THE DI._'TJU BUTIO OF LOAD ON TitOUGH FLOORS FOR BRIDGES.

THE use of steel t roughing for flooring bridges has so many advantages, that its increasing adop­tion gives no gr ounds for surprise, and we note that the system is steadily gaining ground in America, where, for fi nancial reasons, open fl oors have long been in vogue. The question as to the comparative strengths and cost of the various sys­tems adopted for floors has been very thoroughly thrashed out by Mr. Edmund Olander, in an excellent paper read in lt1arch, 1887, before the Society of Engineers, and though several new forms have been devised since that t ime, his paper is so complete that lit tle remains to be said on this head. In the paper referred to, different sections of equal weights and heights were carefully investigated, and conclusions drawn as to

• I

E N G I N E E R I N G.

taining but litUe riveting, all of which can, more­over, be done by machine, consists of triangular troughing, in which heavy angle-irons at t op and bottom are connected together by side-plates in­clined at an angle of 45 deg. All the above require no special sections. A vast number of special sections have, however, been devised, each of which has advantages and disadvantages of its own, and into the comparative merits of which we do not propose to enter, as this has already been done very fully by Mr. Olander, but propose to deal rather with the way in which a concentrated load on one trough is in certain cases distributed over adjoining troughs.

This question of load distribution is very im­portant. In Mr. Olander 's paper it was shown that, taking the case of a locomotive with drivers 7 ft. apart, the load on each wheel being 8 tons, then if, as he assumes in his practice, the load on

Lmtisa.ys Trougfun :w 80 16 roil

I

R =·()13 W J

Pt.g. 2 .11 , ... ... j ..... _ _ __ _....., _ ......... $

IS' •

I

R • "!4 ? W I

.R •

··- ·-- - ~H .............. s # ... ......... •

I I

'

• • I •

• I

R11 • 31? W

•

Stuprs 2 ~ 6 • ctnlrfS

I

R • '142 W I

Ftg. 3 . w

\4 -- - · • I

• I

R,• • 013 W

w --

IS'I8 8 " • OIJ" f 11$ IY • 7•flW ~U9vr f ' '7 ' 'r I IJ1 W # , , 1'1 •111 W f/IS If - OIJ W

3 19

in Fig. 1. 'l'he tendency is constantly towards in­creasing the weight and stiflheHs of the rail, and hence for the purpose of calculation we have assumed that this rail is an 80 lb. rail, 5 in. high, and having a moment of inertia = 31 (inches}'.

Now if a loaded wheel rests over a sleeper, as shown in the figure, the trough under it will sink, and, owing to the stiffness of the rail, part of the load will be transferred to the other sleepers, and the ~mount thus transferred is easily calculable by the principle of elastic work. According to this, the total work don e in deforming the whole struc­ture of rails and flooring is a minimum, consistent with the equilibrium of the forces and reactions acting. Strictly speaking we ought also to take into account the work done in deforming the main girder, but this will not sensibly modify the results, and it has, therefore, been neglected in what follows.

Lindsoy'3 floonng 25 lb. 3pan 01$tr/but1on of' o .s,gle load on one of tht/ tns1d e pa1rs of roi/J .

•

Eg .8

V!O!UtU!U!V!VfV!O!lf'.V!L 1 o 1 t I • 1 I I 1 1 I ' . I I I I I . I I 1 t 1 I I It t: I 1

I I I I If 1 1 I 0 • • • • 1 ' ' I •• ' I! : . 'I

DOJ '"' f¥1 nS 1$4 165 ISf ·liS _, ~f "I

Nobson~ floor'fllg 25 1 span dl<3t1'1butlon of loads on t'M/clerat'ls

Fig .9

• I • • • • • •

--ofrw • • I

- o~z w I I •

s~o • ... 80 {6 rail w/lh ptn JOIIIl' -d'tl I

J~l J 40 J41 ,z~ !W c: ~' ' • LindsfE":S Tro(Jqh/ng

• ..... ' IJ.. IS span.

• I

"

Slttptrs

I

' •

2!. o Cflllrt s

. I • I

- 'OIS W • tU W + t 6& w I ' .H6 W f H I W . # ' 09t W •. .t '007 w. - '039 w

Fig. 6.

. 5.

• : I

+ ' 058 W +13$\V. + '19GW

' •w I

HDh$MS f/oormg lS 'span. Oistrt bultor: of load on

tiiSidt pair of rails

. ? iY'Vt'VTVTV 1' V l'\ IS48.t.• 'T" ~ ~ : ! • ! Y

- ·ozzw ,'07t W 'Z69W.'J63 W 289W 07/ W- 022W.

t he efficiency of the section per unit of weight, and also as to ease of erection-a very important matter ; for, as the author pointed out at t he t ime, the low initial cost of a section may be offset by difficulties in riveting it in place. \Vhere possible nowadays there is a prejudice in favour of machine riveting, and in this respect the various sections are by no means on an equality. The earliest form of section used was a rectangular trough built up of angles and plates . This section, though containing a great number of parts, and re­quiring many rivets, has never theless advantages of its own, in that it is easy to make the pitch of the troughing a multiple of the rivet pitch of the main girders, and, moreover, nearly a.ll the riveting can be done by machine. This troughing has since been modified by substituting channels for t he top and bottom plates, or, in another direction, by substitu­ting Z -irons for the side plates, but in these cases the advantage of machine riveting must be abandoned, though the total amountrequiredisreduced. Another simple built form consists of a splayed channel connected by inclined side-plates, and this gives rather more room for the riveting, which, as before, must be largely done by hand. A built form con-

•

I I I I

I

8 0 l6 rail m ling d1rtctly on troughs

~ '196 w . + tJS w + 'OS 8 W

Hobson's floortng ZS'span Oistrlbuflon ol' load on outsidt po1r of rails .

I I

• I I I

I I I I I T

·oH w. ·z6o w. 481 w. ·uo w. ·o4+ w. - ·o~w.

each wheelis distributed over 7 ft., the weight of a certain section required to carry this load would be 24.17 lb. per foot ., whereas if the whole of the load came on to a single section, the weight would have to be increased to 100 lb. per foot. So far as we know, the way in which the load is distributed over the troughs by the rail has not hit herto been worked out. The process is, no doubt, some­what tedious, as probably about 7 hours' hard arithmetical work is required to work out any special case ab initio, but it may be remarked that this time is but a small fraction of that required for the design of even a small bridge.

As an example, let us consider the case of a single line bridge fl oored with Lindsay's 0 -section trough­ing. This troughing is built up of splayed channels, ~ in. thick at the top and ! in. at the sides. The total depth of the corrugations of the finished floor is 7 in., and the pitch 20 in. The floor weighs 27.10 lb. per ft., and its moment of inertia is about 91.5 (inches)''. The span of the floor has been taken as 15 ft. between the main girders. Let us further assume that the floor, when completed, is ballasted, and the rails laid on cross sleepers at 2 ft. 6 in. apart, as indicated

Fig 10.

Hobson's floormg 25' spon. dt.str/bulto/1 of load on out.s1de ra~ls

A

I " .7 6 . ~

• • . • • •

' I • •

ZGO •4J5 .,JOf •JOf ·435

Fig .11

• • V . 2CO · 09~ - ·Of$

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•

In the case shown in Fig. 1 it has been as­sumed that the rail distributes the load in vary­ing degrees over seven sleepers spaced at 2 ft. 6 in. centres, and that the trough under each sleeper acts quite independently of its neighbours, an assump­tion which we shall justify later on. Now let us consider the work done in deforming one complete section of t he floor by loads placed as indicated in Fig. 2. The distance between the rail centres has been taken as 5 ft. for convenience in calculat ion, though t his is, of course, a shade too great for a standard gauge line. Then in bending a beam the total work done, as is well known,

1 = ...,...2-=E I 0

where M = the bending moment at any point, E the elastic modulus, and I the moment of iner t ia of the section. Taking all units in inches, the work done, in deforming one section of Lindsay's trough­ing 15 ft. long, uy two loads each equal to R placed as shown in Fig. 2,

= 1968 . R2•

E

•

•

320

In the case taken there are seven reactions. That unde~· oach wheel. being taken as R 0, we have for each ratl, on each side of this :

Two reactions eaob

" - R 1 • •• ••• • •• -- R2 • • • • •• • • • -- R~ ••• • • • • • • -

,,

And, a.1so,

(Ro + 2R1 + 2R2 + 2RJ) ="\V,

W being the load on each rail. Hence the total work done on the troughs will be :

Ur = 1~8 { R 02+ 2 R 12+ 2 R 22+ 2 R:~2 } ,

or substituting for R 0, we have 1968

Ur = -E . [(\V-.2R1 -2R2 - 2R3)2+

2 R 12 + 2 R 22 + 2 R:~2J.

Similarly the work done on the rails can be as­certained in terms of R 1, R 2, and R~. Calling this work U 1·, we have the total elastic work of defor ­mation,

say, and U is and R 3•

Ur+ Ur=U, a minimum, with respect toR R

lJ 2'

. dU d U dU -...,..- - - -o . . d .R1

- dRJ - d R3

- •

It is unnacessary to go through the whole work here, but we finally get the three equations :

13,742.8 R 3 + 8000.8 R :! + 5097.5 R, = 1968 W. 8,008.RR3 + 8226.8R..! + 4661.8R1 = 1968. W . 5,097.5 R 3 + 4661.8 R 1 + 6194 3 R 1 = 1968. \V.

The solution* of these equations usina seven­figure logarithms, we make to be as follows!:):

Hence

R1 = .242.245.2 W R2 = .115.406.0 W R3 = - .013.838.8 W

R-> = + .312.375.2 W.

From this it appears that in the above case rather less tha~ one-third of t~e weight directly over a trough Is transferred to 1t, the rest being carried by the adjacent troughs. The results are recorded in Fig. 1.. In practice, howe:er, we have usually to deal with more than one pa1r of wheels, and it is the corn bined effect of the two that has to be con­sidered. As example, take the case of two loads 7 ft. 6 in. apart, then the resulting reactions would be as in the diagram Fig. 3. In this case the maximum reaction is rather greater than one-third the load on one wheeL It will be noted that the negative reaction is less than one-seventieth of the load on one wheel.

Another question arises as t o the effect of the joint in modifying the above distribution. On this hea.d it may be: remarked that with the very stiff joints now used 1_10 .diminution in the distributing power of the rail 1s to be expected, but it was thought of interest to ascertain the modification in the distribution, when the rail had a. perfectly flexible joint. Thus the loading was assumed to be as in Fig. 4, there being a pin joint at the point shown. On making the calculation-a somewhat tedious one-it was found t hat, as was t o be ex­pected, the negative reactions were considerably increased, but the maximum positive reaction was not so much increased as might have been antici· pated, the distribution being as shown in Fia. 4. As even the weakest rail j oint has some degr~e of stiffness, it appears, therefore, that the distribu­tion obtained in assuming a continuously stiff rail may be relied upon as that actually existing. If the load rested directly over the joint, the maximun1 reaction would be . 443 W.

If the rails are laid directly on the troughs without the intervention of cross sleepers, a much more favourable distribution can be obtained. The

*Some remarks on the best method of solving such equa­tions as the above may be useful. Itl will be seen that the determinant of the equations is symmetrical, but the method of solution by determinants is the very worst that can be adopted. In the method of least squares, the simultaneous equations there occurring have also a symmetrical determinant, and for such Gauss has given a method of solution which greatly reduces the labour of calculation, and ab the same time provides a check at every step, and this method will be found fully described in text-books dealing with the adjustment of observa­tions. By it simultaneous equations of five variab)e3 can, we find from experience, be solved easily in about 14 hours at most, whereas the five simultaneous equations used in determining the stresses on the roof of the Olympia Hall, Kensington, took, we understand, ma.ny weeks to solve by the determinanb method, and there was with this latter method far greater liability to mistakes.

E N G I N E E R I N G.

~istance between the points of support of the rail ts ~ow short~ned to 20 in., and the maximum re­actlOn for a smgle load is found to be . 221 of the ~eight .immediately above the trough, the distribu­tlOn being as in Fig. 5. With two sets of loads 7 ft. 6 in. apart, the maximum trough reaction would be about .2G the load on one axle. This ~esult ~how~ the advantage of longitudinal sleepers In conJ.unctwn with trough fl ooring.

Coming now to the case of a double line of rail, w~ may take Hobson's flooring as used in the Liverpool Overhead Railway. This floor consists of troughs pitched at 2 { t. 6 in. centres, and 15 in. d.eep. It is. built up of arch plates 1

56 in. thick,

r1v~ted. to J.-tr.ons at the bottom. The span between mau~ gu~ers Is 25 ft., and the rails are carried by 1 ong1tudinal sleepers. If the rail was the typical one already used, and fixed direct to the trouahing we fit;td t.hat ~n the case of the inRide pair ~ rail~ the ~1stnb~t10n would be as in Fig . o, and for the o.utst~e patr as in Fig. 7. Practically the distribu­tiOn Is.probably a little better than this, as though the rall actually used is not as stiff, we believe, as the typical one taken, the combined stiffness of the longitudinal sleeper and the rail i~ pro· bably greater. With t wo loads 7 ft. 6 in. apart the maxim urn reactions are . 34 W and .435 'V respectively (Fjgs. 9 and 10). Just for comparison we have calculated out the distribut ion on this. floor, if it had been built of the Lindsay 0 sectwn , used on the single-line spans referred to above. ' Ve obtained the r esults shown in the diagram ( Fig. 8). H ere it will be seen that the maximum reaction is only .165 'V. for a single load, and .25 W. with loads 7 ft. 6 in. apart. H ence, though Hobson 's flooring, as used, has a moment of inertia of about 560 (in.)t, as aaainst 91.5 (in. )4 for the light sect ion of L indsay,s

0

floor, taken above, yet the maximum fibre stress in Lindsay 's section would, with equal lo9.ds on the centre pair of rails, be only a lit tle more than twice as great, showing how the greater flexibility of the thinner floor ha! increased the distributing effect of the rail. . This, of course, is only an ideal case, as, even If slrong enough, few would care to use a 7 ·in. floor on a. 25-ft. span, and all makers of t roughing do manufacture thicker floors for double- line bridges.

.lt'rom the above it appears that within a r eason­able degree of approximation the old assumption, of many years' date, that t he rail distributes t he load ove~ t~ree sleepers, can be r elied upon as safe in destgnmg trough floors ; and further, that with longitudinal sleepers on single-line bridges the load may, for the purpose of design, be taken as distri­buted equally over four troughs. These figures are only exact for the cases on w hi eh the calculations above are based, b ut it is probable that they will not vary much with different forms of troughing, and, moreover, the distribution for any particular case can be easily worked out when desired, requiring only a. few hours' work. ~7hen, however, we come t o road bridges, and

the distribution depends on the action of t he road metal or a thin layer of concrete, it is difficult t o believe that any considerable amount of a weigh t is transferred from a loaded trough to its neigh­bours. Apart from such distribution as may be effected by the road metal or concrete, it appears certain that the mere fact of the t rough being con­nected to adjoining ones, cannot transfer much of the load t o t hem. As it sinks relatively t o its neighbours, it tends to both twist and bend them. If the troughs were prevented from twisting, a considerable amount of the weight would probably be passed on to these neighbouring troughs, as their r esistance to bending is large ; but the torsional resistance of t rough sections is very small, and hence, by twisting, the edges of these troughs may easily be defl ected through a distance corre­sponding t o t he deflection of the loaded trough by a comparatively small force.

Thus, in the absence of actual experiment, it d oes not seem advisable to reckon on any considerable distribution of a concentrated weight on a road bridge with trough flooring. On the other hand, for such a load, it seems fair t o take the whole trough betwAen A and B (Fig. 11) as resisting the load, rather than the amount between C and D , as when each of the neighbouring troughs is doing a fair share of the work. R eckoned in t his way, the strength of the trough is appreciably increased. 0 wing to the inefficient distribution in such floors,

[SEPT. I 5, I 893. •

it is advantageous t o use troughs with a wide pitch. So far as we know, the widest pitched trough yet made is of 3 ft. 4 in. pitch. Messrs. ' Vestwood and Bailey make a floor specially for road bridaes w~ich have a cambered upper surface t o corresp~nd w1th the curve of the r oadway. The pitch of the largest of thesQ is, we believe, 2 ft. 8 in.

In his paper on ''Bridge Floors," already re­ferred to, Mr. Oiander suggests the use of arches of 4-ft. span, 8~-in . . rise, and 4! in. thick, the whole to be backed w1th concrete, tha latter being 2! in. thick over the crown. To test the strength of arches of this kind, he had one of 5-ft. span and 9-in. rise constructed, and this bore a load of 14 tons without showing any signs of weakness. The centre of gravity of the load corresponded with one-fourth the span of the arch, and it was dis­tributed over a. length of about 18 in. If con­struc~ed entirely of concrete, so that the backing and rmg make one homogeneous arch , it is easy to show that there would be no appreciable tension caused in such an arch by a concentrated load moving over it. Further, if such an arch 1 f t. wide were loaded with a concentrated load of 1 ton the maximum compression produced would b~ nearly 9 t ons* per square foot. Ex periments made for Mr. Deacon show that good P ortland cement concrete attains a strength of over 180 tons per square foot in 32 to 36 months, and of ~bout 16~ tons in about 18 mon ths. H ence, takmg the h1gher figure, such an arch as described, 1 ft. wide, would carry a concentrated load of 3 tons with a factor of safety of nearly 7, and one of upwards of 4 tons with a factor of safety of 5. The last fig ure is smaller than is usual in masonry, but the famous Maidenhead bridge, which has carried t he main Jine traffic of the Great \Vestern Rail way for upwards of for ty years, is said to have a factor of safety of only 3, though, of course, the dead load in this latter case is a high proportion of the total, and justifies a smaller factor of safety than would otherwise be admissible. It should, however, be noted that the calculated stresses obtained above are those which would ari.sc if the loa~ w~re concentrated on a s ingle p01nt of the medial hne of the arch. Since, how­ever, the load is distributed to a. certain extent over the arch by the road metal, or by t he mass of the arch itself above the medial line, the stresses actualJy arising are \'ery possibly 25 per cent. less. Further, as the direct pressure of the load on the arch is perpendicular to the arch thrust, the material of the arch, being subjected to two stresses o.f the same kind at right angles to each other, 1s under very favourable con­ditions for resisting these stresses. As the 4-ft. arches proposed by Mr. Olander are thinner t han the 5-ft. ones, the calculated stresses on the two arches are nearly the same, in sp ite of the smaller span. A composite arch, such as Mr. Olander pro­poses, is probably somewhat stronaer, if good hard bricks are used, than an arch co~plctely of con­crete, because the maximum compression in the homogeneous arch would occur at its upper surface. The ring of brickwork, however, if built of hard bricks in cement, is probably more unyielding than the layer of cement above it., and hence relieves the Ja.ttor to a certain extent, thus reducin a the

• b max1mum stress.

THE ENGINEERING CONGRESS AT CHICAGO.

(BY oult NEw YoRK CoRRESPONDENT. ) (Continu ed from page 294.)

THE next day this Congress listened to a paper by Samuel A. Thompson , secretary of the Board of Trade of Uuluth, M inn., on " The E conomic Value of a. Ship Canal from t he Great Lakes to the Seaboard." The paper was listened to with much interest. The next paper was on the new and enlarged waterways to meet the demands of commerce in Russia, by Emile Fedorvitch de Hoerschelmann, of Kief, Russia, who is one of the most eminent authorities on the subject of water commerce and t ranspor tation facili t ies. After an interesting discussion, the meeting adjourned to

-* This r~sult is obtaine~ by treating the masonry arch

as an elastic arch of variable moment of inertia.. This D;lethod is not alto~ethe~ satisfactory ; but the line of re­sistance thus obtamed (m the case of arches of uniform section) is that coinciding most nearly with the medial s~rfac~ o~ the arc~, and ~ence that which most nearly h~ w1~hm the middle th1rd of the arching, and which g1 ves n se, on the whole, to the least tension .

..

SEPT. rs, I893·] E N G I N E E R I N G. 32 !

take the lake trip. The following day a paper by Telford Burnham, of Chicago, was presented , showing a. plan for a sh ip railroad t o move ships of he1.vy tonnage from the lakes to the ocean. Other papers were presented and discussed, among them the following : " The Lake Erie and Ohio River Ship Canal, " by Thomas P . R oberts; " I m proved Water R outes from the • reat Lakes to t h E' A tlantic, ' ' by Thomas C. l{eefer, of Ottawa, Edward A. N orth, of New York, Samuel A. Thomp­son, of Duluth, and Chauncey N. Dutton, of Chicago ; '' The Commerce of th e Mississippi River," by George H. Morgan, secretary of the St. L ouis Merchan ts' Exchange ; and " The Chignecto

regarded, however , as chiefly inciden tal to the exploitation of the zinc deposi ts. The total ship­ments of zinc and lead or es from Benton, the prin­cipal station in the south-western part of the lead and zinc r E>gion, amounted in 1892 to 13,800,000 lb., of which the lead ore was 800,000 l b. The lead ores are sent largely to the works of t he P ennsyl­van ia Lead Cvmpany, at Pittsburg, and some go to Aurora, Illinois.

tion between 3 and 6 per cent., and to measure such proportions with fair accuracy.

The hy drogen flame, set to standard size, detfcts gas when present in proportions varying from 0. 2 to 3 per cent. , and measures such proportions with

• • preClSlOn. The p r esence of ga9 is detected by the presence

of the pale "flame-cap ;" its proportion is esti· mated partly by the character of the cap, but mainly by its h eight. In order to t ender the cap more easily seen, a vertical strip of t he interior of the lamp-glass, about an inch in breadth, is smoked by a wax taper. This is arranged to form a back· ground against which the cap is viewed, and serves to throw up the cap and to preven t its obliter ation by cross reflections from the smooth glass surface.

'hip Ra ilway," by H. G. . Ketchum. The Mining Engineers, after a brief address

from the president, Mr. H. ?YI. H owe, listened to a paper by Professor S. B. Cht isty on " Mjn ing Schools." This paper instituted a comparison between the increase in mineral products and the graduates of mining schools and the mining popu­lation. I t appears thn.t neither miners nor mining er.gineers are increasing in the ratio of the general population or t he mineral products. The solution of this appears in the statement that mining in t he United tates is n ot so complex as elsewhere, hence does not req uire as many engineers nor as many miners ; at least, this was one of the theories advanced, and it is probably as good as any other.

'' The Lead and Zinc Deposits of the ~iississippi Valley, " by \V. P. J enney, was the next paper. Twenty years ago these mines produced half the lead of t he United tates. At presen t they pro­duce 21 per cent. , yet in 1873 the product was 22,381 tons, and in 1892 37,000 tons. The author, in conclusion, laid down the following rules for t he district spoken of :

" 1. The old rule 'to follow the ore ' holds good in these as in other mining r egions.

" 2. In all underground prospecting the general rule may be given, to follow the more prominent vertical fissures in the search for ore ; for these have been the channels through which the solutions have entered the rocks and formed the ore bodies, and along the course of which, in favourable ground, the deposits of ore occur.

'' 3. In prospecting new ground, attention should be given to the indication of the course of the fissures and cross-fissures ; th e work should be concentrated upon the areas of crossing or inter­section of t he different belts of fi ssures ; for ex­perience has shown that the largest ore bodies a re situated at such cros~ings of different fissure systems. On the surface t he eourse of the fissures may be traced in some localities by the direction of low bluff~, or breaks, or by sags or lines of de­pression in the even contour of the topography ; also by the strike of outcrops of silicified rock, more or less mineralised and stained with iron. When carefully searched, such outcrops often afford traces of the oxidised minerals resulting from the weather­ing of galena and blende. E vidences of the dis­turbances of the r ocks should be carefully observed; such as b eds dipping locally at steep angles, or in a direction different from that of the prevailing in­clination of t he strata in the region ; and the occur­rence of belts of folded, crushed, or brecciatcd rocks.

F ollowing this came a paper by Dr. Clement L e N e\'e F oster, of Llandudno, urging international uniformity in publishing mining statistics, The sympathy of his audience was with t he speaker for the most apparent reasons, and the doctor was requested to prepare a pamphlet for the Mining Engineers, in which he would correlate the mining sta•istics of all nations. 'Vhether Dr. Foster will be expected to attain the age of Methuselah or not did not t ranspire, but h e has undoubtedly a pretty fair contract to undertake. That day's session concluded with the consideration of a sum­mary of Professor F . P osepny's paper on the "Genesis of Ore D eposits, " together with a kin­dred paper by Professor S. F. Emmons on "The Geological D;stribution of the Useful Metals in the United States."

This latter paper is a review of the progress and present ideas in economic geology in t he United States. The author makes some impor tant sug­gestions for future geological work of scientific and economic importance, in directions where much r emains to be done, many large fields being prac­t ically untouched. The progr ess which has been made in th is science in recent years, and its p rac­t ical results, have been immense ; what more may we not expect in the future with the mental train­ing and manners of thinking that practical geolo­gists now have ? " The t ruly scientific method in t he study of such questions at the present day is the reverse of that which was followed in the early days of geology, when, after the observation of a few isolated facts, eome great geological mind was led to a general theory, and humbler followers were only too apt to do mild violence to nature in order to make her facts conform to i t. It accu­mulates, year aft er year, a multitude of facts of patient observation, supp:>r ted by studies with the microscope and in the laboratory, avoid ing general the :>ries, and only making such deductions in regard to local conditions as are supported by t he over­whelming evidence of facts. " Our new theories, based in this manner, are likely to be of as much service as t he old ones were freq uen tly misleading.

The next paper was '' The Mineral Deposits of 'outh- W est Wisconsin, " by Professor \V. P.

Dlake. This described the appearance of the ores, and told the localities where they were to be found .

