93-72

£. s. d.
3 1 10

2 9 1
0-79

L. V. H.

Signalling-Apparatus on the St. Gothard Railway.
By — Cox.

(Zeitschrift des Vereines deutscher Ingenieure, 1888, p. 1020.)

The difficulty experienced by the brakesmen on the goods trains
in understanding signals given from the engine, while traversing
the long tunnels, has led to the introduction of an electric arrange-
ment devised by the Author. The wire is connected with each
brakesman's lantern (there being a brakesman to every three or
four triTcks), and Ijy pressure on a small pin a slide is made to rise
or fall, so as to show a red;^ green, or white light. By repetition or

Abstracts.] SIGNALLING- APPARATUS ON THE ST. GOTHARD RAILWAY. 471

combination of flashes of these lights a proi:)er code of signals is
established. The red light signal can be given by any of the
brakesmen ; the white or green light by the engine-driver only.
If the couplings break, the red light is shown automatically.

P. W. B.

Diminution of Earth- Temperature in Deep Mines.

(Oesterreichische Zeitschrift fur Berg- und Hiittenwesen, 1888, p. 199.)

At Pribram meteorological and magnetic observations have been
carried on for some years at the thirtieth level of the • Adalbert
mine, at a depth of 1,000 metres from the surface, or 4G5 metres
below the sea-level in the Adriatic. The thermometer used for
taking the temperature of the rock can be read to one-tenth of a
degree Centigrade, and is protected against draughts in an enclosed
space, where the air-temjierature has remained unchanged at 2-i° C.
for five years. The observed temj)eratures of the rock were : —

In 1883 24-5° Centigrade.

At the end of 1885 24-3°

And at the end of 1887 24-1° „

Showing that the rock has been cooling at the rate of one-tenth of
a degree j^er annum since the observations were commenced.

H. B.

An Apparatus for Measuring Earth-Pressure Underground.

(Zeitschrift fur das Berg- Hiitten- und Salinenwesen, 1888, p. 244.)

In order to measure the vertical changes due to the thrust of tlio
unsupported ground in levels, the following contrivance has been
adopted in the Prussian Government salt mine at Stassfurt. A
wooden plug about 1 metre long is driven into a hole in the potash
salt bed forming the floor of the level, and a second similar one in
the salt clay of the roof vertically above the first. A length of
wrought-iron tube, somewhat shorter than half the height of the
level, is screwed to the end of each of the plugs, so that the tubes
do not exactly meet, but a connection between them is made by a
guide-pin attached to the lower one, which slides freely up and
down within the upper one. A board placed on one side of the
tubes is attached by two clamps to one wall of the level, which
keeps it in a vertical position, but without touching either the roof
or the floor. From the outside of the board project two light metal
frames, forming the centres for a pair of unequally ariued levers,
one of which is connected with either tube on its shorter side,
while the longer one moves over the face of one of two graduated
scales drawn on the board. If, in couseqiTence of downward pressure

472 MEASURING EARTH-PRESSURE UNDERGROUND. [Foreign

in the salt rock the roof is depressed, the pointer on the upper
scale rises, and as the arms of the levers are on the ratio of 1 to
10, a depression of 1 millimetre alters the position of the pointer-
arm by 1 centimetre. With the lower tube and scale, a rise in
the floor by upward thrust is indicated in a similar manner by the
movement of the lower pointer in the opposite direction.

The first trial of this apparatus was commenced on the 23rd of
May 1886, when it was set up in the end of No. 26 level, driving
north, the pointer being adjusted to zero. Between that date and
June 4th, 1887, or in a period of nearly a year, the upper pointer
had risen 8j centimetres and the lower one fallen 11^ centimetres,
corresponding to a sinking in the roof of 8f millimetres, and a rise
in the floor of 11^ millimetres. In another trial in the north end
of No. 16 level, the roof sank 26 millimetres, and the floor rose
1 millimetre between April 24th, 1886, and June 4th, 1887.

H. B.

Differences of Level in the Mines of Austria and Hungary.
By F. E. M. VON Friese.

(Oesterreichische Zeitschrift fiir Berg- und Hiittenwesen, 1888, p. 321.)

In a memoir on the determination of altitudes in mines, which
reviews the methods adopted of fixing datum points in the different
mining districts and notices the fact that no general authoritative
datum has as yet been adopted, the Author gives a complete list
of the depths of the principal workings in the Austro-Hungarian
dominions. Some of the more important conclusions are given in
the following abstract. The highest point at which mines are
worked is at the Goldzeche, on the frontier line between Carinthia
and Tyrol, 2,925 metres above the sea-level, and the lowest, the
sump of the Maria shaft at Pribram, 537 metres below the sea, or a
total range of 3,462 metres.

The greatest depths below the sea in the different districts are —

Mines. Metres.

Pribram, Bohemia. Silver lead 537

Ostrau-Karwin, Moravia. Coal 225

Kladno, Bohemia. „ 162

Rossitz, Moravia. „ 71

Wieliczka, Poland. Salt 14

The brown-coal mines of Briix and Dux-Osseg, in Bohemia, and
the salt mines of Maros-Ujvar in Transylvania, are nearly down to
the sea-level.

The vertical range of metallic-ore mining is, as given above,
3,462 metres, from 2,295 metres above to 537 metres below sea-
level ; that of salt mining, 1,951 metres, from 1,928 metres above
to 23 metres below sea-level ; that of Alpine (tertiary) coal mining,
431 metres, from 867 to 436 metres above the sea ; and that of the
coal-measure districts in Bohemia and Moravia, 634 metres, from
409 metres above to 225 metres below the sea.

Abstracts.] LEVELS OF MINES IN AUSTRIA AND HUNGARY. 473

Some of the deepest individual shafts are —

Shaft. Metres.

Pribram. Maria 1080-88

„ Adalbert 10G9-36

„ Anna 9-12-98

„ Franz Joseph 880 • 68

„ Procopi 879*52

Joachimsthal. Einigkeit 533

Schemnitz. Amalia 540 "IT

Elisabeth 448-37

„ Andreas 432-82

Kladno. Mayrau 520

Miroschau. Libusehin 477

Barre' 446

Wieliczka. Joseph 262-99

Elizabeth 259-61

The Hallstatt salt mines, which are worked entirely by solution,
have a range of 503 metres, from 1,233 to 730 metres above the
sea-level. The Schneeberg zinc mines in T^toI, also worked by
levels, are at present worked between 2,522 and 2,2-16 metres above
the sea.

H. B.

On the Relations hetiveen Seismic and Atmospheric Disturbances

and the Disengagement of Fire-Damp.

By G. Chesnau.

(Annales des Mines, vol. xiii. 1888, p. 389.)

After referring to previous researches bearing upon the subject,
the Author proceeds to describe an extended series of observations
made at the Herin pit of the Anzin Coal Company. The micro-
seismic movements of the earth's crust, as he calls them, in dis-
tinction to sensible tremors or earthquakes, were observed by a
tromometer similar to that employed at the Douai School of Mines, ^
consisting of a pendulum 1 • 50 metre (4 feet 1 1 inches) siispended
from an iron pivot fixed in a thick wall, its oscillations being read
by a microscope. The wall was a very old one, of brick, 2 feet
thick, running in a direction from N.E. to S.W., and completely
sheltered from the sun. The most violent winds are from the
S.W., and a series of observations extending over several months
appears to establish the fact that the wind exercises no appreciable
influence upon the apparatus, but that there are certain coincidences
between seismic and barometric movements which Bertilli, of
Florence, has named "baroseismic squalls." Local vibrations,
such as those produced by passing vehicles, are also inappreciable,
being too rapid to affect the weight or bob of a pendulum of this
length, although they may cause nodes and curves in the sus-
pension-rod. A shorter pendulum, while indicating these vibrations,

' The Douai tromometer was fully described and illustrated in the " Annales
des Mines," vol. ix. p. 241.

474 ATMOSPHEKIC DISTURBANCES AND FmE-DAMP. [Foreign

would fail to record microseismic movements having a period of
oscillation greater than one second ; and this is probably the reason
why pendulums of from 1 to 4 metres length (39 to 157 inches),
with a period of oscillation of from 1 to 2 seconds, are found to
give the best results for this purpose.

Observations, taken simultaneously at Herin and Douai, during
the months of October, November, and December, 1887, show a
close correspondence, except on November 22nd and 23rd, when the
violent seismic disturbances in the Mediterranean basin, although
distinctly transmitted to the department of the Nord, appear to
have escaped the Douai observers ; and, generally, the Herin in-
strument would appear to be far more sensitive than that at Douai.

A similar concordance has been noted between the monthly
averages recorded at the observations of Bologna, Florence, and
Velletri.

A series of barometric observations taken at bank, at the pit
bottom (558 feet deep), and in the return air-course, were found
to correspond so closely as to render it immaterial which was
adopted as the standard of comparison ; while from a similar series
of observations, at diiferent hours of the day, as to the disengage-
ment of fire-damp (which it was found could be estimated very
closely by means of the cap or aureole on the flame of the Pieler
safety-lamp),^ it was found that the results obtained at 6 a.m., half
an hour after the miners had assembled, but before they had
fairly commenced work, gave a very close average for the whole
day, and was unaffected by the greater or smaller amount of coal
actually got from the faces. Erom the percentage of fire-damp
found in the return air-course, the daily amount given ofi" was
found by reducing the quantity of air actually passed through the
j)it to a given unit.

A diagram is given for the eleven months, February to De-
cember, 1887, showing (with certain interruptions from various
causes, by which the daily observations are reduced to 180 out of a
possible 230) (a) the intensity of the seismic movements ; (b) the
barometric readings ; (c) the amount of fire-damp given ofi" ; and
the following general deductions are offered : — ■

(1) Seismic disturbances and flow of fire-damp —

Coucordant 81 clays.

Discordant 46 „

Independent 51 ,,

178 „

(2) Barometric readings and flow of fire-damp — -

Concordant 75 days.

Discordant 51 „

Independent 54 ,,

180 „

Minutes of rrocccdinj:;s lust. C.E., vol. xc. p. 170.

Abstracts.] ATMOSPHERIC DISTURBANCES AND FIRE-DAMP. 475

But in order to eliminate such sources of error as might arise
from falls of roof, &c., &c., the value of which cannot correctly be
estimated, it is considered best to take into account only the more
marked variations of the curves as plotted. Taking the tro-
mometer curve as the basis, there are 43 concordances to 17 dis-
cordances; or, inversely, if the fire-damp curve is taken, 17 con-
cordances to 7 discordances ; or in each case, nearly as 5 to 2.

Taking the barometer curve as the basis, there are 1 1 concordances
to 9 discordances; or, inversely, 14 to 15.

It would thus appear that the connection between seismic dis-
turbances and disengagements of fire-damp is fairly demonstrated ;
but that the influence of barometric variations is not so well
established, although the concordances outnumber the discordances ;
and it is interesting to remark that whenever a large increase of
fire-damp has been maintained for several days above the average,
including the very exceptional outburst on December 8th and 9th
(of which some interesting particulars are given), there is a very
remarkable coincidence between all the three curves.

The Paper contains references to numerous other investigations
on the same subject, and especially to an article in Vol. xxxvii. of
Proceedings of the North of England Institute of Mining and Me-
chanical Engineers, containing the first report of the committee
appointed to investigate this subject ; and to one in the Zeitschrift
fiir das Berg-, Hiitten-, und Salinen-Wesen, 1887, pp. 277, 279, con-
taining the result of Mr. Nasse's careful observations. In this case
one district of a mine, which had been walled off to isolate a fire,
afforded a convenient gas-holder of known area and capacity ; and
his experiments show that a diminution of atmospheric pressure,
as observed on the spot, was decidedly favourable to the disengage-
ment of fire-damp.

W. S. II.

Shaft-Sinking hy Haase's Method.

(Zeitschrift fiir das Berg- Hiitten- und Salinenwesen, 1888, p. 225.)

At the brown-coal mine of Guerini, near Cottbus, a seam of lignite
of an average thickness of 7 metres with a roof of bituminous clay
1 -20 metre thick, is covered with about 26* 65 metres of sand very
full of water. A pumping-engine shaft commenced with ordinary
timbering, reached the water-level at 3 metres, and the sinking
could only be carried 3 metres deeper before the flow of water and
sand became so great as to endanger the work. It was then
determined to continue the sinking by Haase's method, which
consists in driving down a series of parallel wrought-iron tubes
side by side to form an impermeable wall, the ground being at the
same time partially drained by the flow of water from the tubes.
The shaft is rectangular in form, 3-30 x 2 • GO metres within the
original timbering, and 2 • 90 x 2-20 within the wall of tubes. The

476

SHAFT-SINKINa BY HAASE S METHOD,

[Foreign

tubes are supplied in 4-metre lengths and are 5 millimetres thick
with an internal diameter of 105 millimetres. In order to keep
them straight during the driving, carefully-planed wooden guides
were screwed to the timbering of the shaft for a depth of 3 metres
with cast-iron cross-bars at the top and bottom fitting the curvatxire
of the tubes. The depth of ground to the coal was 21-85 metres,
requiring six sets of 4 metres in length of the patent tubes.
The work was begun on May 14th, 1887. On the 25th of October
following the clay above the coal was reached, and the tubes could
not be driven down further by pressing. Eighteen rows of tubes
were used on the longer and fourteen on the shorter sides of the
shaft, or sixty-four in all. The actual time required in driving
them was two hundred and twenty-five shifts of twelve hours. The
chief items of cost were as follows : —

11' „=. •,„„^„A■, Lineal Metres Cost per

^I^^^aV K^^ 1 of Tube put Lineal
two Mechanics. ! ^^^.^^ ^^4^^

Set No. I. 24 May— 8 June . . .
II. 9 June— 22 June . .

III. 23 June— 7 July . . .

IV. 8 July— 13 Aug. . .
V. 14 Aug.— 18 Sept. . .

VI. 19 Sept.— 25 Oct. . .

£. «. d.
21 16 5
18 15 0
33 11 9
18 6 9
39 0 3
36 11 9

209-96
237-81
236-84
242-57
243-28
183-58

£. s. d.
0 2 1
0 1 7
0 2 11
0 16
0 3 3
0 4 0

Total for wages . . .

167 17 10

53 17 3

1,676 1 6

204 14 9

1,354-04

0 2 3

Supervision ....
Cost of 1,440 metres of tubes and tools
Coals for boiler firing

Total cost of lining .

2,102 11 4

1 11 1

When the tubular lining was finished, the removal of the sand
from the interior of the shaft and the erection of a permanent iron
lining were commenced. Up to the end of November 1887, 9-50
metres had been completed, down to which depth no alteration in
the position of the tubes had been observed. The flow of water in
the sinking amounted to 1,350 litres per minute, which was kept
down by two j^ulsometers. The filtration of water through the
tube-wall is only apparent to a height of 3-5 metres above the
bottom of the sinking, the ujiper beds having been drained perfectly
dry.

^ KB.

Cast-iron Tubbing for Lining Levels.

(Zeitschrift fiir das Berg- Hiitten- und Salinenwesen, 1888, p. 230.)

At the Eschweiler-Eeserve coal mines, near Diiren, cast-iron
tubbing, put together in segments in the same way as is usual in

Abstracts.] CAST-IRON TUBBING FOR LINING LEVELS. 477

sinking shafts, has been successfially employed in driving a level
through ground broken up by faults.

The tubbing made by Messrs. Haniel and Lueg, of Grafenberg, is
2 • 33 metres outside and 2 • 05 metres inside diameter, the breadth
of the rings to the back of the flanges is 140 millimetres and the
thickness 40 millimetres. The segments, | of the circumference, are
75 centimetres long, and weigh 320 kilograms, each exclusive of the
connecting bolts, which are 32 millimetres in diameter. In the
fixing of these heavy segments, some of which required to be lifted
nearly 8 feet overhead, a special erecting carriage was used of the
following description : —

A horizontal shaft, parallel to the axis of the gallery, is attached
to a pair of standards fixed upon a wooden wagon frame, which
runs upon a railway laid upon the three floor segments of the tubbing.
One end of the shaft carries a large worm-wheel and an arm
terminating in a fork fitting into the back of the segment within
the flanges, which can be moved radially b}^ a sliding motion. When
the segment is taken up by the fork it can be turned radially by
the screw into which the worm-wheel gears, the motion being com-
municated by a ratchet lever, which moves the screw through one-
sixth of a revolution at each stroke, and producing a corresponding
smaller movement of the forked arm. When the segment is
turned into position, it is finally placed in its seat by sliding the arm
outward until the flanges are brought into contact with those of the
segment last laid. By this simple contrivance the work was
rapidly done, and without accident of any kind. The apparatus is
ilhistrated by figures, but no details as to the length of ground lined
are given,

H. B.

A New Modification of the Bessemer Process.

(Oesterreichische Zeitschrift fiir Berg- und Hiittenwesen, 1888, p. 142.)

The following modification of the Bessemer process has been
introduced by Carlsson of Ulfshytte, in Sweden. The pig-iron
treated contains, silicon 1*5 — 2, manganese O'l — 0'15, and carbon
4 per cent., 3*9 per cent, of the latter being graphitic. The
charge, tapped directly from the blast furnace, is blown for five
or six minutes, biit as soon as the blue flame of burning carbonic
oxide appears, the converter is turned and a proportion of the
metal is emptied into a ladle attached to a weighing machine.
This is known as reducing metal, and contains on an average,
carbon 4*15, silicon O'Oo, and manganese 0*07 per cent. The
quantity so removed depends upon the weight of the charge and
the temper of metal required in the ingots.

The converter is then raised, and the blowing goes on until the
remainder of the carbon is oxidized and soft iron is produced ; this
usually contains, manganese 0 • 03, carbon 0 • 05, sulphur (maximum)

478 A NEW MODIFICATION OF THE BESSEMER PROCESS. [Foreign

0 • 02 per cent, with traces of silicon, and is generally red almost.
High, ferro-manganese is then added, and when the reaction is
finished, the final tempering is effected by adding the desilicized
reducing metal in such proportion as may he required to produce
ingots of the proper degree of hardness. The silicon in the
finished metal is usually one-tenth of the carhon.

The advantages claimed for this modification over the ordinary
process are as follows : —

1. The reqiiired proportions of carbon, silicon, and manganese
are more easily obtained.

2. Steel poor in silicon, with any required proportion of carbon,
may be made from the most siliciferous pig-iron.

3. Sound steel products, with silicon and manganese in any
required proportion, are easily and cheaply made.

4. A considerable variation in the hardness of the finished steel
may be obtained without altering the working conditions of the
blast furnace.

5. The formation of pipes in the ingots is more easily prevented.

H. B.

Electrolytic Beduction of Antimony from Ores. By W. Borchers.

(Dingler's Polytechnische Journal, vol. 266, 1888, p. 283.)

Sulphide of antimony, even in very poor ores, as well as all
other antimony compounds which are readily soluble in sodium
sulphide, may be reduced electrolytically with advantage. For
each molecule of antimony trisulphide, three molecules of sodium
sulphide should be present in the solution whose density should
not exceed 12^ Baume when cold, or 9^ to 10^ when hot; about
3 per cent, (calculated on the total quantity of the solution) of
common salt is added, which not only clarifies the liquid and
separates dissolved sulphide of iron, but serves to diminish the
resistance during electrolysis.

The decomposing cells are iron vessels, which also serve as
cathodes, and according to their form the surface of the latter
is increased hj the insertion of plates or concentric cylinders of
sheet iron, insulated lead plates being placed between them as
anodes. The latter are collectively connected with the positive
pole and the decomposing cells and iron plates with the negative
pole of the battery. An electromotive force of 2 to 2h volts per
cell is sufficient to effect the decomposition, the reduced metal
appearing eilher in brilliant scales, or in powder, which partly
adheres to the iron, and can be easily brushed off", and partly
goes to the bottom of the cell.

The reduced metal, after being washed successively with water
containing a little sodium sulphide and caustic soda or ammonia,
clean water, water acidified with nitric acid, and finally with clean
water again, is melted with a little antimony glass, giving a very

Abstracts.] ELECTROLYTIC REDUCTION OP ANTIMONY FROM ORES. 479

pure product. The residual liquor may be utilized as a source of
sodium hyposulphite, the dissolved chloride sodium separating in
the final evaporation. The presence of hydrosixlphide and poly-
sulphides of soda is not injurious to the process as long as the pro-
portion of sulphur to sodium in the solution is so regulated by the
addition of caustic soda that for each atom of oxidizable sulphur
one atom of sodium is present for its neutralization. With a higher
proportion of sulphur, or less of sodium, a separation of sulphur and
consequent disturbance of the process ensues, while on the other
hand more sodium and less sulphur work detrimentally by increas-
ing the electrical resistance of the solution.

According to Borchers, sodium hydrosulphide, sodium disulphide,
and sodium hyposulphide, are developed on the layers by the
initial decomposition of three molecules of water by the current, thus

3H2 0 = 6H-f30

whence the following changes result —

At the cathode Sb., S.^-f 3 NagS + 6H = Sb-f-6NaHS
anode 6NaHS-f30 = 3 H2O -f- 3 Na2 83

Probably, therefore, three molecules of water are decomposed to
one of trisulphide of antimony, and by the development of three
molecules of water, and two of sulphantimoniate of soda, two mole-
cules of antimony are set free, thus

2 (Nag S&S,)4-2NaH04-6H =

2 S b -h 2 Na2 S2 + 4 Na H S -f 2 H., 0.

H. B.

Eledrolytie Copper -Befining in Hungary. By A. Soltz.

(C. A. M. Balling's Electro-Metallurgie,' p. 80.)

At Stefanshiitte, in Upper Hungary, copper smelted from anti-
monial grey ores is reduced electrolytically from blister copper,
which, after partial refining in a reverberatory furnace, contains
6 per cent, of antimony. The copper plates used as cathodes are
either made at the works from electrolytic copper, or of commercial
refined sheets. In the latter case they are first placed in the bath
as anodes until they become perfectly bright. The liquor in the
bath contains 200 grammes of copper sialphate, and 20 grammes of
sulphuric acid per litre. The dynamo, Siemens and Halske's type
Cg gives a current of 100 to 120 amperes and 2 volts electromotive
force at 600-650 revolutions per minute. The internal resistance
is 0 • 00529 ohm. The external resistance 0*011 ohm. The cathode
surface per bath is 2-45 metres, and the density of current 50
amperes per square metre. The six baths in use are each 1 metre

The original is in the Library Inst. C.E.

480 ELECTROLYTIC COPPER-BEFINING IN HUNaARY. [Foreign

in length and depth, and 0 • 5 metre broad. The anodes and cathodes
are left in for about two months. The mud deposited in the bath
contains 3 per cent, silver, 60 per cent, of antimony, and more than
6 per cent, of bismuth. A new extension of the works is j^lanned
to contain forty-nine baths 1 ' 4 metre long, 0 • 6 metre broad, and
1*10 metre deep, to hold eight anodes and seven cathodes each.
The cathode surface per bath will be 5 • 6 metres, corresponding to
a density of current of 43 amperes per square metre. The dynamo,
Siemens and Halske's CH^ gives a current of 240 amperes at
25 volts, when driven at 1,100 revolutions per minute. As, how-
ever, with an external resistance of 0*070 ohm, only 17 volts are
required, a further number of fourteen baths may be worked by
the same power. The productive capacity of the w^orks, based on a
deposit of 6 • 9 kilograms of copper per bath daily, will be about
180 tons annually.

^ H. B.

The Smelting of Gold and Silver Ores in Eastern Hungary and
Transylvania. By Dr. Schnabel.

(Zeitschrift fiir das Berg- Hiitten- imd Salinenwesens, 1888, p. 128.)

In the aiitumn of 1887 the Author visited the smelting works in
the district of Nagybanya in Eastern Hixngary, and has described
the methods carried out in the principal establishments in the
present memoir. The more important of these establishments are
at Fernezely, 3J miles east of Nagybanya, and at Kapnik. At
Nagybanya the ores occur in lodes in greenstone trachyte, and
contain native gold and silver, sulj^hide of silver, ruby silver,
copper pyrites, galena, blende, and pyrites. More compact vein stuff
is subjected at the mines to the Hungarian process of amalgamation
by stamping it fine and passing it through mills containing from
18 to 25 kilograms of mercury, when the free gold is collected
partly by amalgamation and partly by subsidence in the mercury.
After passing two series of mills, the stamped stuff is subjected to
various processes of washing on frames, in order to collect the
pyrites and galena in the form of slime. The amalgam from the
mills, after pressing through leather, is distilled in a cast-iron
retort, and the sponge metal, when melted, is sent to the gold
refinery, at the Kremnitz Mint. The loss of mercury is from 50 to
100 per cent, of the w^eight of gold collected. For instance, in one
case 155 tons gave 1"957 kilogram of gold with a loss of 1*9
kilogram of mercury, while in another 754^ tons gave 5*736 kilo-
grams of gold with a loss of 2 * 9 kilograms of mercury.

The Fernezely Works. — The ores treated at these works, in
addition to the slimes from the amalgamation mills, consist of : —
(1.) Dry or quartzose ores, with native gold and silver, averaging
46 ozs. of silver per ton with 9i to 19 dwts. of gold per lb. As a
rule, the gold contents diminish with increase in the silver, and the

Abstracts.] SMELTING OF GOLD AND SILVER ORES. 481

pyritic ores are riclier in the former metal than the qnartzose ores.
(2.) Pyritic ores in lumps, containing native gold and rn1)y silver
ore, with 15 to 40 ozs. of silver with 2-i dwts. per lb. of gold. (3.)
Pyritic slimes, the richest gold material, containing 10 to 50 ozs. of
silver with 48 dwts. per lb. of gold. (4.) Lead ores in lumps, with
20 to 60 per cent., and slimes with 50 to 60 per cent, of lead, the
silver being about 26 ozs. with 24 dwts. per lb. of gold.

The reduction of the ores is now entirely effected by means of
lead, the pyritic minerals being first concentrated by fusion into a
coarse metal. The lead, when containing 120 ozs. and upwards of
silver per ton, goes to the refinery at once, but when poorer it is
subjected to a preliminary desilverization by zinc. The copper
contents are ultimately concentrated in a regulus, which is con-
verted into blister copper and refined at Felsobanya. It contains
20 ozs. of silver per ton which is not extracted. Formerly a
portion of the ores was at different times treated by Kiss's ex-
traction process, by barrel amalgamation and by Desiguolle's process,
but these have now been entirely given up. The first of these
(Kiss's process) was developed on the works, and for some time it
was thought that the use of hyposulphite of calcium was advan-
tageous in possessing greater solvent powers for gold in chloridized
materials than the corresponding sodium salt, but later experi-
ments have proved that the advantage is, if anything, rather with
the latter. The Designolle process, substituting a solution of
bichloride of mercury, and iron, for mercury in amalgamation,
although recovering 90 per cent, of the silver value of the ore,
only saves 60 per cent, of the gold, and causes very large losses
of mercury, partly as undecomposed bichloride, partly as calomel,
and partty as finely-divided metal which could not be collected.
It has been abandoned since 1887. As regards the application of
barrel amalgamation to these ores, the results of experiments at
Schemnitz show that it is about on a level with smelting with ores
containing 32 ozs. per ton, but for those with less, silver amalga-
mation has the advantage, the most favourable results being
obtained with 16 oz. ores.

The smelting processes now followed consist in a concentration
of the auriferous pyrites into a coarse metal, which, when roasted,
is mixed with calcined and fritted lead ores and smelted for argenti-
ferous lead, and a regulus, which is sulijected to a further series of
fusions, usually three, to desilverize it and concentrate the con-
tained copper to a workable point. The chief points of interest in
the processes are the use of the shelf furnaces of Ollivier and
Perret, of Chessy, for the roasting of the auriferous pyrites, which
are now taking the place of the open heaps formerly in general use.
At the time of the Author's visit twenty of these furnaces were in
course of construction at Fernezely.

The desilverizing of the furnace-lead is effected in 10-ton cast-
iron pots with three zincings. The desilverized lead is freed from
zinc by adding a mixture of sulphate of lead and common salt, and
from antimony by poling.

[the INST. C.E. VOL. XCV.] 2 I

482 SMELTING OF GOLD AND SILVER ORES. [Foroifcn

The zinc-silver-lead alloy is liquated to remove part of the lead,
and then treated hy soaking into a hath of clean lead on the
refining-hearth, the zinciferous dross produced being added in the
reguhis fusion. This method, however, not only wastes all the zinc,
but causes loss of silver by volatilization, so that it is intended to
treat it by distillation in fixture.

In 1886 6,935*6 tons of ores were smelted at Fernezely, pro-
ducing—

Fine gold 230 kilograms.

Fine silver 3,375 „

Market litharge 132-9 tons.

Soft lead 550

Copper 4-5 „

The Kapnih Smelting WorJcs. — At these works both furnace and
wet extraction processes are in use, about 1,800 tons of ores being
treated annualty by the former, and 1,200 tons by the latter method,
which is reserved for dry and pjTitic ores, while those containing
lead in sufficient quantity are passed through the blast-furnace.

Wet Extraction. — This is a combination of the Augustin and Von

Patera processes. It is applied to dressed pjTitic and hand-picked

ores, the former containing about 70 j^er cent, of suljihides, including

blende 16 to 30, copper 1^, and lead 2 to 3 per cent., besides 10 to

11 ozs. of auriferous silver, with 8 to 10 thousandths of gold. The

picked ores are quartzose, and free from lead, with 22 per cent, of

sulphides, half of which is blende, their silver contents ranging

from 16 to 24 ozs. j^er ton, and the gold from 2 to 3 thousandths.

Both classes are mixed as nearly as possible in equal proportions

with 8 per cent, of salt, and subjected to a chloridizing roasting in a

four-storied shelf furnace, about 4 per cent, more salt being added

to the charge when it reaches the third shelf. From 36 to 38 cwt.

are roasted in twenty-four hours. "When the pyritic ores form half

the charge, the heat produced by the burning sulphur is sufficient

to effect the roasting without any additional fuel, but with a

lesser proportion, the furnace must be fired in the ordinary way.

The roasted ore is sifted ; the lumps, about 30 per cent, of the

whole, are ground and roasted with 3 per cent, more salt in a long

reverberatory furnace for six hours. The roasted material from

both kinds of furnaces is next lixiviated in wooden vats, with

perforated false bottoms covered with linen. From 50 to 60 cwt.

are treated at one time, first with 22 to 25 per cent, of brine heated

by steam to 28^ Centigrade, and afterwards for two days with a

cold Avatery solution of hj^posulphite of sodium of 3° to 5*^ Baume

density. By this combined method of extraction, 90 per cent, of

the silver and 80 per cent, of the gold in the ore are recovered,

namely, 60 per cent, of the former metal by the salt solution, and

the remaining 30, with nearly the whole of the gold, by the hypo-

sul})hite. The residues from the extraction are not subjected to

further treatment. The silver is recovered from the brine by

passing it over copper plates in two series of vats, the liquor being

Abstracts.] SMELTING OF GOLD AND SILVER ORES. 483

heated to 28° Centigrade, and the dissolved copper is in its turn
precipitated by iron. The liquor after settling- is returned to the
extraction process, and continues in use for three years. The gold
and silver from the hyposulphite liquors are precipitated as sul-
phides by sulphide of sodium, which is made by boiling flowers of
sulphur with caustic soda in a cast-iron pan. The residual liquor
after the separation of the sulphides is exposed to the air, when the
excess sodium sulphide is converted into hyposuljihite, which goes
back to the extraction works.

The cement silver, and the gold and silver sulphides, are treated
by soaking in a bath of metallic lead heated to redness in a cast-
iron pot. This gives a lead with 200 ozs. of silver, which is refined,
and an argentiferous dross which is treated with lead.

The smelting processes at Kapnik are generally similar to those
at Fernezely, the richer lead passing through the refinery at once,
while the poorer is first desilverized with zinc. There is, however,
no preliminary concentration of the jiyritic ores to coarse metal.

The production of Kapnik in 1886 was 1,520 kilograms of silver,
with 74 kilograms of gold ; 185 tons of lead, and 12 tons of copper.
The whole of the litharge produced is used to supply the lead
required for collecting the silver in the blast-furnace.

The Author also describes in some detail the smelting operations
followed at Zalathna, in Transylvania, which do not differ from
those in previously published accounts.^ The ores treated are
essentially iron pyrites containing gold and silver, and some
tellurium minerals. They are classified into —

Ozs. per tfm of Auriferous
Silver.

Poor pyrites 3 J to 9 J ozs.

Medium rich pyrites 10 to 16 „

Rich pyrites above 16 ,,

The telluride ores, which however only occur in very small
quantities, are divided into —

First class 490 to 1,630

Second class 60 to 320

The pyrites are concentrated by fusion to a coarse metal, part of
which is roasted in the shelf furnaces, while the remainder is
treated with sulphuric acid to remove the bulk of the sulphide of
iron. The roasted metal retains about 6 per cent, of sulj^hur, while
that from the acid treatment, in addition to 8 • 85 per cent., retains
a large quantity of sulphuric acid in the form of Ijasic sulphates,
which give considerable trouble in the subsequent smelting with
lead. This latter operation is performed in small blast-furnaces,
litharge and refining-hearth bottoms being added in sufficient
quantity to produce a lead containing 1 part in 2-iO of gold and
silver. The tellurium ores are added to the furnace charge without

' Minutes of Proceedings Inst. C.E., vol. Ixxxii., p. 447.

2 I 2

484 SMELTING OF GOLD AND SILVER ORES. [Foreign

previous calcination. The average assay value of the lead is, silver
172 ozs., gold 120 ozs. per ton; it is refined to cake silver in
quantities of 90 cwts. in a German refinery fired with wood. The
operation lasts two hours. The resulting silver is 975 fine and
contains 50 • 4 per cent, of gold.

About 28 per cent, of the ore furnace charge is obtained as
regiilus, which is treated first with acid and then smelted with
lead to desilverize it. These operations are repeated until the
residual regulus contains 30 per cent, of copper, which is not
subjected to further treatment on the spot.

In 1886 1,186 tons of pyrites, containing 241*52 kilograms of
gold, and 307*94 kilograms of silver, were smelted at Zalathna.

Gold Amalgamation at Zalathna. — A very considerable quantity
of gold is obtained by battery and mill amalgamation in the
Zalathna district, nine thousand nine hundred and ninety-four
heads of stamps, one hundred and eleven percussion tables, and
one hundred and sixty Hungarian mills having been at work in
1886. The most successful of these appears to be a Californian
twenty-stamp battery at Vulkoy, belonging to a French Company,
which treats in twenty-four hours 35 tons of ore containing 18^
dwts. of gold per ton, of which 82 per cent, is recovered by com-
bined battery and copper-plate amalgamation, the pyrites being
saved in Frue vanners. The total gold production of Transylvania
in 1886 was 1,222-08 kilograms.

H. B.

A Winding-Engine with Sjpiral Balance-Drum.
By K, Habermann and J. von Hauer.

(Berg- und hiittenmannisches Jahrbuch, 1888, p. 120.)

At the No. 1 pit of the Camphausen Colliery at Saarbriicken,
which is 500 metres deep, the winding-engines, of 1,000 HP., have
two horizontal cylinders of 48 inches diameter, and 79 inches
stroke, working direct upon a cylindrical drum of 26 feet diameter,
and 11 feet breadth of face. The balance arrangement consists
of a shaft somewhat smaller than that of the drum, which is
coupled to the latter by a crank, so as to move at the same sjieed,
but in an opposite direction. This shaft carries a double spiral
drxam, with a rope-track for 28 revolutions. The rope, made fast
to the smallest diameter of the drum at one side, passes first over
a guide-pulley at the surface, then down a balance-pit 262 feet
deep, round a loose pulley at the bottom, carrying the balance-
weight, and returns to the surface passing over a second guide-
pulley back to the drum, where the opposite end is fixed to the
smallest diameter on the other rope path. When the engine is
started with the loaded cage at the bottom, as the balance-
rope unwinds from the larger and winds up in the smaller part of
the drum, the counterpoise in the shaft falls, but with a gradually

Abstracts.] WINDING-ENGINE WITH SPIRAX BALANCE-DRUM. 485

diminisliing speed, until the cages meet in the shaft, when it is
stationary, after which the weight rises, the rope being taken up
on the larger, and unwound from the smaller coils. The balance-
pit has a framing of cast-iron pillars, with diagonal struts, carrying
two horizontal cross-girders for the guide-pulleys, which are 13 feet
diameter, the loose pulley in the pit being of the same size. The
axis of the j^it is 144 feet distant from the main winding-drum.

The largest diameter of the spiral track on the drum is 33 feet,
and the smallest 10 feet; the breadth of the drum is 11 feet
5 inches. It weighs 28 tons, and is mounted on a shaft 16 inches
in diameter, and 18 feet long, weighing 6 tons. The movable
counterpoise in the shaft is an old boiler shell, loaded with scrap-
iron, of a total weight of 15 tons.

The winding-cages have three decks, carrying two tubs on each,
the total weight being : —

Tons.

Empty cage 3

Six tubs 2

Coal in tubs 3

Total 8

Eound cast-steel wire ropes are used in both pits ; those on the
cages are tapered from 2*09 to 1 '93 millimetres diameter ; that on
the balance-drum is 1 • Go inch throughout.

H. B.

On the Beer System of Wire Ropeways. By Charles Eaoult,
Engineer to the Beer Engineering and Foundry Company.

(Revue Universelle des Mines, 3rd series, vol. iii. 1888, p. 49.)

This Paper describes improvements in the method of disposing
of slag at the Seraing furnaces of the Esperance-Longdoz Company.

The slag, as it floAvs from the furnace, is conveyed by a channel,
some few yards long, to a cast-iron gutter with a semi-circular
bottom of 8 inches radius, supplied with a stream of water under
slight pressure, with a volume of from 200 to 260 gallons per
minute, by which it is granulated and carried into a basin, from
which it is elevated by a chain of buckets, driven by an in-
dependent engine of 6 or 7 HP., into a circular wrought-iron
receiver, 16 feet 4 inches high by 14 feet diameter, formed with a
conical base so as to discharge from different shoots round its
circumference, and containing about 98 cubic yards.

The ropeway will transport 130 tons per day of ten hours to a
distance of 300 yards. The starting-point is 11 feet 6 inches
above the ground-level, and the point of delivery 160 feet above
the starting-point.

The carrying-rope for the full road is Ij inch diameter, composed
of nineteen wires, each ^j inch diameter, arranged, one in the

486 BEER SYSTEM OF WTRE EOPEWAYS. [Foreign

centre, six intermediate, and twelve exterior. Its weight is
2 If lbs. per fathom, and its theoretical hreaking-strain 37 tons,
the actual breaking-strain being sensibly less. It is strained by a
counterjjoise of 5 tons 18 cwt.

The carrying-rope for the empty road is l^V inch diameter,
composed of nineteen wires, each -j^ inch full diameter, similarly
arranged. Its weight is I2.j lbs. per fathom, and its theoretical
breaking-strain 23 tons. The counterpoise is 3 tons 18 cwt.

The hauling-rope, |^ inch diameter, is composed of a hemp core
surrounded by six strands, each of twelve wires, ^\ inch diameter,
and weighs 4^ lbs. per fathom, with a theoretical breaking-strain
of 14 tons 18 cwt. The counterpoise is 1 ton 19 cwt.

The joints of the carrying-roi:)es, which are made in convenient
lengths, are usually formed by inserting each end into a slightly
conical sleeve, slightly separating the wires, and brazing them to
the sleeve with a special solder. The larger, or adjacent, ends of
each pair of sleeves are tapped with a right- and left-hand thread
respectively, and coupled with a corresponding right-and-left
screT\ ed plug.

In the Beer system, however, instead of soldering, the wires,
after being separated, are wedged into the sleeve, first by three
curved wedges forming conjointly a feather-edged tube or ferrule
between the outer and intermediate layers of wires, and next by a
smaller solid conical ferrule between the intermediate layer and
the central wire, which last is screwed at the end and secured by
a nut.

A series of tests of this coupling, made on a length of 3 feet
3 inches, gave, for the larger rope of 1 j inch diameter, the following
results • —

Load.

Elongation.

4'9 tons.

m\.

9-8 „

0-03 inch.

14-8 „

0-04 „

19-7 „

o-io „

24-6 „

0-62 „

29-5 „

1-21 „

30-1 „

Eup

ure of all the wires

The elongation was partly due to the wedges taking up their
bearings inside the sleeves.

Kone of the wires were drawn out of the sleeves, but were all
broken externally, and the joints were uninjured.

The hauling-rope is endless, the two ends being sjiliced together.
In cases where the gradients are slight, the carrjdng-skeps may be
attached to the hauling-roj^e at any point by a simple friction-clip,
easily engaged and disengaged ; biit where the gTadients are
more severe, as in the present case, thimbles must be fixed on the
hauling-rope, to engage with the clips on the skeps. These
thimbles have hitherto been made solid, necessitating the cutting
and splicing of the rope at each point where one had to be fixed;
but in the Beer system they are made in halves, dovetailed
together, so as to be slij^jied on anywhere, and are secured by a

Abstracts.] BEER SYSTEM OF WIRE ROPEWAYS. 487

small rivet with countersunk heads, thus avoiding the injurious
effect of solder on the rope. They are Ij inch external diameter
and 1^ inch long, and are fixed 38 fathoms apart. When loaded
with a weight of 2 tons, and tested by repeated blows with a
hammer, one of these thiml)les has failed to show any sensible
displacement. It is found desirable to change the position of the
thimbles from time to time, so as to equalize the wear on the rope.