He classified the ores into irregular and brec­ciated, and regular sheets and beds. The r egular and brecciated include most of t he dry-bone de­rived from the oxidation of t he blende in place, which passes downward into unchanged blende. Sometimes the original bedding of tho rocks is but li ttle changed, and there is no disturbance, but in other places there is great confusion, irregular masses of rock being surrounded and invested with a coating of ore, by which they are united into one mllSS.

Ther e are four kinds of ore shipped from the Wisconsin mines- namely, galena, zinc carbonate, Llende, and pyrite. Of these th e zinc ores largely preponderate. The lead ore is not now so much sought as formerly, and most of the old deposits are regarded as exhausted, although now and then new discoveries are made. The production may be

"4. An advisory rule may be given never to sink a shaft without having put down a drill hole in order to ascertain the character of the und~rlying formations, lest time and money be wasted from striking hard and massive strata or areas of barren rock. The diamond drill is not adapted for this work in prospecting in the Cherokee format ion, on accoun t of the loose and open structure of th e ground, and because the hard chert cuts out the diamonds. In the Cambrian limestone the massive and uniform structure of t he beds and the absence of chert are favourable fot the succesEful employ­ment of the diamond drill. "

The next day the Institute assembled, and pro­ceedings were inaugurated by a paper by J ames D ouglas, of New York, who gave a summary of American inventions relating to ore-crushing ma­chinery and concentrators. This paper drew forth a long discussion, and additional inventions over­looked by the author were named by t he speakers.

N ext came the following paper s, one by H enry L ouis, of Singapore, on ''The Specific Gravity of Gold Contained in Gold-Silver Alloys ;" he was succeeded by H. A. K eller. of Butte Mont, on ''Improved Slag P ots ;" and T. A. Rickard, of D enver, read a paper on "The Limitations of the Stamp Mill. 11 The last-mentioned paper was the means of developing an interesting discussion as to the merits of ligh t stamps with a high drop as com­pared with heavy stamps and a low drop.

The next morning the following paper was pre­sented : "The D etection and Measurement of Firedamp in Mines," by Professor G. Chesneau, of France. This was succeeded by '' The Hydrogen Oil Safety Lamp," by Professor Frank Clowes, of England. This ]amp has been devised to burn oil from a flat wick in the usual way for lighting purposes, and also to burn a hydrogen flame of standard size instead of the oil flam~, ·when deli­cat e and accurate gas-testing is to be carried ou t . The change from the oil flame to the hydrogen .flame, and 11ice t'ersc1 , can be made without opening the lamp or running any risk in the presence of gas.

The 011 flame serves for illumination ; and when the wick is drawn down by the '' pricker, " so as t o abolish the light, t he pale blue r educed oil flame ser ves to detect firedamp or "gas " in any propor-

The hydrogen is contained in a small steel cylinder which can be attached at will.

If t he percentage of the gas is to be measured, the wick is drawn down by the pricker until the flame just loses its bright tip, and if a cap is seen its height serves to measure with some approach to accuracy the proportion of gas according to a scale given. If no cap appears over the r educed oil flame, the abEence of gas is not proved, since less than 3 per cent. is not indicated by this flame. The pocket hydrogen cylinder is then attached to the lamp ; the cylinder serving as a handle is grasped in the left hand , while the hydrogen gas is slowly turned on by means of a key appli~d to the cylinder valve by the right hand passed r ound be­hind the lamp. A tvngue of flam e shoots up from the bright .flame as the hydrogen enters ; t h e wick is then drawn down until the oil flame is extin­guished, and holding the lamp with the hydrogen flame on a level with the eye, the flame is set by means of the cylinder valve to 10 millimetres by viewing it behind the standard wire scale. The height of the cap, if any, is then noted, and mea­sures the percentage of gas, accc rding to a scale given. If no cap is seen the gas is less than 0. 2 per cent. in amount.

To bring back the oil flame, it is simply n eces­sary to push up the wick, which is at once kindled on touching the hydrogen flame. The hydrogen gas may then be shut oft', and the cylinder detached and r eplaced in the pocket until it is again r equired. When using the lamp in the mine for the d etection and measurement of gas, the standard hJdroaen flame is t hus made to supplement the reduced o oil .flame, and the two .flames carry the indicati< ns from 0. 2 up to 6 per cent. of gaP.

Next came ''Experimental Investi~ations on the L oss of Head of Air Currents in nderground 'V or kings, " by D. Nurgue, of France. Then the futther discussion of '' Ores and Ore Deposits " was resumed. The metallurgists considered the following : " Microscopic Metallography," by J . Osmand, of Paris ; "Microstructure of Ingot Iron in Cast Ingots," by Professor A. Mart et s, of Berlin. Then followed " Segregation and its Consequences in Ingots of Iron and Sted," by Alexander Pairal, Paris . After stating that liqua· tion in steel had been carefully studied for a long time, and that there was no rule by which the different metalloids and metals are liquated, the author proceeded to submit various instances and to consider them. It was evident that t his study was purely empirical, and his conclusiona are neces­sarily of a general character. They were as follows :

" The atrangement inaugurated at T erre-Noire, in 1870, has been universally adopted to diminish t he most pronounced effects of segr egation in ob taining the largest steel ingots for plates and for heavy artillery. Success has not been obtained for products of such im:[jortance without many failures, and even to-day we are far from being content with t he r esult accomplished, especially for armour plates. RecourE e has been ha~ to hardening, and on good grounds ; but hardenmg cannot render uniform the r esistance to shock of a block which has n ot homogeneous composition . We know th e metal we must n ot use, but do we know the metal the chemical composition of which responds exactly to the requirements ?

"In all cases the metal which f orms the final armour plate differs from the mother metal prepared in the furnace, and the problem thus set us 'What is the mother metal which ought t o give ~ final }Jroduct of certain composition ? ' is eviden t ly not easy to solve so long as the solution depends upon many variables. One and the same mother n;tetal may furnish cast pieces of different composi. twn.

"For cannon of large calibre, if we reject, in

E N G I N E E R I N G. [ 8 =================================~ ~PT. I 5, I 9 3 . ~~~~~~~==~~~~~======~~==~~~=

"'2"' .) -addition to the part cast in sand and called the masse­lotte. (sinking head), on~-third of the upper part of the 1ngo~, we can ?~ta1n a t ube practically homo­geneous 1n compos1t10n, because the central part is naturally removed by the boring of the tube. With extra soft. steels, destin~d for ship or boiler plates, t~e .solutwn fo~ .practteally perfect homogeneity hes 1n t he o btammg of a metal more closely de­serving its name of extra soft metal. 'Ve must recognise the error which has been committed in large constructive industries, whether private or Governmental, in requiring of a metal called extra soft, and slightly or not at all sensible to anneal­ing, ten~ile strength amounting to 42 or 48 kilo­grammes per square millimetre of section (68, 770 lb. per square inch).

" It is certainly right to require for boiler plate a tnetal practically unaffected by hardening. In that case it is by elongation and by striction (' ne?king ')--in which all the pure iron products are defi~1ent-that we should define the mechanical pro­perhes of the metal, leaving tensile strength aside.

''The manganese steels have no striction ; neither h~ve those which contain a high proportion of ntckel. I refer to steels respectively carrying more than 10 pe~ cent. of manganese and 20 to 25 per cent. of ntckel. The cement or non-hardenimg carbon exists only in feeble proportion in these ~lloy.s, in which the iron, by a simple quenching 1n 011, appears to be preserved almost wholly in condition 13. An alloy of 25 per cent. of nickel with 0.80 per cent. of carbon, after quenching in oil, gave, under tensile test, 80 kilogrammes per metre (113, 760 lb. per square inch) tensile strength, and 60 per cent. elongation in 10 centimetres (3. 9 in.).

'' W e can sincerely declare that in a long indus­trial career, the experience of which has a certain practical value (F;ince we inaugurated in 1867 at Terre-Noire the manufacture of extra soft steel with ferro-manganesc containing 80 per cent. of manganese), we have never been able to realise or to see others realise the desideratum of a homo­geneous plate which successfully endured the hardening test with the tensile strength of 42 kilo­grammes (59,636 lb. ) per square inch heretofore re­quired for boiler metal. The lengthwise sample, cut from the bottom of the plate and satisfying a rigorous quenching test, rarely gave a maximum of 40 kilo­grammes (56,892 1b. ). The lengthwise sample from the top of the plate was mediocre, and often abso­lutely bad, under the hardening test. And as to crosswise samples, while the bottom one would sometimes bend double, with a metal giving more than 40 kilogrammes tensile strength, the top one was always defective . . ..

"In our opinion the injurious consequences of segregation must be suppressed by reducing, as far as possible, the elements subject to liquation.

" Upon the basic or neutral open-hearth, and starting with an initial bath of approximately pure materials, it is easy to obtain a metal containing not more than 0.1 per cent. of carbon ; 0.02 phos­phorus and traces of sulphur, with 0.10 of man­ganese. By adding 0.1 per cent. of aluminum the metal can be cast quietly and without altering its composition. Consequently, if from an ingot so cast and destined for boiler plate one-fourth to one­third of the upper part (in which the carbon and phosphorus may reach respectively 0.12 and 0. 03, for example) be cut off, the remainder will be a block of appr oximn.tely perfect homogeneity."

As to boiler plate the author stated : '' The elongation lengthwise of the annealed

plate ought never to be ~ess than 30 per cent. _in 20 centimetres (7. 89 m.); as regards tens1le Ptrength, 40 kilogrammes per square millimetre (56,892 lb. per square inch) as a maximum seems to us too high.

"For ship-plates, whatever may be the import­ance of having a much stronger metal in order to diminish thickness and weight, it is our opinion that too much is sacrificed to t his consideration to the neglect of (1) the more easy and certain manipu­lat ion of a more malleable meta1, and (2) the action of sea water, which may be a fifth or a fourth more rapid upon a metal with 45 kilogrammes (64, 003 1 b.) per square inch tensile strength than upon a softer and more homogeneous metal with only 38 kilo­grammes (54,047 lb.) tensile strength.

'' In the construction of bridges, our preference for the use of an extra soft metal runs counter to the general desire of having for this purpo~e a metal of high elastic li~it. But, nevertheles~, 1t has.not been wished httherto to secure thlS prectous mechanical q uality in bridge metal by increasing

CAPSTAN LATHES. CONSTRUCTED BY :MR. ALFRED HERBERT, ENGINEER, COVENTRY.

(For Desc1·iption, see Page 328.)

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the hardness beyond a certain very moderate limit. vVhy not use a new alloy 7 Chrome steel has already been tested ; and when to a pure metal, like boiler metal, 0. 2 to 0.4 per cent. of chromium has been added, homogeneous blocks have been obtained, and t he limit of elasticity has been raised notably- up to two-thirds of the breaking strain­without sensibly altering the elongation.

'' In the direction of alloys there may be found various advantageous solutions of the problems in­volved in the manufacture of metals destined for civil constructions.

"As a fi nal conclusion of this summary survey, we would call attention to the fact that tensile tests and mechanical tests in general may determine et- prio,·i the intrinsic qualities of a mass of fluid metal, but not those of a solid metallic block,

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r whether before or after work has been done upon it. "

The discussion on this paper must have been quite flattering to the author. One speaker gave the following extract from a specification in a high­grade Bessemer steel : ' ' Samples taken from the steel when poured shall show an amount of phos­phorus not exceeding 0.06 per cent. and sulphur not exceeding 0.05 per cent. Drillings taken from any part of the finished material .shall show an amount of phosphorus not exceeding 0.07 per cent. and sulphur not exceeding 0.06 per cent. "

Another speaker cited the case of some specimens of Swedish pig iron on exhibition at the Ex­position, w hi eh, though cast in iron moulds, was not all white, but showed grey iron in the parts which cooled comparatively slowly. In explana-

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tion of thia, T. Bergendal, of Soderfors, Sweden, r em1.rked that the iron in question- a mixed grey and white m etal for the '' Llncashire " r efinery process-fr~quently changes in texture according a1 the charge of the blast furnace is more or less b asic, other conditions remaining the same. Thus, when the slag is more ba~ic, a pig iron will be obtlined with both the g rey and white sharply divided, while with more acid slag t he colours will b e m 0re irregularly mixed. \Vhich of the several kinds is to be preferred depends upon the purpose for which the pig iron is used.

Dr. Drame gave some analogous experiments shown by the segregation of impurities in freezing wa.ter. H e stated that in making artificial ice the conditions are very similar to those which obtain in the cooling of steel or iron , only the rate of cool­ing is very much slower. Thus a can of water about 13~ in. square and 32 in . high, h olding about 200 lb. of wator, require~) ab()ut two days to be frozen. In such a ca.se one would expect the graatest concen tration of impurities to be in the middle or upper p ortion of the interior cone, but in the blocks examined the largest amount of im­purit ies was found in the lower portion of the interior of the blocks. This was due doubtless to some p eculiarity in the cir:mlation of the cold brine around the outside of the can.

Bearing on the question of the relation between the d egree of elimination of impurities and the rate of cooling are the results of analyses of different l1yers of natural ic ) cut from a deep p ond. The water of the p:>nd contained a considerable amount of dissolved and suspended impurities, and it was noticed th1.t each succe3sive layer from the top downward was purer than the one above. There could have b een no difference in the condit ions of freeziug in these layers, except the rate ; that is to s:1.y, the rate of f reezing was probably slower as the ice increased in thickness.

The President read a paper on "Heat Treatment of S teel, " and then came the paper on ' ~ Micro­Structure of Steel ," by AI bert Savern, of South Chicago. He st1ted certain propositions as to the characteristics of steel, illustrated by plates, and from thes9 he drew the conclusions that the phy­sical properties of a sound piece of steel depend :

1. On the proportion of pearlyte and ferrite, or pearlyte and cementite, present in t he metal (and this is governed solely by the percentage of carbon), and

2 . On the proportion of p earlyte and ferrite, or p earlyte and cementicll composition, and heat treatment.

With steel of average hardness, the amount of ferrite is very small ; the grains are in close con­tact, and the work of measuring can generally be much shor tened by neglecting altogether the area occupied by the network itself. All that is neces­sary then is merely t o f~llow ~ith the planime~er the outline of the space, 1ncludmg all the full gratns visible in the field of the microscope, to count them out, and to figure the average area.

In dealing with sof t steel, h e measured indi­vidually a sufficient number of grains of soft B essemer steel containing 0.11 per cent. carbon magnified 500 diameters . By measuring each of the 41 indtvidual grains he found a tota.l area of 1650 sq uare mil lim~tres, which gives an average size of 40 square millimetres, or, if red uce~ ~o an enla rge­ment of 100 diameters, 1.6 square millimetres. Most of the t est -bars were cut l in. square and 20 in. long. A thin section was _cut at. one end of each test polished, etched, and 1ts gra1n measured. The test~ were then subj ected to tensile strains, and the maximum load in pounds per square inch, and t he elonaa.tion and reduction per cent., were r ecorded.

I; steel rails h e found the lines of reduction and elonaation follow remarkably well the changes in the ~ize of the grain ; both falling rapidly as th e grain incrcaa ~s, and the ~eduction d~minishin_g more rapidly than the elongatwn. The s1ze of grain does n ot by any mea'ls so much affect the tensile strength. The fall of that line is very gentle. The grain in­creasing from 35 to 221 square millimetre~, i.e., sixfold, the corresponding decrease of t ensile strength is only about 10,000 lb.

He conclud€d that the r esults obtained show that there is a const~nt relation between the size of the grains 9.nd the properties of the metal. They constituts however, only the firat step toward an extensive' series of experiments ; but they have already given much useful infor~ation, and thrown much l ight on the way steel IS affected by heat treatment.

E N G I NE E R I N G.

The next day the me!allurgists again discussed steel , especially its manufacture. The Bessemer process in Sweden was r alated by Professor Acker­mann, of Stockholm, and the open -hearth process in the U nited States was presented by H. H . Campbell, of Steelton, P ennsylvania. The same day the mining engin~ers considered ''The B ertha ~inc Mines, " by W. H. Case ; "Handling of L arge Quantities of Iron Ore," by J ohn Birkinbine ; the discussion was largely as to th e use of th e steam shovel in stripping and handling ore ; "Improve­ments in Ore Dressing," by 0. Bilharz, Germany; in the discussion of which the Luhrig system of coal­wa~hing plant employed in Europe was described ; "An Improved Hanging Compass," by G. R. J ohnson ; and " Electricity in Mining," by F. 0. Black well.

The compass being novel and interesting, we give the description almost in full. A is the compass swung in gimbals , as in the usual form of the in­strument; B and BL are two small levels, sunk into the bottom of the compass-b ox, one on the N .-S. and the other on t he E.-W. line. With these the instrument can be levelled perfectly. Outside leveh would have interfered with the gimbals. The folding sights are of the usual pat­tern. In surveying in the chutes these are n ever

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raised, unless the line of sight is near the mag­netic meridian. D is a plate into which the cap E of th e J acob's staff screws. This departure from the usual form of J acob's staff-heads, in which the instrument turns on a spindle, the prolongation of the ball of the ball-and-socket joint, was occa~ioned by the n ecessity of having an easily por table in­strument. The socket for the usual spindle would have made the carrying case much too bulky. The compass having been made fast to the head, r e­voh·es on t he centre F, the head E t urning with the instrument. In surveying the levels, the screws G and G1 are loosen ed, and the compass is taken out of the gimbals. I t is t hen used with the Jacob's staff, as in the ordinary form of the instru­men t. With the arrangement above described, which entails the carriage of only on e extra piece (the J acob's staff), the levels can be surveyed in about one-half t he time formerly occupied, and the por tl.bility of the instrument is not affected. Also bEtter speed can be made in the chutes, as the sligh t extra weight, especially that of the plate D, makes the compass much steadier on the cord.

(T o be continued. )

THE DEVELOPMENT OF SOUTH AFRICAN RAILWAYS.

( Contimted from p3ge 295.) TH E lines projected in 1879 were to extend from

Durban northwards to Pietermaritzburg, and thence t o Ladysmith and to the Free State border n ear H arrysmith, with a branch to Newcastle and Charlestown to serve the Transvaal border and the 1ich coalmining district in the neighbourhood of Newcastle. A second line was to s tart from Durban for the north-east frontier,passing through Verulam, and a third line along the coast to Tsiyingo . . For the first sections of these lines, that Is, to P1eter-

maritzburg (70 miles), Verulam (20 miles), and Tsipingo (12 miles), a sum of 899,037l. was voted and appropriated. This first portion amounted in length to about 99 miles, and was opened for traffic in 1884, and to L~dysmith, an additional 91 miles, in 1886. At t.his p oint the line bifurcated, one branch diverging towards ihe Orange Free State and Harrysmith and the Transvaal border, and th e coal districts n ear Newcastle and Dundee. Twehe miles beyond La.dysmith the main coal branch to Dundee and coal station (48 miles) was started at Biggarsberg Junct ion. Although these extensions were pushed on fairly actively, neither objective was reached in the period of which we are speaking, 1877 to 1887. It was unfortunate t hat N atalshould have been deprived of the legit imate advantages due to her geographical position for so many years, while the Cape was making hay while the sun shone so brightly.

In 1881 an attempt was made to start a new era of railway development in the Cape Colony by passing the Grahamstown and Port Alfred Rail­way Act. The idea was to r e,·ert to the original principle of building railways through private companies with State aid, but the effectual and reasonable assistance of a guarantee of interest on capital was unfortunately abandoned for the more que3tionable policy of a subvention. The r esults have been such as to discredit and discourage a most praiseworthy a ttempt to supplement and complete the large railway undertakings which, under the circumstances of long distances and sparse populations, called for and warranted direct Government intervention to secure their timely catry­ing out, by smaller ones in which Gov€rnment was but indirectly interested, and were therefore more legitimately within the scope and means of private enterprise, more especially as they would paes through the more settled and populous and more directly remunerative districts of the colony. The Grallaml!­town and P ort Alfred Rail way concession, with a subvention of 50,000l. , was taken up by an English company, the first sod was cut in October, 1881, and the first 30 miles (from Port Alfred towards Grahamstown) were opened for t raffic in December, 1883, and the r emaining 13 miles be­fore the end of 1884, at a cost of 380,000l , or 8837l. a mile. This line, howev€r, owing to t he local depression in agriculture and the disasters in ostrich farming, was not long in getting into financial difficulties, and passed into the hands of a receiver, and was worked by a local committee t o prevent its being entirely shut up. The Govern­ment was asked to tak e it over, and a Government engineer was sent to inspect it, and estimated its value at 51,000l . in 1890. So this line, which pro­mised so fairly in the inception, and which might have, with a guarantee instead of a subsidy, tided over the period of local depression, has been irretrievably wrecked before it had time to stand fairly on its legs. In 1882 an Act was passed authorising Yaluable concessions of land for the construction of a rail way from the neighbourhood of Tuivani (Stormberg) to the Tudwe coalfields, the subvention being 1000 acres of coal-bearing land , and either 50,000l., or 25,000 more acres of other land near th o railway and 25,000l. This concession was taken up by a com­pany of King William's Town and East L ondon merchants, but from that day to this has never been carried out. In 1883 an Act was passed giving a concessicn for a line from Worcester to Ashton (Montague) in the Western Province, together with a subvention of 50, OOOl., in addition t o a sum amounting to the total custom dues on the materials for its const ruction. This was taken up by an English company, entitled the Cape Central Rail­way Company, Limited, and the works were com­menced in September , 1884, and the line (42 miles in length) was opened for traffic in the middle of 1887 ; but in 1889 the line got into difficulties, and negotiations are still on foot for cession to Govern­ment. The next rail way system init iated during the second railway period which we have been con­sidering was the one connected with Delagoa Bay, and the history of the Por tuguese portion of this undertaking is probably without parallel in the annals of concessions.

Delagoa Bay, in the first place, as a harbour ia as good as, if not better than, any other on the South African coast; it is also, in respect to the Transvaal, as conveniently placed as Durban; but, in respect to the former, it possesses the conspicuous advantage of belonging to a nation which would be open to coercion in a way no British colony could ever be.

-

E N G I N E E R I N G.

The development and perfecting of the outlets to the Transvaal through the British colonies has been entirely due to the i~itiative of .those colonies, and more or less in desptte of the w1shes of both Dutch Republics. A convent ion was signed between t he Transvaal and P ortugal in December, 1875, by which the respective Governments were to promote M railway communication between Pretoria and Lorenzo Marques, the advantages to be offered by ~ both Governments being somewhat similar, includ­ing a. subvention of half the cost of the line, free entry of all railway materials for fifteen years, and

CAPE GovERNMENT R AILWAYS, 1892.

lltil • 8. I Aver age Cost per I

.Mile. Total Cost.

--

)ape Town to Y1yburg, incl u~ing Sttll~J?· I d. £, P. d. £, 8. Wes'ern sv~tem. 815 8,101 17 9 6,603,037 7 3 aio line .. .. • • • • ••

bosch and dock lints, E( rsle Rtver, and ;)Jr Lowry 's Pass.

29 5,993 4 0 17 3,502 16 0 clalmesbury line .. f{ raaifontein to Malmer.bur.v . . . . • 211,232 12 9 • • •• • • 6 35,205 8 10 ~alt River to Wynberg (doubl~) .. ynberg line .. • •

• • . . • • Wy nberg t:ia Kalk Ba.y to Simon's Town 14 16,358 2 10 21o,013 19 0

Simon's Town line • •• • • • • - - -Whole system, total 86! 8,336 18 1 7,203,086 15 0

• • •• . . - ·

all Government land required for the rail way M gratis. The Transvaal proceeded at once, in 1876, B to raise a loan for this purpose of 300, OOOZ. in v H olland, and it was partially subscribed, but the o Portuguese Government, with whom the matter was 0

not of the same importance. and who wished to avoid having to give a subsidy, allowed the matter lt to quietly slumber. The particulars of the rail way

Jfi dland System ain line .. • • • • • • • • Por t Elizabeth to De Aar and N aa.u wpoor : 4(0 9,649 7 11 3,8f9,758 0 6

Junction to Narval's Point. 121 6,85R 6 1 829,848 18 7 Nor val's Point to Bloemfontein loemfootein line • • •

0 1,378,000 (l 0 . . . . • 212 6,600 0 •• •• • Bloemfonteio to Vaa.l River aal River line .. 1,386,063 lt 1 • • •• : : Zwar t Kops and Graa.f Reine~ 178 7.786 16 4 raaf Reioet line . . .. •

6 2 • • •• 36 15,343 8 2 637,019 . . ..\liceda.le to Orahamstown ra.bamstown line • • •• • •

• • • • -- I 7,990,679 Whole system, total 946 8,446 8 0 15 4 •• • • •

' -Eastern System. Buffalo Ha rbou r to Aliwal North 282 10,696 8 6 3,016,392 3 7

bin line .. . . . . H 10 • • . . •• . .