The hauling-rope is driven by a 9-HP. vertical engine, placed
under the platform at the loading or starting station. A pinion
8 inches diameter on the crank-shaft, which makes 120 revolutions
per minute, gears into a spur-wheel 7 feet G inches diameter, keyed
on the same shaft as the driving-drum, which has two grooves
lagged with wood. The rope passes twice round this pulley, and
once round a single-grooved idle pulley placed above it in the
same vertical plane, and is led away horizontally over two guide-
pulleys. The return-pulley at the discharging station is movable,
and weighted with a counterbalance of 1 ton 19 cwt. to keep the
rope taut. At each station thei'e is a fixed rail, on to which the
skeps are shunted, so as to be passed in the one case round the
return-jiulley, and in the other round the receiving hopper, so that
they may be filled from any of the shoots before described. Movable
switches at the starting station allow the skeps to be removed for
repairs, &c. The travelling-sjieed is about 2j miles per hoiir, and
it is noticed that the hauling-rope constantly revolves on its own
axis, and always in the same direction.

The discharging station consists of a platform 66 feet high,
carried on a light but very substantial framing, steadied by guy-
rojies. It stands on an old spoil-heap.

There are three intermediate supjiorts, consisting of wrought-
iron lattice posts of elegant design, bolted to masonry foundations.
The tallest is 72 feet high. Each is provided with two cross-bars
for supporting the carrying- and hauling-ropes, which are one
above the other in the same vertical plane. The hauling-rope is
simply carried on grooved pulleys, but the support of the carrying-
ropes is a more complicated problem, as it is found that, owing to
variations of temperature and in the positions of the loaded skeps,
they have an endlong movement to and fro of 10 inches or more.
If the motion of the two ropes is in the same direction, it tends to
overturn the supporting posts ; if in opposite directions, to twist
them. If the ropes are arranged simply to slide on their supports,
they soon get set fast, no matter how well greased ; if carried on a
simple pulley, they soon show signs of wear, from want of a more
extended bearing ; if on a block carried on small wheels, it soon
works itself to one end or other of its track, and there sticks. In
the Beer system the blocks are carried on pro])erly-formed blocks,
slung from pendulum-rods, allowing a perfectly free motion end-
ways, but restrained from side oscillations by qtiadrant guides.
A quarter turn-over is given to the carrying-roj)es from time to
time, so that all sides may be eqiially Avorn.

Five persons only are employed ; one to attend to the engines

488 BEER SYSTEM OF A^TEE ROPEWAYS. [Foreign

and macliiner\% a filler and a hooker-on at the starting point, and a
boy to tip the skeps and a hooker-on at the delivery point. The
clii:)S which engage with the thimbles are antoniatically released
by coming in contact with a fixed trijjper-bar at each end of their
travel.

It is claimed that a saving of 66 per cent, is eifected, as compared
with the system previously employed.

The Paper is fully illustrated with engravings of the general
arrangement and details described.

W. S. H.

Desrozier's New Dish-Bynamo. By E. Meylan.

(La Lumifere Electrique, toI. xsix. 1888, p. 401.)

This Paper, which is well illustrated by diagrams, describes
what is probably the greatest novelty that has been produced in
the design of dynamo-machines for several years. The magnetic
field is multipolar, the poles being arranged similarly to those of
the Siemens alternate-current machines, with their opposing faces
brought nearer together, as the space between is that required
for two layers of the wire forming the armature ; this latter is
formed of a series of radial wires, with junctions alternating
between the external and internal ends ; these jimctions are not,
however, between neighbouring radii, but between those that are
almost sjnnmetrically placed with respect to the magnet poles ;
that they are not qidte spnmetrical is due to the fact that after
one progression roimd the circumference the next series of radial
wires is reached, and thus the whole area is filled up, and the arma-
ture wires connected in one series. By an ingenious arrangement
of the connections on the anterior and posterior faces of two
annular disks of insiilating material, they are made without any
difiiculty, and at the same time without crossing of the wires.
Adopting for simplicity's sake a six-pole machine, the disk arma-
ture may be likened to the geometric projection on two parallel
planes of the contour lines of the teeth of a circular cutter, this
cutter having a number of parallel teeth helically arranged, three
teeth of deep gnillet forming one circumference ; the front and
back edges of the teeth would represent the radial conductors, and
the junction-pieces would be formed by the gullet and external
face of the teeth respectively ; the two parallel planes being neces-
sitated by the fact that in half the length of the imaginary helix
the front and back edges of the teeth woiild be in one line. In
such a machine each elementaiy coil, corresponding to one com-
plete tooth in the imaginary cutter, is connected to three plates on
the commutator, each 120^ apart, these connections being also
arranged with great mechanical simplicity ; there are thus only
two brushes, and all sparking at the commutator is eliminated.
The advantages to be gained by this form of machine result from

Abstracts.] DESROZIER's NEW DISK-DYNAMO. 489

the ease with which the three elementary requirements, that make
for power, can he secured, viz., intensity of magnetic field, density
of current, and linear velocity ; while the absence of iron in the
armature, and its open construction, aflbrd effective means for pro-
curing a very good commercial efficiency ; the only drawback —
which obtains in all multipolar machines — being the division of
the magnets, with the consequent extra expenditure in excitation.
Four of these dynamos have been suj^plied to the " Formidable "
(French ship), each driven direct by a Bregxiet steam-engine, and
furnishing 12,250 watts, with a commercial efficiency of 79 per cent.

F.J.

Gadot Accumulators, pattern 1888. By J. Laffargue.

(L'Electricien, 1888, p. 562.)

The new accumulator of the Gadot type tested recently by the
Author consisted of ten negative and nine positive plates of the
following weights and dimensions : —

Lb.

Negative plate 1 • 89

Positive „ 1-88

Plate, without oxide 0-97

Active material iu the negative plate 0 • 924

„ „ „ positive „ 0'915

Inches.

Total thickness 2-28

Height 59-00

Breadth 59-00

Mean distance between the plates in the liquid 2-36

The total weight of the nineteen plates is 35-87 lbs. The
accumulator gave a useful discharge of fifteen hours, when the
potential, which was 2 • 0-i volts at the beginning, had fallen to
1 • 75 volt. The initial current strength was 15 • 9 amperes, and 13-8
at the end of the fifteen hours ; the maximum internal resistance
was 0 • 003 ohm, and the total useful capacity in ampere-hours was
225*7 or G-29 per lb. of plates. A diagram is given in the Paper
showing the results of the tests in the form of curves.

J. J. W.

Account of a Series of Experiments made on Hessner's Cell.
By W. Chukoloff.

(Electrichestavo, St. Petersburg, 1888, p. 63.)

The Author first tested the adaptability of this cell to inter-
mittent electric lighting, but it proved to be quite unsuited for
this purpose. For telegraphic or telephonic purposes, however,
the cell was found to be most efficient, especially in cold climates.

490 SERIES OF EXPERIMENTS MADE ON HESSNEr's CELL. [Foreign

The battery was connected with an electric bell of 12 ohms resis-
tance, and periodically rung from January 26 to February 28, with
an average weakening of 3 • 8 per cent, of the electromotive force of
the cell during the period of the experiment. The longer the
circuit be closed the greater is the fall of the electromotive force,
and the fall is most sudden at the beginning of the action ; thus,
during the first hour the fall in volt-power was 0 • 04 volt, while
the average fall per hour in twelve hoiirs was 0-01 volt. Also the
longer the cell be kept at rest, the greater is the rise in its electro-
motive force, and the rise is more sudden during the first hour of
rest than the succeeding hours, so the average rise for one hour
was 0-01 volt, and that for seventeen succeeding hours was 0-02
volt. The rise is slower the nearer it approaches the normal
electromotive force of the cell.

To test the behaviour of the cell under conditions of heat and
cold, the following experiments were made. The cell was cooled
from -1- 20^ Centigrade when its electromotive force was 1-32 volt
to — lo"^ Centigrade, when the electromotive force was found to be
1*28 volt. After being exposed for five hours at -(-oO^ CentigTade
when the electromotive force was 1 -34 it was cooled to -f 20° Centi-
gTade, when the electromotive force was found to be 1 • 32 volt,
and its internal resistance 0"o5 ohm, and the cell was then ex-
posed to a frost of — 17"^ Centigrade for twenty-four hours, and
— 15° Centigrade, when its electromotive force was 1*28 volt and
its internal resistance 0-65 ohm. After being exposed five days
to a Irost of —17° Centigrade, which went as low as —26° Centi-
grade, the electromotive force was 1*27 and the internal resis-
tance 0-7 ohm. Then after being three days in a room at -f-20°
Centigrade, the electromotive force had risen to 1*3 volt, the
internal resistance reduced to 0-55 volt. Thus the electromotive
force during these experiments had only decreased by 4 per cent.,
and the internal resistance risen 21 per cent., or the general
weakening of the cell m.ay be taken at 30 per cent.

The results of these experiments, together with the facts that
the cell contains no liquid, and that the chemicals do not require
lenewal for over a period of two years, lead the Author to conclude
that this cell is one most fitted for telegraphic and similar purposes.

G. K.

0)1 the Measurement of the Resistance of Suhmarine Cahles.

By A. EOUILLARD,

(L'Electricien, 1888, p. 707.)

In testing the conducting resistance of a subaqueous cable by
means of the " repioduced deflection " method, the line (with its
distant end earthed) is connected through a shunted galvanometer
and reversing key to earth, the battery being joined to the key in
the usual way. As, however, in this arrangement, the battery

Abstracts.] RESISTANCE OF SUBMARINE CABLES. 491

is not in circuit when readings of the earth currents c are observed,
its resistance is not taken into account ; hence an error is intro-
duced, which, in the case of strong currents, may be a considerable
one. The strength of the observed earth current is

'° " E'

e being the electromotive force and R the conducting resistance of
the cable. When the deflection d is noted, the battery (of resist-
ance r and electromotive force Ej is in circuit and the current
strength is

E + g

The value actually required is I' = — , since the current of

strength I' is reproduced through a resistance R plus r, or that of
the battery. Therefore, in eliminating i^, the expression becomes

E-f e

which differs from I' by a quantity c representing the error in
question.

If € = I' - (I - i) =

e
then, as — = ^_,,

r e

R (R 4- r)'

R-hr /R^^

and as the deflections are proportional to the strength of the
currents producing them, the formula

d^— d — c -{•

gives the deflection d^, which has to be rejiroduced by means of the
battery through a resistance R, the value of which will then be
equal to that of the cable under test.

The value of this correction e is important, especially when a
fault has to be localized. For instance, assuming the earth current
to vary from — 20 to -f- 20 divisions, then with a battery of 40
Callaud cells (each of 9a) resistance) r = 40 x 9 = 360 ohms, and a
cable having a resistance of 4,000 ohms, the correction expressed in
divisions of the scale is

492 BESISTAIsCE OF SUBMAEINE CABLES. [Foreign

and if, with the constants chosen, one division represents 20 ohms,
the error has a value of 33 ohms, equivalent to about 10 miles of
cable.

By aid, however, of a resistance r (equal to that of the battery)
inserted between the testing-key and earth, the necessity of
applying this correction is avoided. This supplementary resistance
can be short-circuited by means of a key, so that the readings of
the earth currents can be taken, with r in circuit, by pressing
down this key, and when the deflection d is observed r is cut out
by leaving the key in its normal position. For the rapid readings
essential in this method of testing, the Author has found a
Desprez d'Arsonval galvanometer very suitable. The tests re-
ferred to in the Paper were made with an instrument of this class
having a resistance of 200 ohms, whilst that of the shunt was 1 to
2 ohms, according to the resistance under measurement.

J. J. W.

Pliilippart' s Electrical Tramcars in Paris.

(L'Electricien, 1888, p. 617.)

The motive-power is supplied by a battery of one hundred and
forty-four Faure-Sellon-Volckmar twin-plate accumulators, of a
storage capacity of 150 ampere-hours, at a normal rate of discharge
of 25 amperes. Taking 1 • 8 volt as the mean useful electromotive
force per accumulator, the total cajiacity is 37,000 ^ watt-hours,
equal to 50 ^ HP. hours, or say an effective energy of 40 HP.-hours,
sufficient to drive a car for six hours without re-charging the
battery.

The motor consists of a Siemens dynamo, coupled to a counter-
shaft by means of a Eaffard endless rope. On the shaft, which is
in two lengths joined together by a differential coupling, there are
two pinions geared to the rear wheels of the car by chains of the
Gall type. The driving-wheels work independently of each other,
and on the straight parts of the track the speed of the two pinions,
and consequently that of the wheels, is equal, but on curves the
action of the differential coupling causes the two pinions to revolve
at different velocities, so that curves of very small radius can be
passed over withoixt difficulty. The cars are running between the
Place de I'Etoile and Porte Maillot ; the weight of each vehicle,
inclusive of accumulators, motor, transmission gearing, and fifty
passengers, is about 9 tons.

J. J. W.

These figures should be by calculation 39,000 and 52 respectively.

Abstracts.] THE TELEPHONE-EQUATION. 493

On the Telei^hone-Equation. By C. L. Madsen.

(Elektrotechnische Zeitschrift, 1888, p. 462.)

The experiments forming the subject of this Paper were nntler-
taken Toy the Author with a view to the further development of
Preece's equation for the limiting distance of telephonic speech,
viz. :

K being the total resistance of the line in ohms, C its electrostatic
capacity in microfarads, and K a coefficient. The value of K, as
determined by various experimenters, ranges from 2,000 to 15,000;
it is therefore probable that some uncertainty exists respecting the
actual meaning of the above expression. In general, trials appear
to have been made simply to find out through what length of line
of a certain type conversation could be carried on, but scarcely any
data have been put together relative to the electrical values of
such line, number of offices, construction of the apparatus, &c.
Then, as regards the transmission of speech, it is important to know
whether the adopted standard expressed a condition which enabled
every word to be distinctly heard without repetition, or merely one
that just admitted of an articulation being sent through the line.
In order to remove all ambiguity from the factor ?/, the Aiithor and
his coadjutors adopted the figure 100 to express a conversation of a
certain uniformity, as regards the strength and clearness of the
sound, whilst other interchanges of speech were valued according
to their prevailing quality, whether better or worse than that of
the standard. The experiments were made by means of the latest
improved form of Bell-Blake instruments, and in the Exchange
Offices the electro-magnets were connected in shunt, so as to avoid,
as far as possible, the weakening effect of self-induction. Electrical
measurements were obtained of the ajiparatus in the central
stations and subscribers' offices ; some of the main lines were also
tested, and from the various data thus acquired the exact value of
K for the telephone lines in Denmark was determined. The
equation now has the following definite form : —

T ""

K . C

or for a telephone circuit, having a " figure of merit " equal to the
standard

T = 100 = :- J^=jr, ,

K • C l^ • re

where Ir is STibstituted for E and Ic for C ; r and c being respec-
tively the resistance and capacity per given unit of length I.

The Table in the Paper embodies the results obtained on

494 THE TELEPHONE-EQUATION. [Foreign

nineteen telephone lines, which, were connected with Copenhagen.
Sixteen of these circuits are in work, and the other three, Aarhiis,
Odense, and Malmo, were employed for the elucidation of some
special technical details. As an example of the enormons gain
that has been obtained from the nse of hard drawn copper wire, or
bronze wire 2 millimetres in diameter, in place of iron or steel
wire, the Author mentions the Helsingor-Copenhagen line, on
which telephonic conversation is now uniformly loud and clear,
whereas with the latter kind of wire the transmission was very
imperfect. Hard-drawn copper wire is practically free from self-
induction, which weakens speech almost to the same extent as
doubling the resistance of the line. The experimental results
give 300,000 as the absolute vahie of K for the telephone system
in Seeland. The equation is then

_ 300,000

and if T is foimd to be equal to 100, when the actual values of R
and C for any particular line are inserted (R being doubled in the
case of iron or steel wire), then the line is a standard one as regards
its power of transmitting speech.

The tabiilated results are, in some instances, of general interest,
as proving that the excellence of a telephone line depends far
more on the kind of wire used and the number of Exchange offices
in circuit than on the actual distance separating the two end
stations. For instance, the line Copenhagen-Ringsted, 67*9
kilometres in length, consists of 1 kilometre of cable, 61*5 kilo-
metres of copper or bronze wire, and 5*4 kilometres of iron or
steel wire. When worked with only two intermediate Exchanges
in circuit, this line has " a figure of merit " of 302, whereas the
Copenhagen-Kjoge circuit, which is 20 kilometres shorter, but is
composed of 46-9 kilometres of iron or steel wire and 1 kilometre
of cable, is only 199. Again, in the case of a second circuit between
Copenhagen-Ringsted, the lengths in kilometres being 2*5 of
cable, and 72*1 of iron wire, with four intermediate offices in
circuit, the "figure of merit" fell to 76.

J. J. W.

The Telephone Line hetiveen Paris and Marseilles.

(L'Electricien, 1888, p. 647.)

The line, which is almost an aerial one throughout, consists of
two bronze wires, each 4^ millimetres in diameter, the cross-
section being 15-9 square millimetres, the conducting resistance
1 ohm per kilometre, conductivity 97 per cent, of that of pure
copper, weight 146 kilograms per kilometre, and breaking strain
45 kilograms per square millimetre. The distance between the ter-
minal stations is 900 kilometres, consequently 1,800 kilometres of

Abstracts.] TELEPHONE LINE BETWEEN PARIS AND MARSEILLES. 495

wire are used for the complete circuit. The suliterranean cables
are of the Fortin-Hermann type ; each conductor consists of a strand
of seven copper wires each 0*7 millimetre in diameter. Beads of
paraffined wood are strung at intervals on the strand, and six such
conductors, each having a resistance of 7 ohms per kilometre, are
cabled together helically and encased in a leaden tube. Two of
these conductors are used for the Paris-Marseilles telephone line.
As the dielectric is, for the most part, air, the insulation is as high
as 4,000 to 5,000 megohms per kilometre, and the electrostatic
capacity 0*053 microfarad. The only parts of the line where
cables are used are from the Exchange, in Paris, to the railway
station at Yincennes, viz., 3 kilometres ; two lengths of 100 metres
each in tunnels, one near Paris, and the other not far from Lyons ;
also one length of 800 metres in the Saint-Louis tunnel near
Marseilles.

In order to minimize inductive disturbances, the wires are
attached to the posts in such wise as causes a reversal of their
relative positions at each kilometre. The ordinary telegraph wires
are also fixed to the posts, the principal circuits being worked
with Van Eyssell^erghe anti-induction apparatus. At each ter-
minal station there is a set of microphone transmitters with
induction bobbin and the usual telephone receivers, whereas at
Lyons there are two such sets. Ordinarily, Paris and Marseilles
work on separate circuits to Lyons, so that each terminal town can
be in communication at the same moment with the intermediate
station ; but whenever direct terminal working is required, the
operator at Lyons effects the necessary connection of the main
wires. The battery at each end station consists of six Lalande
and Chaperon cells, three in series and two in parallel, and at
Lyons each set of apparati;s is worked by three similar cells in
series. The electromotive force of each cell is 0 ■ 8 volt, and its
internal resistance 0 • 1 ohm. The transmitters and receivers are
of the D'Arsonval pattern.

J. J. W.

The Begulation of Are Lamps. By E. Hospitalier.

(L'Electricien, 1888, p. 276.)

Arc lamps in parallel are more easily regulated when the
difference of potential is in excess of that actually required. For
instance, with 60 volts as the standard, a nearly constant arc can
be maintained with 60 volts, and a still steadier one with 70 volts.
If this method be extended, it is found that with 100 volts a single
arc can be kept perfectly constant when the surplus electromotive
force is absorbed by a resistance of about 5 ohms, the normal
current strength being 5 amperes. Assuming that an arc has to be
maintained with a current strength I of 10 amperes, the difference
of potential e at the terminals being 50 volts, and the useful power

496' THE REGULATION OP ARC LAMIPS. [Foreign

Pu (= el) in the arc, 500 watts. A knoAvledge of the variations of
these three elements, when the apparent resistance of the normal arc
of 5 ohms fluctuates between 4 and 6 ohms, is easily obtained by-
means of the graphical method, which also furnishes convenient
data for determining the kind of regulation that should be employed
for each jiarticular case.

The cur\'es shown in the Paper are numbered respectively
1, 2, 3, and have reference to three different conditions, viz. :

1. An electric generator having a constant electromotive force of
100 volts; the total resistance of the circuit, exclusive of that of
the lamp, being 5 ohms.

2. Generator of 70 volts ; external resistance, 20 ohms, irrespec-
tive of that of the lamp.

3. Generator of 50 volts ; resistance inappreciable Tas in the ease
of a battery of accumulators) ; resistance inserted in the circuit
theoretically null.

A comparison of the cur\-es demonstrates that all the conditions
of good regulation are at hand, when working with an electromotive
force of 100 volts, and are absent when fifty volts only are avail-
able. It can also be seen that a regulator which maintains el
constant is not ai:)plicable to the first case, but gives good results
when applied to the third. The regulating power of the electro-
magnet ordinarily applied is a function of I, whereas the action of
an electro-d;^Tiamometer is proportional to I'-. The use of the latter
accessory would therefore increase the sensibility of the regulating
system, and although the lamp could not be run satisfactorily with
50 volts, it would work well with 60, instead of 70, which is the
voltage almost universally adopted at present for mixed distribu-
tions having arc and glow lamj:)s simultaneously in action.

J. J. W.

TJie Electric Lighting of the City of Geneva.
By EoGER Chavaxnts.

(La Lumifere Electrique, vol. sxis., 1888, p. 451.)

In the Central Station there are three Piccard high-pressure
turbines, each of 200 HP., with horizontal axes, carrjdng a central
cro^^^^ of vanes ; the water enters from the outer circumference
by means of a distributor, and the flow is so regulated by a
centrifugal governor that the variations of speed are within 1 per
cent. The governor consists of a self-acting hydraulic motor ; it
operates a cylindrical slide-valve which admits the water at high-
pressure into a vertical piston that adjusts the orifice of the dis-
tributor. The motion of the valve is efl'ected by means of a lever,
having at its fulcrum a rod jointed to the vertical piston. The
cover of the governor forms the movable point of this lever. By
the action of the regulator the valve is opened, bixt the motion of
the piston tends to close it ; these opposite effects are so balanced

AbstractB.] ELECTRIC LIGHTING OF THE CITY OF GENEVA. 497

as to give a regulating system of extreme sensibility. The water
enters the turbines at a constant pressure of 13^ atmospheres ;
constancy is maintained by means of a reservoir situated about 135
metres above the level of the lake. Each turbine drives two Thury
hexagonal-shaped dynamos, each giving a current of GOO amperes
at a jDotential of 110 volts, and speed of 350 revolutions a minute.
The three-wire system of distribution is employed, and the mains
consist of Siemens concentric lead-cased cables. At present, the
circiiits are confined to a portion of the town on the left bank of
the river. The main cables or feeders are joined at five diff"erent
points to intermediate cables by means of junction-boxes, and the
service-wires are led from distributing-boxes into the hoiises. Each
pair of shunt- wound dynamos is connected in series, each machine
being joined to the distributing conductors on the switch-board by
means of three cables ; that is, two for the main, and one for the
shunt-circuit. The lower part of the board is fitted with the
rheostats, or current-regulators, which are in circuit with the field
magnets. The rheostats are arranged in pairs, and can be mani-
pulated either singly or altogether, by means of suitable gearing.
In the main circuit of each group of machines two cut-outs are
inserted ; one of them acts automatically, and causes a disconnection
in case of any accidental reversal of the current. The switch-board
is also provided with voltmeters and ammeters. In the houses
which are lighted, the consumption is recorded by Aubert's meter
when the lamps are few ; by Aron's single-coil meter in the case
of a medium supply, and by a double-coil meter of this type when
forty lamps or more are in action.

J. J. W.

Self-Begulating Electric Search-Light. By W. E. Eein.

(Centralblatt fiir Elektroteclinik, 1888, p. 5G4.)

In an electric lamp devised for military and naval purposes, the
chief requirements are, that the arc should remain in the focus of
the reflector, and the regulation be eff"ective at any angle of inclina-
tion. When the motion of the carbons is efiected by means of the
superior weight of the upper holder, the lamp only works well in
a vertical position ; hence hand-adjustment has been introduced.
The Author has constructed an automatic lamp which can be used
in any position.

The carbons are carried by two square rods working horizontally
between friction rollers. The frame containing the rollers for the
upper, or positive carbon-holder, is fixed to an upright which is
screwed to one end of a cast-iron base-plate ; the negative holder
works in a guide, which with its rollers is suspended in four rails
beneath the upper holder, and is entirely insulated from the latter.
At the ojiposite end of the base-plate is a second upright, to which
is fixed an electro-magnet E, having its armature in front of the

[the INST. C.E. VOL. XCV.l 2 l<

498 SELF-EEGULATING ELECTRIC SEAECH-LIGHT. [Foreign

movable framing formed by the rails. The central roller of each
system is kept in contact with its carbon-holder by means of two
spiral springs ; each of these two rollers is fitted with a ratchet-
wheel, the pawls being joined together and to the armature of an
electromagnet e by a steel bar. As soon as the current actuates the
armature of e, the pawls are drawn downwards ; the armature is
then automatically released, springs back to its former position,
and causes the friction-rollers to revolve simultaneously in opposite
directions, whereb}^ the carbon-holders approach each other.

The electromagnet E is in the main circuit, and directly the
current traverses its coils, the armature is attracted, causing a
separation of the carbons and formation of the arc ; when the
distance between the carbons becomes too great, the current in
the shunt circuit of the electromagnet e increases until the armature
is actuated, and the carbons drawn together by the motion of the
friction-rollers, as described above.

The horizontal position of the carbon-holders enables one of them
to be placed in the axis of the reflector, so that only a single slot is
required for the reception of the other holder. All the rays from
the crater of the positive carbon are thrown radially on the inner
surface of the paraboloidal reflector, and the projection outwards
is more complete than in the case of lamps with vertical holders.

The case containing the mechanism is so mounted as to admit of
motion in any desired direction.

J. J. W.

Electric- Light Installation on the Arniour-elad Cruiser " Admiral
Nahimof\" By Lieutenant Kolokoltzoff.

(Morskoi Sbornik, St. Petersburg, January 1888, p. 41.)

This is the first Russian armour-clad lighted throughout by
electricity. The installation was set tip by the Jablochkoif Com-
pany, and consists of four comjDound-wound Gramme dynamos,
designed for an output each of 140 amperes at 65 volts, driven by
four separate engines, and feeding three hundred and twenty glow-
lamps (8-candle power and 50 volts electromotive force), and two
Mangin search-lights, placed at the ends of the fore-bridges. The
two dynamos for feeding the search-lights are placed amidships on
the gun-deck, and the other two, for lighting the decks, are placed
amidships on the main-deck. The engines working each pair of
dynamos are connected by separate steam-pipes to both the main
and auxiliary boilers. Each dynamo can be switched on to any
circuit at will, and each pair of dynamos can be connected in
parallel arc. The switching of any dynamo on to the deck- or
search-lights is done by means of two three-way commutators
attached to each dynamo.

The construction of the cruiser is as follows : Above the pro-
tected deck, along the whole length of the vessel, extend the gun- j

Abstracts.] ELECTRIC LIGHT ON THE " ADMIRAL NAKIMOFF." 499

and main-decks, and under the protected deck, in the central part
of the vessel, are placed the engines, and in the liows and stern
the ammunition magazines and provision-stores. The conducting
mains form three closed double circuits, all connected to the main
switchboard. Two of these double circuits supply the gun- and
main-decks, one pair extending along the port side of the gun-deck,
descending at the bows to the main-deck, thence led aft along the
whole length of the port side of the main-deck, and ascended at the
stern to the gun-deck, where the respective conductors join, and thus
form each a complete circuit. The second pair of conductors travels
along a parallel path, but on the starboard side of the vessel. The
third pair of conductors supply the engine-rooms, stokeholes, and
magazines. Owing to the uneven distribution of the lamps along
the decks, the conductors are not of uniform section throughout,
one half being 20 square millimetres (0"31 square inch), and the
other half 40 square millimetres (0*62 square inch.) The cor-
responding main conductors of the port and starboard circuits on
the gun- and main-decks can be connected together at the fore and
after part of the ship by means of switchboards, to which they are
connected by supplementary condiictors. The lights on the fore
and after orlop decks are regulated by auxiliary switchboards,
so that they can be fed direct from the dynamos, or, in cases of
need, from one hundred and fifty accumulators on each deck.

The advantages claimed by the Author for this system of lighting
on war-ships are, that the laying of the conductors on the gun- and
main-decks in an annular j)ath prevents the extinction of any
lamp, in the case of a single injury to one of the conductors by an
enemy's shell ; as main conductors will be still connected at the ends
to the dynamo, and the circuit will not be broken ; also by joining
the circuits at the fore and aft switchboards, even the total severa-
tion of one pair of the conductors leading to the main switchboard
would not cause the extinction of any lamp; and thirdly, that
the orlop decks, where the chief engines of war are situated, being
supplied either by accumulators or the dynamos, their illumination
can be cut off only by the destruction of the decks themselves.

The main switchboard consists of a marble slab, on which are
placed all the commutators necessary for regulating the lighting of
the whole vessel. The commutators are of three kinds — plug-com-
mutators, ordinary friction-commutators, and a special form of
double pole friction-commutator. The switchboard is so arranged
that the positive and negative poles of the dynamos are connected
respectively with commutators situated at the two sides of the
slab, and for each dynamo in a separate horizontal line. The main
conductors are similarly connected to the board, biit in vertical
lines. The dynamo commutators are placed in serial order ; thtas
the upper commutator is connected with the first dynamo ; the
next lower commutator with the second dynamo, and so on. So
also with the circuits : the left-hand commutator is connected with
the port circuit ; the next commutator with the starboard circuit ;
the third commutator with the engine-room circuit, &c. The

2 K 2

500 ELECTRIC LIGHT ON THE " ADMIEAL NAKIMOFF." [Foreign

double-pole friction commtitators allow the current to be measured
at any moment without interrupting the circuit.

The Paper is furnished with drawings of the various com-
mutators, lamps, and other appliances, and gives detailed descrip-
tions of the management of the main and auxiliaiy switchboards.

G. K.

On Siemens and Hahhes Electric Winding-Engine at
Neu Stassfurt.

(Oesterreichische Zeitschrift fiir Berg und Hiittenwesen, 1888, p. 105.)

In 1885 an inclined shaft was commenced at the bottom of the
Keu Stassfurt mine, in order to explore the continuation of the
potash salt bed in depth. The winding in this shaft, which had a
slope of 40 degrees, is effected by a geared engine driven by
electricity from a primary djmamo and steam engine at the sur-
face, which has already been in use for some time as the motive
power of an electric railway, about 1,500 metres long, on the
300-metre level of the same mine. The engine at the surface being
155 metres from the shaft bank, the depth to the bottom of the
mine 360 metres, and the distance from the shaft bottom to the
driving dynamo 40 metres, a total length of 555 metres of double
conductor was required to convey the cuirent to and from the
engine. The conductors at the surface are of bright copper wire,
while in the pit and underground a covered cable laid in a
wooden trough is used. The work to be performed consisted of
the lifting of one loaded tub weighing 1,200 kilograms gross,
and the lowering of an empty one of 400 kilograms through a
height of 100 metres, on an inclined plane 155 metres long, once
in four minutes, or, having regard to the time lost in hooking on
and landing, in an actual working time of three minutes, or an
average working speed of 3 feet per second. This requires an
effective power of 431 kilogrammetres per second for lifting, and
21*2 kilogTammetres for overcoming the frictional resistance; or,
in round numbers, 450 kilogrammetres i^er second as the useful
work of the secondary dynamo ; or, taking 40 per cent, as the effect
realized, about 15 HP. is required at the steam-engine. The useful
electrical effect realized is at least 53 per cent., about 25 per cent,
being lost by the driving gear of the rope-drum.

The primary dynamo is of the Makers' Dg type, giving a current
of 22 amperes and 370 volts, the loss in the conductors being only
5 or 6 per cent. The secondary dynamo, or electromotor, is of the
D, type, and converts 75 per cent, of the electric energy into
power. It makes one thousand revolutions per minute, and drives
an intermediate shaft by means of a belt 160 millimetres (6j inches)
broad at about one-third of that speed. This motion is again
reduced by means of spur gearing to 13*3 revolutions on the rope-
drum, which is 1,240 niillimetres (4 feet 1 inch) in circumfer-

Abstracts.] SIEMENS AND HALSKE's ELECTRIC WINDING-ENGINE. 501

ence, and moves at the rate of about 3 feet per second. The axis
of the drum is horizontal, and the direction of the windng-ropes is
reversed by guide joulleys 1 metre in diameter, at a distance of 4
metres from the drum. The whole of the machinery is contained
in a gallery 3*G metres high and 18-5 metres long. The transmis-
sion of the power by a intermediate shaft driven by a belt, against
which some objections were raised, has proved to be advantageous
in practice, as the load is started and stopped without shock, and
great regularity of motion is obtained.

In order to prevent injury from heating by sudden changes in
the current when starting or stopping, a series of resistance
elements are attached to the motor, which can be put in or out of
the circuit simultaneously with the action of the reversing belt, in
order to regulate the current to the motor. The reversal of the
current is effected by lifting or lowering one or other of a pair of
brushes, placed diametrically opposite to each other in regard to
the commutator.

The engine was in continual use, without accident of any kind,
from the beginning of November, 1885, to the end of March, 1887,
during which period the sinking was carried to a depth of 132
metres, and several trial drifts were made at the bottom. The
purpose for which it was undertaken having been accomplished
the work was then stopped. The makers observe, in conclusion,
that with their im})roved forms of dynamo since introduced a
nmch higher effect may be realized from a similar plant.

H. B.

0)1 the Connecting of Lir/htning-Concluetors ivitli Water- and
Gas-Pipes. By L. Weber.

(Elektrotechnische Zeitschrift, 1888, p. 285.)

In this Paper the Author has embodied many of the considera-
tions which led the sub-committee (appointed by the Berlin
Electrotechnical Society to investigate the question of lightning-
conductors) to pass the following resolutions : —

" The joining of lightning-conductors to the gas- and water-
pipes does not cause injury to the latter. These pipes are as much
endangered when no such junction exists as they would be by the
absence of a conductor. It is therefore imperative that lightning-
rods shoiild be in permanent metallic connection with the system
of pipes within a building. This connection should be made at a
suitable part of the pipes, and at an external point as regards the
principal meter."

The following is an outline of the data on which these reso-
lutions were based : —

1. Danger to buildings due to the promotion of electrical dis-
charge by water- and gas-pipes.

As an underground system of pi})cs is usually in intimate

502 CONNECTING LIGHTNING-CONDUCTOES [Foreign

connection with the conducting mass of the earth, it forms a path
of least resistance, and in buildings where the upper branches of
the system are carried to the topmost floors, there is no doubt that
the discharge finds its way to these branches through the roof or
•walls.

2. Danger to the gas- and water-pipes.

The nature of the damage to the pipes depends upon their
position and the way in which they are struck.

(a) If the lightning strikes any part of a pipe which is out of
doors and exposed to the air, a slight fusion may be caused, result-
ing (in the case of thin gas-tubesj in an explosion of gas. When
the point which is struck lies either in water, earth, or a wall,
considerable mechanical destruction often takes place.

(6) If the discharge passes to pipes caulked with a badly con-
ducting material, they are in danger of being cracked, but the gas
is not likely to be exploded when the caulked joints are in the
groxmd, as even explosive mixtures cannot be fired by a spark
unless they are collected in some large hollow space.

3. The manner in which the dangers cited under §§1 and 2 are
affected by a lightning-rod having no connection with the water-
and gas-pipes.

Lightning-conductors are joined to ground-plates which, as
regards surface and close contact with the earth, are quite in-
effective in comparison with the large network of underground
pipes. Consequently, whenever any distant in-door branch of this
network is situated near a lightning-rod, the discharge has a
tendency to spring from the rod to the pipe, and thence pass to
the mains below. If the two metallic discharging paths are
separated by several metres of air-space, in which conducting
substances would not be likely to stand, even temporarily, the
springing across of the lightning might not occur ; but in dwelling-
houses such a condition is never fulfilled, because each bell-wire,
gilt cornice-pole, &c., constitutes a conducting bridge.

4. By means of a metallic junction between the lightning-rod
and pipes the dangers above specified can be avoided.

When the connection is established, there is, in the majority of
cases, immunity from danger, and in no instance can such a
junction be productive of an increase of risk.

5. It is necessary that the connection be made with the two
systems of pipes.

It is not advisable to rely on making a " good earth " with one
system of mains only, but both should be joined to the lightning-
rod, in order to avoid lateral inductive discharges. Owing to the
close proximity of the two sets of pipes, either in buildings or
undergTound, such discharges and their attendant sparks are very
common, when only one set is connected with the rod.

6. Objections to a metallic junction between the lightning-
conductor and pipes.

During repairs to the pipes, the metallic continuity is sometimes
intermitted at certain places, and it is contended that, at these

Abstracts.] WITH WATER- AND GAS-PIPES. 503

parts, not only the pipes, but the workmen engaged in repairing
them, are exposed to danger while a thunderstorm is in progress.
There is, however, ample evidence to show that this risk is slight,
and can, if necessary, be easily prevented by bridging over the
gap with a wire rope. Any j^ermanent lack of continuity at
the joints can be avoided by making the use of lead caulking
compulsory.

7. Is a special earth-plate required for the lightning-rod when
the latter is joined to the mains ?

The system of pipes with which a rod is connected may form a
metallic network of considerable extent around a building, and as
this network may have gaps in it, it is best to join the lightning-
conductor to a separate earth-plate.

8. The kind of junction to be employed, and in what jiart of the
conducting system it should be made.

The metallic rope or band used for the connection should have
the same conductivity as that of the lightning-rod, and be well
soldered to the latter. The junction between the metal surfaces is,
in this case, easily made, but greater i^recaution is required in
respect of the connection with an iron pipe. The rope or band
should therefore be soldered to an annular clip of large internal
surface ; the part of the pipe where the joint has to be made is
scraped clean and a piece of sheet-lead placed around it ; the clip
is then put over the lead and tightened up. The joints should be
made in such places as are easy of inspection, and the junction
with the iron pipe ought to be on that side of the principal meter
which is nearest to the mains. A supplementary connection
between the lightning-rod and branch-pipes in the topmost storeys
is also usefiil, but in this case the water- and gas-meters should be
bridged by a metallic by-pass to guard against any want of con-
tinuity incidental to their construction. The joints in the pipes
must also conduct well, or be bridged over in the same manner.

In order to avoid any damage to the mains that might arise
from galvanic action set up between the copper earth-plates and
iron pipes, the ground-connection of the lightning-conductor can
also be effected by means of an iron j^late.

9. Precautions to be observed when a house has no lightning-
rod, but is fitted with gas- and water-pipes.

The parts of the pipes nearest to the outer walls and roof should
be connected with strong wires which are led to the outside of the
house. The joints of the pipes and the meters must then be
protected as explained above. Such precautions, are, however,
only a makeshift, and must not be regarded as an efficient substi-
tute for good lightning-conductors.

J. J. W.

504 DECOMPOSITION OF SALT BY ELECTKOLYSIS. [Foreign

The Decomposition of Salt hy Electrohjsis. By N. N. Beketoff,

(Zapisky Iniperatorskavo Eusskavo Technicheskavo Obstchestva, 1888, p. 25.)

After pointing out the great importance of common salt to the
arts and mamifactures, and the abundant and widespread oc-
currence of this suhstance in Russia, the Author proceeds to dis-
cuss the best methods of manufacturing soda in that country ; and
he advocates the decomposition of salt into its component parts by
electrolysis when in a fused state, confirming his view by the
following calculation : — •

The heat evolved in the combination of sodium with chlorine
being 96 '7 calories, the electromotive force required for the
decomposition of salt is 4 • 5 volts. The conductivity of fused salt
is 8660 ; that of mercury, being 100 or 150 millions ; that of silver
being taken as 100 millions; the temj^erature of the fused salt
being 500'' Centigrade in each case. The number of amperes
required to decompose 1830 lbs. (50 poods) of salt, giving 732 lbs.
(20 poods) of metallic sodium and 1098 lbs. (30 poods) of chlorine,
is 16,000 amperes per twenty-four hours; or, at 5 volts, the work
necessary would be 80,000 volts, or about 120 HP. Assuming that
120 HP. i^er day is eqtiivalent to the combustion of 13,176 lbs. of
coal (360 poods), and that the fusion of the salt requires 1,464 lbs.
of coal (40 poods), there will be required 14,640 lbs. of coal at
7s. 6d. per ton (6 kopeks per pood), or £2 8s., and the cost of
1,830 lbs. of salt at 15s. per ton, or 12s.; the manufacture of 732 lbs.
of metallic sodium and 1,098 lbs. of chlorine comes to £3. So that
taking the average value of these products at £9 6s. per ton (1 rouble
50 kopeks per pood) and IBs. loss, there results a clear profit of
£3 12s.

The Author goes on to mention the best ways of employing the
chlorine and metallic sodium.

G. K.

The Wimshurst Machine. By E. Dieudonne.

(La Lumiere Electrique, vol. xxix., 1888, p. 613.)