10 11,766 7 6 117,563 Kin~ Will iam's Town line on which the convent ion was based were the follow­ing-1st section : L orenzo Marques to Transvaal M border, 56! miles, estimated at 6,500l. a mile. 2nd section : Border to Top of Drakensberg Mountains, 142 miles, estimated at 11,500l. a mile ; this was r e-surveyed and considerably cheapened on con­struction. 3rd section, to Pretoria, 80 miles, esti­mated at 6, 750l. a mile ; this third section was to

• • • Bla.ney to King William's Town • • . . Burgbersdorp to Springfontein 67 8,658 0 0 680,000 0 0

be omitted at fi rst., and the traffic worked by ox wagon. Towards the end of 1883, however, it be­came apparent that there would be a gold Loom in the Transvaal, and t his brought the question of the Delagoa Bay Rail way once more to t he front. The prospects of this railway in view of this boom were so alluring, that the Portuguese Government were able to get the concession (signed December 14, 1883) for their por tion of the line taken up by a British company without a subvention on the basis of the Portuguese Government plans from L orenzo Marques to the supposed frontier line at the 81.970 kilometre. The terms of the concession were briefly the following : Construction to be completed within three years of approval of plans ; company to fix their own scale of rates ; plans to be presented within 140 days, and works commenced as soon after as possible; Government to grant no competing conces­sion within 100 kilometres on each side of line. This concession was viewed with extreme disfavour by the Transvaal, who feared that the outlet they had hoped to control was falling into British hands, and was likely to become just as objectionable to them in respect to rates as the colonial ones. Pressure was brought to bear on the P ortuguese Government, and two memorand a in respect to the railway con­vention, dated May 16 and 17, 1884, were signed bet ween the two Governments. The former appeared in the Portuguese White Book for 1885, but the second was not divulged till May, 1889, incidentally on a debate in the Portuguese Cortes.

The published memorandum bound the P ortu­guese Government to use their best offices to induce the company to grant a. favourable scale of rates for the Transvaal traflic. The secret memorandum bound them, in the event of the company being obstinate, to give the Transvaal leave to themselves build a t ram way from their border to L orenzo Marques to carry the materials for the construction of their lines, and in certain events to work pas­senger and goods traffic over it. To strengthen the hands of the Portuguese Government as against the company, the Transvaal also raised the question of the position of t heir frontier, declining to accept the delimitation made previously by the P ortuguese engineers, according to which the railway terminus had been fixed on the plans attached to the railway contract. Rumours of the secret memorandum which leaked out through Holland seriously ham­pered the D0lagoa Bay Rail way Company in raising their capital, and delays occurred. The plans were not presented before 200 days, nor approved till June, 1884, and no work having been begun by December, 1885, an extension of one year's time was granted, subject to works being commenced not later than June, 1886. But the company was not in a position to commence even by that date, and the Transvaal becoming impat ient, the Portuguese Government commenced the works themselves. These were taken over in lVIarch, 1887, and the company pushed on the construction on their own a.ocount from that time. In June of that year the question of the terminus of the lino, that is, the position of the frontier, was brought forward prac­tically, it having been agreed between the Trans­vaal and Portugal that its position lay 8 kilometres further inland than was shown on the railway

Bethuli e Junction • • .. 0 . . •• • •

83 5,6 18 4 0 468,010 0 id laod and E~tern Junction Middleburg to Stormberg • • • • • • • --

Whole system, total 442 9,438 16 7 4,171,965 18 5 • • • • •

I • . ' .

Toto.l of three systems, 2252 miles. Average cost., 8600l. ~ mile. Total cost, 19,365,632l. Ss. 9d. Amount autbor1secf, 201 m1Llons.

plans. The P ortuguese Government th~reupon, in despite of the railway company's protest, m June, 1887, sent their engineers to survey and mark ?ut this additional portion. In Decem her, 1887, the lme was opened for traftic to the 81.970 kilometre, the point indicated by the original plans as the Transvaal frontier. The Portuguese Government thereupon declared that the company had n ot complied with the terms of their concession, and informed them that th e line on the original plans was incomplete, and that the frontier was at t he Incomati P oort, where the Transvaal R ail way would end, and that they must extend to that point. The company demurred, stating that all their undertaking and contracts were based on the original plan being correct, and that they objected to extending their line to what was, for aught t hey k new, foreign territory. This dispute led to diplomatic intervention on the part of G.rea.t Britain and the U nited States in favour of the company, but the Portuguese Government would not yield, and on October 24, 1889, a decree was issued informing the company that they must complete their surveys and extend the line to th e new terminus (600ft. above sea level) in eight months, or their concession wouldj be forfeited and the line confiscated. The company protested that the rainy season (October to May) would preveut them from surveying or carrying out the works, and that, therefore, the eight months were too short to comply with the Government order, but they would do what they could, and they commenced work in May, 1889, on an additional 3 kilomet.res of line, and this notwithstanding that some 12 kilo­metres of t heir open line had been partially destroyed in January by floods. Further diplo­matic intervention with a view to obtaining an ex­tension of time took place, but this did n ot prevent the issue of a decree on June 25 to Eeize the line, and the actual seizure by force of the company's works t ook place on the 29th. Further diplo­matic action supervened, and proposals were made to meet the tariff question by the P or tuguese Governm ent giving a. guarantee of interest on the company surrendering their right to fix the tolls, but the Government would n ot give a guat·antee on more than 500, OOOl. capital, so this at t empt also fell through . The Government then proceeded t o sell the line by public auction, and t he whole mat ter was finally referred to internat ional a.r bitra­tion, with results which have not yet been made public. There i~, however, little doubt that this added one more notable example of the list of failures of rail way enterprise in private hands in South Africa ; and without reflecting at all upon the behaviour of the Portuguese Government, t here is no doubt that its action was entirely due to its being placed in the ugly predicament of being " 'twixt the devil and the deep blue sea."

In 1879 a concession was very n early obtained from the Free State Governmen t for a line from the Orange River near Colesberg to J agersfontein, with a branch to B!oemfontein. On e vote in t he Free State H ouse of Assembly lost the concession. The Government of the Cape offered the Free State exemption from customs duties on all rail way material used for their lines if they would construct a. system connecting their principal centres of com­merce with the ends of the colonial lines at Coles­berg and Aliwal North ; but this was not at that

time, and for ten years afterwards, accepted. In 1885-86 overtures were made by private companies to the Free State Government to undertake exten­sions of the Cape railway systems into their t erri· tory, but these also met with no success. Jealousy of th e extension of British infi uence, populatiou, and capital were the main obstacles against which the n ecessity for modern conveniences of transit had to contend, and the battle was for years a drawn battle. The two inland republics turned a deaf ear for years to th e overtures of both colonies, who were practically competing the whole time for the service of the gold fields in the very r easonable hope t hat by so doing they would materially aid tl: e financial prospects of the Dela.goa Bay route, which was to a much larger extent through their own territory, and whose outlet was in the posses­sion of a. foreign Government which they hoped to influence and control in a way they could never ex­pect to do their British colonial nejghbours. They also possibly hoped to obtain an outlet to the sea of their own, through which they would have infinitely preferred to conduct their commerce, and finally acceded to the Cape proposals in despair at the delay which their lEgitimate aspirations encountered on all sides. A convention for the extension of the Cape rail way system to the Orange lfree State was entered into in the early part of 1889, and this was supplemented in December, 1890, by a customs union, including British Bechuanaland. This was the effective commencement of the third period of rail­way enterprise in South Africa; but, as the nego­tions were most acti,·ely carried out for several years previously, the assumed date of 1887 is fairly correct . The above convention was followed in J a.nuary, 1890, by one between the South African Company and the Governments of the Cape and British Bechu&naland for the extension of the Kimberley line to Vryburg and Mafeking, the first instalment of the through line to Kha.ma, Matebele, and Mashonaland, or, in other words, the South African Company's territories. This con \rent ion arranged for a land contribution of 12, 000 square miles from British Bechuanaland, and the loan of the Cape Government credit t o raise the money for the undertaking. The Cape Government Rail­way Department carried out these extensions, and they were almost wholly done departmentally and by the small sub-contract system, and as the country was particularly easy, the work proceeded with great rapidity. The first line commenced was from Colesburg to Norval's Point (23.30 miles) where a. new bridge of twelve spans of 130 ft.~ total length 1626 ft. - was to be erected. Surveys commence.d and rails were laid by October, 1889, the old bndge nearer Colesburg being in this case not utilised. A t emporary bridge, 6.25 ft.. above low water, with 1 in 40 approaches, to convey rail­way material across, was erected in October · the floods, however, rendered this useless from th~ end of t~at month to Christ~as, but it proved of good serv1ce through .1890 t1ll November, when it was finally given up, to be r emoved when the floods per­mitted. The Bloemfontein line from N orval's P oint, 121 miles in length, was commenced in August, 1889, with ruling gradients of 1 in 80 and curves of 10 chains radius, and was completed and opened for traffic in December, 1890, at a cost of 829. 848l., or 5858l. per mile. The extension in

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E N G I N E E R I N G. - --

PRESSED STEEL CAR AND TRUCK FRAMES: COLUMBIAN EXPOSITION. CONSTRUCTED BY THE :FOX SOLID PRESSED STEEL CO~IPANY, JOLIET, ILL., U.S.A.

(Fo1· DescriptiO'Jt, see Page 328.)

-~ -

--- ----

Bechuanaland, 126t miles in length, was carried of 1890 the survey of the extension from Bloem- 1 was begun in February, 1890, complet,ed in out semi-departmentally, and the buildings, &c., fontein to Vilpen's Drift on the Vaal River (212 August, and the earthwork by t he end of the year, were entirely of wood and iron, and inferior to the miles in length) was commenced. Construction and it was open for t ra tlic about the same date as other lines but the speed of its construction and was begun in January, 1891, plate-laying in l\Iay, the extension to the Vaal River, at a cost of about opening w~s phenomenal, as it included two large and the whole line in the following May, 1892, the 580,000l . . or 8658{. per mile. - This is expected to bridges one over the Vaal at ]fourteen Streams 212 miles being completed in 16~ months. The enable East London to make full use of her and on~ over the Barb~. Here temporary bridges survey on the Bethulie junction line from Burgers- geographical position in competition with the Natal were erected to open the line, but the permanent dorp (eastern system) to Springfontein on the mid- railways, and it must be confessed that the former ones replacing them were complete~ in 1891. This ]and extension to Bloemfontein (66. 70 miles in apparently requires all the help that can be afforded line cost 730,7691., or 5840l. per m1le. At the end length), passing over the Orange River atBethulie, her to make up for much leeway in the past. In

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CLUB RAILWAY CAR AT THE COLUMBIAN E X P 0 S I T I 0 N. CONSTRUCTED BY MESSRS. HARLAN AND HOLLINGS\VORTH, vVILMINGTON, DELAWARE, U.S.A.

(For Description, see Pc.ge 329.)

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addition to these very important extensions, the Cape Government opened a 5 miles 36 chains ext ension to Simon's Town in December, 1890, and a 14 miles 6 chains branch from Eerste River vid Somerset " rest to Sir Lowry's Pass in February, 1890, and the junction line from Middleburg Railroad viu Stynsberg to Stormberg junction, 83 miles in length, on February, 1892, in a little over a year. The Table on pago 325 records the particulars of the Cape Government system of railways at the end of 1892.

In the meantime Natal had pushed on her rails beyond the Free State boundary to Harrysmith (opened October, 1892), 58 miles from Ladysmith, and beyond her coalfields to the Transvaal boundary at Charles town (304 miles) from Durban. The former line there is no intention of extending into the Free State for the present, as the midland ~ystem has occupied the field. Surveys are, how-

ever, being made to extend from Charlestown to Elsburg (100 miles), a point on the Nether lands railway system close to Pretoria, and the conces­sion is expected to be confirmed by the R~ad this year. At the end of 1892 the Natal Government system of rail ways consisted of the following :

-----Miles Avera.~e I Open per Mile. Total Cost.

- -!JI a i n Line. I .£ I £

Durban to Transvaal frontier :i02! l Branches. I

Ladysmitb to Harrysmilib I }- 11 ,153 1 4,628,242 (Orang e F ree State) . . 71~ • •

I Big~arsberg to Dundee •• 8 Tsipingo .. 12 • • • • • • I Verulam .. •• • • • • 20 /

-Wt-ole system . . .. I 414!

£ /evotton of Frome '<- • I - ~ -1Ji rt>d ;,

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The Transvaal in 1887 arranged a loan for rail way purposes, i .e., to connect Pretoria with Port Eliza­beth and Delagoa Bay, with the Rothschilds for 2,500,000l., and the Netherlands Company was formed to undertake the bu)lding of railways throughout the country. The first railways to be built were two lines each of about 30 miles length from J ohannesberg as a centre to Krugersdorp and Boksberg ; these were intended chiefly for the use of the Witwatersrandt Goldfields, the latter being to bring down coal to the fields.

In 1889, the Delagoa Bay Railway having been completed so far as to enable it to be used for the transport of permanent way material, the Trans­vaal Government commenced their connecting line through the heavy mountainous region of the Drakensberg, 6000 ft. above sea level. The first portion (10 miles) through the Crocodile Poort

(1100 ft. above sea level) was built under contract, cost 25,000l. per mile, and proved pa.rticularly un­healthy t o the constructors, owing to the miasma blown up from the low country, and to animals being within the t etse fly belt. The portion through the Elansberg (Devil' a Contoor) is also very heavy, involving tunnelling, &c. The construction has been advancing steadily, the line having been completed nearly to the end of the second section, with a branch t o Barberton (40 miles) in 1892, and it is confidently anticipated that the Nether lands Company will open to Pretoria by the end of this year.

Before the Cape system reached the Vaal River the construction of the earthworks on the Pretoria line had been already commenced, and t he line will probably be completed to Pretoria (65 miles) this year. The Transvaal Railway system, as

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at present contemplated, will consist of the follow-• 1ng:

P artly Opened and under

Construction. M ain line-Orange Fcee State border Miles.

to Portugu~se border, via Pretoria... 344 Branches from J ohannesberg, &c.

(completed) . . . . . . . . . . . . 60 Branches to Barberton, &c. (completed) 40

, Marahastad (contemplated) 175

T otal . .. .. . . .. 619 Of these 444 miles will be completed in 1893.

W e come t o the latest, though n ot least, im­portant system in South Africa, situated in P or t u­guese territory, known as the Pungwe-Massi K esse or Beira Railway. Immediately M ash on aland was opened up to British influence by the efforts of the S outh African CharteredCompa.ny,it became evident that an outlet to the sea must be found closer than any of the colonial routes, but which would unfortu­n ately have t o pass through the territory of a foreign P ower by no means friendly to Brit ish influence.

By November, 1891, four r outes had been pro­spected to the interior from t his pa r t of the eastern coas t. The one selected runs from a p oint opposite Lukambaio, on the Pungwe River (12 miles above Beira, and 60 miles from the mouth of the river), the river being navigable for vessels up t o 20ft. draught up t o this p oint (N ueves Ferreira). The line which has been selected goes from N ueves l~"erreira to J obo (River Busi, 12 miles), through Meforga and Gomani to Massi Kesse (:L\-l ashona frontier), under 200 miles in length. The gradients will be seldom over 1 in 100 for the first 150 miles ; the longest span bridge will be 80 metres, over the Banduri, the n ext longest being t hree of 50 metres. Near Massi K esse the gradients will be 1 in 40, ani a tunnel of one mile in length will probably be n ecessary. The Fort Salisbury branch would start from Munesse, east of Massi Kesse. The saving in distance by this route to Fort Salisbury would be 1000 miles in distance, time two-thirds of present, and r educe cost to one-third actual. The company was approved by t h e P ortug uese Government in F ebruary, 1892, and made a first issue of 250,000l. d ebent ures last October. The works on a first sec­tion of 75 miles from Nueves F erreira, estimated to cost 225,000l. (or 3000l. per mile), were commenced about the same date under contract by a British contractor, and are proceeding satisfactorily, so that t h is section should be opened by the middle of this year. The only matter t o be regretted with r esp ect to this, the last-born of the South African rail ways, is the gauge, 2 ft., but there seems t o be some prospect of this being increased to the stan­dard South African gauge b efore the construction is even completed.

(To be continued.)

HERBERT'S CAPSTAN LATHES. OuR illustrations on page 322 represent a type

of capstan lathes manufactured by Mr. Alfred Her­bert, engineer, Coventry. These lathes are all made on the interchangeable syst em, and are so arranged that they can be supplied either in their simplest or most complete forms without any al tera­tion to the pat terns. This is well shown by our en­gravings, where Fig. l represents the la the with simply a pla.in hollow spindle, plain cut-off rest, and a capstan rotated by hand. In Fig. 2 the sa.me lathe is shown, fitted with a capstan rotating automatically, a n alternative wormwheel feed which can be thrown in and out of gear instantaneously, a sliding cut-off rest, and an automatic chur.k and feed motion, by means of which the stock is advanced with­out stopping t he machine. As will be seen, the la the is well adapted for producing all descriptions of repeti­tion work. Special care has been devoted t o securing the rigidity of the machine, and in arranging its various handles as conveniently as possible for the attendant. The end thrust is taken up on a cast -steel ball bearing. The spindles are ground true on dead centres and run in bronze bearings. The cut-off rests have double adjustable stops, a nd are fitted with wedge adjustments for the tools. The capstan has an adj ustable conical h ardened bearing, and is fitted with an independent locking lever, enabling the capstan block to be clamped absolutely solid when doing heavy cutting. T he locking r ing is of st eel, hardened and ground, whilst the locking bolt, which is also hardened, is fitted in a long slide with adjustments for wear. The mechanism is, moreover, completely covered and pro· tecterl from dirt. The capstan slide is operated by a machine-cut steel rack and pinion, the latter being cut solid on its shaft. T he lathes, we may add, are built in three sizes-viz., 5-in. , 6-in. , and 8!-in. centres, and take bars up to 2! in. in diameter.

E N G I N E E R I N G.

FOX'S P RESSED STEEL FRAMES . TnE great success that has attended the Leeds

works of Messrs. Samson Fox and Co., induced the firm to establish large works in the United States, so long ago as 1889, for the manufacture of pressed con­structive steel , for which they had al ready earned a high reputation . The American firm trade under the name of the Fox Solid Pressed Steel Company, with offices in New York and Chicago. The works are at J oliet, Illinois, about 40 miles from Chicago ; they employ some 400 men, and turn out about 80 car trucks, besides other work, per day. It is satisfact ory to note that all the heavy machinery in the works was made in England, and is in all respects similar to that used by the Leeds Forge Company, of Leeds. We may mention that the hydraulic p umping plant was supplied by Messrs. Tannett, Walker, and Co., of

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showing this exhibit, which takes a second or third place amongst the exhibits of the steel manufacturers of Amerioo. at the World's Fair. The two steel flat cars, one of which is illustrated on page 326, which have been built for carrying loads of 100,000 lb. of pig iron, have attracted much attention amongst railroad men in the States, from the fact of the essential de­parture from ordinary methods in the construction of the framing, which consists of the Fox pressed steel frameplates strongly riveted together, and combining simplicity, lightness, and strength in a remarkable degree. Each of these cars is mounted upon the Fox pressed steel freight car truck, which has met with such success that it is now in use upon upwards of seventy roads in the United States, amongst them the New York Central, which has over 3000 of them now in regular service. The form of this truck or bogie is well shown by the reproduction of the photographs on

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Leeds, and the boilers by the Leeds Forge Company. This firm does not make any exhibit at Chicago, but the J oliet Company have a very fine display in t he American section of the Transportation Exhibits Building. I t is located opposi te the Pullman train, and covers about 1500 square feet. The exhibit con­sists of a selection of the specialities of the firm, prin­cipally consisting of Fox pressed steel trucks, steel car frames, passenger car trucks, and an assortment of various ar ticles press forged and shaped, for railway and other purposes. The Fox Solid Pressed Steel Company own the largest hydraulic forging plant at present in the United States, one of their presses having a table 26 ft. long by ll ft. wide, capable of exerting an aggregate total pressure of 3000 tons. The works are equipped with t he most modern and improved hydraulic appliances for working steel plate into the many forms in which it is used for pat ent freight and passenger car trucks, &c., and the success which has attended the introduction of this system has been such that further extensions are in progress for the purpose of developing the business of building steel car frames for various types of American rolling stock. A number of examples of this system have been at various times referred to in ENOINEERtNG, principally in connection with the use made of the system on English railways ; and we have the oppor­tunity of producing for the firs t time the illustrati1ns

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page 326 ; it is of the rigid bolster type, having springs ov~r t he axle-boxes, and primarily consists of four main parts which are strongly riveted together. The pressed steel passenger trucks have been in use on the Pennsyl­vania Railroad with complete success for the past two years; and a number of other types of trucks are in course of construction for various forms of service. There is also exhibited one of a large number of still­heads, 84 in. in diameter by i in. thick, dished 21 in. deep; these plates are made at one heat by hydraulic pres~ure between suitably formed dieR. Another excellent form of pressed steel work is in t he locomotive front end plate, which consists of flanged plates, and replaces the ordinary method of cast eud used in American locomotive practice; we understand a very large number of these patent locomotive front end plates have been fitted during the past year. Some miscellaneous examples of pressed steel work in the shape of truck bolsters, centre plates, cylinder casings, &c. , are well worthy of examination, as show­iug what is possible to be done by a suitable use of the Fox process.

The Leeds Forge Company, at Leeds, who are the users of the same system in this country, have re­cently made considerable development ia their methods, principally for colonial railway work; the system is also steadily meeting' with continued favour upon English roads, and they are now making

underframes for passenger cars for the South-Eastern Ra.ilway ; se,·eral hundred pas~enger cars 01~ the London and South-Western Radway are equtpped with pressed steel ca.r trucks, and a very large numb~r of pressed st eel frames for goods wagons are now m use in England.

The illustrations on page 328 show clearly the con· struction of a standard four-wheel truck (New York Central and Hudson River Railroad ), as made by the Fox Pressed Steel Company, of J oliet. We may add in conclusion that the manufacture of trucks for street railway cars is a speciality of the Fox Company, no less than 6000 of them being in use. Examples. of such trucks are shown in place in the Transportatton Building by the McGuire Manufacturing Company, of Chicago.

THE "NIAGARA " PUL VERISER. vVE illustrate on page 323 the Niagara pulverising

mill, as designed and manufactured by .MP.~srs . Coward and Ihlee Railway-place, Bath. The null generally consists of a drum, inside of wh~ch revolves an e~ge runner operated by a shaft earned on two ou_tstde bearings. Round the inside of the drum is a sene~ of buckets, into which the material passes after bemg milled and when the contents fall from the buckets at the tu;ning of the drum th_e finer parti?les are drawn by an exhaust fan into a sttve-room, while the coarser material falls again to the track of the edge runne.r. Figs. 1 to 6 show. the genera~ arrangemen~s of a. mill of 8ft. internal dtameter, whlle the engravmgs, F1gs. 7 and 8, are from photographs of a 72:in. mill d.estined for use abroad in the treatment of baste slag. F tg. 8 shows the bedplate and driving gear, the crushit;lg drum being removed. The drum, as shown on F1g. 7, re­volves at a speed of about 30 revolu~ions per min~te upon the four friction rolls of equal stze, a path bemg formed on the rolls. The friction-roll shafts are all of steel and fitted with white metal bearings adjust­able to' t ake up the wear, which, owing to tb~ slo~ speed, is very slight. The. edge runner, wh~ch IS

shown on section Fig. 4, weighs about 2 tons m.the 72-in. mill, and in addition is weighted by. a spnng, as shown. It is made up of three parts (Ftgs. 5 and 6), one disc with a l~eavy boss keyed to t~e shaft, and the second disc passmg over the boss w1th a sleeve. Both are conical on the periphery (inwards), and when held together by four bolts they clamp the ch.illed iron rina. This ring, which is really the crushmg edge, canbtherefore be replaced at any time with the minimum of trouble. The edge runner, of course, is. driven l>.Y cen­trifugal force, and the wear of the crus}ung p~th 1s pro­vided for by its being made up of twelve. chtll~d. cast­iron segments laid into the drum and held m vosttlon.by one wedge piece (Fig. 4), so that here also httle fittu~g or skilled labour is required for placing a new path m position. The material is fed through a. hopper fitted to the front cover-plate into the leading side of the edge roller, by which i t is crushe~. ~t accumulates in the rear of the edge runner, and xs picked up by the series of buckets on the inside of the drum, and from them showered as shown in Fig. 4. The sma.ll par­ticles are drawn by the air current induced by a fan, while the heavier particles drop again in front of the edge runn~r. The position of th~ fan is .shown. on Fig. 1, whlle the arrangement of dtscharge m to sttve­room is seen on Fig. 3. Across the connecting chamber are arranged five worm conveyors, and it is scarcely necessary to explain the principle upon which the air current secures a distribution into these conveyors of the particles according to their specific gravity

CLUB RAILROAD CAR. THE rapid growth of American cities, like that of

crowded centres in this country, has had the effect of causing business men to take up their residences in the country at a greater or less distance from their town offices. In the United States, where distances are less respected than they are here, colonies of suburban residences abound, so far away that the heads of families have but lit tle opportunity of en­joying them, except on Sundays or holidays. The daily journey to and from their places of business may occupy a.n hour or even two, and it is desirable that this considerable portion of each day should be passed as agreeably as possible. It naturally happens that friends and neighbours in these suburban colonies should travel backwards and forwards together, and should even look to occupy the same car ou the out­ward and home journeys. Latterly it was sug­gested that it would be more pleasant to retain a special car, and out of this idea grew that of the railroad club car, which rapidly found favour, and of which many examples a.re to be found in service to-day. Such a car we illustrate on page 327 ; it is built by Messrs. Harlan and Hollinsworth, of Wilmington, Delaware, and is shown by them in the Transportation Building of the Col urn bian Expo­sition. It is intended for service on the Central Rail­road of New Jersey, and will run between Plain field and Jersey City. The members of the club controlling

E N G I N E E R I N G. this car pay an annual subscription, in addit~o~ to the ordinary fares the rai1road company proVIding the car and attend~nts. The length of the car is 71 ft. 6 in. over frames and the width 10ft. ; it is carried on two six·wheeled' trucks, the rigid wheelbase being 10 ft. ; our illustration shows clearly the arrangemPnt of frames and framing, and it will be noticed that the side frames are very strongly braced. As for. t~e arrangement of the car, it will be seen that 1t IS

divided into two compart ments, for smokers and non­smokers, and that at one end there is a commodious

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lavatory. There is a couch in ~ach co~partment, ~ut otherwise the seats are luxunous chatrs, on one stde grouped in fours and separated by tables, which are not entirely innocent of cards and other means of pas.s­ing t ime, which may sometimes drag slowly, even 1n such a vehicle. Cupboards are formed between the windows for the use of members, and light refresh­ments can be obtained when travelling. In every detail completeness and luxury are apparent, and the club car, which bids fair to become a railway institu­tion in America, is a d istinr.t advance on the Pullman drawing-room car for those persons who desire ex­clusiveness and are willing to pay for it.

NOTES FROM THE UNITED STATES. PHILADELPHIA, September 5.

LAST Saturday the Thomas Iron Company reduced quotations on foundry irons 25 cents per ton. This week other producers are pursuing the same course, making No. 1 14.50 doh., and No. 2 13.50 dols. - the lowest quotations for standard brands for years. Pro­duction is being restricted rather than increased. Un­favourable reports are being received from western centres. Buyers are holding off, awaiting further pos~ible unfavourable developments. The American Iron and Steel Association has presented a memorial to the Ways and .Means Committee, arguing against any further tariff r eductions at present. General apathy exists throughout the furnace and mill inte­rests, and in iron and steel works generally. There is no disposition to place orders for future delivery, even a.t the present exceptionally favourable prices. Bar mills are working irregularly . Plate and struc­tural mills a.re booking no new orders. Steel rails are quoted at 29 dols.; none selling. A reaction must soon arouse buyers, but manufacturers are prepared to take advantage of the first improvement to make better terms. Locomotive builders report a general falling off in orders. The cancellation of orders is quite general in all branches of industry. The finan­cial question is still puzzling the Senate, and until the business interests can see their way to a certain and early solution of it , business will continue in its present sluggish condition.

NOTES FROM THE SOUTH-vVEST. P oll;u,tion of the Yeo.-Threatened by the Sherborne

Rural Sanitary Authority with an action at law for polluting the Y eo with the sewage of Milborne Port, the Wincanton Rural Sanitary Authority adopted a scheme, of which the Local Govf'rnment Board had expressed approval, for the removal from the river of the effluent sewage from the tanks which had been the cause of the alleged nuisance. Under this scheme, the liquid is to be carried over the river and distributed upon a wide expanse of land, a sewage farm being thus created. The works, which a.re to cost a sum approaching lOOOl., are now nearly completed. In its desire to avoid litigation with the Sherborne Sanitary Authority Wincanton, by Temoving the effluent from the river, ba.s incurred, how­ever, the risk of a lawsuit with the trustees of the estate of Mr. Wing£eld Digby, M.P. At the last meeting of the Wincanton Sanitary Authority a. letter was read from Messrs. l<,awlence and Squarey, the agents of the estate, stating: '' We a.re surprised to find that the Milborne Port Sewage Works are in progress under a. scheme which will apparently deprive the Goa.thill Mill of all t.he effluent water, which, during the summer months especially, forms a. large percentage of the available supply. Mr. Digby would be extremely sorry to h3.ve to take any adverse action in the matter ; but he has no alternative but to bring the matter before his trustees, as obviously if be allowed the matter to pass he would be liable to impeach­ment for waste."

Card-iJT. -In consequence of the. return o~ the t)outh Wales miners to their work, every t1p at C~rdtff, Pena.rth, and Barry has been fu1ly employed .d.unng the last f.ew days. A lar~e fleet of steamers and sa.tlm.g vessels, w~Ic.h had been wa1ting for coal, is now thm~nng off, 8nd 1t IS

eKpected that matters will resume the1r normal appear­ance in about a week. The best steam coal has ~e.en making 16s. to 17s. per ton, while secondary quahties haYe brought 14s. to 15s. per ton. As regards household coal, No. 3 Rhondda large has made 15s. 6d. per ton. Coke ha~ been in good demand a~ from 18s. to 24s. per ton, according to quality. The u~n ore trade has re­mai,ned quiet. The manufactured uon and steel trades have presented scarcely any new feature. A better demand has prevailed for tinplate bars.

Bournemouth.-Bournemouth promenade pier is to be lengthened 130ft. to meet the requirements of gr~a.tly increased steamer traffic .

The "Oambrian."-The Ca.mbrian, having . been un­docked a.nd moored head and steri?, the mach1ne~y con­tractors, Messrs. Hawthorne, Leshe, and .eo., tried her engines on Friday. The sta_.rboard engmes. w~nt all right but after a few revolutwns the eccentnc rmgs of the port engine broke. As the rings to replace the broken ones cannot be procured at Pembroke, i~ is ex­pected that the official trial of the engines, whiCh was proposed to take place this week, will be pos tponed.

Admi1·alty I nspection.-The Admiralty yacht Eocha.n­tress sailed from Portsmouth on Saturday for Pembroke, where she embarked on Wednesday the L ords of the Ad­miralty who have commenced their annual inspection of the dockyards. The cruise is expEcted to last about a. fortnight.

The " /Eolus" and the "Spartan."-Tbe .i.Eolus and the Spartan, cruisers, are to be taken in band a.t once at Devonport, to have certain defects which have been reported since the termination of the autumn manceu vres made good. The repairs of both vessels a.re to be com· pleted in six weeks.

South Wales Coal and I ron.-The shipments of coal from the four principal Welsh ports in August were as follows: Cardiff-foreign, 301,76~ tons; coastwise, 66,974 tons. Newport-foreign, 65,475 tons; coastwise, 42,835 tons. Swansea-foreign, 73,971 tons; coastwise, 50J.007 tons. Llanelly-foretgn, 11,164 tons; coastwise, ti725 tons. It follows that the total shipments of the four ports in Auguet were: Foreign, 452,378 tons; coast­wise, 166,541 tons. The shipments of iron and steel from the four ports in August were: Cardiff, 2335 tons; New­port 1243 tons; Swansea, 124 tons ; Llanelly, 4 tons; tota.i, 3706 tons. The shipments of coke were : Cardiff, 3176 tons; Newport, 187 tons; Swansea, 395 tons; Llanelly, nil; total, 3758 tons. The shipments of patent fuel were: Cardiff, 13,041 tons; Newport, 5528 tons ; Swan­sea, 31,512 tons; Llanelly, nil; total, 50,081 tons. The aggregate shipments of coal fr~m the four prin?ipa.l Welsh ports in the eight ~onths endmg August 31thts year were as follows: Cardiff, 7,413,2-19 tons; Newport, 2,988,916 tons; Swansea, 1,029,975 tons; Llanelly, 117,025 tons; total, 11,549,165 tons. The .~ggregate shipD?ents of iron and steel from the four ports 10 the first eight months of this yea.r Wdre: Cardiff, 22,897 tons; Newport, 12,660 tons; Swansea, 1150! tons; Llanelly, 12 tons; total, 36, 719~ tons. The aggregate shipments of coke were : Cardiff, 58,599 tons; Newport, 3709 tons; Swansea, 2042! tons; Llanelly, nil; total, 64,350f tons. The aggregate ship­ments of patent fuel were: Cardiff, 192, 72~ tons; New­port, 32,825 tons; Swansea, 216,631 tons; Llanelly, nit; total, 442, 185 tons.

The "Northumberland."-The Northumberland line­of-battle ~hip, which is undergoing a. refit at D evonport, was to have been out of the dockyard by December, but the date of her completion has been deferred until Ma.r<'h, 1894. The Lords of the Admiral ty, in sanctioning the postponement, state that the ship must be completed during the present financial year, as they have no inten­tion to make provision for her in next year's Estimates. The total cost of the Northumberland's present refit is estimated a.t 50,121l., of which 32,8211. is to be expended during the current financial year. The delay in com­pleting the vessel is supposed to be due to the manner in which work has been pushed forward on the Bonaven­ture, the Astr~a, the Hermione, and the Antelope, in order to get them completed for sea.

Port Talbot.-Mr. Maconochie recently visited Port Talbot Docks, with a view to making surveys, &c., for their improvement.

The Electric Light at T o1·quay.-The Torquay Town Council again considered, on Tuesday, a proposal to light the town by electricity. The electric lighting com­mittee reported the result of some correspondence betwe-en the town clerk and Mr. Trentba.m, electrical engineer. It appeared that the latter estimated the cost of the electric current at 6d. per unit, which wa.s the same rate a.s gas a.t 4s. 5d. per 1000 cubic feet, or, when economised by turning out lights not actually required, 3s. per 1000 cubic feet. Details were given as to the cost of the various systems suggested. Mr. Trentham maintained that the high-pressure system was the best for Torqua.y. The committee recommended that the town clerk should ascertain Mr. Trentham's terms for preparing the neces­sary specifications and drawings for carrying out the scheme. The estimated cost of the works was 17,403l., and maintenance 3100l. per annum; th~ probable re­venue at 6d. per unit wa.s set down at 3320l. per annum. The mayor moved the adoption of the report of the com­mittee; but, after discussion, the council decided to adjourn the further consideration of the subject for six months.

7 E N G I N E E R I N G. (SEPT. I 5, I 893.

DETAILS OF EIGHT-WHEELED PASSENGER LOCOMOTIVE: COLUMBIAN EXPOSITION. CONSTRUCTED BY THE NE\V ' 70RK CENTRAL AND

.l H UDSON RIVER RAILROAD COMPANY .

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THE New Y ork Centra l and Hudson R iver Railroad Company show a locomotive in the Transp ortat ion B uilding at J ackson P a rk, r emarkable from the fact that in June last it made the journey from New Y ork to Chicago in about 18 hou rs, thus inaugu rating the new rapid service which has s hortened the journey by about six hours . L ocomotive 999 m ay be regarded as a type of the most advanced locomotive practice of the United S tates, and for this reason we propose to publish somewhat complet e details and the specifica­tion of this eng ine. W e commence the publication of the dra wings above and on our t wo-page pla t e in the current issue, a nd shall delay g iving particulars for the present .

H.M. S. "THESE US." O UR illustrations on page 334 represent the first·

class cruiser Theseus in course of construction a t the works of the Thames Iron Company, at Blackwall, and the same vessel read y for launching. This cruiser is one of t he flee t built under the Naval D efence Act. Of the type there were nine vessels, two of which , t he Grafton and Theseus, were constructed a t Blackwall. These vessels hM·e been d escribed in previous issues,* so that i t is only necessary now t o mention their chief fea­tures. The length is 360ft ., beam 60ft., and on a mean draught of 2:3 ft . 9 in. t he displacement is 7391 to~s. The eng ines ind icat e 12,000 horse-power, and g tve the vessel a speed of 19Jf knots un~er forced ~raugbt. There is no side a rmour, but there 1s a p r otective de.ck right fore and aft;, with an armoured breas twork of 6- m. steel protecting t he engine cy li~ders. . The arr.ange­ment of the deck is well shown m our tllustratiOn of the ship under const ruction. It has a ma~imu'? thickness of 5 in., where the g reatest protection 1s r equired , t apering t o 2 in. The 5-in. parts ar~ made up of t wo thicknesses of 1! -in. plat es and one th1ck~ess ?f 2~- in. plates. The d eck bea~s are of_angle bulb, wh1ch,. m the midship part, have a 9-ln. vert1cal flange and 3~ -m. horizonta l flange, while in the forwa rd and after parts the d epth is 7 in. Ther e is a beam t o every frame, as shown in the illustra tion, and the a ttachment of beam and frame is streng thened by guss~t plate~. The frames ar e of Z -section, 3! in. b,Y 6 m. ~y 3 _m.' .. ~he latter being t he r ever se flange. The pla.tt?g 1s l v 10. above the water line, t he sheer stra ke be1ng do~bl~, and 22.5 lb. below the wat er line, b ut the skm IS

doubled over the g reat er part of its ar ea., a ll the bow being flush on t he outside. The double bottom ~x ­tends over the whole of the machinery and magazme

------------------------• See ENGINEl!BI~G . YOl. liii., page 180 ; vol. l v.,

.PagE's 200 and 912 ; and page 180 ante.

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s~a.ces. The inner keelplate is tu iu. and the outer ft m . The vertical web is ! in. in thick ness. T here a re, a~ shown in the engraving, four longi tudinals on each s1de of the keel. The main deck, which is of wo?d, has steel stringers about 3 ft. 3 in. wide. T he mam and upper d eck beams are ofT-bulbs 8 in. deep and 5 in. horizontal flange amidships, and 7 in. for­ward and aft, but under the 9.2-in. guns they are 9 in. deep. T he par t icula rs of t he vessel, her ar mament, engines, and equipment, were fully described in our p revious article in our issue of August 11, on the occasion of t he vessel being open for public inspection, and w e content oursel ,-es now by referring t he reader t o that a.nd the ot her art icles indicat ed.

ENAMEL FOB I RON CASTINGS. - Messrs. F letcher, Rnssell, and Co., L imited, vV a.rrington, a.re int roducing the " chimatto" enamel for coati'lg 1ron castings, either in matt or dead surfaces. The colours and shades are endless in variety, and one of the principal properti~s is t hat the enamel is unchanged by red heat continued for long periods. It has been tried on little hand gas stoves for boiling ket tles, and the lustre has not been affected, so that it is suitable for enamelling alJ kinds of stoves and grates, and only requires dusting or washing in the ordinary way like china.ware. The enamelling, too, applied to orna­mental railings would give very fine effects. :Messrs. F tetcher ha.ve put down special plant for the product ion, and intend to exbibib specimens in their show-rooms at an early da te.

---THE L ATE ~IR. T HOMAS \VILLIAM KENNARD, C.E .­

~Ianr will lea rn with regret of the death of Mr. Thomas \Vilha.m Kennard, C. E., who passed a. way, after a short illness, on Sunday, the lOth inst ., a t his residence, Orchard H ouse, := unbury. Born in 1825, the second son of the late Mr. R. W. Kennard, M.P., he was educa ted for the profes­sion of engineering, and early t oo_k a.n active pa~t in rail way works in England. . Am~mgst h13 W<?rks certamly ~be best known is the Crumlm V1aduct, a bndge 200 ft. h1gh and 1650 ft. long constructed on the girder principle patented by W arren a'nd K ennard . . It is 10 t en sp~ns resting u pon iron piers and was opened m 1857, when 1t was one of the most rem'arka.ble, and is still one of the most interest ing, types of bridge-building in the country. It forms a. ~on­necting link between Monmouth and G~a.morg:a.n shues in the chain of the Great W estern Ra1lwa.y 10 Wales . Many other bridge works were uudert.aken in other parts of the world ; the Crumlin W orks, founded m 1854 being acti veJy employed. In 1869 the sub­ject of' our memoir le~t the management of t~e works to his brother , a.sststed by Mr.- :Mayna.rd, theu engineer, while be proceede~ to Amer1ca to l&:Y out as engineer-in -chief and supermten.d the const ruct10n of t?e Atlantic and Great W estern Ra1lwa.y, and here he dts­played that resourceful energy whic~ not only ea~ily over­came d iffioult ie.9, but quickened the)nterest and mdustry

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of h is staff and work men. H e also, in conjunction with the Marq uis of Salamanca, desig-ned and constructed a large number of viad ucts and br1dges in Spain and Italy. H is kindness to his men and a ffable disposition generally made h im greatly respec:ted and esteemed.

H.~I. BATTLESHIP " DEVASTATION."-T he Devastat ion, after undergoing a thorough renovation and reconstruc­t ion in hull, machinery, and armament at Portsmouth, underwent her eight hours' steam t rial under nat ural draught on Tuesday, the 12th inst . H er t rim was 25 ft. forward and 26 ft . 8! in. aft. T he average boiler pressure was 140 lb., and the mean vacuum was as high as 28.2 in. starboard and 28; in. port. With 94.4 and 93.2 revolu­tions the engines developed an indicated horse-power of 3139 and 2861, gi vicg a collective mean power of 6000 horses, or, in other words, 500 beyond the contract. The mean air pressure in the stokeholds was i in., and the coal consumpt ion 1.8 lb. per horse-power per hour. Tbe speed obtained was 13.25 knots, as taken by patent log. The trial was satisfactory though the speed was slightly under the estimate. The rehabilitat ion of the earliest of our sea-going mastless turret ships, built in 1869-72, must be regarded as a. noteworthy naval event. T he central internal portion of the bull has been rebuilt. This modification involved the rearrangement of the main watertight subdivisions, the construction of addit ional coal bunkers, the fi t t ing of new watertight doors and gearing, and boiler, engine, shaft, and t hrust bearings, new casings between decks, and new ventilating arrangements. T he ship has been furn ished with a modern installat ion of electric lights. A fight ing platform or military top has been added to her mast. This enables a couple of 3-pounder qu ick-fi r ing guns to be mounted in one of the most effective positions on board. The new armament is as follows : ]four 10-in. 29-ton br~ech1oading s uns, two 7-pounder 200-lb. guns, six 6-pounder quick-firmg guns, eight 3-pounder quick-fi r ing guns, five 5-barrel .45-in. Gardners, t welve 14-in . torpedoes, two submerged tubes, '' A " proportion of torpedo and elect rical stores. The new machinery for the D evastation has been fur­nished by Messrs. Maudslay, Sons, and Field. In her unreformed condition the monitor was propelled by engines of the d irect -acting trunk type, supplied by Messrs. J obn P enn and Sons, Green wich. The new pro­pelling machinery consists of two sets of inverted triple­expansion engines, of the collective power of 5500 with natural draught , and 7000 with forced draught. The cylinders are 34! in., 61 in ., and 76 in. in d iameter by 42 in. stroke. '!'be condensers have a total cooling sur­face of 9000 sguare feet, and the working pressure of the main boilers 1s 140 lb. on the square inch. \ Vith natural draue-ht the estimated speed of the shi p was 13.4 knots, and tb is expected that> with forced draught a speed of 14 knots will be obtajned . . In the ~a'1' E stimates the probable cost of the Devastat10n's refit ts gtven at 156,261l., mcluding 67,555l. for hull fittings and equipment , 63,187l. for machinery, and 11,324l. for gun mountings and tor· pedo gear.

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EIGHT-WHEELE D PASSENGER LOCOMOTIVE AT THE WORLD'S COLUMB IAN EXPOSITION.

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E N G I N E E R I N G.

SUSPENSION FOOT-BRIDGE AT BANCHORY. CONSTRUCTED BY ~IR. LOUIS HARPER, ENGINEER, ABERDEEN.

~{R. L ouis HARPER, C. E., of Aberdeen, has recently erected a. couple of foot-bridges on the suspension principle, one at Feugh Cottage, near Banchory, and over the River Carron, near Fa.lkirk, and the former of these is shown in our illustration above. These bridges are, as will be seen, of a light and graceful design, and are of ample strength for any load likely to come on them. The road way is 4 ft. wide, and is built of planking laid on larch cross-bearers which a re fastened with hooks to the platform ropes. The suspenders are iron rods, and are fixed at 2 ft. intervals, connecting together the main ropes and the platform ropes. The parapet is of galvanised wire netting. The columns at the end of the bridges are of larch, and rest on concrete foundations. At each abutment they are connected together at the top by cross-rods. The span is about 100 ft. in the case of Feugh Cottage Bridge, and 90 ft . in the case of the a.rron Bridge. The former cost 160l. complete, and the latter, which, however, had cast-iron colnmos at the abutments in­stead of larch, 220l. Mr. Harper has received an order for the supply and erection of a third bridge of this type over the River Trent in Staffordshire for t he Duke of utherland.

THE ECONOMICAL SPEED OF STEAMSHIPS.

T o 1'HE EDITOR Or' ENGINEERING. SIR,-I have re~d with great interest ¥r. W. J. Mplar's

article on economtcal speed of ijteamshtp~. There 1s one thing which I fail to understand. Bes.ide the. consum.I?­tiod of fuel, surely, there are many thmgs whtch consti­tute the cost of navigation : the interest on the capital required to establish t_he shippi~g business, the ~eprecia.­tion of all the properttea beloogmg to the esta.bhshment, the fees and duties of various kinds, the wages for officers a.od men en~aged, the cosb requi~ed to .maintain the a\lx.iliary engmes on board the eh1p 10 workmg order, and other sundry expenses. Mr. Millar overlooks them altogether. They a.re quite independent of the speed of the ship. Let this constant expenditure be expressed in an eqUivalent term of fuel and denoted by F. Then for a. certain length of time we have

Income A V A V - ---==-=~= - - ' Cost P + F mV3 + F

A being a. coefficient. Differentiation gives us the maximum

ratio, when 1- 3m V 3 = 0.

n~V3+ F

value of this

Therefore the most economical speed of the ship" ould be

•

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m= - , vs

• • • (1)

we have, therefore, 3 --=:-

--==F ~ A3J 2 P = \ . 'V F . V3 2P

V=

Hence the most economical speed i~ obtained when

F = 2 P • . • . . (2) In other words, a.t the most economical speed of the

ship, the money paid for fuel for the sole purpose of pro­pulsion should be one-third of the total cost m oa.rrying on the trade. We get then,

Income A V 2 A V - -~~ -

Cost P + F 3lf A - . 3mV2

AV 3P

- AV --

Thus we see that the depression of freight, or the ad va.nce of price for fuel, tends to increase the most economical epee>d of the ship and vtce versti. So that the most econo­mical speed for any steamship is by no means a certain fixed speed, but it is greatly dependent on the states of the general trades; and the time when the economical speed is high is a. bad time for the shipping trade, When the trade is vPry bad, the speed rises so high that there would be no profit to be gained in the business. H ence the laying idle of so many slow-speed steamships at dull seasons.

L et C1 denote the displacement coefficient of propul· sion; then,

Therefore,

F= 2V3

D~ Ct .

By transformation wa get

V=V _ FCl . 2D!

• • . (3)

I obtained this formula and communicated it to the Society of Engineers in Tokio, J a. pan, last year. Subse­quent!y, I was very much rejoiced to nod in a. very excel­lent paper of Mr. Hollis, of the United States Navy, p~bhshed in the J ourna.l of the American Society of Naval Engineers in February of the present year, that the pra.ctically same formula had been worked out by Chief Engineer John Lowe, United States Navy, ten years a.go. His formula. is intended for war Yessels, in which the main question a.t issue is the distance covered per ton of fuel consumed, and not the money earned for a. certain amount of capital invested. So that the value of constant Fin above equations stands in his formula. for nothing but the consumption of fuel for various auxiliary purposes outside of propulsion.

The above deduction is based on the following assump­tions:

1. That the resistance of the ship varies aa the square of the speed .

2. That the boilers, the engines, and the propellers have constant eflicienoies for a.ll speeds of the ship.

3. That the ship always maintains her normal displace-

331

ment, notwithstanding frequent loading and unloading of her cargoes at the ports of call and the daily consump­tion of fuel during voyages.

4. That the ship's bottom is always clean. 5. That there is no tidal current nor wind to interfere

with the steam navigation. 6. That the length of time during which the ship is

kept a.t her ports of call is a.l ways regular. 7. That the length~ of voyage~ remain constant. 8. That the interest on the c.a.pita.J, &c , which consti­

tutes a part of the cost of shipping enterprise does not fluctuate.

9. That the weights assi~oed and the spacee provided for cargo and fuel are not 10tercha.ngea.ble.

10. That there is nothing in the shape of Government restrictions or otherwise to pr-event free competition.

Many of the above suppositions are far from being practicable. So that the equation (3) is, a.t best, of very little use. We can find the really most economical speed of a. steamship only when the absolutely true relations between the power and the speed are known, as well as the constant expenditure in carrying on the trade. Let x a.nd y represent the cost and income of a steamship at any speed ; then evidently

y = f (x);

therefore the relations between them can be represented by a. curve with reference to a system of co-ord10a.te axes 0 X and 0 Y. Take any point P 1 in the curve (Fig. 1) a.nd join 0 P1• Let the angle P1 0 X be denoted by 0. Then the ratio of income to cost at the point P1 is

Income = J!_ = tan 8• Cost x

The line 0 P1 cuts the curve at another point P 2 , so that the economy is identical for these two points. Now let us suppose the angle 8 to increase as fa.r as it is possible

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to do so. Then the points P 1 a.nd P2 will approach each other nearer and nearer, until a.t last they coincide at the point P 3• It goes without saying. then, that this is the maximum limit of economy. At this point we have

dy_y - --. d X X

For, as a. property of a geometrical tangent, we have

d Y =tan 81• d x

The point P~ becomes known, therefore, when the equa­tion y = f (x) is of a known form. To know the true relations between the functions x and y for a.U speeds of the ship, it is necessary to conduct coal consumption trials or to collect reliable data from long experience on board the ship, and to prepare a diagram of cost and income as described above. The tangent to the curve from the origin of the co-ordinates will touch the curve at the point that is most economical. Fig. 2 is a. diagram to solve the financial problem for a. steamboat favoured with Govern­ment subsidy, and serving on a. river as a ferryboat, and periodically going up a.nd down the current. In the fir~t place, the curve of coal consumption is prepared with reference to co-ordinate axes 0 1 X and 0 1 Y 1 from the data. of actual trials. On the axis 0 1 X, produc~d back­ward, 0 1 0~ is set off, representing the constant expendi­ture in equivalent terms of fuel. On the line 0 1 0 3 we next set off the length 0 3 0~, representing the Govern­ment s~bsidy, also_in the sam~ equivalent terms. Through the pomt 0 2 the hne 0 2 Y 2 1s drawn parallel to the axis 0 1 Y 1• On this new axis 0 2 Y :2, the length 0 2 V c is set off on both sides of the &:\.is 0 2 X, representing the current of the river. The tangents V el P 1 and V c p , drawn to the curve from the points Ye l and Vo and touching it at the points P 1 and P2, would give the most economical speeds 02 vl and 02 v2 relatively to the sur­sounding water, when the ship is steaming along with the current and when against it respectively. This is merely a.n imaginary problem, of course; but it will be sufficient

332 t? sh ow . advantages of gra. ph ioal methods in some ar­tlOula.r mstances. Apologising for the length of pthe letter, I am, Sir, yours faithfully,

N Y. WADAGAKI.

ewcastle-on-TynP, September 11, 1893.