Dr. Vigouroux has made some improvements in this machine in
order to render it more serviceable in electro-therapeutics. The
metallic sectors or carriers, instead of being flat throughout, have
a raised boss along their vertical axis, and the brushes are so fixed
that they only make contact with the ^projections thus formed,
whilst the remaining parts of the rotating plates are untouched.
When the sectors are flat the brushes sweep across the entire
surface of the disks and gradually wear away the varnish. In
place of combs, collectors made of flat metal tubing are j^rovided
and fixed as near as possible to the plates. The knobs which
carry these collectors are mounted direct on glass pillars ; the
socket and discharging-rods are dispensed with.

Abstracts.] THE WIMSHUEST MACHINE. 505

According to Dr. Vigoiiroiix, the action of tlie Wimshurst
machine may be explained as follows : Assume that a sector on
the front plate is in contact with one of the fine copper wire
brushes, say, a, whereby a difference of potential is produced and
the sector charged with a small quantity of positive electricity,
which is retained as it moves away from the brush. As soon as
the charged carrier reaches the collector B, towards which the
rotation of the plate is bringing it, the initial positive charge is
parted with ; the carrier now approaches the other brush b, but
while doing so it remains influenced by the positively charged
collector B, and in such wise as causes the upper half of the sector
to be electrified negatively by induction, and its lower half posi-
tively. Directly contact is made with the uninsulated brush b,
this distribution is disturbed, and the sector, when receding from
b, is in the negative state. It parts with its negative electricity
to the second collector A, which likewise acts inductively on the
sector until the latter again makes contact with the brush a, and
the cycle of effects is repeated. At the second contact with a no
initial charge is required, because the carrier is already infiuenced
or polarized by the negative electricity on A. All the sectors
undergo the same series of changes, and the electrical condition of
one-half of the circular plate is s;^^umetrical as regards the other
half, but opposite in sign. The same applies to the second plate,
but as it turns in the contrary direction, the distribution on the
halves of this plate is the reverse of that on the other one. Hence
static induction is also exerted between the two sets of carriers,
and augments the total effect. When the machine is once started,
the principal factor in the continuity of the action is the inductive
influence of the collectors. If the insulation of either of them be
diminished, thereby causing a corresponding loss of charge, the
output of the machine is lessened. This is an effect peculiar to
the Wimshurst machine, and distinguishes it from other influence-
machines.

J. J. W.

TJie Gldser Influence Machine.

(Elektrotechnische Zeitschrift, 1888, p. 452.)

This machine, which has an exceedingly high efficiency, consists
of a fixed horizontal steel rod mounted between two iron uprights, the
latter being screwed to a rectangular wooden frame forming the
base of the apparatus. On this rod there are two ebonite tubes or
axes, each carrying a small pulley and an ebonite drum. The
pulleys are keyed on the ends of the axes near the iiprights, and to
the other ends are bolted the drums, one of which is of such
dimensions as enable it to revolve within the other. The driving
gear is arranged to work between the lower part of the two
standards ; it consists of two axles WjW.^, each fitted with a large
]uille3^ I'J^ transmitting the motion, l)y means of belts, to the small

506 THE GLASER INFLUENCE MACHINE. [Foreign

pulleys. The rotation of the drums in ojiposite directions is
secured by aid of toothed wheels on WjWo. Midway between the
uprights are two glass rods fixed on opposite sides of the wooden
base ; each rod carries at the top a brass knob to which is screwed
a vertical brass rod ending in a second metal knob. In the upper
knobs the discharging rods work, and to the lower ones are fixed
the collecting combs for the outer drum. Near the middle of the
steel rod is a short vertical bar, which carries the collecting combs
for the inner drum, these combs being so placed as to form a
right angle with the outer ones. Eigidity is given to the upper
part of the apparatus by an ebonite tie-rod secured to the upright,
and a bar of the same material is screwed crosswise to this rod and
serves to hold the ui3j)er jDortion of the discharging ajoi^liance
firmly in position.

The initial excitation is imparted by means of a strip of rubbed
ebonite held just above the outer drum. The machine can be
charged whether the handle be turned clockwise or in the contrary
direction, and the electrical effect is good even in damp places.
J. J. W.

Banger-Indicator for the Prevention of Collisions at Sea.
By P. Marcillac.

(La Lumifere Electrique, vol. sxix., 1888, p. 516.)

This apparatus, which has been devised by Messrs. Orecchioni
and Cavalieri, of the French military marine, consists of a sub-
marine boat shaped like a fish torpedo, and divided into three
separate compartments. The fore part is fitted with the danger-
signalling-gear ; the central chamber contains the electric motors,
and the one aft, the submersion mechanism and leading-in boxes
for the cables. At the bow is a conical contact-j^iece, riveted to a
rod, which passes through a stuffing-box into the front part of the
boat. When the cone strikes against any obstruction (such as a
submerged rock, the hull of a passing vessel, &c.), it is forced
inwards, and an arm at the rear end of the rod actuates a contact
lever, whereby the circuit of a battery and alarm bell on board the
protected ship is closed. The range of action is amplified by
means of jointed arms fixed to the cone, and, according to the part
of these arms which comes into collision with the obstacle, the rod
is either drawn out or pushed in, closing in each case the alarm
circuit. The signal boat is driven ahead of the vessel it protects
by means of an electric generator, the current being conveyed
through two conducting cables to a series of motors mounted on
the propeller shaft of the boat. The hydraulic gear for effecting
the submersion and maintenance of the boat at a certain depth
consists of a three-chambered cylinder, in which three pistons
work. The rod carrying the topmost one ^3, ends in a circular
disk, which butts against the inner face of a ciirved lever, uaovable
on an axis that is carried liy a support on the outer wall of the

Abstracts.] PREVENTION OF COLLISIONS AT SEA. 507

cylinder. The other end of the lever is jointed to a rod having a
thread on its lower end, which passes through a bracket screwed
to the oiitside of the cylinder. The rod can he raised or lowered
by means of a wing-nut, in order to regulate the pressure of the
curved lever on the upper piston. The other pistons pj and p., ^i"^
carried by a rod that works in a stuffing-box fitted in the central
chamber of the cylinder. Between the faces of p^ and ^3 is a
strong helical spring, which transmits the opposing force to the
lowest piston _p,. Attached to its rod by a crank-pin is the first arm
of a system of levers in connection with the submersion-blades,
and as soon as the boat is propelled forwards the pressure of the
surrounding water drives the piston p^^ inwards, the length of the
stroke and consequent action of the levers being dependent on the
amount of the opposing pressure, which has been calculated before-
hand for the required depth of submersion. Normally, the position
of the submerged boat is in a straight line with the longitudinal
axis of the vessel it precedes, but when the latter veers, say, to
starboard, the cable on that side is pulled taut, whereas the one on
the port side is slackened. At the stern of the boat is a steering-
bar, which projects 1^ metre on each side. As the cables are
attached to this bar, it partakes of their motion, and the boat is
thereby speedily swung into its initial position. In each cable is
run a leading-wire for the alarm circuit. The weight of the boat
is 900 kilograms for the large pattern and 500 for a smaller size.
The cables are 280 to 400 metres long, according to the dimensions
of the vessel and its protecting signal-boat.

J. J. W.

Studies on the Gas-Thermometer, and Comparison of tlie
Mercury- TJiermometer therewith.

By P. Chappuis.

(Archives des Sciences et Naturelles. Geneva. July-September, 1888, pp. 1 ct scq.^

The Author states that the air-thermometer does not always give
uniform results, and that it is necessary to select a definite gas,
deviating least from Boyle's law. The Author was commissioned
by the International Committee of Weights and Measures to make
experiments upon nitrogen, carbonic acid, and hydrogen gases, to
determine which was most suital)le for the purpose of a standard
gas-thermometer. The apparatus used in the experiments is very
fully described, and all possible corrections were made and sources
of error eliminated. Standard mercury thermometers were prepared
for comparison. The gas-thermometer reservoir used consisted of
a cylinder of platinum iridium, and its capacity exceeded 1 litre
(63 '4 cubic inches). The coefficient of the expansion of nitrogen
gas was found to be 0 • 00367466 for 1° Centigrade (1-8° Fahrenheit)
between 0^ and 100° Centigrade (32° and 212° Fahrenheit), and
the nitrogen gas-thermometer was found at 40" Centigrade (104°

508 STUDIES ON THE GAS-THERMOMETER. [Foreign

Fahrenheit), to read 0*097° Centigrade lower than the mercury-
themiometer.

Two values of the coefficient of expansion of carbonic acid
were found at diflerent pressures ; at the higher pressure it was
0-00372477, and at the lower jiressure 0-0037163-i for 1° Centi-
grade (1'8° Fahrenheit), between 0" and lOO^ Centigrade.

The carbonic acid gas-thermometer, at 40° CentigTade (104°
Fahrenheit), read 0*048 less than the mercury. In the hydrogen
experiments the Author foimd the coefficient of expansion of
hydrogen to be 0*00366254 for 1° Centigrade (1*8° Fahrenheit),
and the hydrogen gas-thermometer at 40° Centigrade (104° Fahren-
heit), read 0* 107° CentigTade less than the mercury.

The Author fully discusses the divergences of the expansion of
the three gases, and states that the more perfect the gas, the
greater the divergence from the curve of the exj^ansion of mercury.

Tables are given to readily correct readings on a mercury-ther-
mometer to nitrogen, carbonic acid, or hj^drogen gas-thermometers.

D. C.

The Foisonoiis Action of Water-Gas.
By Heinrich Schiller of Zurich,

(Zeitschrift fiir Hygiene, 1888, p. 440.)

A short time ago the workmen in a hat manufactory, in the
neighbourhood of Zurich, were attacked by various forms of illness,
which manifested itself in headaches, dizziness, vomiting, debility,
&c. In the preparation of the hats, iron moulds were used to
j)ress the felt, and these moulds were heated by numerous small
jets of water-gas, of the description furnished by a Dowson gene-
rator. The factory inspector satisfied himself that the illness was
probably caused by the diffusion of the unconsumed gas which
passed into the atmosphere, in consequence of the liability of many
of the small burners to become extingiiished. The Author, who
was charged to investigate the behaviour of the Dowson gas, gives
a sketch of its composition and preparation, and an account of the
use of water-gas in America, where, in ten gasworks and one
hundred towns, it is employed for ilhiminating purposes.

AVater-gas is only now used for lighting and heating at one
jilace in Switzerland, in Messrs. Sulzer's works at Winterthur, but
Dowson gas has been introdiiced in several different localities.
The points the Author had to determine are formulated in a series
of propositions, eleven in number, which deal with the effects of a
mixture of the gas with the atmosphere on animals, the least
quantity actually fatal to life, the percentage harmful, the toxic
agent in the gas, the sjnnptoms of Dowson gas and Avater-gas poison-
ing, &c. An apparatus of special design was contrived to prepare
uiixtures of Dowson gas in various proportions, an illiistration of
which is given. A number of ex]icriuicnts were conducted with

Abstracts.] THE POISONOUS ACTION OF WATER-GAS. 509

cats, rabbits, guinea-pigs, mice, and frogs, the results of which are
set forth in tables, and similar experiments were carried out with
water-gas. The conclusions arrived at are as follow : — As the
gases are devoid of smell, it is only when evolved from fuel con-
taining sulphur compounds that an odour of sulphuretted hydrogen
is perceptible. Both gases are strongly poisonous. The symptoms
are identical with those of poisoning by means of carbonic oxide
gas. A fatally poisonous mixture is an atmosphere with aboiit 1 per
cent, in the case of water-gas, and 1 • 5 per cent, in the case of
Dowson gas. Symjitoms of jioisoning are produced by abotit 1 per
mille with the former, and three parts per mille with the latter
gas. In non-fatal cases a rapid recovery, as a rule, ensues. The
poisonous principle is the carbonic oxide gas.

G. R. R.

Heat of Comhustion of Coal of the North of France.
By — Scheurer-Kestner.

(Annales de Chimie et de Physique, 1888, p. 262.)

Thfe Author has determined the heat of combustion of twenty-
one samples of coal from the Bassin du Nord, and the coal-basins
of Charleroi and the Pas-de-Calais. A Favre and Silbermann-calo-
rimeter was used, and the oxygen in which the combustion was
conducted was moist, in order to avoid error by carrying away
water of combustion. Chemical analyses of the samples were made,
and the whole results are tabulated in the Paper.

In the Tables the actually observed heat of combustion is given,
and compared with values calculated by different methods from the
analysis.

The maximTim observed heat of combustion was 9,030 calories
(35,831 English heat-units), and the minimum 8,5-15 calories
(33,906 English heat-units). The nature of the coke produced from
each sample is also given.

D. C.

( 511 )

INDEX

TO THE

MINUTES OF PKOCEEDINGS,

1888-1889.— Part I.

Accident to tlie Czar's train at Borki, Oct. 1888, 358.

Accumulators, Gadot, pattern 1888, 489.

Adams, Gr. F., admitted student, 112.

, T., Paper on the friction of the slide-valve and its appendages, 167, 18G,

189.

" Admiral " class of British -war-vessels. See Ships of War.

" Admiral Nakimotf," armour-clad cruiser, electric light installation on the, 498

Alexander, Prof., surveyor-general of Hawaii, and Lyons, C, district maps of
Windward Hawaii, 196.

, Prof. T., and A. W. Thomson. — Correspondence on Friction-Brake

Dynamometers : Etficiency of the Ajipold brake if properly used, 70.

Allen slide-valve, experiments on the friction of the, 173.

" Alpine Engineering" L. F. Vernon-Harcourt (S.), 237. — Alpine passes and
roads, 237. — Semmering railway, 241. — Brenner railway, 245. — Mont Conis
Fell railway, 249. — Considerations affecting main lines through the Alps, 253.
— Mont Cenis railway, 255. — Mont Cenis tunnel, 257. — Influences of the Mont
Cenis railway, 261. — St. Gothard railway, 262. — St. Gothard tunnel, 265. —
Arlberg railway, 268. — Arlberg tunnel, 269. — Proposed Mont Blanc railway
and tunnel, 271. — Proposed Great St. Bernard railway and tunnel, 272. — Pro-
posed Simplon railway and tunnel, 274. — Comjiarison between the three
Alpine schemes, 276. — Appendix : Data concerning Alpine railways, 278.

Amos, C. E. See Appold.

Anderson, A., elected member, 113.

Andrews, W. W., elected associate member, 113.

Annealing, influence of, on the strength of steel, 129 et seq.

" Anson," H.M.S., speed trials of, 325 et seq.

Antimony, electrolytic reduction of, from ores, 478.

Appleby, 0. J. — Correspondence on the Strength of Bessemer-Steel Tires : Experi-
ments with oil-tempered axles of Bessemer steel, 160. — Mistaken impression
that Bessemer steel would not harden, 161. — Tempering a more proiicr term
than oil-hardening, 162.

Appleton, E., transferred member, 112.

Appold, W., and Amos, C. E., compensating brake-dynamometer of, 7 et seq. —
Ditto, experiments with, 71.

512 INDEX.

Aqueduct. " The Fnihxre of the Kali Nad i Aqueduct on the Lmcer Ganges Canal"
abstracted by W. H. Thehvall (S.), 283.— Original design of the aqueduct, 283.
— Revised design, 284. — Partial destruction of the aqueduct, 285. — Complete
destruction, 286. — Design for new aqueduct, 287.
Arc lamps, the regulation of, 495.

Arnold, J. O. " On the Influence of Chemical Composition on the Strength of
Bessemer-Steel Tires" 115. — Discussion on ditto: Various and occasionally
mutually destructive criticism of his Paper, 155. — Molecular change versus
" fatigue," 156. — Steel identical in composition capable of varying largely on
the machine, 156. — Alleged change wrought by annealing in the state in which
carbon exists in steel, 156. — Brittleness of unannealed steel castings, 157. — ■
Quality of open-hearth steel tires giving the best results, 157. — Chemical com-
position of the struts used in his tests, 158. — Alleged rarity of tire-breakages
of late years, 158. — Fractures of tires on German railways, 158. — The practice
of annealing, 159. — Analysis of Belgian steel used for the tires on Victorian
Government railways, 159. — Simple means of bringing his experiments into
accord with those of others, 159.

Ashworth, J., memoir of, 394.

Aspinall, J. A. P. Discussion on the Strength of Bessemer- Steel Tires : Crystallization
of steel after long work, 140. — Annealing of mild steel, 141. — The suggestion
to trace the life of a tire from day to day throughout its life impracticable, 141.
— Wear of the tire often the measure of the period during which an engine
could be kept out of the shops, 141. " TJie Friction of Locomotive Slide-
Valves" 167. — Discussion on ditto: Further exijlanation of the experiments,
179_ — Earity of broken valve-spindles, 191. — Use of thick glycerine in the
hvdraulic cylinder of his apparatus, 191. — Lubrication of slide-valves, 192. —
Diaphragms versus cup-leathers for the indicator, 192. — Lubrication, 192. — Mode
of applying the weights, 193. — Very slight wear of cast-iron eccentric-straps, 193.
— Substitution of cast-iron for brass valves on the North-London railway, 193.

Atkinson, L. B., A.K.C., elected associate member, 113.

Atmospheric and seismic disturbances and the disengagement of firedamp, 473.

Attard, W., elected associate member, 113.

Austin, C. E., rapid survey made for, in Asia Minor, 209.

Aveling and Porter, Messrs., mode adopted by, for lubricating the axles of
traction-engines, 187.

Ayres, P. P., elected associate member, 113.

Ayrtou, Prof. W. E. — Discussion on Friction-Brahe Dynamometers : Transmission
and absorption-dynamometers for electro-motors, 51. — Dynamometer-couplings
for electro-motors, 53. — Practice of varying the arc of contact to neutralize the
variation of the coefficient of friction in compensating absorption-dynamo-
meters, 54. — Kuotted-belt absorption-dynamometer, 55.

Bagnall, H., M.A., B.E., transferred member, 112.

Balk's compensating brake-dynamometer, 10.

Bamford, C. F., admitted student, 112.

Banks, J., elected associate member, 113.

Barker, — , mode of testing steel tires adopted by, for the Great Indian Peninsula

Railway, 135.
Barnes, C. A. A., elected associate member, 113.
Barr, Prof. A. Discussion on Friction-Brahe Dynamometers : Question whether a

friction-brake could or could not give a scientifically accurate measure of the

INDEX. 513

work done by a motor, 29. — Different forms of dynamometer, 30. — Hia rope-
brake dynamometer, 31. — Spring-balances v. weights for dynamometers, 31. —
Rope-brake attributed to Prof James Thomson more probably due to Sir
William Thomson, 33. — Froude's brake at the Owens College, 33. — Use of the
dash-pot, 34. — Prof. James Thomson's mode of regulating the action of his
brake, 34. — Using of Eankine's formula in regard to friction-brakes, 35. —
Apix)ld's compensating-levers, 36. — Brake-trials of the Royal Agricultural
Society, 36.

Barratt, S. H. H., admitted student, 112.

Bates, O., elected associate member, 113.

Batterbee, R. C, memoir of, 382.

Bayne, T. J., admitted student, 112.

Beattie, W. G., paper by, on a balanced slide-valve for locomotive engines,
167, 186.

Beaumont, W. W. " Friction-Brake Dynamometers," 1. — Discussion on ditto :
Ayrton and Perry's brake, 29. — Controversy with regard to compensating-
lever brakes, 29. — Brake-trials for the Royal Agricultural Society, 68. — Com-
parison of indicators and friction-dynamometers, 68. — Rise and fall of the load
on a dynamometer, 68.— Use of springs instead of weights, 69. — Use of the
dash-pot, 69. — Alleged abuse of mathematical method in the calculation of the
maximum tension on the brake-straps, 69. — Coope's friction-brake, 70. — Use of
leather-covered brake-blocks, 70.

Beer system, the, of wire ropeways, 485.

Beketoff, N. N., the decomposition of salt by electrolysis, 504.

Bell, J. McK., elected member, 113.

Bentabol, H., a folding levelling-staff, 415.

Berkley, G., Vice President. — Discussion on the Strength of Bessemer Steel Tires ;
Importance of chemical knowledge in regard to steel, 148. — Alleged ten-
dency among engineers to specify high tensile steel for tires, 149. — His practice
in regard to testing tires, 149. — Effects of cliromium and other elements on
steel, 150. — Experiments by Professor Kennedy and Dr. Riley in 1882, 150.
— Practical impossibility of tracing the life of a tire day by day, 151. — Objec-
tions to chemical analyses, 151. — His practice in mechanical testing, 152.

Bessemer-steel tires. See Steel.

process, a new modification of the, 477.

Betchworth tunnel, Dorking. See Tunnel.

Beveridge, J., elected associate member, 113.

Bidois, C, pulverization of clay, and its application at the works of the Societe
Arnaud, Etienne & Cie., 422.

Binet, E. P., elected associate member, 113.

Biss, C. H., admitted student, 112.

Blackshaw, W., elected associate member, 113.

Blasting under water at the Panama canal works, special plant for, 448.

Bloys van Treslong, C. — Correspondence on the Withani Out/all Improvement
Works: Three works of different character simultaneously executed on the
Witham, 108.— Grand Sluice, 109.— Cut through the Scal^j, 109.— Cutting of
the Hoek van Holland, 109.— The case of the Donge and the Oude Maasje
analogous to that of the Witham and the Welland, 109. — More advantageous
on the score of cost to bring the outlet of the Welland to Clayhole than
to Lynn Deeps, 109. — Small width of the Witham channel to Boston, 110.^
Means of providing a deep-water outlet for the Welland, 110.
[the INST. C.E. VOL. XCV.] 2 L

514 INDEX.

Bonnami, — , yield of li}-draulic motors, 421.

Borchers, W., electroh'tic reduction of antimony from ores 478.

Boston Dock Cut, the, 97.

Bottle, F. ^y., admitted student, 112.

Boulle, M., Jandin's comi^ressed-air dredger, 450.

Bow-gii'ders. See Girders.

Bradley, A. "W., admitted student, 112.

Bragg, J. W., B.A., admitted student, 112.

Brakes, friction-. See Dynamometers.

Brancher, A., the Laon steep-gradient railway, 468.

Brauer, Prof. E., Paper on brake-dynamometers by, 28.

Brenchley, J. V., elected associate member, 113.

Bridge, New York and Brooklyn, the cable railway on the, 453.

over the Po at Casalmaggiore for the Parma-Brescia railway, 438.

Bridges, highway, of iron and steel, 430.

, railway, inspection and maintenance of, 432.

Brown, J., memoir of, 361.

, W. A., memoir of, 363.

Brownlow, Col., E.E., and the design for the Kali Nadi aqueduct, 289.
Bruce, Sir G. B., President — Bimussion on the Witliam Outfall Improvement
Works : Question of Mr. Duif Bruce as to the mode of handling the material
dredged from the river, 104.

, W. D. — Discussion on the Withmn Outfall Improvement Works : Question

as to the mode of handling the material dredged from the river, 104.
Brush, C. B., facts in relation to friction, waste and loss of water in mains, 459.
Brustlein, H. A. — Correspondence on the Strength of Bessemer-steel Tires: The
metal experimented uj^on by Mr. Arnold a manganese-steel with a small
percentage of chromium, 162. — Testing-jjractice at the Unieux works, Francci
162. — Superiority of chromium to manganese as an alloy for iron, 162.
Bucknall, H., admitted student, 112.
Budge, 0., elected member, 113.

Building materials, methods of testing the resistance of, 416.

Bunuugal, parish of, county of Eipon, Victoria, survey of, 215.

Burgess, S. E., elected associate member, 113.

, W. E., admitted student, 112.

Burmau, E. S., elected associate member, 113.

Burstall, H. R. J., Wh.Sc, elected associate member, 113.

Burton, C, elected associate member, 113.

Butler, W. R., elected associate member, 113.

Button, F. S., B.E., elected associate member, 113.

Buyers, W. L., elected member, 113.

Byng, H. A., his improvements in Balk's compensating brake dynamometer, 10.

Cable railway. See Railway.

Cables, submarine, on the measurement of the resistance of, 490.

Caland, P. — Coirespondence on the Witham Outfall Improvement Works : Efficient

nature of this work of river-improvement, 105.
" Camperdown," H.M.S., sj^eed-trials of, 325 et seq.
Canal, Ganges. " The Failure of the Kali Nadi Aqueduct on the Lower Ganges

Canal," abstracted by W. H. Thelwall (S.), 283.
, Panama, special plant for blasting under water at the works of the, 448.

INDEX. 515

Canals, Hague, the, renewal of water in the, 450.

Capper, D. S., M.A., " The Speed-Trials of the latest additions to the Admiral class
of British War-Vessels," 325.

Carbon, influence of, on the strength of steel, 115 et seq.

Carr, H., memoir of, 364.

Casalmaggiore bridge. See Bridge.

Cell, Ressner's, account of a series of experiments made on, 489.

Cements, methods of testing, 416.

Chapman, G. J., elected associate member, 114.

Chappuis, P., studies of the gas-thermometer, and comparison of the mercury-
thermometer therewith, 507.

Chavannes, R., the electric lighting of the City of Geneva, 496.

Chesuau, G., on the relation between seismic and atmospheric disturbances and
the disengagement of firedamp, 473.

Chromium, influence of, on the strength of steel, 119 e< seq.

Chukoloff, W., account of a series of experiments made on Hessner'a cell, 489.

Clark, E. G., elected associate member, 114.

Clarke, W. J., elected associate member, 114.

Clay, pulverization of, and its application at the works of the Societe Arnaud
Etienne & Cie., 422.

Cleaver, H. L., elected associate member, 114.

Clifton, C. T., elected associate member, 114.

Clyde. See Eiver Clyde.

Coal of the North of France, heat of combustion of the, 509.

Cochrane, J. H., admitted student, 112.

Cockerill and Co., J., Seraiug, steel tires supplied by, for the Victorian
Government railways, 142.

Coey, R., assistance rendered by, in Mr. Aspinall's experiment on the friction of
locomotive slide-valves, 178.

Collisions at sea, danger-indicator for the prevention of, 506.

Compensating-brake dynamometers. See Dynamometers.

Congress on inland navigation, proceedings of the second, at Vienna, 1886, report
of the French delegates on the, 440.

Connor, Major A. S. W., memoir of, 396.

Coomber, W. H., elected associate member, 114.

Coope's dynamometer-brake, 49.

Cope, W. A., admitted student, 112.

Copper-refining, electrolytic, in Hungary, 479.

Cost prices on railways, 469.

Cowan, D., elected member, 113.

Cowper, E. A. — Discussion on the Strength of Bessemer-Steel Tires : Falling-weight
test of no avail to alter the molecular arrangement of a steel tire, 139. —
Experiments of the London and North Western Railway on axles, 140. —
Alleged brittlcncss of steel castings prior to annealing, 140. — Influence of the
amount of work put upon steel, 140. — Hardness in a tire not necessarily
provocative of fracture, 140. — Discussion on the Friction of Locomotive Slide-
Vahes: Less power required for east-iron valves than for those of other
material, 190. — Balanced slide-valve, 190. — Reasons why a large valve required
more power to work with a short stroke than with a long one, 191. — Breakages
of slide-rods in marine engines, 191.

Cox, F. N., admitted student, 112.

2 L 2

516 INDEX.

Cox, — , signalling-apparatus on the St. Gothard Railway, 470.

Crawford, R., elected associate member, 114.

Cripps, F. S., elected associate member, 114.

Crook, C. R. E., elected associate member, 114.

Cross, W. — Discussion on the Friction of Locomotive Slide-valves : Subject very
little understood, 179. — Fracture of valve-spindles, 179. — Apparatus con-
structed by Mr. Marshall and himself for obser\-ing the friction of marine-
engine slide-valves, 180. — Doubtful advantage of cup-leathers in Mr. Aspiuall's
apparatus, 181. — Paper by Messrs. Marshall and Weighton on high-sijeed
engines, 182.

Cubitt, Sir W., recommendations of, in respect to the River Witham, 81.

D'Aeth, J., elected associate member, 114.

Danger-indicator for the prevention of collisions at sea, 506.

Dare, H. H., B.E., admitted student, 112.

Dashpot, use of the, with friction-brakes, 34, 69.

Davidson, W., elected member, 113.

Davies, J. T. L., admitted student, 112.

, M. "W., elected associate member, 114.

, W. A., elected associate member, 114.

Dawney, A. E., admitted student, 112.

Dawson, J. S., admitted student, 112.

Deas, J., his Paper on the River Clyde, 279.

Debenham, F. B., admitted student, 112.

Denny, R., memoir of, 369.

Deprez's compensating brake, 4, 60.

Desrozier's new disk-dynamo, 488.

Dickinson, T. R., elected associate member, 114.

Diesclhorst, W., elected associate member, 114.

Dieudonne', E., the Wimshurst machine, 504.

Dimier, P., A.K.C., elected associate member, 114.

Disinfecting power of steam. See Steam.

Donkin, B., jun. Correspondence on Friction-Brake Dynamometers : Experiments
in 1876 with an Appokl brake fitted with Amos adjusting-levers, 72.

Dredger, compressed-air, Jandin's, 450.

Dudley, Dr. P. H., his experiments on the chemical composition of steel rails, 133.

Durand-Claye, L., methods of testing the resistance of stones, cements, and other
building-materials, 416.

Dynamo, disk-, Desrozier's new, 488.

Dynamometers. " Friction-Brahe Dynamometers" "W. "W. Beaumont, 1. — Mea-
surement of power with friction-dynamometers, a subject of dispute, 1. —
Prony brake and modifications, 2. — Deprez brake, 4. — Imray brake, 6. —
Amos and Appold's brake, 7. — Balk's compensating brake, 10. — Water-cooled
brake of Messrs. Richard Garrett and Sous, 12. — Druitt Halpin's brake, 15. —
Professor James Thomson's brake, 16. — Professor Kennedy's brake, 17. —
Proportions and dimensions of brakes, 17. — The Appold friction-brake dyna-
mometers, 22. — Results obtained with a water-cooled brake by Messrs. J. and
H. McLaren and by the Engineers to the Royal Agricultural Society, 27. —
Discussion : ^Y. W. Beaumont, 29, 68.— Prof A. Barr, 29 ; Dr. E. Hopkinson.
37; R. E. Froude, 39; P. W. Willans, 47; Prof. A. B. W. Kennedy, 49;
G. Kapp, 50; Prof. W. E.^Ayrton, 51 ; J. Imray, 55; Prof R. H. Smith, 56;

INDEX. 517

D. Halpin, 62; J. Goodman, 67. Correspondence: Prof. T. Alexander and
A. W. Thomson, 70; B. Donkin, jun., 71 ; F. Garrett, 73; Prof. A. Jamieson,
74; W. Schonheyder, 76; J. E. Sweet, 77.

Earth-pressure underground, an apparatus for measuring, 471.

temperature, diminution of, in deep mines, 471.

Earthwork. ^^ Hurst's Triangular Prismatic Formula /w EartMcorh compared
luith the Prismoidal Fonnida" J. W. Smith (S.), 229.

Earthworks on the railway from Gien to Auxerre, consolidation of the, 466.

Eddy, E. M. G., elected associate, 114.

Edwards, L., designer of the Grand Sluice, River Witham, 83, 100, 105.

Eiffel, G., the Garabit viaduct, 434.

Electric light installation on the armour-clad cruiser " Admiral Nakimoff," 498.

. Regulation of arc lamps, the, 495.

. Self-regulating electric search-light, 497.

lighting of the City of Geneva, 496.

— machine, Wimshurst, 504 ; Glaser, 505.

winding-engine at Neu Stassfurt, 500.

Electrical tramcars in Paris, Philippart's, 492.

Electrolysis, the decomposition of salt by, 504.

Electrolytic copper-refining in Hungary, 479.

reduction of antimony from ores, 478.

Ellis, E., elected associate member, 114.

Ely, T. N., elected member, 113.

Embankment of the Po, at Turin, the, 449.

Emdin, A. R., admitted student, 112.

Emery testing-machine, application of the principle of the, to slide-valve in-
dicators, 185.

English, Col., experiments of, on the increase of tenacity in steels of various
chemical composition, 137.

Eversley, Viscount, memoir of, 360.

Examination of surveyors in the Australian colonies, 215.

Extension, critical, of bodies strained simultaneously in several directions, 410.

Falling- weight test v. other modes of determining the strength of steel, 166
et seq.

Fein, W. E., self-regulating electric search-light, 497.

Fell, J. B., his centre-rail railway over Mont Cenis, 249.

" Ferndale," steamer, sunk in the entrance channel of the Port of St. Nazaire,
raising the, 465.

Firedamp, on the relations between seismic and atmospheric disturbances and the
disengagement of, 473.

Fitz, N., B.E., admitted student, 112.

FitzGerald, M. F. — Discussion on the Witham Oidfall Improvement Worhs:
Importance in works of river-improvement of securing a free outfall at the
lowest possible level, 166. — Periodical excess of the flow of a river over the
observed rainfall as instanced by the Shannon, 106. — Effects of the new
Witham outfall channel on the discharge-channel of the V/elland, 108.

Flood of the river Wytham, October, 1883, 87, 101.

Flower, J. J. A., memoir of, 384.

Floyer, G. W., elected asssociate member, 114.

518 INDEX.

Foster, J. F., admitted student, 112.
Fowler, C. P., admitted stiideut, 112.

, J., memoir of, 371.

, P., transferred member, 112.

Francis, W., memoir of, 374.
Fraser, A., admitted student, 112.

, P. A., transferred member, 112.

Frere, F. H., A.K.C., admitted student, 112.
Friction, new theory of, 407.

brake dynamometers. See Dynamometers.

of water in mains, 459.

, slide-valve. — " The Friction of Locomotive Slide-valves." J. A. F.

Aspinall, 167.
Friederichs, H. F., admitted student, 112.
Friese, F. K. M. von, diiferences of level, in the mines of Austria and Hungary,

472.
Froude, R. E., Discussion on Friction-Brake Dynamometera : Variations of the

frictional resistance in respect of the accuracy of the record, 39. — Turbine

dynamometer invented by Mr. William Froude, 45.
, W., his turbine djniamometer-brake, 33 et seq. — His mode of determining

the internal resistances of the engines of war- vessels, 330. — His modification of

the Griffiths form of screw-propeller, 326.
Fulton, A. R. AV., transferred member, 112.

, J. E., transferred member, 112.

Furnace, smoke-consuming, Wilmsmann's, 464.

Gadot accumulators, pattern 1888, 489.

Ganga Ram, Rai Bahadur, transferred member, 112.

Garabit viaduct. See Viaduct.

Garrett, F. — Correspondence on Friction-Bralic Dynamometers : Exaggerated im-
portance sometimes attached to the construction of friction-brake dynamo-
meters, 73. — His experiment with the water-cooled brake referred to in Mr.
Beaumont's Paper, 73.

, R. and Sons, water-cooled brake used by, 12, 18, 21.

Gas, oil-. " Tlie Mmuifacture of Oil-Gas on the Pintsch System, and its application
to the Lighting of Railway-Carriages" G. M. Hunter (S.), 218.— Manufac-
ture, 218. — Compression, 222. — Application to the lighting of railway-carriages,
223. Appendix : Experiments to test the candle-power of gas, 228.

Gas-burners, comparative trials of various, 462.

Gas-thermometer. See Thermometers.

, water-, the poisonous action of, 508.

Geneste, F. A. B., memoir of, 375.

Geneva, electric lighting of. See Electric light.

Gerrard, A. S., transferred member, 112.

Gibson, A. S., elected member, 113.

Giddiugs, C. M., paper on the friction of slide-valves, 182.

Gilbert, C. H., Wh.Sc, admitted student, 112.

Giles, A., M.P. — Discussion on the Witham Outfall Tmpjrovement Worhs : General
effects of the new works, 96. — Boston Ocean Dock bill, 97. — Moral obligation
of all the persons whose land was improved by the works to contribute to their
cost, 97

INDEX. 519

Girders, bow-, jointed, the theory of, 426.

of the machinery hall of the Paris Exhibition of 1889, erection of the,

440.

Glaser influence machine, the, 505.

Gloyne, E. M., elected associate member, 114.

Gold ores, the smelting of, in Eastern Hungary and Transylvania, 480.

Goliath rail, Sandberg's, 354.

Good, G. L., elected associate member, 114.

Goodman, J. — Discussion on Friction-Brake Dynamometers : Use of leather-covered
brake-blocks, 67. — Discussion on the Friction of Locomotive Slide-Valves:
Diajahragm indicator on the princiiole of the Emery testing-machine, 185. —
Friction of the glands of slide-valve spindles, 186. — Friction of balanced slide-
valves, 186. — Mode of experimenting adopted by Mr. T. Adams and Mr. W.
G. Beattie, 186. — Lubricants for slide-valves, 187. — Mode of lubricating trac-
tion-engine axles adopted by Messrs. Aveling and Porter, 187.

Gradients, parabolic, for railways, principles of, 165.

Grand Sluice, river Witham. See Sluice.

Gray, J., of the Manchester and Liverpool railway, the first to adopt balanced
slide-valves for locomotives, 191.

Gribble, T. G. " Preliminary Survey in Neio Countries, as Exemplified in the
Survey of Windivard Hawaii," (S.), 195.

Grimshaw, J. W., elected associate member, 114.

Gruber, Prof. M., on the disinfecting action of a current of superheated steam,
461.

Haase's method of shaft-sinking, 475.

Habermann, R. and J. von Hauer, a winding-engine with spiral balance-drum,
484.

Hadfield, R. A. — Discussion on the Strength of Bessemer-Steel Tires : Experiments
of Mr. Dudley in the United States, 133. — Tests with varying proportions of
manganese, 133. — Tests by the Terre Noire Company in 1878, 134. — Effect
of the work put upon steel, 134. — Mode of testing steel tires adopted by
Mr. Barker of the G. I. P. railway, 135. — Microscopic examination of steel,
135. — Work of Mr. Howe of Boston, U.S.A., 135. — Influence of temperature
at working on the future characteristics of the steel, 136. — A good pyrometer
a desideratum, 136.

Hague canals, the, renewal of the water in the, 450.

Hallett, H., admitted student, 112.

Halpin, D., his water-cooled brake-dynamometer, 15. — Discussion on Friction-
Brake Dynamometers : Alleged inability of the dynamometer to give scientifi-
cally accurate measurements of work done, 62. — Brake-tests for the Royal
Agricultural Society at Newcastle-on-Tyne, 62. — Use of the Moscrop recorder
in brake trials, 63. — Mode of conducting the Newcastle trials, 64. — Discussion
on the Friction of Locomotive Slide- Valves : Paper by Mr. C. M. Giddings in
the Transactions of the American Society of Mechanical Engineers, 182. —
Results of experiments with Mr. Giddings' indicator, 184. — Causes of the
variation of the resistance during the stroke, 185.

Hamilton, W. L., admitted student, 112.

Harbord, F. W. — Corresjyondence on the Strenr/th of Bessemer-Steel Tires: Con-
clusion that high tensile steel can only be obtained at the expense of
ductility and general reliability, 163.

520 INDEX.

Harbour works, La Rochelle, the new, 454.

Hardening, influence of, on the strength of steel, 129 et seq.

Harpur, S., memoir of, 385.

, TV., transferred member, 112.

Hartley, Sir C. A., K.C.M.G. — Discussion on the Witham Out/aM Improvement

Works : Threefold results of the improvement, 93.
Har\-ey, F. J., admitted student, 112.
Haselkoos, N., on the testing of paper, 420.
Hauer, J. von. See Habermann.
Hawaii, survey of. See Survey.
Hawkins, G., memoir of, 397.

, H., admitted student, 112.

Hawkshaw, Sir J., recommendations of, in respect of the river Witham, 81, 92

et seq.
, J. C., Discussion on the Witham Outfall Improvement Works : Reason

why the improvement had been so long deferred, 92. — Condition of the district

before the completion of the works, 92.
Henard, E., erection of the large girders of the machinery hall at the Paris

Exhibition of 18S9, 440.
Hessner's cell, account of a series of experiments made on, 489.
Hewitt, J. E., elected member, 113.
Higgins, G., elected associate member, 114.
Highway bridges. See Bridges.
Hills, Staff-Commander G. H., memoir of, 398.
Hobbs, G., elected associate member, 114.
Hobhole sluice, river "Witham. See Sluice.
Hobley, C. W., admitted student, 112.
Hodgkinson, A. J., elected associate member, 114.
Hoek van Holland, cutting of the, 109.
Holliday, J., admitted student, 112.
Holmes, E., elected associated member, 114.
Hopkinson, Dr. E. — Discussion on Friction-Brake Dynamometers : Froude's

hydraulic brake, as improved by Prof. Osborne Reynolds and used at the

Owens College, 37. — Disadvantages of the Prony brake, 38. — Brakes made for

the triple-expansion engines in the Whitworth laboratory at the Owen

College, 39.
Hospitaller, E., the regulation of arc-lamps, 495.
Howe, — ., his work on the " Metallurgj' of Steel," 135.
Hughes, "VV., M.E., transferred member, 112.
Hull, P. W. admitted student, 112.
Humphrys, Tennant «fe Co., machinery of H.M.S. " Anson " constructed by, 325

et seq.
Hunter, G. M. " The Manufacture of Oil-Gas on the Pintsch System, and its

application to the Lighting of Bailway-Carriages," (S.), 218.
Hurst's prismatic formula for earthwork, 229 et seq.
Hurtzig, A. C. — Discussion on the Witham Outfall Improvement Works: Probable

effect of the larger volumes of water now passing in and out of the river, 103.

— Adoption of sandstone for the hollow quoins of the lock, 108. — Eifect of

onshore gales in promoting silting up, 103.
Hydraulic mortars. See Mortars.
slide-valve indicator, Aspinall's, 168 et seq.