SPEED PREMIUMS. T o THE EOITOR OP ENGINEERING.

SrR, - In your last you refer to a. bonus of 40,000l. paid upon one. vessel for the above. In Mr. O'Neill's paper (Pro~eedmgs of the .United States Naval Institute) he e.d~uts-as. I . have pomted out for years past - that

The e~c1ency of the pro.peller is one of the primar and most Important fact_ors 10 steam propul9ion, to which e. great deal mor~ attentLOn ought to be p aid. T oo often a vessel ~oes on tr1a.l with scre ws totally unadapted for the spee~ mtended; and when the same has been found wa~tmg, <;>ther screws. are substituted, whose elements are enttrely dtfferent, whiCh realise anticipation."

A1so: " . yY'it~ suitable propelle~s a spee.d .of 12 per cent. over

e.ntlCtpatwn can be ob tamed, g1 vmg a premium of 200,000 dols.; under natural draught an excess wil be reached on the specified power, which m~ans lOO,OOOdolP."

I have long ag? asked any Government to freely try my system ; and 1t seems to me that it w0uld pay the ~eople of the United St~tes to do so. A very small por ­tLOn of one of s~ch premmms devoted to a free trial of my system of altermg t~~ d eveloP.ed p ropulsive area to suit the vessel and cond1t1ons while running would save the mo~ey of that or any other country, and enable n earer estimates of speed capacity to be attained for future go­vernment. I made the offer- by pamphlets and letterc.­to all con;cerned, vet:y long ago; and by your courtesy I now pubhcly r epeat It.

Your obedient servant, RoBERT M cGLAssoN

Selhurst, S. E., September 11, 1S93. ·

BALL BEARINGS. T o 'rHE EnrToR o~<· E~GINEERI~G .

. SI~,-In reply to your correspondent, Mr. A . G. Ram age, tn th1s week:s ENGINKER.ING, it may be mention ed tha.t I h~d to do wtth about etghteen electric launches fitt ed With baU thrust bearings, which, a.lthou~h well designed, ~ere n ot madE:' accura.t E:>ly enough, a s 1t seemed im pos­SJ ble to get the hardened s teel surfaces absolutely true in themselves and a lso in relation t o each other · conse­quently the load was very unequally dis tribut;,d, and d.oubtless one ball at a. tin:' a took the whole load, and occa­swnally a ball crushed, w1th results that can be imagined· any want of trut~ also causes th.e ba;lls to cr?wd ~ogether: and the surfaces 10 contact movms- 10 oppos1te directions no doubt causes considerable frictl~n. '

In the bearings referred to above the centre part was at.tached to the ~haft, the inclosing sh ell being provided w1th grooved dtscs to take the thrusts ahead or astern as the case might be. '

If the part attached to the shaft could be so made as to admit of a slight rockin g motion, so that it could take a fa;ir bearing ag~inst ~he balls, or the non -rotating g rooved discs could be fitted m a rounded bed to attain the same ob).ect, better results might be obtained .

The be~rings cause a dull rumbling s0und on the ·.ressel. The wnter ha.s now to design some thrust hearings to

work. a.t a. ~ax1mum thrust of only 500 1b. , but previous expenence wtth balls hardly warrants their use.

Yours faithfully, Brighton, September 9, 1893. 1I AGNUS VoLK.

To THE EurTOR Ol.t' ENGINEERING. Sn~.,-Referring t o the letter _of Mr. Ramage in your

last Jssue, may I suggest that 1f ball or roller bearings are u aed in close contact, one of a slightly smaller diameter should be interpolated between each of the bearing ones ? As usually fitted, there must be con­siderable friction and wear at the points where the balls came in contact with each other, and this might easily be avoided. Y our obedient servant.

RonER'l' M cGLASSON. Selhurst, S.E. , September 11, 1893.

To THE F.f>ITOR Or' ENGISEEHING. Sm,-W e n otice in your issue of the 8th inst. the letter

of your correspondent Mr. A . G. Ramage, with reference to ball bearings for thrust block of propeller shafts. We d o not know of any ca.se where balls have been applied to reduce friction in this particular application, and from our exp~rience we do not think any arrangement of balls only would b a found to work satisfactorily. It may, howe\·er, interest your correspondtmt to know tha t we hope shortly to be making trials with our anti-friction r oller bearing applied to propel1er shafts, and shall be pleased to let him know the r esults of the said trials when made. In our arrangement rollers a re used to take the direct pressure, and balls are used as " spacers" for the said rollers. Yours faithfully,

P URDON AND W ALTER.·. 2, G~orge-street, W e~tminster, S . W.,

September 11, 1893.

To TUE EmTOR or-, ENGINEERING. SIR,-Toe lEt ter on this subject in your iRsue of the 8th

inst. wage 310) recalls the fact that Mr. li'yfe, formerly Crinan Canal engineer. built a small wooden screw ste~mer about 1865 or 1866, which had a thrusb bearing with balls working against a. single col1ar. I saw the arrangement, although not at work; but I believe it did all right. Yours truly,

CLYDE.

E N G I N E E R I N G.

CONCRETE BEAMS. _To THE EDITOR OF ENGINEEUING.

SIR,-\V1th reference to the experiments on the strength of con crete beam s, by Mr. S. L owcock, quoted in ENGI­NEERING of September 1, I should like to know if that g~ntleman has any explanation to offer of the fact that the constant C is , in the case of 1- G cement, lower at twenty-one days than at fourteen days . As regards his formula, should n~t L be the span m stea.d o~ the length of the beam, and are the dimensions of .the? thud beam accurately given as :39 in. by 18 in. by 19 m . . I am, Sir, yours truly,

STUD .ENT. B edford Pa.tlc, Chiswick, September D, 189:3.

CONTRACTORS AND THE ADMIRALTY. To THE Enrron Or' E~c INEEHING.

Sm,-Your leading article of the 1s t inst. must have opened the eyes of many contractors desirous t o get their ?cames placed on the Adruiralty list. Mr. Hanbury says ~here ought to be proper means for making a fair com~

parison be~ween the . ~st of .a sh~p t;milt in a dockyard, and ! he price of a stmilar sh 1 p bu1lt m a. pri va.te yard." But 1t would also ~sponish m any to learn the vast d iffer­ence of the supervtston and extra requirements which are de!t'a.nded by many unscrupulous Admiralty overseers in pri vat~ yards., ?ompared with what obtains in the con­structtOn of similar vessels in the R oyal dockyard e. Some of these gentl~men will actually stand by and allow a lar~e quantity of work to be completed and then order 1~ to be pulled to pieces, for some worth'less " fad " of .their own-dem oralising alike to both contractors and ~ork.me~~ When que.stioned, they point to their spe01ficat10n as may be dtrected, and to the satisfaction of .t~e overseer," &c. ; also, "any dispute or difference of opm10n between their L ordships' officers and the con ­tra~t?r, ~he Controller of the Navy is to decide, and his dectSton 1s to be final. " This all worked very wdl some year3 a~o, when the Admiralty were d isposed to interpret the va.r10us cl.a? ses of the ~peci fica.t~ons r~garding un­known quantities and reqUirements 10 a fau and liberal manner.

The treatment of contractors is shown in the case of the first and seco.nd class cruisera, where the Admiralty have refused to g1ve more than a third of the sum they have allow~d the dockya~ds for additions and im prove­m ents_ carrt~d out by pnvate yards. This is certainly s~eatmg w1th a vengean ce, House of Commons resolu­tLOn and clause in specification notwiths tanding.

I ~uld wax more eloguent, and givE' you more particu­lars d1d your space admit of it, although I have only been an onlooker.

I am, S ir, your obedient servant, September 13, 1893. Sun-CoNTRACTOR.

'fHE "TEUTONIC " AND " NEW YORK." To THE Eonon OF ENGINEEIUNG.

Sm,-In. your issue of the 8th inst. you state, and quite correctly, m your note on the Lucania that the New Yo_rk on h~r last eastward trip deliver~d her mails in Londo~ ~afore the T eutonic. Perhaps it may be just to th~ Brittsh steame~ to add a. few furth er particulars. It 1s not very mater1al to sc;ate that the T eutonic sailed abou~ an hour before her r~val. But it is m~st important to pomt oub wha.t the part1sans of the Amencan line care­fully suppress, viz. , that the T eutonic had no special mail from Q~eens~own . She reach ed Queenstown at 3.30 p .m. The ~ail tram left at 1 p.m. The hours lost by this pro­ceedmg ~~re far mo!e tha;n those by which the New Y <;>rk a.nttct_pated bAr 10 .matl delivery. The wisdom of ~h1~ course IS not to be discussed in a let ter; the fact is mdlBputable. Yours truly,

. B. w. GINSDURC. 12, Kmg's Bench-walk, T emple, E. C., Sept. 11, 189~.

LOCOMOTIVE ENGINES. To TilE EDI'l'OR OF ENGINEERING.

Sm,-The following Table, compiled from the railway companies' official returns, shows the number of locomo­tives on the important railways on D ecember 31, 1892. It may be added that some of the companies also possess some old or duplicate engines which they do not include in the list.

L ist of L ocomotives on t.h,e Important Linu, December 31, 1892.

Company. Engines. L ondon and North-Western ... ... 2712 Midland . . . . .. . .. . . . . . . 2172 G reat W estern .. . .. . .. . . . . 1690 North· Eastern .. . . . . .. . . . . 1560 Lancashire and Yorkshire .. . ... ... 1171 Great Northern .. . .. . . . . . . . 949 Great Eastern ... .. . .. . . . . .. . 928 Manchester, Sheffield, and L incolnshird... 708 Caledonian . . . . .. . .. . . . . . . 696 North British . . . . .. .. . .. . . .. G92 L ondon and South-\Vestern ... ... 598 L ondon. Brighton, and South Coast ... 417 South-Eastern ... .. . . . . . . . . . . 378 Glasgow and South-Western . . . . . . 313 L ondon, Chatham, and Dover . . . . . . 210 Ta.ff V a. le . . . . . . . .. . . . . . . 190 G reat Southern and W estern (Ir~land) ... 178 North Stafford . .. . .. . .. ... 1~8 Great Northern of Ireland . . . . . . . . . 137 Furness... ... . .. . .. ... ... 123 Midland Great W estern (Ireland ) ... 114 Nor th L ondon . . . . . . . .. . . . 104 Hi~hla.nd ... . ,. .. . ... .. , 100

L S EPT. Is, I 893·

The t otal number of engines in the United Kingdom at the close of last year w&a, according to the returns, 17,439. Yours truly,

L CLEliENT E. STRETTON, C.E.

eicester, August 21, 1893.

NOTES FROM THE NORTH. GLASGOW, Wednesday.

Gla~gow P ig_·I:on 11-farket.-A Bomewhat stronger tono ruled m the pig-tron warrant market last Thursday when SOJ?e 15,000 tons of Scotch iron were dealb in. Th~ cash pnce for Scotch rose in the early part of the day to 42s. 7~d. per ton, finishing in the afternoon at 42s. 7d. One lot of Cleveland was disposed of at 35s. Gd. twenty­five da.ys, but hema~ite iron rE:~a~ned unchanged, no busi­nes~, however, bemg done m It to test prices. The closmg settlement prices were-Scotch iron, 42s. Gd. per ton; Cleveland, 35s. 3d.; Cumberland hematite iron 45s. l~d. p er ton. The market was qui~t on Friday fore~ noon. About 7000 tons of Scotch warrants were dealt in one. lot going a.t 42s. 7!d. ca~h, with 1s. forfeit in seller'~ ?PtLOn, and a~other at 42. lOd. one month, with Is. forfeit m buy~r s. opt10n. No business was done in Cleveland or hemati.te uon. The market was idle in the afternoon, but pnces were steady at the forenoon level. Near the close of the market, however, there was some buying of Sc~tch, which stiffened the price, up to 42s. 8~d. cash bemg done, or ld. per ton ?P from the morning. Aboub 5000 tons changed hands 10 the afternoon. Cleveland was quoted ld. up, while Middlesbrough hematite iron was marked 1~d. per ton down. The settlement prices at the close w~re-Scotch iron, 42s. 7~d. p er ton; Oleve­~and, 35s. 3~.; Cumber land and Middlesbrough hematite n on respect tyely 45s. 1~d. and 43s. 4!d. per ton. Busi­~ess was qutet on Monday forenoon, the dealings includ­m~ only 4000 tons, Scotch iron exclusively . 'fhe cash pnce rose ld. per ton, at 42s. 9~d. Quietness was also ih~ rule i~ the afternoon, so far as the amount of bus10ess domg was concerned, but the price of Sc?tch was very steady, and 42s. 9d. cash was pa1d. About 6000 tons were disposed of. One lob of 500 tons was done at 42s. 8d. next Monday with a ','plant .. " At the close the settlfment prices' were­Scotch 1ron, 42~. 9d. per ton ; Cleveland, 35s. 3d. ; Cum­berland and M iddlesbrough hematite iron, 45s. l !d. and 43s. H d. p er ~on respectively. Tueeday's forenoon ma.rkeb was ''ery qmet. About 4000 tons of Scotch iron were sold-500 tons for 43s. one month, and 500 tons at 42s. ~~d. c~sh, ;epresenting a. gain of ! d . per ton on the previous mght s close. The remaining 3000 tons were clone at 42s. 8d . and 42s. 8~d. next week, with" plants." Cleveland also rose in price {d. per ton. In th e after­no?n the market was steady, with rather more business domg. Some 7000 or 8000 tons were dealt in and the ca-sh price at the . finish marked a drop ~f ~d. per t.cl? from the mornmg. Business was also d0ne ex·offiCially. a t ~s. l Od. ]fr iday, with a. call. Cumber­la~d hemat1t~ n on was quoted 2d. per ton under the prtces asked m the forenoon. The set tlement prices a.t the close were- Scotc:h iron, 42s. 9d.; Cleveland, 35s. 3d.; Qumberla.nd and Middlesbrough hEmatite iron, respec­tively, ~5s. a.nd 43s. 4~~ · per ton. ome 3000 tons of Scotch u on were dealt 10 this forenoon- 2000 tons ab 42s. 8~d . cash, 500 tons a.t 42s. 11!d., and 500 tons a.t 43s. cash one month, with ls. forfeit in buyers' option The market was steady in the afternoon but still idle. Only 5000 tons of Scotch iron were dealt in and at th~ close the <;ash . quotation showed a. drop of' ld. per ton from the mornmg at 42~. 8d. cash sellers. The following are a few. of the q uotatLOns for No. 1 special brands of makers' Iron : Clyde, 47s. per ton ; Gartsherrie and Summerlee, 49s. ; Ca.lder, ~9s. 6d.; L angloan, 55s. 6d.; Coltness, 56s.-the foregomg all shipped at G lasgow· Gl~nga.rnock (shipped at Ardrossan), 49s. 6d. ; Shott~ (sh1pped at Leith), 51s. 6d. ; Carron (shipped at Grange­mouth), ?3s. 6d. p er to~. . There al'e still only 39 blast furnace~ m .actual operat10n m Scotland, as compared with 79 at thts time last year. and that fact is t ending to keep the market_ steady. With such small stocks as there are at present m the makers' yards and the public warrant stor~s, and as they ar e now being. en croa.ched upon, makers con.sider themselves. wa.rrant.ed m puttmg up their prices, wht?h . they are qUietly domg. L ast week's shipments of ~tg Ir2 n from a~l Scotch ports amounted to 6641 tons, aga10s~ 17G7 tons m the corresponding week of last year. They .mcluded 500 tons f.or Canada, 320 tons for South Amertca, 135 tons for Ind1a). 480 tons for A ustr9.lia, 100 t ons for Italy, 460 t0ns fCJr uermany, 410 tons for Russia 985 tons for Holland, smaller quantities for otbe~ ?ountries, and 3041 tons coastwise. 'fhe stock of warrants m !Yiessrs. Connal and Co.'s public warrant stores stood at 334,347 tons yesterday afternoon, as compared with 335,080 tons yesterday week, thus showing a reduction over th~ week amounting to 753 tons.

F ini.shed I ron and Steel T rades.-The m alleable iron trade 1s now reported rather better in Coatbridge and other districts than it was some few weeks ago. Orders for common ~ars and shee~s, both for local consumption and to replemsh me!chants stocks, are being placed daily. Large o.rders fo~ smgle~ a~d special gauges have been boo~ed m t he W1shaw distriCt for Australia. Tube strips are m large dem.a.n.d for C~atbridge and district tube­w~rks, and .there IS m some mstances a slight ad vance in prtces. ~t 1s rep~rted that steel cannot be bought except at a considerable 1ncrea~e on th~ old figures of a couple of DJOJ?ths ago.. There 1s a. feehng that if the recent ad­vance m the prtc·e of coal could only be dropped even one­h~lf there would be some large orders for st eel placed wtth Glasgow and Lanarkshire makers ; on the whole however, many of the works are running fairly wel l. '

'l'hc Coat Trade.-There is no mater ial change to rerort

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SEPT. Is, I 893·] in respect of the coal trade of Lanarkshire and adjoining counties. There continues to be a good hea.l~hy demand for fuel for export purposes, and ho~.e. reqUI~f!me~ts are satisfactory ; but, owing to the fa01h~1es be~ng st1ll un­equal to the necessities of the occas~on, shipments are not being as prGmptly effected as desirable, and as they should be. T his, in various quarters, has natur~lly created somewhat of a. surplus, and producers, bemg unwilling to hold stocks, are shading _prices i~ order ~o get rid of them. At the moment,_ constd~ra.ble mterest Is felt as to the action employers w1ll take lt;l r~spe?tl of. the wages question. A large number-the maJOrity, 1t mtght b& said-are strongly in favour of the las~ ls. of ad v'!-nce being taken back on the ground that pnces have gtven way substantially from _the top, and that cu~rent quota­tions (these may be gtven as folio~: ~Iam coal, Ss. to Ss. 3d. ; ell, 9s. to 9s. 6d. ; splint, Ss. 6d. ; and stf a. n, 10J. to U s. per ton f.o.b. Glasgow) do not justify the present rate of pay. On the other band aome of the larger producers are decidedly oppo~ed to a~y alteration being made, and ar~ue _that not~ung should be done until the future of the E nghsh coal sttua­tion is more clearly defined.. A private meetin&" of the Lanarkshire Masters' executtve was to be held thts after­n oon to again consider the question, and it is not i_mpro­bable that it will be submitted to a. general meetmg_ of the association on Friday. The men are concertmg measures to counteract the threatened reduction, and they are to hold a conference on Friday also to consider the subjecb. Some of thE\ leaders are: disposed to argue for a. return to the four-days-a.-week policy, but that unques­tionably would be a distinct breach of the tacit under­standing come to when the last advance was conceded, when it was recognised that after the second 1s. was given the men w~uld _give a fi v~-days-a-week output; and if the men perstst m returnmg to four .d~ys per w~ek, while desiring to retain the last advance. 1t IS a certa.mty that sooner or later a. serious crisis will develop in the trade.

N ew Shipbuild~ng Contracts.- An order has been place~ with the L ondon and Glasgow Shipbuilding and Engt­net:\ring Company, Govan, for a. single-screw steel stea.t;ner of about 400ft. long, and about 5000 tons gro~s ca.pa01ty. She is intended for the "Glen" Line of Chma. traders, for which many steamers have been built by the same company. The L ondon and Glasgow yard is now '~ell provided with work (three large steamers) for the ensumg winter. J\.Iessrs. Robert Duncan and Co., Port-Glasgow, have secured a contract to build a large four-masted steel sailing ship, to carry 3SOO t ons, for the " Shire " Line of Messrs. Thomas Law and Co., Glasgow. Messrs. John Shearer and Son, Kelvinba.ugh shipyard, Glasgow, have contracted with J\.Ir. John Simpson, Glas­gow to build for him a steel screw steamer of extra pow~r, and specially desirned for his general coasting trade, to carry over 600 t~ns, and to have all the most modern appliances. It 1s also reported that Messrs. Alexander Stephen and Sons, Linthouse, Govan, who are well provided with new work, have lately taken a con­tract for a new steamer of 6000 t ons.

Clyde L ighthouses Trust.-The trustees of the Clyde Lighthouses have under consideration a proposal to lay down fog-signalling apparatus at the Cloch and Cum­brae Lights, at an estimated cost of well-nigh 4000l.

Proposed Harbour I mprovements at Peterhead.-An ex­tensive scheme of improvements has just been submitted to the Peterhea.d Harbour Trustees, the author of which is Mr. Shield, :M. Inst. C E. The scheme. which has re­ceived the approval of the trustees, is not unlikely to in­volve an outlay of at least 30.000l. Authority has been given to the trustees to go to Parliament next session for the necessary Parliamentary powers to carry out the lesser of two schemes devised by Mr. Shield.

Glasgow and South- Western Railway Co'Tnpany.-At the half-yearly meeting of the shareholders of this company, which was held in Glasgow yesterday, Sir W. Renny \Vatson, chairman, stated how a. very big sum of money had been expended on the doubling of the line between Ayr and Girva.n, lines and works open for traffic (includ­ing extensions at St. Enoch and from Glasgow &c.), doubling the line between May bole and Girvan ( Bridgeton Cross extension), two new steamers, &c., and he also men­tioned various important works that are to be commenced during the present half-year, or are already in pro~ress, one of them being the new passenger s teamer at Prmce's Pier, Greenock.

Suleskerry Lighthouse.- W ork was resumed at Sules­kerry Lighthouse (which lies out in the Atlantic some miles west of the Orkneys) on April 17, when twenty­seven workmen, including boatmen, with all requisite stores, &c., were safely landed. All the mason work has now been completed, and the tower made ready to receive the lantern, the contract for which has been placed with Messrs. Steven and Struthers, engineers, Glasgow. It is understood that the lantern and apparatus for lighting will be the largest and most powerful in the Northern Lighthouse service. The highest ground on the i~land rises to 50 ft. above the sea., and it is on this eminence that the lighthouse is erected. From the base of the tower to the light the height will be about 70 ft.; thus a light about 120 ft. above sea level is given, and it should be visible from 25 to 30 miles. The dangerous island known as the St'\ck lies 4! miles south- w~t of Suleskerry, and the light will, of course, warn the numerous vessels which pass in this direction of its proximity. Owing to fine wes.ther the work procetded without a hitch, and as now only inside fittings remain to be done, Mr. Aitken contemplates finishing his contract in a few months next season. As the tower has been completed and ready to receive the lantern, the work could not be advanced any further this year, so all the men-mostly Shetlanders-

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were removed from the i land by the contractor's smack on August31. D espite the number of workmen on S~les­kerry, the se&· f~w 1 and seal~ s~ill s_eem~d to r~ard 1 t as their own domam. and no dmnnut10n m the1r numbe; s was apparent. The dwelling-houses for four keepers 1n connection with this lighthouse, situated at Stromness, were completed and taken over in May last.

Manufacturers of iron and steel are, as a. ru_le, only ful­filling contract orders, and are wr~tin&" to theu custofe~s that they cannot guarantee dehvertes: The res'! ~ 18 that a mass of work which ~nd~r or~10ary condttiOns would be placed in the distr1~t 1s bemg &en.t to Brt~ country or Continental compettto~ for exe~ut10n. . us1

NOTES FROM CLEVELAND AND THE NORTHERN COUNTIES.

MIDDLESBROUGH, W ednesday. The Cleveland I ron Trade.- Y esterday there wa.~ a

numerous attendance on 'Change, and the _market was 10 a. fairly cheerful state. A good deal of bus10ess. was done. but nearly all the iron sold was for promJ?t dehvery, and this is unusual for September, for at tbts seas~n of the year Continental consumers general!Y come mto the market for their autumn supplies. Just now, however, few orders from abroad are coming to hand, our custom~rs there evidently regarding the ea~ly future as uncertam, and waiting m the hope of buymg on more favourable terms than they can secure at. present. Makers here opine that prices are more hkely to advance than to recede, and declare that No. 3 is scarce. Yesterday transactions were recorded ab 35s. 6d. ~or . prompt f.o.b. delivery of No. 3 g.m.b. Cleveland p1g tron, and pro­ducers generally would not quote below that figure, but business was also done at 35s. 4~d., and there we~e a good few merchants willing to sell at the latter pnce. No. 1 was sold at 37s. Gd , No. 4 foundry at. 34s., a~d grey forge at 33s. The last mentioned quahty was 10 good demand and consid&rable orders might hb.ve been booked at 32s: 9d. Hematite pig iron was in f~irly good request, not~ithstanding the limited supphes to the Sheffield distr1ct. and 43s. Gd. was _gener.ally asked for mixed numb~rs of local brands. A fa1r busmess ha3 been done in warrants during the past few days, as they have been cheaper than makers' iron. Y esterday ~1tddles­brough warrants closed 35s. 3d. cash buyers. To-day there was no alteration in the market.

ManufactU'rcd I ron and Steel.-Little new ea? be said of these two important industries. If anythang. _they are somewhat improved, but we cannot repot t . higher rates. There is, however, a little more work gomg on, and quotations are stiffish. Com~on iro~ bars are quoted 4/. 17s. 6d.; best bars, 5l. 7s. 6d.; Iron sh1p-plat_es, 4l. 15s.; iron ship angles, 4l. 12s. 6d.; and steel sh1p angles, 4l. 15s.-allless 2~ per cent. discount for cash, Heavy sections of steel rails remain at 3l. l7s. Gd. net at works, but it is said that ~ trifle less has been accepted.