INDEX. 521

Ikin, A. J., elected associate member, 114.

Imray's self-adjusting brake dynamometer, 6.

, J. — Discussion on Friction-Brake Dynamometers : Investigation by the

late Mr. W. Fronde and himself of the conditions of the frictional hold of

belts on pulleys, 55. — Description of the brake used, 56.
Influence-machine, the Glaser, 505.

^ tlie Wimshurst, 504.

Inland navigation congress, second, at Vienna in 1886, reports of the French

delegates on the proceedings of the, 441.
Instruments used in surveying, 202 et seq.
Iron highway-bridges, 430.
Itizkowski, R., regulation of the Isar according to Wolfs method, 445.

J. R., water-supply in the Kingdom of Wurtemberg, 458.
James, A., B.A., admitted student, 112.

Jamieson, Prof. A. — Correspondence on Friction-Brahe Dynamometers : Dynamo-
metrical tests of a Griffin gas-engine and forms of brake used, 74.
Jandiu's compressed-air dredger, 450.
Jaques, W. H., Lieut. U.S.N., elected associate, 114.
Jasper, N. P., elected associate member, 114.
Jenkin, C. F., B.A., admitted student, 112.
Jenkins, W. J., elected associate member, 114.
Jones, H. H., admitted student, 112.

, H. S., elected associate member, 114.

Joyan, — . See Lethier.

Kali Nadi Aqueduct. See Aqueduct.

Kapp, G. — Discussion on Friction- Brake Dynamometers : Rope-brake for testing
electro-motors, 50.

Keith, J., elected associate member, 114.

Kennedy, Professor A. B. W. — Discussion on Friction-Brake Dynammneters :
Brakes tested in motor-trials undertaken for the Society of Arts by himself,
Dr. Hopkinson, and Mr. Tower, 49.

and Riley, Dr., experiments by, on tire-steels of

varying chemical composition, 150.

Kershaw, S., information as to the manufacture of oil-gas on Pintsch's system, 227.

Kerviler, — , and — Prcverez, raising the steamer "Ferndale," sunk in the
entrance-channel of the Port of St. Nazaire, 465.

Killou, H. B., admitted student, 112.

King, J. W. — Discussion on the Strength of Bessemer-Steel Tires : Great advance
in steel manufacture since the date of Mr. Arnold's experiments, 163.

Kirkaldy, W. G. — Discussion on the Strength of Bessenner- Steel Tires : Sufficiency
of mechanical tests for steel, 146. — Increase of hardness not necessarily co-
incident with increase of tensile strength, 146. — Importance of the mode of
preparing the test-piece, 147.— Tests of steel by Messrs. D. Kirkaldy and
Son, 148.

Kolokoltzoff", Lieutenant, electric-light installation on the armour-elad eraiser
" Admiral Nakimoflf," 498.

Lafi'arguc, J., Gadot accumulators, pattern 1888, 489.
Lamansky, S., comparative trials of various gas-buruers, 462,

522 INDEX.

Lambert, J., admitted student, 112.

Landon, W. H. F., admitted student, 112.

Landslip at Zug, Switzerland, July 5, 1887, 411.

Lang, S. A., admitted student, 112.

Langley, H. W., admitted student, 113.

Lawton, R. J., elected associate member. 111.

Lee, A. G. V., admitted student, 113.

Lethier, — , and Joyan, — , consolidation of earthworks on the railway from

Gien to Auxerre, 466.
Levelling-staif, folding, a, 415.
Levels, lining, cast-iron tubbing for, 476.

Leverich, G., the cable railway on the New York and Brooklyn bridge, 453.
Lewis, W. B. — Discussioti on the Strength of Bessemer-Steel Tires : Quality of the

steel in a contract for tires let by the Victorian Government to Messrs.

Cockerill and Co., 142.— Similar tires since made by three English firms, 143.

— Qualities of the steel in the foregoing tire-contracts, 143. — Mr. J. T. Smith's

observations of the wear of soft steel rails on the Furness railway, 143.
Libbis, G. H., elected associate member, 114.

Lightning-conductors, on the connecting of, with gas- and water-pipes, 501.
Lindsey, E. S., admitted student, 112.
Littlejohn, H., elected associate member, 114.
Locomotive slide-valves. See Slide-valves.
Lopes, G. " The Reparation of the Betchicorth Tunnel, Dorlcing, on the London,

Brighton and South Coast Eailway" (S.), 291.
Lorden, F. L., admitted student, 112.
Loss of water in mains, 459.
Lovegrove, E., admitted student, 113.
Lyons, A. 0., elected member, 113.
C. See Alexander.

Macalister, D.— " The River Clyde " (S.) (Abstract), 279.

Macandrew, H., admitted student, 113.

Macdonald, D. G., elected associate member, 114.

Machinery Hall of the Paris Exhibition of 1889, erection of the large girders of

the, 440.
Maclaren, J. W. B., elected associate member, 114.
MacLean, L. F., elected member, 113.
McCallum, T. S., elected associate member, 114.
McDonnell, A. — Discussion on the Strength of Bessemer-Steel Tires: Practice of

annealing tires, 155.
McKenzie, L. S., admitted student, 113.

McLaren, J. and H., form of friction-brake used by, 15, 18, 21, 24.
Madsen, C. L., on the telephone equation, 493.
Magee, W. S. T., elected associate member, 114.

Mains, facts in relation to friction, waste, and loss of water in mains, 459.
Mair, J., Wh. Sc, admitted student, 113.
Maitland, General, his exi:)erieuce of the effect of working steel to varying

degrees, 154. — Ditto ditto oil-hardening, 161.
Manganese, influence of, on the strength of steel, 115 et seq.
Manning, 11., his observation that the flow of a river sometimes exceeds the

observed rainfall on its drainage area, 106.

INDEX. 523

Marcillac, P., danger-indicator for tlie prevention of collisions at sea, 506.

Markham, C, memoir of, 377.

Marks, E. C. R., admitted student, 113.

Marshall, F. C, apparatus for measuring the actual strains on a slide-valve, 181.

, F. C, and Weighton, R. L., Paper on high-speed engines, 182.

Marten, H. J. — Discussion 07i the Witham Outfall Improvement Works : Nature of
the works and mode of execution, 97. — Influence of the new Witham outfall
on the channel of the Welland, 98. — Works at the Grand Sluice, 98.

Martin, E. M., admitted student, 113.

, H. W., elected member, 113.

Martindale, W. B. H., elected associate member, 114.

Martin-Leake, S., elected associate member, 114.

Mason College, Birmingham, friction-brakes used at the, 59.

Materials, strength of, modes of testing the, 416.

Maud Foster Sluice, river Witham. See Sluice.

Maudslay Sons and Field, machinery of H.M.S. " Campcrdown," constructed by,
325 et seq.

Mercury-thermometer. See Thermometers.

Merewether, E. A. M., elected associate member, 114.

Meylan, E., Desrozier's new disk-dynamo, 488.

Miles, H. P., admitted student, 113.

Milues, G. P., elected associate member, 114.

Mines, deep, diminution of earth-temiJerature in, 471.

of Austria and Hungary, differences of level in the, 472.

Mittelhausen, C. J. A., admitted student, 113.

Molesworth's formula for earthwork, 229 et seq.

Montresor, C. E. C, elected associate member, 114.

Moore, C. J. A. P., admitted student, 113.

Morant, E. F., memoir of, 387.

Moriarty, A. D., admitted student, 113.

Mortars, hydraulic, yield of, 421.

Nansouty, Max de, special plant for blasting under water at the Panama Canal

works, 448.
Napoleon I., Alpine roads constructed by, 238 et seq.
Nevill, P., elected associate member, 114.
Nisbet, T., elected associate member, 114.
Norman, C. E., transferred member, 112.

Oakes, C. S., admitted student, 113.

Ocean Dock (Boston) scheme, the, 97.

O'Hara, J. G. M., admitted student, 113.

Oil-gas. See Gas.

Osborne, F. C, admitted student, 113.

Outfall channel (new) of the river Witham. Sec Eiver Witham.

Outram, F. D., admitted student, 113.

Owens College, Manchester, Froude turbine-dynamometers at the, 39 et seq.

Paper, on the testing of, 420.

Park, J. C. — Correspondence on the Friction of Locomotive Slide-Valves : Adoption
of cast-iron instead of brass for slide-valves on the North Loudon railway, 194.

524 DIDEX.

Partridge, W. A. M., elected associate member, 114.

Passes, Alpine, 237 et seq.

Paterson, P. J., admitted student, 113.

Pazzani, J., memoir of, 379.

Pedder, D. P., admitted student, 113.

Peutland, A. T., elected associate member, 114.

Perceval, R. D., elected associate member, 114.

Permanent-way. " The Permanent-way of some Railways in Germany and in
Austria-Hungary" translated and abstracted by W. B. Worthington (S.), 303.
— Table of dimensions, &c., of rails, 303. — Alsace-Lorraine State Railways,
306. — Bavarian State railways, 310. — Saxon State railways, 312. — Rhenish
Bavarian (Palatinate) railways, 313. — Hessian Ludwig's railway, 315. — Austrian
State railways, 316. — Baden State railways, 318.— Austrian Southern railway,
320. — Hungarian State railways, 321.

Perry, Prof J. and Prof. W. E. Ayrton, experiments of, with transmission and
absorption-dynamometers, 51.

, W. A., elected associate, 114.

Petroff, N., new theory of friction, 407.

Philip, A., analysis by, of tire-steel for the Indian Government Railways, 163.

, W. M., elected associate member, 114.

Philippart's, electrical tramcars in Paris, 492.

Phosphorus, influence of, on the strength of steel, 115.

Pichler, M. R. von, renewal of water in the Hague canals, 450.

Pinchin, R., memoir of, 388.

Piutsch's oil-gas as used on the Caledonian railway, 218 et seq.

Pilot, C. L. E., admitted student, 113.

Playfair, W., admitted student, 113.

Potable waters. See Waters.

Port, construction of a, at Prague, 447.

Portsmouth, J., admitted student, 113.

Powell, A., elected associate member, 114.

Prague, construction of a port at, 447.

Prescott, H. E., elected associate member, 114.

Presentation of medals and premiums, 1.

Pressure, earth-, underground, apparatus for measuring, 471.

Preverez. See Kerviler.

Price, J., jun., B.E., elected member, 113.

Prinetti, T., the embankment of the Po at Turin, 449.

Prinsep, R. S., elected associate member, 114.

Prismatic formula for earthwork. See Earthwork.

Prismoidal formula for earthwork. See Earthwork.

Prony brake, principles of the, 2 et seq.

Pulverization of clay. See Clay.

Pyrometer, trustworthy, want of a, 136.

Quarrying by wire, 424.

Rails. " On the Use of Heavier Rails for Safety and Economy in Railway Traffic,"
C. P. Sandberg, Abstract (S.), 354.— Goliath rail, 354.— Experiments at the
Domnarfvet works, Sweden, 355. — English permanent- way, 356. — Supplement :
Accident to the Czar's train at Borki, October 1888, 358.

INDEX. 525

Railton, A., admitted student, 113.
Railway, Arlberg, 268.

, Austrian North Western, permanent-way of the, 303, 308.

, Austrian Southern, permanent-way of the, 304, 320.

, Brenner, 245.

, Caledonian, lighting of carriages by oil-gas, on the, 218 et seq.

, cable, the, on the New York and Brooklyn bridge, 453.

carriages, lighting of, by compressed gas, 218.

, Gien and Auxerre, consolidation of earthworks on the, 464.

, Great St. Bernard (proposed), 272.

, Hessian Ludwigs, ijermanent-way of the, 304, 315.

, London, Brighton and South Coast, reparation of Betchworth tunnel on

the, 291 et seq.

, Mont Blanc (proposed), 271.

, Mont Cenis, 255.

, , (Fell), 249.

, St. Gothard, 262. — Signalling-apparatus on the, 470.

, Semmering, 241.

, Simplon (proposed), 274.

, steep-gradient at Laon, 468.

structures, inspection and maintenance of, 432.

Railways, Alsace-Lorraine, permanent-way of the, 303, 306.

, Austrian State, permanent-way of the, 304, 316.

, Bavarian State, permanent-way of the, 304, 310.

, cost prices on, 469.

, Hungarian State, permanent-way of the, 304, 321.

, Rheinish Bavarian (Palatinate), permanent-way of the, 304, 313.

, Saxon State, permanent- way of the, 312.

Rainfall at the Grand Sluice, Boston, 90, 91.

in the Witham Drainage District, October 1883, October 1885, 87, 101.

Raising the steamer " Ferndale," sunk in the entrance channel of the port of
St. Nazaire, 465.

Ranken, A. W., A.K.C., admitted 8tudent,'113.

Ransomes, Sims, & Jeflferies, Messrs., forms of friction-brake dynamometer used
by, 10, 18, 21.

Raoult, C, the Beer system of wire ropeways, 485.

Reid, R. N. H., admitted student, 113.

Rendel, Sir A., K.C.I.E. — Correspondence on the Strength of Bessemer-steel Tires :
Testing tires for the Indian State railways, 163. — Analysis of tire-steel for
the same, 163.

, W. S., transferred member, 112.

Rendell, A. W., elected member, 113.

Rennie, Sir J., recommendations of, in respect of the river Witham, 81.

Reynolds, E. — Discussion on the Strength of Bessemer-Steel Tires: Hardness not
the only quality essential for long wear, 131. — Steel tire made by Naylor
Vickers & Co. for the Great Western Railway in 1868, 131. — " Body " iu
steel, 131. — The so-called molecular change iu steel under certain conditions,
132. — Quality alone to be relied upon if high results were expected, 133.

Richards, R. W., elected associate member, 114.

Ricour, G., cost prices on railways, 469.

Rilev, Dr. Sec Kennedy.

526 INDEX.

Ringel, A., measurements of the flow of the Elbe in Saxony, 1886 and 1887, 444.

River Clyde. " The Eiver Clyde," D. Macalister (S.) (Abstract), 279.— Changes
in the navigable and subsidiary channels from Dumbarton to Greenock
between 1860 and 1880, 279.— Old channel, 280.— Volume of water passing
Garvcl Point, 281. — Works necessary for maintaining the channel, 282.

Donge (Holland), affected by the Oude Maasje, 109.

Elbe in Saxony, measurements of the flow of the, in 1886 and 1887, 444.

Isar, regulation of the, according to Wolf's method, 445.

Moldau, improvement of the, at Prague, and the construction of a port

there, 447.

Nadi, aqueduct carrying the Lower Ganges Canal over the, 283.

Oude Maasje (Holland), influence of the, on the Donge, 109.

Po, embankment of the, at Turin, 449.

Shannon, flow of the, 106.

Welland, influence of the Witham new outfall on the, 95 et seq.

Witham. " The Witham New Outfall Channel and Improvement Works,"

J. E. Williams, 78. — Course of the river from its rise, 78. — Grand Sluice,
79. — Unfavourable nature of the river previous to 1878 for drainage
and for navigation, 79. — Recommendations of the General Commissioners
of the Witham in 1879, 81. — River Witham Outfall Improvement Act,
1880, 81. — Execution of the works : Excavation, 81. — Embankment, 82. —
New channel, 83. — Enlargement of the Grand Sluice, 83. — New locks, 84. —
Widening between Grand Sluice and Tattenhall Bridge, 85. — Cost of the
works, 86. — Appendixes : I. Flood report, 1883, 87. — H. Flood report, 1885,
88. — in. Tidal curves at Boston before and after completion of the new
channel, 89. — IV. Rainfall at the Grand Sluice, Boston, 90. — V. Greatest
rainfall in one day at the Grand Sluice, Boston, 91. — Discussion: J. E. Wil-
liams, 92, 104 ; J. C. Hawkshaw, 92 ; Sir C. A. Hartley, 93 ; L. F. Vernon-
Harcourt, 94 ; A. Giles, M.P., 96 ; H. J. Marten, 97 ; W. Shelford, 99 ; J. G.
Symons, 101; A. C. Hurtzig, 103; F. Wentworth-Sheilds, 103; Sir G. B.
Bruce, 104. — Correspondence: P. Caland, 105; M.F.Fitzgerald, 106; C. Bloys
van Treslong, 108.

Roads, Alpine, 237 et seq.

Roberts- Austen, Prof. W. C. — Discussion on the Strength of Bessemer- Steel Tires :
Mode of existence of the carbon in hard and in soft steels, 136. — Influence of
added impurity in metals probably governed by a law, 137.

Robins, W. H., elected associate member, 114.

Robinson, J. P., admitted student, 113.

Robson, R. O., elected member, 113.

Rochelle Harbour. See Harbour.

Rochfort, J., elected associate member, 114.

Rogers, R. B., M.A., elected associate member, 114.

, W., memoir of, 380.

Roome, G. W., admitted student, 113.

Ropeways, wire-, the Beer system of, 485.

Rose, F., jun., elected associate member, 114.

Ross, G. H., memoir of, 382.

Rouillard, A., on the measurement of the resistance of submarine cables, 490.

Rowlandson, C. A., elected member, 113.

Roy, N. W., elected associate member, 114.

Royal Agricultural Society, dynamometers used by the, 18 et seq.

INDEX. 527

Salt, decomposition of, by clectrolyBis, 504.

Sampson, J., elected associate member, 114.

Sandberg, C. P. " On the Use of Heavier Rails for Safety and Economy in
Railway Traffic (S.) (Abstract), 354.

Scheurer-Kestner, — , heat of combustion of the coal of the North of France, 509.

Schiller, H., the poisonous action of water-gas, 508.

Schnabel, Dr., the smelting of gold and silver ores in Eastern Hungary and
Transylvania, 480.

Schiinheyder, W. — Corresijondence on Friction-Brake Dynamometers : Type of
friction-brake most suitable for general engine-testing, 76. — Alleged difficulty
of adjusting brakes fitted with compensating-levers, 76. — Efficiency of the
water-cooling arrangement for brake-wheels, 76.

Schwartz, A., admitted student, 113.

Search-light, electric, self-regulating, 497.

Seller, — , Wilmsmann's smoke-consuming furnace, 464.

Sewage-works, East Orange, the, 460.

Shaft-sinking by Haase's method, 475.

Shaw, J. J., elected associate member, 114.

Sheilds, F. Wentworth-. — Discussion on the Witham Outfall Improvement Works :
Question as to the direction of the flood-tide in the Witham, 103.

Shelford, W. Discussion on the Witham Outfall Improveinent Works : Physical
aspect of the Fen rivers, 99. — Omissions of tidal observations and tidal
diagrams from the Papers of Mr. Williams and Mr. Wheeler, 99. — Keasons for
adopting a slope of 4 to 1 in the new channel, 99. — The designer of the Grand
Sluice, 100. — Effect of its construction, 100. — Question of self-maintenance of
the new channel, 101.

Shenton, H. 0. H., admitted student, 113.

Ships of war. " The Speed-Trials of the latest additions to the Admiral Class of
British War-Vessels," D. S. Capper (S.), 325.— H.M.SS. " Camperdown," and
" Anson," 325. — Engines of the " Camperdown," by Messrs. Maudslay Sons and
Field, 325. — Engines of the "Anson," by Messrs. Humphrys, Tennant and Co.,
327. — Mode of conducting Admiralty official trials, 328. — Trial of the " Cam-
perdown," 330. — Trial of the " Anson," 332. — Special conditions influencing the
design of the machinery of war- vessels, 334. — Differences between the engines
of the " Camperdown " and the " Anson," 337. — Appendix, Tables : I. Abstract
of mean results obtained at trials of H.M.SS. "Anson" and "Camperdown"
in 1887, 343. — II.-V. Half-hourly records of trials with open and closed
stokeholds, 845. — VI-VII. Temperatures of engine-rooms and stokeholds
during trials of the " Anson," 349. — VIII. Particulars of machinery, 357. — IX.
Ditto, ditto, ratios and coefficients, 352. — X. Comparative table of weights of
engines and boilers, 353. — XI. Data for twisting moments, 353.

Siemens and Halske's electric winding-engine at Neu Stassfurt, 500.

Signalling-apparatus on the St. Gothard railway, 470.

Silicon, influence of, on the strength of steel, 115 ei seq.

Sillcm, W., admitted student, 113.

Silver ores, the smelting of, in Eastern Hungary and Transylvania, 480.

Skelton, K., A.K.C., elected associate member, 114.

Sketchley, H. G., transferred member, 112.