The Fuel Trade.-At Newcastle the demand for steam coal is good and best Northumbrian is quoted as high as 13s. f.o.b., though less is accepted in some cases, a?d a good deal is being delivered on old con tracts at constder­ably below this rate. There is a good supply of small steam, the price of which is about 5s. ~he ~a~es ques­tion in Northumberland and Durham l S ex01tmg much interest. Several employers complain that advances granted under special circumstances like the present are difficult to get back when a norm~} demand ! eturns. Such is undoubtedly the fact, but, w1th everythmg CO?­sidered, it would be pleasant to see ~he loyal way m which the miners have stuck to work suttably recog01sed.

Cleveland Miners' Wages. - At a recently-held meeting of the Cleveland Mineowners' Association a letter was read from Mr. J oseph Toyn, agent and president of the Yorkshire and Cleveland Miners' Association, asking the owners to meet the executive committee on the question of what wages should obtain after September 30, and also to discuss the ratchet question. A deputation of miners attended the meeting, and after the general ques­tion of wages had been discussed, the following reply was made by the mineowners: "The condition and pro­spects of the Cleveland iron trade entirely preclude the owners from assenting to any advance of wages, believin~, as they do, that such advance would be likely to result 10 a large reduction of t_he outpu.t, a_nd conseguently lessen ­ing of employment m the d1stnct. Whtle the owners would be happy to see these conditions and prospects so altered a-s to warrant an advance of wages, they regret that trade since the last wages settlement, and the present out­look, are far from holding out any such hope, but, on the contrary, would in their opinion have justified a. reduction. Under these circumstances the most they can propose is to leave the present rates of wages unchanged until D e­cember 31 ; or, desiring to afford to the men the fullest information as to the present position and future pros­pects, they ~re willing, if so requested, that the rates payable in the Cleveland mines should be made the sub­ject of a formal arbitration to determine what, if any, alteration therein, up or down, should be made. The ad va.nce the men had sought was 5 per cent. During the meeting the ratchet question was mentioned, but no arrangement was come to with respect thereto.

NOTES FROM SOUTH YORKSHIRE. SHEit'FIELD, W ednesday.

T he H t.avy Trades.-Trade in the heavy departments is practically at a. standstill, and complaints come in on every side. Most of the blast furnaces hereabouts are damped down, and though prices of pig have been ad­vanced, sales are very slow both for foundry and forge. The former commands 40s. to 42s. per ton, and the latter up to 44s. Manufacturers of both iron and steel have, in the majority of instances, had to suspend operations owing to neither coal nor coke being obtainable, or in limited supply at figures which cannot be afforded. In the Leeds district the fuel famine is more severe than at Sheffield. Thousands of workmen who have nothing to do with the dispute are out of employment, and much distress pre­vails; but this is not the worst feature of the case.

ness in marine material was expandiDg, but 1t has re~etved a severe check. It is impossible at p~es~nt to est1~ate the damage to the future trade of the d1stncti as the drrect result of this interruption.

A'rmour-Plates, G'Uns, d:c.-Rollers of armour-plates a.~e looking for orders at an early date from the home ~utbon­ties as the naval programme must find constdera.b]e further employment. There is a good dea.! of speculatiOn as to the manner in which the contracts Wil~ be p~aced, as any requirements can be locally ~ea.lb ~Vlt_h, etther a~l­steel compound 01 H~rveyised. 'Ibe prm01pa.l orders m band at present 'are for Spai~ and Russia. '!'he call ~or finished guns and gun parts IS belc;nv the average, but "'!1 improvement is looked ~or later m the year. Some fall' lines are in band for sohd steel shot and shell. Slack· ness in these departments is throwing a..l?t of men out of work or on short time. For best quallt1es of cast s_teel there is a good inquiry, mainly tool steel~ for the Umted States, South Afri~a, and the North. of l!ouro~e, but con­verters are much hampered in . the1r op&ratiOns by the scarcity and dearness of Yorkshire c~ke, that fr~m other districts b~ing inferior an~ not sUitable for h1~h-cla.ss material. It may be ment10ned_that houses turmng ?ut the largest forgings _are in recetpt of some encouragmg inquiries from the shtpyards. .

Engineeri'Yig Depart·me.nts_.-Th~re are many complamts as to falling off of W?rk 1.n var1<?us ~ranches, and the number of half-timers 1s be10g raptdly mcreased. In and about L E:seds machine requirements by local manufacturers show a great reduction as compa~ed with the c~rrespoi?d­ing period of last year. L ocomot1 ve and tract10n e~gme builders are not favourably placed, _and the outlo?k 1s not very encouraging. Those turnmg out ag_r10ultur~l machinery for exl?or~ have a~out got through th1s seas~n s orders. Some fa.1r hnes are m hand for quarlz-crushmg machin~ry for expor~, ht~t all departments appear for the time bemg to be lackmg m energy.

The Coal Crisis.-Stocks of coal, of every description, are almost exhausted here, and where engine slack can be got 14s. and 153. per ton is paid for it. The _attempted importation of Durham coal only _leads to ~1ot,_ as the colliers on strike have expressed the1r determma.t10n Rot to permit it. In the majority of instances agents and coa.lowners have ceased to attempt the introduction of north country fuel on the market, and the strike hands have consequently been more peaceable during the past few days. In South Yorkshire the men are as determined as ever not to submit to any reduction, though they are suffering great hardship~, and the union funds. are well­nigh exhausted. Last mght, however, a most lmE_ortantl announcement was made in the adjoining Derby­shire coalfield one that may lead to a radical change of front here.' A leader of the Derbyshire Miners' Union counselled the men to go back to work where the old rate of wages was offered. This has taken all by surprise, as it is a direct violation of the mandate of the federation. If th~t is done so near, ib will not be long before the example ~s followed in this district as thousands of hands are m favour of that course. ' Many pit-own~r~ are prepared to resume ~pera­tions on the old cond1t10ns. Those most expenenced believe this will lead to the solution of the difficulty, and that the end of the strike is approaching.

NrcKEL STEEL ARMouR TRIALs AT CnxusoT.- A specimen of some nickel-steel armour plates which have been manufactured at Le Creusat for the new Russian Black Sea. battleship Tri Sviatitelia (Three Saints) has been tried at Le Creusot in the )?resence of the members of the Russian Naval CommissiOn, and has given some remarkable results. The plate measured 8 ftl. by S ft., and was 15.9 in. thick. The conditions of acceptance were that it should receive four blows from Holtzer pro­jectiles of chrome steel, weighin~ 317 lb. apiece, and fired from a 9.4-in. gun with a. strikmg velocity of 1945 foot­seconds ; and it was stipulated that no pieCE\ of the target should be broken off, and that in no case should the base of the projectile penetrate the ta-rget to a depth of as much as 7. S in. The four rounds were fired at the angles of a. square which was painted on the centre of the target, and which measured 4 ft. each way. The order of the shots was-(a) right lower corner; (b) left lower corner; (c) left upper corner; (d) right upper corner; and the following, according to the Times, were the striking velocities and injuries to projectile and plate: (a) Velo­city, 2001 ft. per second. P enetration of the point of the projectile, 14.1 in. The projectile flew backwards with the point smashed and the shoulder somewhat set up. The target showed three Vbry fine cracks running from the wound. (b) Velocity, 194S ft. per second. P enetration of the point of the projectile, 10.9 in. The projectile flew backwards, broken into numerous frag­ments. As before, three fine cracks developed in the target. (c) Velo<:ity, 1923 ft. per second. Penetration of the J?Oint of the projectile, 14 in. The projectile flew back w1th the head smashed and the cylindrical part some­what set up. A single fine crack was remarked. (d) Velo­city. 1962 ft. per second. Penetration of the point of the projectile, 9. 9 in. The projectile flew backwards. broken into numerous fragments. There were no fresh cracks, and the old ones were not increased. Examina­t ion of the back of the target revealed the existence of low swellings, varying from 1 in. to 1. 7 in. in elevation~ behind each point of impact. Behind points (a) and (bJ there were some fine cracks, behind points (c) and {d ) there were no cracks at all,

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E N G I N E E R I N G. [SEPT. 15, 1893.

H. M. F IR ST-CLASS CRU I SER "THE SE US." ..

CONSTRUCTED BY THR THAMES IRON\VORKS AND SHIPBUILDING COMPANY, LII\liTED, BLACK\VALL, LONDON.

(For Description, see Page 330.)

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AGENTS FOR " ENGINEERING." At:STRIA, Vienna: Lehmann and Wentzel, Karntnerstrasse. CAPE Tow~ : Gordon and Gotch. Eoil\BURGH : J ohn Menzies and Co., ~z. Han_ove:·~treet.. FRANC&, Pa ris: Boyveau and Chevtllet, Ltbra.me Etranger e, 22,

Rue de la Banque; M. Em. Terquem, 3lbll Boulevaa·d Haussmann. Also for Ach·ertisements, Agence Ha,·as, 8, Place de la Bourse. ( ee below.) .

GBRlUNV, Berlin: ~Ie rs. A. A her and Co., 5, Unter den Lmden. Leipzig : F . A. Broc:khaus. ~Iulhouse : H . tuckelberger.

GLA~SGOW : Willia.m Love, INDIA Calcutta: Thacke1·, Spin !<, a nd Co.

' Bombay : Thncker and Co. , Limited. ITALY: U. Iloepli, ~Iilan, and any post office. Ln"ERPOOL: .Mrs. Taylor , Landing Slage. M.\NCUE TER: J ohn Heywood, H :l, Dean gate. N:&w Ot'TU WALKS, ydney : Turner and Henderson, 16 and 18,

Hun ter-street. Gordon and Gotch, George- treet. QttEENSLAND (Sot'TJJ), Brisbane : Cordon and Cotrh.

(NORTll), Townsville: T. Willmet.t nnd Co. R OTTERDAM : IT. A. Kramer and on . SOCTfl AUSTRALIA, Adela ide: W. C. R igby. U~ITKD STATES, New York: W. II. Wiley, 53, East lOth-stre~t.

Chicago: H . V. Holmes, 44, Lakeside Buildmg. YICTORIA MSLBOURNB : Melville, Mullen and Slade, 261/264, Collins­

street.' Cordon and Gotch, Limited, Queen-str·eet.

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TELEGR.'\I)rr•c AoDRBss-ENGINEERING, LONDON.

T P.LEPIJONJ<: NP~IBRR-3663.

ENG INEERING is registered for tr~Ulsmission abroad .

CONTENTS. PAOB PAGB

The Distribut ion of Load on The "Teutonic" and " New Trough Floora for Bridges York" . . . . . . . . . . . . . . . . . . 332 (lllu~tratecl) . . . . . • . . . . . . 319 Notes from t he NorLh .. .. • . 332

'Ihe Engineering Congress Notes from Cleveland and at Chicago ( I Uustrated) . 320 t.he Northern Counties . . 333

The De,·elopment of South Notes from South Yorkshire 333 African R'\ilways ....... . 324 The Trades Union Congress,

Herbert 's Capstan Lathes l e93 . . . . . . . . . . . . . . . . . . . . 335 (Illustrate l) ... . .. . ..... 328 Some Recent Boiler Explo-

Fox's Press, d Steel Frames sions ........ .. ..... . ... . 336 (lltu11t rated) .... . ...... 328 The Waste of Shipping .... 337

'I he •· Niag~ra" Pul·reriser Offic ial Tests in Norway (ltlt~.Atrated) ..... . . .... 329 with Small-Calibre Rifles 838

Club Railroad C.u (lllttS· The New Spa oish Cruiser trated) .. . .. •..... . ..... 329 "Infanta A1aria. T eresa" 338

N ote3 from the U oited Literature .. .... . . .. ..• •• , 339 States .. . .. . . . . . .. .. . . . . 329 Books Received.. . .. .. . . . . • 341

Notes from the South West 329 Not es .................... 341 Locomotives a.t the Colum- Miscellanea. ... . ...... .. .. 342

bian Expo~it"on (Illut .. · Reid's Automatic Stea.m-trated) .... ....... ... . 330 Reducing Yalve (l llus-

II . ~ .S. " These11s" (lllUJt· trated) ........ .•.. . ..• . 343 ttated) . . . . . • .. . . . . . . .. . . 330 I ndudtrial Notes .. . . .. .. . . 313

Stt .. pension Foot Bridge at On the Middl~shrough Salt Ba nchory (llhtst raterl ) .. 331 Industry (Jllustrated) .... 3H

T he Economical Speed of The Manufactu re and Test-Steamships (IUust,·ated) 331 ing of Portland Cement .. 345

S Jeed Premiums .......... 332 Ex periments on ' 'Serve" B~ll Bearings .... ......... 332 Tubes in Marine Boilers l •oocrete Beams . . . . . . . . . . 332 ( flltt8trated) . . . . . . . . . . . . 346 CJotractors and the Admi- I Launcht!s and T• ial Trips .. 348

r alty .. ........... ... . .. 332 " Engineering" Patent Re-Lo: om )tive Engines ... . . . 332 cord (lltustrat1 l ) .. .. .. _. 349

lf' itlt a two-page engraving flj cm EIGHT-Wll EELED p .AS­SElYGER LOCOJfOTlT'E ~T TilE WORLD'S COL UJI­lJlilN EXPOSITION .

ENGINEERING.

NOTICE. The New Cunarders "CAMPANIA" and "LU­

CANIA ;" and the WORLD'S COLUMBIAN EXPOSITION OF 1893.

The Publlsher begs to announce that a Reprint 1s now ready of the Descriptive Matter and Illustra­tions contained 1D the issue of ENGINEERING of April 21st, comprising over 130 pages, with ntne two -page and four single· page Plates, printed throughout on speolal Plate paper, bound 1D oloth, gUt lettered. Price 6a. Post free, 68. 6d. The ord1· nary edition of the issue of April 21st 1s out of print.

E NGINEERING. FRIDAY, SEPTEMBER 15, 1893.

-THE TRADES UNION CONGRESS, 1893.

THE twenty-fifth Trades Union Congress has come and gone, and its proceedings, like those of all former Congresses, have become matters of his­tory. On the whole, it has been a remarkable Congress, in some respects. It was held in the one town of all others in which local prejudices are strong, even most vehement at times, but mainly on political and religious questions. These, how­ever, sometimes take an industrial and social turn, and develop an animosity and even a hatred which finds expression in feuds and violence among work­men generally working together at the same branches of trade, and even in the same work­shops. Only a few weeks ago scenes of violence were enacted in the town and vicinity of Belfast, which seemed to augur badly for the then forth­coming Congress. But those feuds had so far died out, or were hushed into silence in the Labour Par­liament, that no one could have disoovered that any such existed. Protestants, Catholics, and Dill­senters, Tories, Unionists, Liberals, Radicals, and Socialists met in the same hall, sat around the same tables, disoussed the same problems, and ultimately voted on the questions submitted wit hout regard to any of the foregoing divergences or predilections. The delegates differed upon the subject-matter before them, and voted accordingly ; but they were not materially influenced by the "isms " or schisms above referred to. They seemed to be non-existent.

The Belfast Congress was not so large, in point of numbers, as several of the more recent ones, the total number of delegates being only 380, as compared with 495 last year, a decrease of 115 delegates. The total number of members of unions represented at the Congress was stated to be 900,000, as against 1,219,934 last year, a decrease of 319,934. The relative proportion of members represented by each delegate was 2464 in 1892, and 2370 this year. The cash balance last year was 1214l. ; this year it is 1262l., less the cost of the Congress. The proceedings this year have been less boisterous than on some former occasions, and the personal element in debate was less rancorous. One cur ious incident was t he expulsion of a delegate one day on the ground of disqualification, and his re­instatement the next, t hough all the facts remained precisely the same. But there were no allegations against the delegate except that he was not qualified according to a recent standing order made only last year. The only other incident of an exciting character was an attack by the delegate of the Fawcett Association (postal employes) upon the labour members. But the very men whom he attacked hold letters of thanks from him, written by the authority of his committee, thanking them for what they had done on behalf of the postmen. Generally the proceedings and debates were charac­terised by good-humour, though at times there was a babel of sounds, in the course of which the chairman lost his voice and the bell its tongue ; the discovery of the latter fact led to a hear ty genuine laugh and restored good-humour just at the moment when it was most needed, as the Congress was in an excitable mood.

The Trades Congress is more and more ceasing to be a deliberative assembly, and is becoming merely a recording body of resolutions often hastily dra wn, and generally but very little debated. Two facts alone will indicate what is here meant . With the exception of the chairman's address, and in one or two other instances, the speeches were limited firs t t o five minutes each, and then to three minutes each. This limitation may be necessary in order to enable all the talking delegates t o have their say,

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but it is impossible to put any case. either for or against a. resolution of importan~e In three or five minutes. The inevitable result 1s that hasty con­clusions are arrived at, and resolutions a:re passed which it is quite impossible for the Parliamentary Committee to deal with in the course of the current year. The newer men at t hese Congresses lack the idea. of proportion, and the Congres~ t~ere~y los~s that characteristic which formerly dlStingUished _It of being a practical body, seeking to emho~y In legislation, from year to year, some of t he subJects relegated to the Parliamentary Committee. That was the object which the Congress originall~ ha~ in view when the committee was created and Insti­tuted. As a result of this change of policy the Parliamentary Committee have not been able to register a single Act of Parliament as the result of their own initiative. In lieu of this they gave prominence in their report to t hree Acts passed by Mr. George Ho well, one relating to trade unions, one to friendly societies, and one to industrial and provident societies. The committee had numerous Bills before Parliament, but not one of them has become law. This failure to enact is the outcome of a policy of haste.

The programme for the ensuing Parliamentary year is larger and wider than that adopted in any previous year. I t is so wide and far-reaching, that if t he whole of the autumn session and the whole of next year were devoted t o it, the major portion of the subjects could not be dealt with. Indeed, if the whole time of the present Parliament were de­voted to the subjects enumerated by the Congress, to the absolute exclusion of all others, t he measures could not be carried through both Houses and be embodied in law. A reference to the old Parlia­mentary reports of t he committee will show that they arranged a programme in an order of pre­cedenoe as things to be attempted in each suc­ceeding session. Now, there is no indication of preference, and no selection of possible measures. Progress is therefore purely a matter of chance, even when progress can be made, and the way is left open for other members of Parliament to "cut in/' to use a P arliamentary phrase, to the exclusion, if not the extinction, of the Congress leaders who may happen to be in Parliament. But worse remains behind. Some of the reso­lutions passed, and those the most far-reaching, are impossible of realisation, certainly within the period of the present century. The keynote of t he policy adopted by the Congress is to be found in the very lengthy resolution as regards labour re­presentation, which was carried by 160 votes to 32. This resolution proposed to institute an electoral fund, to be formed by a contribution by each society of 6s. per 100 members, the administration of which is to be in the hands of a committee of t hirteen persons, inclusive of secretary and trea­surer. All candidates receiving support from such fund must pledge themselves to support the labour programme of the Congress. Now that programme was tolerably definitely decided by an amendment carried by 137 to 92 votes, on t he motion of a London delegate. The amendment was : "Candi­dates receiving financial assistance must pledge themselves to support the principle of collective ownership and control of all the means of produc­tion and distribution, and the labour programme as agreed upon from time to time by the Congress. " The resolution with this addendum strikes dead the Trades Union Congress, and the whole indus­trial system which called it into existence, in so far as a paper pellet can strike anything dead. It is political and socialistic, if you please as was admitted by all its chief supporters,' but it ~ardly squares with t he objects and in­tentwns of a '' Trades Congress. " How is the object to be attained ? By Act of Parlia­ment ? Supposing that the end and aim are good, all measures in favour of '' betterment " of whatever _kind, ~ill tend rather to perpetuat~ the present Industrial system, by making it more endurable. Therefore progress must be brouohtto a standstill in order to cultivate and intensify discon­tent, so that in the deadlock a socialist ic revolution can be evolved out of the chaos. This closing of the ranks is the death-knell to the proposed elec­toral fund, and will shut the door to men other­wise useful to the labour cause. The only thina that it can do is to open the door t o a number of candidates. who wil~ pr~mise everything and per­form nothmg, but It will have no weight in the councils of the nation, and produce only thorns and thistles in what is called the Labour Party.

Capital may rest satisfied with the conclusion arrived at, for the leaders will be too busy outvying each other, fighting each other, and attacking each other to allow of any time for real organisation and real work, while the weary workers will con­tinue to suffer.

The best bits of work done at the Congress for practical purposes were the resolutions and discus­sions on the Employers' Liability Act and the Bill now before P arliament to amend it. This discussion was opportune, in view of the decision of the Government to take that measure in the autumn session. Then the subject of factory inspection was also opportune ; but while it is wise t o relax the examination in some particulars, so as to allow workmen a chance of being appointed, it is not desirable t hat the relaxation shall be permanent. Workmen have a chance to qualify if they will but educate themselves, and there is no end of oppor­tunities in that direction. Besides, the Congres3 is insisting upon examination in other directions. Another pertinent and useful resolution was that in which fair wages and Government contracts were considered. The resolution was a long one, so as to em brace all the points relat ing to the subj ect. Then the Congress adopted a re­solution a-ffirming the propriety of appealing in the recent case of Templeton 'V. Russell as to conspiracy. The unemployed were dealt with in another r esolution on rather open lines, so as t o allow of movement in that direction if the opportunity occurs. But there was an intentional sting in that resolut ion. Further amendment of the Merchandise Marks Acts was proposed and carried, and also a s tring of resolutions r elating to boiler examination, coroners' inquests in Scotland, and a variety of other matters. The eight hours' resolution of previous Congressea was re-affirmed, with a sort of local option, except in the case of the miners, to which the federation will not agree. The oddest thing at the Congress was the attack upon the newspaper preRs and the reporters. The chief object of the resolution was directed against par­ticular men, but the terms of it will recoil upon t he Congress itself.

The chief interest of the Congress was centred after all in t he election of secretary of the P arlia­mentary Committee, the committee itself, and of the place for the n~xt meeting, in 1894. Mr. Charles Fonwick, M.P., was elected secretary by 251 votes to 89 for Mr. Keir Hardie, M. P . This vote was the largest in t he Congress, 340 out of 380 voting. The election of Mr. Fen­wick saved the Congress from practical extinc­tion. The change in the personnel of the Par­liamentary Committee is not great, but its character is very materially altered. Mr. Broad­burst reappears on the committee, while Mr. Har­ford of the Railway Servants' Union, is displaced. Mr. Anderson, of the Amalgamated Society of E ngi­neers, is replaced bY: Mr. Burns, M.P., an~ Mr. John Wilson, M.P., g1ves place to Mr. E. Cow1e, the President of the Miners' Federation. All the others were re-elected. Mr. George Shipton, of the London Trades Council, was not elected, nor were others of the older order of trade unionism, such as Mr. J ohn Inalis of Glasgow, and Mr. Stuart Utley, of Sh~ffi~ld. The balancing element is defective in numbers and in force. The aggressive element is strengthened by two out of the three new members elected. The tactics of "capture" have, to some extent succeeded, but the final issue of the change will o~ly be seen when the next year's report is presented. Congress promises will then be tested by the amount of work done, and its qualit~. N orwich was selected as the place of next. yea.r s gatherin()' a city which boasted of a textile ln­dustry b~fore Manchester was heard of in the in­dustrial world. The gathering in Belfast was his­t orical in many respects, and the treatment of the delegates was exceptionally good. P ossibly the effect will be to draw closer t ogether the English and Irish workers in all matters affecting labour, and thus break down some of the old p rejudices that have long exi.nted.

S0~1E RECENT BOILER EXPLOSIONS. THE result of eleven years' working of the

'' Boiler Explosions Act " has been materially to reduce t he number of these casualti~s, and to correspondingly lessen the annual . bill of mor­tali ty which had to be regularly pa1d before that Act was passed. The investigations conducted by the Board of Trade, and of which we have from

E N G I N E E R I N G.

time to time given full r eports in these columns, have been in the main minute and thorough, and although we have occasionally dissented from the judgments of the Commissioners and ventured to point out where we thought they erred, still, taken as a whole, the conclusions arrived at have been equitable, and the publication of the information gained has been an educational medium that has not failed to be of service. The inflict ion of penalties, too, where default has been brough t home, has had due weight, for it is an axiom that the fear of suffering in pocket will influence some people far more than the teach­ing of any number of moral lessons. But t hough serious explosions are not so numerous as formerly, t he list is still much too high, especially when the fact is borne in mind that such an event as the bursting of a boiler ough t to be of very rare occurrence. Given a well-constructed and well­kept boiler, equipped with the fittings necessary for security, and att ended and examined by a duly qualified man-all of which conditions are but reasonable-and an explosion ~hould be rendered impossible. This is the point which should be strictly borne in mind by those who are interested in the safe and progressive development of commer­cial enterprise. A mere reduction in the yearly loss of life should not be sufficient ; practically entire prevention should be the goal kept in view.

That great ignorance, the most reprehensible r1egligence, and a flagrant non-recognition of due responsibility, still exist, and that these facts should, by legislation or some other means, be grappled with, is illustrated by several recent Government inquiries, particulars of which we have duly given to our readers. The adoption of even the most elementary methods for attaining safety is still the last thing t hought of- if thought of at all-by many persons, and the question may well be put, Why should such persons be allowed to possess and to work for their own profit, and at great risk to life, such a dangerous apparatus as an ill-made and ill-kept boiler ? Measures to prevent this are, in numerous cases, as much needed now as ever, and this cannot fail to have struck the reader of the reports which we have from time to t ime published.

Four of the most recent Board of Trade investi­gations may be briefly referred to, inasmuch as they contain points worthy of more consideration than the mere recital of the facts will afford.

The first of these dealt with an explosion w hi eh occurred off Yarmouth ('Vide E NGINEERING, July 28 last, page 112). The boiler was used on board a fishing smack, and, when the explosion occurred, the vessel was burnt to the water's edge, and the boiler lost in the sea. The skipper was seriously injured, but, with the exception of the t hird hand, who was somewhat hurt, the crew were all rescued and safely landed unharmed. The boiler was a small vertical one made in 1882, and from that time up to the date of the explosion only superficial exami­nations were apparently made. The Commis­sioners, in their judgment, stated that in all pro­bability the firebox collapsed owing "most likely to the plates having become so reduced in thick­ness by internal corrosion as to be unable to with­stand the pressure." The boiler being lost, no examination could, of course) be made, and the Commissioners simply had to follow the evidence and form their conclusions therefrom. I t does not appear that any statements were made by the witnesses to substantiate the corrosion theory, and although this defect is a prolific source of ex­plosion in the case of these vertical boilers, more especially from collapse of the fireboxes, no proof was adduced that it existed in the boiler in ques­tion. On the other hand, the evidence, we think, pointed to another cause, and which was probably the real one. The spring balance of the safety valve had been, it was stated, originally fitted with a ferrule to prevent the valve being screwed down and locked fast, but this ferrule had at some time or other been removed, so that there was nothing to prevent the accumulation of pressure to a dan­gerous extent by a few turns of the nut. I t was affirmed, during the inquiry, that at the por t of Yarmouth the safety valves on the boilers of fishing smacks were "habitually tampered wit h. " In the official report just issued by the Board of Trade the Commissioners say: "We have been told that it is a common practice of smacks­men to screw up the nuts of these levers so as t o obtain any pressure which they may desire to have, and it has been proved

that on many occasions coin<3 and washers have been found jammed between the valves and levers. . . . . . We are very strongly of opinion that measures should be taken to stop this practice." Looking at those facts, it appears to us more than likely that this explosion was due rather to exces­sive pressurA through tampering with the safety valve than to the cause assigned by the Commis-

• swners. The Commissioners recommended the adoption

of a lock-up valve. Seeing that the valves at pre­sent used are so constantly tampered with by the men on board these vessels, who appear to have no idea of the danger they incur, we certainly think t he recommendation is a wise one. Further, inas­much as explosions on board iishing smacks and other small craft are increasing, and now form a large proportion of the gross annual number of ex­plosions from various deEcriptions of boiler, it is but reasonable that some means should be taken to insure greater safety for the crews of such vessels. It may be said that if a man is so stupidly ignorant or leek­less as to endanger life and property in the manner referred to, it is his own affair and his own loss if he suffers, and that there is no reason why there should be a systematic endeavour to control all the evolutions of human perverseness. Unfortunately, however, it is not always that the wrongdoer is the victim or sole victim of his own act ; very often others are punished who have had no hand in originating the danger, as in t he case under review, where the smack was burnt to the water's edge, and the lives of the crew placed in jeopardy. It there­fore appears that t here is a clear call for a better state of things, and that the Government should carefully consider the question at its earliest oppor­tunity. The boilers on board passenger steamers are certified by the Board of Trade, and we seeno reason why a similar precaution should not be taken in the case of humbler craft, the men on board of which, it would appear, go to sea with their lives in imminent peril, as. in addition to the ancient danger of being lost in the storm, they are in too many cases now confronted by the modern but entirely sur­mount able danger of being at any moment blown up by the boiler. The report just issued on the explosion at Yarmouth is one to which the atten­tion of the Board of Trade should be specially directed.

The second investigation which we may briefly touch on r eferred to an explosion at an iron works near Bilston ('Vide ENGINEERING, August 11, page 188). The boiler was of ancient make, and of the old-fashioned egg-ended externally-fired type. I t burst simply from a seam rip, a defect to which this class of boiler is peculiarly prone. The back end was blown 170 yards, but luckily no injury resulted, as no person happened to be in the way of the flying fragments. The Commissioners, in their judgment, after stating that the boiler had been in use many years before being laid down at Bilston, exonerated t he owners from blame, inasmuch as ' 'the seam rip could not have been discovered. " When introducing his case, Mr. Gough, on behalf of the Board of Trade, specially mentioned that many boilers of t his type had burst from a similar cause, and we should have though t that the Com­missioners would, under the circumstances, have given a note of warning in condemnation of the practice of keeping such a dangerous construction of boiler in use. lf hidden defects may exist which at any time may develop a disastrous explosion, dealing death and destruction around, surely steam users should be put on their guard, and so risky a type of boiler should be emphatically condemned. But in the present case the Commissioners merely gave utterance to a mild word or two to the effect that "persons purchasing second-hand boilers should ascertain their age and have them carefully examined," although the defect in t he exploded boiler had just been pronounced to be beyond dis­covery. All boilers of a type notoriously liable to suffer from defects which cannot be found out by inspection ought to be cut up and thrown on the scrap heap. This would be hetter than to daily risk the lives of the many men who, especially at iron works, frequently are employed in the im­mediate vicinity of such boilers.

Bearing closely on this phase of the question, however, is another, viz., that the boiler was in­sured by a company which, according to the chief engineer 's evidence before the Court of I nquiry, existed by taking risks. So long as dangerous boilers can be insured in case of blow up, on pay­ment of a money premium, so long will there be

found owners who are willing to run the risk of working them. The presiding Commissioner said that in adopting the practice of insuring such boilers a company might be, justified "legally," and he might well have finished the sentence by adding that it was doubtful if they were justified morally. We certainly think that the custom, where it exists, of insuring bad or untrustworthy boilers in order to make a dividend, with little or no examination, is wrong in principle ; by so doing the owners, rightly or wrongly, are led to think that the boilers are safe, while at the same time a dangerous class of boiler is perpetuated, and an unworthy, though perh 1ps quite unintentional, disregard of the safety of their workpeople is the result.

Tae remaining two investigations upon which we may say a word both dealt with explosions from small vertical boilers used at farms. (Vide ENOI· NEERINO, August 25, page 240.) In each case the boiler was corroded and worn out, and, although in use for years, no examination worth the name had been made. In one instance a blacksmith had managed to impress the intending purchaser with a sense of his ability to examine boilers, and at his recommendation the purchase was eff~cted, although the boiler at the time must have been in a highly dangerous condition. T wo lives were lost by this explosion, and the Commissioners rightly expressed their opinion of the conduct of this amateur in­spector by fining him 20l. There are far too many of these incompetent examiners in the country, and the worst of it is that their neighbours have too often implicit faith in their capabilities in this direction. Pvssibly the fact that their services may, as a rule, be obtained very cheaply, lies a.t the foundation of the faith.

In the other ca'3e the boiler had been bought second-hand for 4l. 10J., and here also an incom­petent person hld professed to examine it, and to give his advica, which, of course, was quite worthless. The Commissioners considered that the owner had erred through ignorance, and ordered hiru to pay 15l. towards the costs of the investiga­t ion, which, it was stated, amounted to 100l. They dwelt strongly on the importance of careful inspec­tion, which would have prevented both t hese explo­s ions and saved the Jives sacrificed. We are in­clined to regard as inexcusable an ignorance which prompts its possessor to buy a boiler for 4l. 10s. , and to keep it in work for ten years without the slightest semblance of efficient examination. If it were a solitary case we should pass it by with merely a momentary thought, but when we know that the same neglect of precaution has occurred over and over again, and will continue to occur, we are constrained to ask whether it is not time that some effectual means of prevention should be enforced. If owners ca.nnot keep their boilers 15 1.fe, one of two courses should be followed : either they should be compelled to call in t rustworthy examiners, or the matter should be taken out of their hands and under taken for them by some really competent and responsible authority.

THE vV ASTE OF SHIPPING. TnE enormous production of shipping, which

goes on continually- although with so great fluctua­tion-as the tide of demand ebbs and flows, is made commercially possible by reason of t wo chief causes, namely, t he waste t hat constantly goes on , and the expansion of the world's commerce. The second cause is one that ca.nnot be summarised, but a fair estimate of the former can be arrived at by means of t he valuable "Statistical Summary " prepared by Lloyd's Register; the complete sheets of which for the past year have recently been issued. By these tables we learn that during 1892 t here were lost 215 steam vessels of all nationalities, counting only ships of over 100 tons ; vessels of above that size being alone dealt with in this notice. The aggregate net tonnage was 164,749, and the gross aggregate tonnage 257,048. Of this number vessels belonging to the United Kingdom supply by far the larger propor tion, namely, 105 out of the total, the gross tonnage being 144,746, or con­siderably over 50 per cent. of the total tonnage for all nations. This would be not far off the proport ion of losses that would be due to this country taking into consideration the number of steam vessels we own, as compared to those sail­ing under foreign flags, although in this respect the figures are rather against us. Thus we find that the percentage of loss for the United Kingdom is 1.74 on the total numl)er of steamships owned ;

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whilst if we base the estimate on gross tonnage, we find the percentage of loss for the past year was 1. 69. Comparing the figures referring to ton­nage- which, perhaps, afford the mor~ ju~t esti­mate-with those of eleven other countnes (mclud­ina our colonies), we find that six of them show better averages; thus the United States lost 1.67 per cent. of its gross steam tonnage, Austro-Hun­gary 0.90 per cent, Holland 0.17 per cent. , Ger· many 1.16 per cent., Italy 1.10 per cent., and R ussia 1.12 per cent. The countries which show a heavier proportion of tonnage lost are as follows : British colonies, 2.41 per cent. ; Franc~, 2.62 per cent. ; Nor way, 2. 72 per cent. ; Spain, 3.40 per cent. ; and Sweden, 2.39 per cent. In order that a closer estimate may be formed of our position, we give the numbers and gross tonnage of steam vessels lost by the countries named duting the past year : Colonies, 15 vessels, 12,440 tons ; United States, 9 vessels, 9560 tons ; Austro-Hungary, 2 vessels, 1548 tons ; H olland, 2 vessels, 488 tons ; France, 19 vessels, 22,412 tons ; Germany, 10 vessels, 12,591 tons ; Italy, 2 vessels, 3409 tons ; N orwa.y, 8 vessels, 9137 tons ; Russia, 1 vessel, 2297 tons; Spain, 9 vessels, 14,871 tons; Sweden, 9 vessel~:;, 5013 tons. I t may be added that the remainder of the tohl of steam losses is made up in t he tables as follows : Other E uropean coun­tries, 8 vessels, 6905 tons ; Asia, 6 vessels, 4638 tons ; Central and South America, 9 vessels, 6590 tons ; other countries, 1 vessel, 313 tons. The tables give eight columns, into which the losses are divided under the headings of "Abandoned at Sea," " Broken up, Condemned, &c.," "Burnt," h Collision," "Foundered," "Lost, &c.;' " Miss­ing," and "Wrecked." A consideration of these sub-heads will show that the total figures quoted must not be taken as final in the light of "figures of merit " for the respective countries. Thus we find that Germany did not condemn a single steam vessel during the past year, and this largely accounts for her good average of steam tonnage loss-namely, 1.16 per cent. France, on the other hand, condemned four steamships, c:f a gross tonnage of 5188, out of the total fleet of 532 steamers, equalling 853,799 tons gross, owned by the nation. The United Kingdom condemned 20 steamships, equalling 23,610 tons gross, out of our total steam fleet of 6035 ships, of 8,601,679 tons gross. It may be stated t hat Germany stands next to the U nited Kingdom in total steam vessels owned, the figures for that country being 846 ships of 1,088,830 tons gross. Our colonies own a steam fleet exactly equal to that of Germany in numbers, but the gross tonnage is less, only 515,204; which shows that the average steamer of the British colonies is not much more than half the size of the average steamship of Ger­many. The other countries, besides those already named, which own over300,000 gross tons of steam shipping are : United States, 572,252 tons ; Italy, 317,197 tons; Norway, 335,547 tons; Spain, 436,925 tons. Turning to other sources of loss, we find that England abandoned t hree vessels at sea, the colonies one, and France one. F our British vessels were burnt, two American, one Swedish, one Asian, and two Central American. By collision England lost thirteen ships, the colonies two, Austro-Hungary one, France four, Germany six, Norway one, Spain one, other Euro· pean countries two, and Central and South America one. This gives thirty-one steamers lost by collision out of a total of 215 losses from all causes, including the forty-six condemned. Under the headingof "Foundered" England has three ships tabulated, the colrJnies one, France one, Germany one, and Russia one. The figures are promising, although it may be hoped that this heading will become all but unnecessary before long. The figures in the "Lost" and the " Missiug" columns do not call for comment ; but under the heading of " Wrecked " we find t he most prolific record, there being in this column a total for all countries of 103 vessels, or nearly 50 per cent. of the total losses. Under the heading'' V\7recked " are included vessels lost through stranding or striking on rocks, &c., and of the total England supplies 54 ships the colonies 4, the United States 4, Austro~ HuJ?gary 1, France 8, Germany 2, Norway 5, Sp~un 5, Sweden 5, other European countries 4 Asia 5, and Central and South America 6. '

So far. we. have dealt wi~h the figures relating to steam shtppmg only, and 1t could be wished that this country appeared t o more advantage in the matttr of ve~sels lost. The figures, as t hey stand ,

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put England in a so mew hat higher position than she should hold if the "Broken up and Con­demned " column were eliminated. Thus we find that neither Holland nor Italy lost a single ship, the total wastage of both these countries being d ue to two ships condemned in each case; that is to say, not a single Dutch nor Italian steamer was wre~ked during 1892. Of course, it would not be fa1r to pit these comparatively small maritime P owers, owning respective1y uut 201 and 227 steamers, against our mercantile fieet of over 6000 steam­ships ; still it is to be hoped the British record will improve, and that we may stand at the head of nations in the safety of our steamships at sea, as would become the greatest maritime State the world has ever seen.

The second table of the return under review gives cor responding figures for sailing vessels, and here our own country appears to greater advantage if we take as our standard the percentage of losses in terms of the total tonnage owned, for there are but three countries showing a better average, namely, I taly, R ussia, and Spain. Were the "Broken up and Condemned" column eliminated, however, we should not occupy so high a position, for though we possess by far the biggest mercantile sailing marine, we have not condemned so much tonnage last year as some other countries. Speak­ing generally, it may be stated that the tables show a greater waste of sailing vessels as compared to steam ; which, of course, is in accordance with what might be expected. Th~ total number of sailing vessels of under 100 tons of all nationalities wrecked or condemned during the past year was 793, the total tonnage being 368,176. Of this number the United Kingdom supplies 144 out of a total of 3255 vessels owned by the nation, or nearly 100,000 tons lost out of the total of over 2~ millions owned ; percentage of tonnage lost, 3 .56. Our cc,lonies own 1859 sailing ships, tonnage 782,821, and lost 90 vessels of 40,939 tons ; percentage of tonnage lost, 5.23. The United States own 2866 sailing ships, of a tonnage of 1,354,174, out of which 117 ships were lost of 48,468 tons ; per­centage of tonnage lost, 3. 58. Austro-R ungary owns 207 ships, of 101,437 t ons ; 12 were lost their tonnage being 9228, or a tonnage loss of 9.10 per cent. The number of Danish sailing ships is 604, tonnage 136,782 ; 24 were lost of 5257 t ons, giving a tonnage loss of 3. 84 per cent. Holland owns 316 sailing ships, tonnage 150,987 ; she lost 20 of 9025 tons, which equals a tonnage percent­age of 5. 91. French sailing ships number 678, tonnage 203,909 ; the loss was 45 ships, tonnage 15,053; percentage tonnage loss, 7.38. Germany owns 1005 ships of 614,924 tons; the loss was 54 of 26,749 tons, eq ualling a tonnage loss of 4.32 per cent. I taly has 1173 sailing ships of 501,643 tons· the loss was 37 ships of 17,351 tons, or 3.46 per c~nt. · this percentage is a trifle better than that of th~ United Kingdo~. Norway. ranks only after Eng­land and the Untted States 1n the number of sail­ing ships she owns, the figures being 2818 ships tonnage 1,346,212; she lost 141 ships, of a tonnag~ of 68,135, or a loss of 5. 06 per cent . on the number owned. The next two countries, Russia and Spain, are the only ones showing a percentaae of loss considerably below that of England, but

0 the

number of ships owned by Spain is so small that the comparison is not of much value, whilst it must be remembered that a considerable number of Russian ports are closed during the winter which is more particularly the wreck season ; ~till the country deserves all credit for showing the lowest average in sailing ships. Russia has 947 ships of 276,706 tons ; she lost 14 ships of 4542 tons or l.n4 per cent. Spain owns 471 sailing vessels ton­nage 118,037 ; the loss was 7 ships of 2024 to~s, or 1. 71 per cen t. on tonnage. Sweden owns 960 sail­ing vessels of 288,751 tons; she lost 41 vessels of 14,989 tons, or 5.16 per .cent . of her total tonnage. Ot~er European countn es ~ost 28 sailing vessels, Asta 18, and other count ries 1. Turning to the causes of loss, we find t hat 104 vessels were aban­doned at sea, 152 broken up or condemned 29 burnt, 41 lost in collision, and 32 foundered.' In the columns " L ost, &c.," and " Missina "-under which headings appear those vessels of which full in­formation is not forthcoming-there are 86 vessels . whilst 349 sailing ships are returned as "Wrecked ,! that is, lost through stranding or strikioa rocks &~

Taking steam and sailing vessels together we' find that our percentage of loss is second in merit only to two ?ther countries, namely, Russia and Denn1ark , 1f we take tonnage as a basis of

calculation, whilst only Russia and Spain show better averages if the number of ships be con· sidered. Our loss in all vessels (over 100 t ons) was 2.59 per cent., tonnage loss 2.11 per cent . Denmark lost 2. 86 per cen t . of her vessels and 1. 69 per cent. of her tonnage. Russia lost 1. 25 per cen t. of her vessels and 1.42 per cent. of her tonnage. Spain lost 1. 82 per cent. of her vessels and 3. 04 per cent. of her tonnage. If, however, we take only the big shipowning countries of the world, we find the United Kingdom has the best average all round ; and we will conclude our quotations of figures by giving those for both steam and sailing t onnage, relating to those countries which possess over 1, 000,000 tons of shipping in vessels of over 100 tons. U nited Kingdom, 9620 vessels owned of 11,157,662 tons ; lost 249 vessels of 235,659 tons ; percentage vessels lost, 2. 59 ; percen tage of ton· nage lost, 2.11. Colonies, 2705 vessels owned of 1,298,025 tons ; lost 105 vessels of 53,379 tons; percentage of vessels lost, 3. 88 ; of t onnage, 4. 12. United States, 3297 vessels owned of 1,926,426 tons ; lost 126 vessels of 58,028 tons ; percentage of vessels lost, 3.82; of tonnage 3.01. France, 1210 vessels of 1, 057,708 tons ; lost 64 vessels of 37,465 tons ; percentage of vessels lost, 5. 29 ; of tonnage, 3. 54. Germany, 1851 vessels of 1, 703,754 tons ; lost 64 vessels of 39,340 tons ; percentage of vessels lost, 3. 46 ; of tonnage, 2. 31. Norway, 3333 vessels of 1, 681,759 t ons; lost 149 vessels of 77,272 t ons ; percentage of vessels lost, 4. 4 7 ; tonnage, 4 . 59 per cent. To the above we will add the figures for Italy, as she comes not very far short of the 1, 000,000 tons, and more· over has a very creditable average. I taly, 1400 vessels of 818,840 tons; lost 39 vessels of 20,850 t ons, percentage of vessels lost 2. 79, percentage of tonnage lost 2. 55. As in the above figures relating to vessels lost are included those broken up and condemned, we will give the figures under this heading for the principal countries, so that our readers may correct the percentages of actual loss by n1isadventure if they wish. United Kingdom, 40 vessels of 29,522 tons ; Colonies, 24 vessels of 10,587 tons ; United States, 17 vessels of 10,837 t ons ; France, 12 vessels of 7117 tons ; Germany, 15 vessels of 8308 tons ; Norway, 30 vessels of 10,996 tons; I ttLly, 13 vessels of 9145 tons.

Although, as will be seen, we have the lowest percentage of loss amongst the seven big shipown· ing nations of the world (including our colonies), yet we cannot look on our position as altogethel' sa.tisfactory. There are many reasons why we should stand first, and when these are discounted there is not, perhaps, a great deal left for us to boast about. In the first place, in virtue of our position our ships should be t he best found and safest of all nations; yet Russia beats us on every p oint. The large number of steamers we possess should gh·e us an advantage, but we find by the r eturns t hat in safety of steam tonnage we only stand in the second division, being seventh amongst the twelve countries of which averages of loss are quoted. The large proportion of steam tonnage comprised in our ocean liners, which are so little liable to accident, gives us a great advantage over other countries; and it must not be forgotten t hat many of our sailing vessels are of great size and well appointed. We have more engineering estab· lishments, more shipbuilding yards, and more marit ime resources generally than any other P ower ; our coasts are magnificently lighted, our harbours are safe and commodious, and our shores are patrolled by. po~erful tugs. yte have special ~nd stringent legislatwn, and a trained body of officials to enforce the State regulations. In spite of all these advantages we have to depend on our sailing :fl eet to give us the moderate position we hold in r egard to the safety of ships at sea. There is cer · tainly roo1n for improvement.

OFFICIAL TESTS IN NORWAY WITH Sl\1ALL·CALIBRE RIFLES.

A NUMBER of exhaustive and interesting tests with small·calibre rifles have recently taken place a.t the instance of the Norwegian military a.uthori. ties. The tests, which have been conducted by a special commission, have resulted in the recom· tnendation of the 6. 5-mm. Krag-Jorgensen rifle. The tests having in the fi rst place shown with what kind of powder they should be conducted, riftes of 8 mm., 7.65 mm., 7 mm., and 6.5 mm. were tested, t he latter proving decidedly superior in ballistic qualities. A commencing velocity of 700 metres

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was recorded, with a pressure in the barrel of about 4000 atmoapheres. As the pressure in the barrel increases as the calibre decreases, it will, at least at present, not be advisable to adopt a smaller calibre than 6.5 mn1. Experiments have been made with 5·mm. calibre, but the results have not been satisfactory. As the 6.5-mm. calibre is exposed to a very serious strain, the tests also comprised its being able to stand a large number of shots. The results were very satisfactory, a 6.5·mm. rifle being sub. jected to 4000 shots without having perceptibly deteriorated.

The preliminary tests having t hus resulted favourably for the 6.5-mm. calibre, exhaustive corn. parative tests were made with 8·mm. and 6.5.mm. rifles, the former calibre having already been adopted by several countries. The r esults were as follows:

\Vith the 6. 5-mm. calibre a considerably greater " rasance , is obtained than with the 8·mm. calibre.

With the 6. 5·mm. calibre, a greater accuracy in hitting, especially at the shorter distances, will be obtained than with the 8.mm. calibre.

The deviation of rotation and the effect of t he wind are no greater with the 6.5·mm. calibre than with the 8-mm. calibre.

The 6.5·mm. projectiles have great er power of penetration in wood than the 8·mm. projectiles, and quite as much in earth and sand.

The 6.5-mm. projectiles do not so easily lose their shape as the 8·mm. projectiles.

The projectiles used were of lead, with a coating of nickel·plated steel or nickel bronze.

I t was observed that where as the power of pene· tration into wood was greatest at a distance of about 300 ft.-about 12 per cent. greater for the 6.5·mm. than for the 8-mm. calibre-and while it gradually decreased for every 300 ft., the power of penetration into sand was comparatively small at a distance of 300 ft., whereas it rose up t o bet ween 1300 ft. and 1600 ft. when there was not much dif· ference between the two calibres. The twist of the rifling in the barrels has been so arranged that the projectile is comparatively long, so that it corn· bines a fair weight with a small diameter ; still 100 6.5·mm. projectiles weigh no more than 76 8·mm. projectiles.

The tests with regard to mechanism and maga­zine comprised the Krag.Jorgensen, the Mann· licher, and the Mauser rifles; the Kropatchek rifle (Portugal), the N agaut rifle (Belgium), the L ee· Speed rifle (England), the Schmidt rifle (S witzer· land), the Marga rifle, and others, having also been duly considered and discarded. The three rifles first named have been tested in the most varied and thorough manner. There were tests for q uick. firing with and without aim, tests of endurance (500 shots without cleaning the barrel, 400 from magazine, and 100 as single loader , but with loaded magazine), dust tests, tests of rusting, of firing with increased charges (giving a pressure of not less than 5000 atmo­spheres), and finallytests with defective cartridges. That the ease with which the various mechanisms could be handled also was tested, goe(almost with­out saying.

In order to test the different rifles as far as dust was concerned, they were placed in a special box, and for two minutes exposed to a blast of fine sand; they were then taken out of the box ; they were slightly shaken so as to remove the surplus of sand, and were then tested, both as single and as maga· zine loaders. In order to t ry the rifles with regard to rusting, the handles were screwed off, the breech­loading mechanism, the magazine, &c. , were cleaned from all grease, and were then immersed in salt water for four hours (with closed mechanism, and as high as the cartridge chamber); they were then left in the open air for two days, and subsequently twenty shots were fired from t he magazine without any cleaning whatever.

The commission recommends the adoption of the Krag-Jorgensen mechanism and magazine arrange· ment, on account of t he following advantages : I t gives the most perfect corobi11ation of single· loader with magazine as reserve, and magazine rifle proper, being equally serviceable as single· loader, even if the magazine gets out of order. The ! fi lling and refilling of the magazine can be effected with loaded rifie, with mechanism closed and t rigger cocked. The magazine remains intact when using the rifie as a single·loader, so that there is always a reserve of five cartridges, whereas with the M a user there are four left, w bile the Mannlicher cannot be used as a single loader. Finally, the loading and refilling of the K rag-J orgensen rifle is

---easily accomplished from all positions, as compared with the two others. There is no spring resistance to be got over, so the loading req uires only a very slight movement, which is a great advantage for the soldier, when he, for instance, is in a recum· bent position. The weight of t he rifle complete is under 9 lb., with bayonet attached about 5 oz. above 9 lb. I t is intended to furnish each soldier with 150 cartridges, which will weigh bar ely 9 lb.