Slide-valves. " The Friction of Locomotive Slide-Valves," J. A. F. Aspinall, 167.
— No trustworthy data extant of the friction of slide-valves under steam, 1 67.
— Mechanism devise<l to give a diagram of the exact force required to move the

528 INDEX.

valve at each point of the stroke, 168. — Table I. Experiments on the friction
of the apparatus, 169. — Method of dealing with the diagrams obtained, 170. —
Table II. Experiments with the valve pulling and pushing, 171. — Discussion
of the results, 172. — Table III. Pressure on valve and valve-resistance at mid-
stroke, 176. — Table IV. Percentage of power lost in friction of valves and
eccentrics, 177. Discussion: J. A. F. Aspinall, 179, 191; W. Cross, 179;
D. Halpin, 182; J. Goodman, 185; B. Tower, 188; W. Stroudley, 188; E. A.
Cowper, 190 ; E. Woods, Past President, 191. — Correspondence: J. C. Park, 194.

Slow-cooling, influence of, on the strength of steel, 120.

Sluice, Grand, river Witham, enlargement of the, 79 et seq.

, Hobhole, river Witham, 79 et seq.

, Maud Foster, 79 et seq.

Smeaton, J., usually credited with the design of the Grand Sluice on the river
Witham, 100, 105.

Smijth, E. C. B., transferred member, 112.

Smith, J. W., " HxirsVs Triangular Prismatic Formula for Earthwork compared
with the Prismoidal Formula" (S.), 229.

, Prof. R. H. — Discussion on Friction- Brake Dynamometers : Description of

his transmission-dynamometer, 56. — Friction absorption-dynamometers, 57. —
Type of brake used at Mason College, Birmingham, 59. — Deprez's brake, 60.

Soltz, A., electrolytic copper-refining in Hungary, 479.

Sorby, Dr. H. C. — Discussion on the Strength of Bessemer- Steel Tires: Microscopic
structure of steel, 144. — Phenomenon of hardening as observed under the
microscope, 145. — Necessity for prolonged individual study in regard to steel,
146.

Sowerby, W. — Correspondence on the Strength of Bessemer-Steel Tires : Shocks to
tires in testing by the falling weight not of the same nature as those occurring
in actual work, 164. — Parabolic gradients on railways, 165. — Use of manganese
and of chromium by early Indian and Sjianish steel-makers, 165. — Mode of
working steel for swords and guns in India, 165.

Speed-trials. — " The Speed-Trials of the latest additions to the Admiral Class of
British War-Vessels." D. S. Capper (S.), 325.

Spencer, C. T., memoir of, 391.

Steam, elucidation of the disinfecting power of, 462.

superheated, on the disinfecting action of a current of, 461.

Steel. " On the Influence of Chemical Composition on the Strength of Bessemer-
Steel Tires." J. O. Arnold, 115. — Importance of the subject, 115. — Tendency
of railway engineers to specify high tensile steel for tires, 115. — Proper limits
of carbon in Bessemer tire-steel, 116. — Eifect of the varying proportions of
the different elements usually present in tire-steel, 117. — Effect of chromium,
119. — Influence of slow cooling on the arrangement of the molecules, 120. —
Influence of the amount of work put on steel, 122. — Views of the engineer on
the mode of testing as distinct from those of the manufacturer, 127. — How far
the makers' tests indicate the fitness of tires for the work to which they will
be subjected, 128. — Influence of hardening and of annealing, 129. — Dis-
cussion: E. Reynolds, 131; R. A. Hadfield, 133; Prof. W. C. Roberts-Austen,
136; W. M.Williams, 137; E. A. Cowper, 139 ; J. A. F. Aspinall, 140; W. B.
Lewis, 142; Dr. H. Clifton Sorby, 144; W. G. Kirkaldy, 146; G. Berkley,
148; T. E. Vickers, 152; W. Stroudley, 154; A. McDonnell, 155; J. O.
Arnold, 155. Correspondence: C. J. Appleby, 160'; H. A. Brustlein, 162;
J. W. King, 163; Sir A. Rendel, 163; W. Sowerby, 164; B. W. Winder, 165.

INDEX. 529

steel, Bessemer-, i^rocess, a new modificatiou of the, 477.

, highway bridges, 430.

Steep-gradient railway. See Kailway.

Stephens, F. C, elected member, 112.

, H. F., admitted student, 113.

Stephenson, E. P., elected associate member, 114.

Stewart, S., photometric tests of oil-gas, 227.

Stone-cutting and quarrying by wire, 424.

Stones, methods of testing the resistance of, 416.

Stoney, E. D., admitted student, 113.

Stothert, P. K., elected associate member, 114.

Strain. On the critical extension of bodies strained simultaneously in several
directions, 410.

Streatfeild, H. S., admitted student, 113.

Strobel, C. L., experiments on a new form of strut, 428.

Stroudley, W. — Discussion on the Strength of Steel Tires: Experience on the
Brighton Railway with tires of various compositions of steel, 154. — Discussion
on the Friction of Locomotive Slide-Valves: Mode of lessening the friction by
plugs of tin inserted in the face of the valve, 188. — Slide-valves of the B, C and
D classes of engines on the Brighton railway,. 189. — Reasons for discarding
balanced slide-valves, 189. — Experiments made under other than the working
conditions not of much value, 190.

Structures, railway, inspection and maintenance of, 432.

Strut, new form of, experiments on a, 428.

Sulphur, influence of, on the strength of steel, 115.

Surveying. " Preliminary Survey in Neic Countries, as exemplified in the Survey
of Windward Haicaii." T. Gr. Gribble (S.), 195. — Physical features of the
island, 195. — Proposed railway to convey produce from the interior to the
coast, 195. — Mode of surveying determined upon, 196. — Optical work at the
gulches, 198. — Field-book, 199. — Appendixes, I. : List and description of instru-
ments, 202. — II. Field-book, 204. — III. General principles of telemetry and
telemeters, 207.

, '■'Rapid Surveying" F. D. Topham (S.), 209. — Route survey in

Asia Minor, 209. — Mode of working with the prismatic compass, 209.

The Practice of Surveying in the Australasian Colonies." S. K.

Vickery (S.), 211. — Organization of the several Government departments
employing surveyors, 211. — Surveying in the colony of Victoria, 212. — Appen-
dixes, I. : Examinationof surveyors, 215. — II. : Survey of block with check-line,
215.

Sweet, J. E. — Correspondence on Friction-Brake Dynamometers : Application of
the platform weighing-machine for producing resistance, 77.

Sykcs, C. M., elected associate member, 114.

Symons, G. J. — Discussion on the Witham Outfall Improvement Worhs : Rainfall
of September, 1883, in the Witham Drainage District, 101.

Syson, R. C, elected associate member, 114.

Tait, W. A. P., B.Sc, admitted student, 113.
Taylor, F. M. S., admitted student, 113.
Telegi-aph cables. See Cables.
Telemeters. See Telemetry.
Telemetry, general principles of, 207.

[the INST. C.E. VOL. XCV.] 2 M

530 INDEX.

Telephone equation, on the, 493.

Telephone line between Paris and Marseilles, 494.

Terre Xoire Company's, the, tests in 1878 of steels of varying chemical compo-
sition, 134.

Testing of building materials. See Materials.

of paper. See Paper.

of steel. See Steel.

Thelwall, W. H. — " Hie Failure of the Kali Nodi Aqueduct on the Lower Ganges
Canal" (S.), 283.

Theodolites, modem, 202.

Thermometers. Studies on the gas-thermometer, and comparison of the mercury
thermometer therewith, 507.

Thomas, A. D., elected associate member, 114.

Thompson, C. W., admitted student, 113.

, J., admitted student. 113.

Thomson, A. W. See Alexander.

, Professor J., rope dynamometer, proposed of, 16 et seq. — Variation of

the arc of contact in friction-brakes, due to, 54.

Thurston, Professor K. H., water-cooled brake-dynamometer described by,
18, 20.

Tires. — " On the Influence of Chemical Composition on the Strength of Bessemer-
Steel Tires" J. O. Arnold, 115.

Topham, F. 'D.—^'Bapid Surveying" (S.), 209.

Tower, B. — Discussion on the Friction of Locomotive Slide-Valves: Question as to
the mode of a^iplying the weights in Mr. Aspiuall's experiments, 188. — Defect
of the frictional indicators, 188. — Mr. Cross's diaphi-agm indicator, 188.

Tramcar, electrical, Philijipart's, in Paris, 492.

Trickett, J., memoir of, 392.

Tubbing, cast-iron, for lining levels, 476.

Tunnel, Arlberg, 269.

, Betchworth. " T/ie Beparation of Betch worth Tunnel, Dorking, on the

London, Brighton and South Coast Bailioay," G. Lopes (S.), 291. — Circum-
stances attending the failure of the old tunnel, 291. — Works of reparation :
timbering, 292. — New brickwork, 297. — Connecting the new work with the
old, 300.— Cost of the work, 302.

, Great St. Bernard (proposed), 272.

, Mont Blanc (proposed), 271.

, Mont Cenis, 257.

, St. Gothard, 265.

-, Simplon (proposed), 274.

, Stuttgart, alignment of, 415.

Tumbull, N. K., Wh.Sc, admitted student, 113.

Vernon-Harcourt, L. F. — Discussion on the Witham Outfall Lnprovtment Worhs :
Difficulties in connection with the removal of the Grand Sluice, 94. — Recom-
mendation of Sir John Hawkshaw, in 1877, for dealing with the floods, 94. —
Proposed enlargement of the Grand Sluice, 95. — Conflicting interests of the
rivers Witham and Welland, 95. — Probable insufficient width of the new
outfall channel, 96. — District above Lincoln not yet secured from floods in
very wet winters, 96. — " Alpine Engineering " (S.), 237.

Viaduct, Garabit, the, 434.

IKDEX. 531

Vicars, J., B.E., admitted student, 113.

Vickers, T. E. — Discussion on the Strength of Bessemer-Steel Tires : Mr. Arnold's
mode of experimenting varying from the received methods, 152. — Composition
of a good steel tire, 153. — Alleged molecular changes in steel of high temper,
153. — Chromium as an alloy of steel, 154. — Reheating of tires, 154.

Vickery, S. K. — " The Practice of Surveying in the Australasian Colonies " (S.),
211.

Victoria, practice of surveying in, 211.

Wakeford, J., memoir of, 393.

Walker, A., elected associate member, 114.

, C. L., elected associate member, 114.

Walz, A., elucidation of the disinfecting power of steam, 462.

Ward, T. H., elected associate member, 114.

Waring, H. F., memoir of, 394.

Warner, W., elected associate member, 114.

Wash, the, and the Fen rivers, 78 et seq.

Water-cooled brake-dynamometers, 13 et seq.

Water-gas. See Gas.

, loss of, in mains, facts in relation to friction, waste, and, 459.

, renewal of, in the Hague canals, 450.

supply of the kingdom of Wurtemberg, 458.

Waters, potable, the qualities of, 457.

, waste of, in mains, facts in relation to, 459.

Wearing, W., elected associate member, 114.

Weber, L., on the connecting of lightning-conductors with gas- and water-pipes,
501.

Wehage, — , on the critical extension of bodies strained simultaneously in
several directions, 410.

Weightman, W. J., elected associate member, 114.

Weightou, R. L. See Marshall.

Werner, E. A., the theory of jointed bow-girders, 426.

Wheeler, W. H., proposal of, for treating the Fen rivers, 82, 99.

Whitaker, J., Wh. Sc, admitted student, 113.

White, H. T., admitted student, 113.

Widmann, — , the alignment of a tunnel at Stuttgart, 415.

Willans, P. W. — Discussion on Friction-Brahe Dynamometers : Trials of an
Appold dynamometer, 47. — Fronde's turbine dynamometer, 47. — Coope's
brake, 49.

Willcox, B., elected associate, 114.

Williams, J. E. — " Tlie Witham New Outfall Channel and Improvement Woi-hs,"
78. — Discussion on ditto : Effects of the new channel, 92. — Effect of concen-
trating the scouring action of the tide on the new outfall channel, 104. — Scour
of the Witham not always advantageous to the Welland, 104. — Provisions of
the River Witham Improvement Act in regard to the Welland, 104. — Area
benefited by the present works, 105. — Reasons for adopting a slope of 4 to 1 for
the banks, 105. — The designer of the Grand Sluice, 105. — Mr. Symons's rainfall
observations, 105. — Material of the hollow quoins of the lock, 105. — Disposal
of the dredging, and cost, 105.

, W. M. — Discussion on the Strength of Bessemer-Steel Tires : Alleged

tendency of railway engineers to specify for high tensile steel tires, 137. —

532 IKDEX.

Col. Englisli's experiments at Sir John Brown's Atlas Works, 137. — Inability
of steel to resist shock when under vibrating strain, 138. — Influence of man-
ganese on steel, 138. — Admiralty specification of 1878 for ship steel, 189.

Wilmsmann's smoke-consuming furnace, 464.

Wilson, R., his balanced slide-valve, 190.

Wimshurst machine, the, 505.

Winder, B. W. — Correspondence on the Strength of Bessemer Steel Tires : Mode
of occurrence of carbon in high-grade steels, 165. — Importance of co-operation
of the diflerent persons concerned in producing and using steel if the question
of molecular change was to be solved, 466.

Winding-engine, a, with spiral balance-drum, 484.

, electric, Siemens and Halske's, at Neu Stassfurt, 500.

Wire, stone-cutting and quarrying by, 424.

Wire-ropeways. See Eopeways.

Wise, B. D., elected member, 113.

WolFs method, regulation of the Isar according to, 445.

Woods, E., Past President. — Discussion on the Friction of Locomotive Slide-Valves :
Mr. John Gray, of the Manchester and Liverpool railway, the first to use
balanced slide-valves, 191.

Worthiugton, W. B. — " The Permanent-way of some Bailicays in Germany and in
Austria-Hungary" 303.

Wrench, F. H., admitted student, 113.

Wyatt-Smith, A., admitted student, 113.

Yonge, M. E., admitted student, 113.

Zug, Switzerland, landslip at, July 5, 1887, 411.

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i'ii 7 > / :%■ / .■767

:i 7 :i'i

^r!)l>. 2i;r.j

111(11 1

Hjul ill' Nj'itlttlr

s,-,-i c

I'M 11 Ihi

PULLING END OF HYDRAULIC CYLINDER-

SLIDE VALVE DIAGRAMS FPOM AM EXPRESS CN«IMC WTtm M*€m

>iajle for Stftjjn I'ylinjljr ili/itfmmj$ tt
Hrtile for Vah-e if

Hodo P,-et:«un 160 lbs

a I J I : ;'.v"7

Erit/ ot\'<fHitfllf

u::' a its Anmt .•« IoA»

A.K A£HI11AJ>7-,DELT

PUSHING END OF HVORAtttlC CrVl«»li

Mmutes of Pi-m-eearngs o:' The lustitunon ct' v'-.v-.'. Euj;"iii-

r«lVt DIAGRAMS FROM AN EXPRESS ENGINE WITH ALLEN VALVES.

/v//... /^^,

Srul ofA'pttiflle 254 ■ (>'

/-W7 I /U tlu7,«t on \UI\-.

Fu) : n.

48 5 - 1-16'Sei - eei^
t;e72. 28 z: = isse .

En J ufspmiUe 3)0 a

1S7S-6 Ibn thrjjitt on- Hih-r

■ I v.v

D ■••--.

/ :
/ V

■ '■': B Iht thnijtt mi Kih-e.

62 75 ■ 2H-27 - 1773 ,1

Eiui of spindle 2S4 t>

■Ul r,.-, 12(7. .7 CI - .^71; 7
■717 7 • 2H27 - 1(702 !)

EnJ „rxpuitlU 2.'t4 (7

l/i4,1 H 11,.- Ihru^i „„

PUSHING END OF HYDRAULIC CYLINDER.

JijjtiUtoon of Cml En^neers Vol. Xcf . Session , 1 888 8.? J'ari/ 1

B,<il,;Prm«iirr li;(> lh.-<

X.Y. .SV,,,„, fhr.sl J);

^'°^- .78-8 ■ 121! ' .76V " 7» 7
7:>7-2H27 - 2253 1

K,„l „r.sp„„ll,-

APcJ^lis

-^2' sa «.;»»•-..-&/ - 7:ij

73 4 k2827 = 2t>7oO

End cfspmJU StO-ri

176*6 lis dtnut <•> lu^>

.V;'A

671-2827 - ..x.-'b.*

End ot'spuuile 310^

IS»i4 Mc Humat tm HAm

l:ll2 (7 ll^- tJtiiisI im I'li/lf

PUSHING END OF HYDRAULIC CYLINDER.

SLIDE VALVE DIAGRAMS FROM A GOODS ENGINE WITH ORDINARY SRAS& ^AL^ES .

A«/<. fl»

/>,/••>• /■?

A.RJMjLMi«

I'UJSII

Hcala for fiteam Cyijii/J/r- cUa^rornji u
ScaZo for VaJyei Jt

r.^.

13'5 ■ 126^3&i — i-^-M
2233x2651 - e07 8

End afspinJU 190 I

IS :i > I2U - .7 67 :W fe'ff
2S(ili ■ i'S.^I To-'' r

/;■«// or.-riiuUe is:i I

:u:) I /A.v /«,// ,./' li/Ai

^0£/«r 3essure_m}_lb;,

■St,, Hit -r/„.v/ /)v»\s'»;> /;'/ //«

^° 'lH4o. I^e*5m - 4145
41 46 '2827 — 1171 i

End cfaputdL, 119 S

I P3ie u.

Sd2 0 Ihn thniat on Vklu

r.i i: , 1 -^df^Gl = 46-4Z
I.-,.I2> 28-21 - 1284

And afapimUe ISB-3

Jtm 1 /i.s /J,n,.-i „„ i;,h:

eiexzs-zi - mtioi

End ofspind/i

250- n
leeOo Uk.- Ihnt<st oil Fahr

- A y ASPISALL. DELT

Mmutes of ft-oceedings ot' The Insutunou a£ Oml Engineer. Vol. XCV S^ssue :f»*..S?

;i»»l«S rSOM * 5000S ENGINE WITH ORDINARY BRASS VALVES .

I'lqs: 15

Fifls: 16

Figs: 11 .

Bode,- Bvsxure 1401/,

-Af^

-4 :i,-, 12C f JJbl - 4S dH
4S89 , 26S1 - 1Z80-2

End of spindle 255-0

ir,y>o lbs-pull

£oiL;- B-cssiu-e Ufl lbs

<:a-95.l2C-t5ei " 3314
:i3-14x 28-27 — 2650 0

End atspindle 271 -2

2378 S //,.-■ lliniM ,m liilu

Sfnlrn -Chest F,

4Sti \I2H^5-Gt = eS I
eS I . iG-Sl - IS05 3

End cfspuuUe- 262 9

2i>6S 2 Iks fiuU .»! fi/iv

ic IflTHnnoD of Ci»ii En^n.'iern . Vol. XCJ V. Seseaon

raO" KEU, * SOS, UTH •W-KTSa S' ,-UVEXT Iv^HMS

PLATE. 5

lAILWAY-CARf

JF'i

ThFtniia/se Gnat^e-

Tb^SzrpinyGvtufC'

SECTION CD. IT ELEVATION. HALF BACK ELEVATION.

h.-^=4!^^^jj

1,1888-89. Part THD?-KEli & son, .TXTH. OO king- S- CCvTSKT GAPOiEN.

11,,,/.

''Ilk

SCH SYSTEM, AND ITS APPLI C AT I O N TO TH E LIGHTING OF RAILWAY - CAR R I AGE S .

C M EVBTEP.. DtL

MinuWB of ProosainlB of Ths Incuuilinn of CivU En|-moois Vol XCV Seeaion, 1888^89. Piun. 1 .

liSON.imi. «; los? 5« ccnnaiT GAK»

ALp]?]i i?]a]?]i2/j],i§.

. I '/EHBOB-HARCOUIIT. CELT.

Mmutes >,f ft>x«^l-.r

A L p J ?] £ 1 ?j a J ?] 1 :i /! J ?] a

l-!.,:i;.

ALT } i-i % :s ?j a ] ?] 1 1 ji] ?] a =

A L P !1 jM E 2 Kl 6 J M g E Ifi Q Kl 5

Ifloq ^jee^ «lm,vt' Spa y-vi'l.,

.-'liiif^'; of Tlw Inotitiition of Cr/il En^meers.Vol: XCV. Session 1888-89. Part I.

PLATE . 8 .

THOSKEU, 8cS0jr,LITH.40,mN-G- SP. COVENT GAHUEN.

)if'gSi0-iri«iii5!iiL!§ 101? isKDvasKi Wii^a- yggisiLs.

_ (i„A„r»j„z, „w.„z„;,„j p,.,.,r.

•^'...t.„/r ( 1 > t f

. S. CAPPER. DEL?

Minuton of Piocoedinga of Tile InntAuuon of CmLEngineeis. Vol. XCV. Se88ion"l688-89. Part I.

R A I L W A Y S .

i'linutes ot' Procfledings at The Lasutution c4" Civil iinguwars

« A I I. w A Y s . siVyll

o; Cr^l En^maors. Vol ZCV Skekjh 1S88-83 Part

TA Institution of Civil

1 Engineers, London

1^79 Minutes of proceedings

V.95

pt.l

Engin.

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