THE NEW SPANISH CRUISER " INFANTA MARIA TERESA."

THE latest addition to the Spanish Navy-the cruiser Infanta l\1a.ria Teresa-which has been built and engined by La Sociedad An6nima de los Astilleros del Nervion (formerly Martinez·Rivas Palmer), at t heir splendidly equipped works at Bilbao, proceeded last week to Ferrol, in the north of Spain, to go on her steam trials. This is one of a fleet of ships for the construction of which the Spanish Government in 1889 voted an extra· ordinary credit of 10,000,000l. Through the influ. ence of Mr. Mar tinez, one of the most enterprising capitalists in Spain, and that of his partner , Sir Charles Palmer, Bar t., the experienced and vigorous head of the J arrow firm, the building of three of the ships was intrusted to the Bilbao firm, one of the stipulat ions being t hat in every case pre· ference must be given to Spanish material and industries-one of t he primary objects being to foster the national industr ies, and more especially those of the province of Vizcaya. In J uly, 1889, the contract between the Government and Don Jose Martinez de las Rivas for the construction of the hulls of the three cruisers was signed, and mmediately afterwards efforts were begun to transform what was nothing but a marsh on the banks of the River N er vion into impor tant ship­building, engineering, and ordnance works. Engli~h managers and leading workmen were engaged by Sir Charles Palm er, and, after an enormous amount of labour, the various machine sheds, frame-bonding sheds and furnaces, joiners' shops, &c. , were erected ; expensive machinery was brough t from England, and t he actual building of the ships begun . So st renuously was the work prosecuted, t hat in the short space of thirteen working months the fi rst cruiser was launched with great eclat by the Queen Regent of Spain.

As stated in a former article,* when we gave a detailed description of the works, the original intention was t o send out the principal parts of the n1achinery finished fr01n Jarrow, where they were to be constructed at Messrs. Palmers' ; but it was afterwards decided, upon the appoint· ment of Mr. McKechnie as manager of the engine works, to build the engines in Spain, as he under· took the responsibility of the entire construction of the machinery at the N ervion Works. There· upon the large and spacious engine and boiler shops, with iron and brass foundries, coppersmit hy, bol t and rivet shop, &c., were begun , t he most improved machinery being sent from this country. E very· thing progressed well t ill May 1, 1891, when the engine works wore completely destroyed by fire. The work of reconstruction was tackled in a systematic manner, and with so much success that in three months the workshops were re­erected, and the construction of the cruisers' ma· chinery proceeding as if nothing extraordinary had occurred. Many important parts of the engines were destroyed by the intense heat, and by the water which was poured upon then1 during the progress of the fi re.

In the beginning of 1892 the firm of Martinez­Rivas Palmer was transformed into a limited liability company,+ with a capital of 1,200,000l. , and the progress of work upon the ship and guns, as well as the reconstruction of the engines, went on satisfactorily until the end of April, 1892, when, through a disagreement between the firm and the Government, the works were temporarily closed. But the Government ultimately decided to take over the establishment with the intention of finishing the cruisers on their own account, and the E nglish managers and workmen were retained upon their old terms. As official director over the con· cern, the Government appointed General Cervera, an experienced naval officer . Under his energetic efforts the work forged ahead, and his pleasant and gentlemanly manner gained him friends among

* See ENGINEERING, vol. xlviii., page 504. t Ibid., vol. li. , pa.ge l 27.

EPT. 15, 1893.]

Spaniards and Englishmen alike. He remained for about seven months in command of the Astilleros, when he was appointed Minister of Marine, being succeeded by General Rocha, who has continued in charge up to the present. And now, after all the difficulties and troubles with which the undertaking has been beset since its beginning, the firs t of the three cruisers is completely finished and armed. The other two cruisers are in an ad­vanced state, and may soon be completed. It is hoped that satisfactory arrangements will then be come to for the continuance of the establishment. Hitherto the Government has not been disposed to relinquish their control over the works until the cruisers were finished, and consequently dis­couraged the construction of merchant vessels. It is hoped now that as soon as terms have been settled with the company on the part of the Govern­ment, that either the company will be put in a position to carry on the works, or that they will be purchased by some of the capitalists who are credited with a desire to see the establishment as a.cti vely engaged as it might be. Certainly it is as well equipped as any British yard, and if en­coumgement is given, as is suggested by the Ship­ping Bounty Bill brought before the Legislature, the construction of these cruisers may mark an im­portant epoch in the industrial history of Spain. The vessels built clearly prove what we have written as to the efficiency of the works, as will be appreciated from a short description, deferring fuller details until a later date, when we hope soon to fully illustrate the vessels and their machinery.

The Infanta Maria Teresa is built entirely of Siemens-Martin steel, is 340 ft. long between per­pendiculars, and 364 ft. over all, with a breadth of 65 ft., and a depth of 38 ft., displacing 7000 tons on a mean draught of 21 ft. 6 in. She has the usual ram bow, and carries two masts, each having a military top and signalling yard. The masts and funnels have just enough rake to give her a very smart appearance. For 315 ft. amidships she has an armour belt 5 ft. 6 in. broad, backed by 6-in. teak. The plates, which were supplied by Messrs. Cammell and Co., are 12 in. thick, secured by 3!-in. bolts. She has the usual cellular double bottom, and has eleven transverse watertight bulk­heads, the bunkers being arranged in the usual manner to afford the machinery as much protection as possible. She carries in all twelve boats, includ­ing a 60-ft. 17 -knot vedette boat, four large sailing pinnaces, a 30-ft. gig, 28-ft. whaleboat, two dingies, a 25-ft. canoe, and two 30-ft. 8-knot steam launches, the machinery of the latter being constructed in the Astilleros. Forward she has a very power­ful capstan, and a large warping winch aft, and is fitted with Muir and Cald well's patent steam steering gear. The total bunker capacity is over 45,000 cubic feet, and 490 tons of fresh water are carried under the boilers. Her principal ground tackle consists of two 90-cwt. and two 30-cwt. ordinary anchors, two 80-cwt. stockless, and two kedge anchors of 14 cwt. and 8 cwt. respectively. The pumping arrangements and ventilation of the ship have been we11 looked after, and throughout the whole ship a proper and complete system of voice-pipe arrangement has been instituted. Be­tween the bridges, conning tower, steering gear, and engine rooms, as also between the engine and boiler rooms, &c., l\fessrs. Chad burn's patent tele­graph gear has been fitted. Mr. J ames Clark, formerly of the Barrow Shipbuilding Company, who went to Bilbao at the commencement of the works, succeeded Mr. J. P. \-Vilson as manager of the shipbuilding department, and the short time in which the first cruiser was built speaks well for the management.

The ship has in all eight torpedo tubes, and the principal armament is as follows : Two 28-centi­metre guns (one forward and one aft) mounted in harbette turrets,* ten 14- centimetre guns, two 7 -centimetre guns, eight 57 -millimetre Nor­denfeldts, two 11-milliruetre N ordenfeldts, and eight Hotchkiss. The forgings for these were brought from England, but they were turned and finished in the Astilleros Gun Factory, all the employes of which are Spaniards. This department is managed by Colonel Albairan, who has had con­siderable experience in the Govocnment gun fac­tories, and who has satisfactorily finished the work entrusted to him, which excels by far similar work produced in the Spanish Royal Dockyards.

The propelling engines are of the vertical triple-

* See ENGINEERING, vol. 1., page 319.

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expansion surface-condensing direct-acting type, driving twin-screws, and are designed to deve~op collectively about 13,500 indicated horse-power with forced draught, the contract speed for which is. 20 knots. The dimensions of cylinders are: High pressure, 42 in. ; intermediate pressure, 62 in .; and low pressure 92 in., by 46 in. stroke. The cylinders are fitted throughout with Whitworth's fluid com­pressed stee~ liners. In both engine and . boiler rooms there IS plenty of clear space. The cyhnders, cylinder covers, pistons, and steam chest doors are all of cast steel. The high-pressure cylinders are fitted with piston valves, and the intermediate pressure and low pressure with valves of the ordi­nary flat-faced ported type. The piston-rod~, which are 7i in. in diameter, are of Siemens-Martin steel, as are also all the forgings. The high-pressure rods are fitted with Beldam's patent packing, the packing for the intermediate pressure and l_ow pressure having been supplied by the CombinatiOn l\ietallic Packing Company. The thrust blocks and collars are of cast steel, the latter being of the horseshoe shape and lined with " Magnolia" metal. The main surface condensers, which are 10ft. 8 in. long, are made entirely of brass, having a total sur­face of 14,600 square feet. Each condenser carries over 5000 brass tubes 10 ft. 8 in. by ! in. in diameter. The crankshafts, which were supplied by Messrs. Cammell and Co., R.re of the ordinary three-throw type, being made of steel, the external diameter being 16! in. The reversing gear is of the ordinary all-round type, both hand and steam gear being provided. In each engine­room there is a lOO-gallon Kirkaldy's distiller, each with a circulating pump, as also an evaporator on Weir's system with its 4-in. cylinder feed pump. There are four ash-hoisting engines, having two 4!-in. cylinders by 5!-in. stroke, and efficient means have been provided for handling the ash-buckets under forced draught . The engines for working the ammunition hoists are placed one forward and one aft, both working double hoists. The ammuni­tion hoists themselves are provided with safety gear, to prevent the charges falling and causing an explosion on board, in case of the rope suspending them being shot away. The main steam pipes are 18 in. in diameter, and are all of copper, the sheets having been brazed and wrought up in the copper­smithy.

Forward of the mainmast a boat-hoisting engine has been fitted, having 9-in. cylinders, and capable of lifting 18 tons, the mast being provided with a suitable boom for raising and lowering the heaviest boats. Air-compressing machinery, supplied by Schwartzkopff, for charging the torpedo tubes and torpedoes, has also been fitted for working up to 1500 lb. pressure. The exhaust steam from the auxiliary machinery is carried into two auxiliary condensers 8 ft. long-one in each engine-room­each condenser being provided with its own air and circulating pumps, which are worked by entirely independent engines. These condensers, like the main, are made entirely of brass, and each contains about 700 tubes.

In all there are over fifty separate and auxiliary engines, the whole of which, excepting the windlass, steering gear, distillers, and vedette boat machi­nery, have been constructed in the Astilleros. In a situation convenient to the engine-room an engi­neers' workshop has been erected, and fully pro­vided with all the requis ite machines, tools, and grinustones. The two propellers are three-bladed and cast of Stone's patent No. 3 bronze, the bosses and tail-pieces being of gun-metal, and the blades fixed by bolts in the usual manner. The propellers have a diameter of 16 ft. 5 in. and 20ft. 6 in. pitch, the expanded surface being 73 square feet. For each engine there are four lengths of straight shafting, which was supplied rough turned and finished in the Astilleros. The diameter of the intermediate shaft ing is 15! in., that of pr:>peller shafting being 15~ in.

Steam is supplied by four double-ended boilers 16 ft. 3 in. in diameter, and two single-ended boilers 16 ft. 3 in. long by 10 ft. 6 in. in diameter, and working at a pressure of 150 lb. per square inch, the test pressure being 250. Following out the usual plan, to provide greater safety, the boilers are placed in two separate compartments, the bunkers being run along each side in the usual way. There are two fu11nels, 9ft. in diameter, the height from dead-plate to top of funnel being 69ft. 'fhere are in all 40 Purves patent boiler flues 6 ft. 6 in. long, and having a mean diameter of 3 ft. 3 in. The double-ended boiler tubes are 6 ft. 3 in. by

339

2! in., the single-ended boiler tubes being 6 f~. 9 in. by 2!-in., the length between tubeplates being ~or double-ended 6 ft. 3 in., for single-ended 6 ft. 9 In. The grate surface is 845 square feet; t ube surface, 22,270 square feet; heating surface, 25,_92~ square feet. F or supplying steam to the elect_r~chght_and steering gear engines, there are two auxiliary_ boilers on the protective ~eck forwa~d, each 8_ ft. 10 In. l_ong by 7 ft. 9 in. in diameter, w1th a 3! -In. Worthmg­ton system pump provided. The usual stokehold arrangements for running un~er forced dr~ught have been fitted, there being nme fans, having a diameter of 5 ft. 6 in. The designing and construc­t ion of the engines, boilers, and auxiliary machinery, as well as the construction and equipment of the engine works, have been carried out by Mr. James MoKechnie, who has been assisted by Mr. James Brown, formerly of the Clydebank engineering staff.

LITERA'l,URE. Pioneers of Science. By 0LIVER L oDGE, F.R.S., Pro­

fes~or of Physics in Victoria. U ni varsity College, Liverpool. London and New York : Macmillan and Oo.

THIS book of 400 pages is the outcome of a course of lectures given in 1887 by Professor Lodge in University College, Liverpool. It is not always that professors elect to write out their lecture-notes for publication. Tyndall did so, and gave students his manuals on Light, Heat, and Sound ; rrait expanded his notes into his ' 'Recent Researches in Physical Science ;" Stokes developed his into his admirable book on Light ; and Ball's Christmas lectures at the Royal Institution (1887) have be­come the ''Star-Land '' that delights every reader of popular astronomy. Dr. Lodge, too, has filled in the outline of his course, and t hereby given the general scientific reader a work full of varied and useful information.

His pioneers, however, are not selected from every part of the field of science. Only those are introduced who explored, or contributed to explore, the vast domain of astronomy and some conter­minous regions. By means of biographical details, gathered fron1 all "readily available , sources, he tries to make his pioneers live their life and do their work before the reader. Their studies and successes are chronicled, their trials and failures recorded, t heir honours and hardships are all vividly described, and t he moral opportunely pointed. Thus, speaking of Newton (page 185), he says:

"His method of fluxions was still unpublished; a second edition of the Principia., with additions and improve­ments, had yet to appear, but fame had now come upon him, and with fa1ne 'Worries of all kinds., [The italics are ours. ]

Galileo's ''energy and imprudence " elicit the exclamation, '' \V hat a blessing that youth has a little imprudence and disregard of consequences in pursuing a high ideal !"

Kepler 's ill-health, weak constitution, and con­tinual distress awaken his sympathy, and he writes (page 75) :

. " Once more Kepler ~a.de a determh:~ed attempt to get bts arrears of salary patd, and rescue h1mself and family from their bitter poverty. H e travelled to Prague on purpose, attended the imperial meeting, and pleaded his own cause, but it was all fruitless ; and, exhausted by the journ~y, weakened by over-study, and disheartened by the failure, . be caught a fe~er, and died in his fifty­moth year. H1s body was buned at Ratisbon, and a century ago a proposal was made to er~ct a. marble monu­I?ent to his memory, but nothing was done. It matters httle one way or the other whether Germany having almost refused him bread during his life, should a. cen­tury and a half after his death, offer him a stone.!'

On page 50, Tycho Brahe's work, in his island home of Huen, is rapidly sketched, and we are told that :

'' ~hilosophers, statesmen, and occasionally kings (in­cludmg our own J ames I.) came to visit the great astro­nomer and to inspect his curiosities. And very wholesome for so~e of those great personages was the treatment they met With. For Tycho was no respecter of persons. His humbly-born wife sat a.t the head of the table whoever was there; and he would snub and contradict a chan­cellor just a-s soon as be would a. serf. ,

Descartes's easy-going way of working is noticed as offering a humane suggestion to over-laborious students of the present day. On page 147 we read :

. "He recommends idlene~s as necessary to the produc­tiOn of good mental work. He worked and meditated but a. few hours a day ; and most of them in bed. He used to

•

340 thit;1k best in bed, he said. The afternoon h~ devoted to soCietY: and recreation. After supper he wrote letters to var10us persons, all plainly intended for publication a.nd scrupulously preserved. He kevt himself free from c~re and was most cautious aboub his health, regarding htmself, no doubt, as a subject of experiment, and wishful to see how long he could prolong his life.~>

Part I. is entitled, ''From Dusk to D ayli rrh t " th '' . , b . e ' e. pwneers etng Copernicus, Tycho Brahe, Gahleo, Descartes, and Newton. Part I I. is called '

4 A Couple of Centuries' Progrees ;" it introduces Roemer and B.radley, Lagrange and Laplace, and (somewhat furhvely) Adams and Leverrier. ~he wor~ of .each of these men is analysed, and

t~e1r c.ontnbutwns to the progress of science indi­vtduahsed and duly emphasised. Each lecture is preceded by a summary of facts which must be invaluable to the student-reader. The whole is presented in an interesting and scholarly form. The peculiarities of the author-and Professor Lodge has a few - naturally manifest themselves here and there.

On page 165, he finds an opportunity for firina a shot at examiners. Speaking of Newton, h~ says :

" By the end of the year (1664) he was elected to a scholarship and took his B. A. degree. The order of merit for that year never existed or has not been kept. It would have b~n interesting, nob as a testimony to Newton, but to the sense or nonsense of the examiners."

This comment is unkind and puzzling, considering that Dr. Lodge has year after year applied for the Ex.a.minership in Experimental Philosophy at the L ondon University. But perhaps the explanation may . be found in the ''very modern spirit " descnbed on page 146. When speaking of Descartes he says :

"In this, as in many other things, he was imbued with a very modern spirit, a cynical and sceptical spirit which to an outside and superficial observer like myself seems rather rife just now. "

Examinations -even the Cambridge Tripos-do not command his confidence. Adams "had gradu­ated as Senior Wrangler, it is true, but somebody must graduate as Senior Wrangler every year, and every year by no means produces a first-rate m~the­matician" (page 324) ; besides,

" The labelling of a young man on taking his degree is much more worthless as a testimony to his services and ability than the general public are apt to suppose."

This sounds strange from one who compelled himself to toil for years to get his D.Sc.London, and who subsequently accepted an honorary LL.D. degree.

We find a trace of this ''modern" spirit, en­livened this time with a dash of humour, in the paragraph descriptive of Sir Isaac Newton's nomi­nation to Parliament. I t runs thus :

" We are a curious, practical, and rather stupid people, and our one idea of honouring a man is to vote for him in some way or other; so they sent Newton to Parliament. He went, I believe, as a Whig ; but it is not recorded that he spoke. It is, in fact, recorded that he was once ex­pected to-speak when on a Royal Commission about some question of chronometers, but that he would not. How­ever, I dare say he made a good average member. "

In referring to Kepler's poverty, he suggestively writes : "What Kepler might have achieved had he been relieved of [from ?] those ghastly struggles for subsistence, one cannot tell." This is not the only broad hint thrown out as to the necessity of endowing research. Frederick of Denmark and Rudolph of Bohemia are praised for their patron­age of Tycho Brahe; and our own George lii. is mentioned on account of his generous treatment of Herschel. The case of Newton, who gave up his unremunerative Lucasian Professorship for the Mastership of the Mint, rouses his indignation :

"But what a pitiful business it all is? Here is a man sent by Heaven to do certain things which no one else <:ould do. and so long as he is comparatively unknown be does them, but as soon as he is found out, be is clapped into a routine office with a big salary; and there is, com­paratively speaking, an end of him."

Professor Lodge's mode of treatment-like his way of lecturing~is often som~what nonchalant, if not phlegmatic. Re occasiOnally, however, allows himself to warm up into a little glow of enthusiasm over the achievements of one or other of his" pioneers." When Newton heard of Picard's determination of the length of a degree, he began to review his speculations concerning gravity:

"With intense excitement he runs through the work­ing his mind leaps before his hand, and as he J>ercei ves the' answer to be co~nin~ out ri~ht, all the infimte me~n­ing and scope of h18 m•ghty d1scovery flashes upon h1m,

E N G I N E E R I N G. and he can no longer see the paper. He throws down the pen, and the secret of the universe is, to one man, known. "

Of kindred dramatic interest are the lines which conclude a vivid description of Galileo's ever famous experiment from the top of the Leaning Tower of PLsa : "The simultaneous clang of those two weights sounded the death-knell of the old system of philosophy, and heralded the birth of the new."

In the following lines, with which Lecture ·vr. opens, Dr. Lodge shows und(,ubted capacity for poetic colouring : "A generation of slow and doubtful progress must pass before the first ray of sunlight can break through the eastern clouds, and the full orb of day itself appear. "

P er cont1·a, he sometimes lapses into trivial school­boy phraseology. An instance will be found on page 338, where, speaking of meteoric bodies, he says they may ''splash" into an atmosphere and drop on to its surface, or they may "duck" out of it again and revol'"'e r ound us unseen in the clear space between the earth and the moon.

On page 164 young Newton at Trinity "gets hold of a Euclid and a Descartes' Geometry. The Euclid seemed childishly easy and was thrown aside. " On page 178, Newton's disappointment with the result of his first calculated value of the constant of gravity is most interestingly described ; and then we are assured that '~ so far as is known, he never mentioned his disappointment to a soul."

Again, on page 42, we read how Tycho Brahe's fiery nature ., led him into an absurd though somewhat dangerous ad venture. A quarrel at some feast on a mathematical point, with a countryman, led to the fixing of a duel, and 1t was fought with swords at 7 p.m. at the end of Decem­ber, when, if there was any light at all, it must have been of a flickering and unsatisfactory nature. The result of this insane performance was that Tycho got his nose cut clean off."

Further on we are told how the Danish astro­nomer constructed an artificial nose, "some say of gold and silver, some say of putty and brass," and also that" he used to carry about with him a box of cement to apply whenever his nose came off, which it periodically did."

In discussing the third law of motion, Dr. Lodge brings forward the objection often urged by engi­neers who say, ''If the cart pulls against the horse with precisely the same force as the horse pulls the cart, why should the cart move 1" To this Dr. Lodge, with something like "an impul~ive rush ," indignantly replies, '' 'Vhy on earth not 1"

Galileo found experimentally that all bodies, light as well as heavy, tend to fall at the same rate. "Now this was clean contrary to what he had been taught," page 88 ; and on page 90 we are assured that the great philosopher '' was not con­tent to be pooh-poohed and snubbed."

The following must have been penned to show the author's contempt for what some people are pleased to call English grammar : '' In twelve months observational astronomy had made such a bound as it has never made before or since" (page 112).

It is trite to say that tastes may differ ; but there will undoubtedly be many who will admit that such tit-bits of writing would find a more appropriate place in a school· book on composition or sty le as exercises for correction rather than in a professedly didactic volume recounting the achieve­ments of pioneers of science.

Of still more questionable propriety is the sub­stance of Lecture V., in which the author takes infinite pains to describe the treatment of Galileo by his contemporaries, and chiefly by the officers of the Inquisition. The same dissonant note is sounded again and again iu the lectures on Coper­nicus, Descartes, and Newton. In fact, Professor Lodge does not begin to recover his normal equanimity until he has delivered himself of a solemn warning to the opponents of the Darwinian theory of evolution, which warning ominously concludes thus : "Take heed lest some prophet, after having excited your indignation at the follies and bigotry of a bygone generation, does not turn upon you with the sentence, 'Thou art the man'" (page 135).

Dr. Lodge, in his opening lecture, makes a sweeping assertion about the middle ages. vVith­out specifying any definite period, he asserts t hat '' the dark ages came as an utter gap in the scien­tific history of Europe." To this we must say that our Hallam and our Maitland demur. Some cen-

[SEPT. I 5, I 893.

turies of the medi~eval times were dark-dark like the lines in the solar spectrum, i.e. , by com­parison, a.nd not absolutely. Indeed , those ''dark ages" were among the palmiest days of the great Universities of Oxford and Cambridge, Paris and Bologna, Padua and Pavia. They saw the discovery of our English coal measures, the invention of clocks, the staining of glass, the introduction of the compass. Surely all this meant scientific knowledge, as did also the erection of those build­ings of marvellous solidity and giant architecture with which the Continent and our country were studded over, and which excite the admiration of knowing visitors to the present day.

. Another stricture we shall permit ourselves before taking leave of Dr. Lodge's " Pioneers. " This time it refers to the lecture on comets and meteors. We are glad to find that Dr. Lodge advocates the theory established by the labours of Tait, Lord Kelvin, Schiaparelli, H. A . Newton, and Lockyer. He rejects en passa,nt Sir Robert Rall's ·riew that all bodies which fall upon the earth were originally projected from terrestrial volcanoes in ages long past, and he emphasises his inability to draw a dis­tinction between the countless numbers of cosmic bodies that constitute our meteor streams and those daring adventurers that pierce through our atmo­sphere and crash down upon our earth.

But surely the labours of the late Professor Adams in connection with the meteoric theory deserve more than a three-word notice, especially as Leverrier is awarded the lion's share of com­mendation for the discovery of U ran us. It was the memorable star shower of 1866 that led the Cambridge astronomer to undertake an investiga­tion among the most ponderous in mathematical astronomy. On the night of November 13 of that year the earth plunged through the swarm of meteorites since known as the Leonids from their appearing to radiate from the constellation Leo. During six: hours, from 10.30 P.U. to 4.30 A.M., our planet kept ploughing its way through the broad stream of these countless masses. Myriads of them dipped into our atmosphere, while millions of others found in its middle strata a ready crema­torium in which they flashed for an instant and then left their ashes to settle down and tell of their destruction.

This widely-observed display gave rise to some discuesion as to the constitution of these flying visitors, and especially as to their movements through space. Professor H. A. Newton, of Yale College, New Haven, was among the most careful observers of meteoric phenomena, and his observa­tions and conclusions still command general atten­t ion . He admitted that the meteors were discrete bodies of all sizes, each fulfilling its own destiny as it circled round the sun in conformity with Kepler's laws. The fact that ·the main body of the shoal crossed the earth's path on November 13 fixed one point in its orbit; the direction in which the meteors were observed to move gave a tangent to the plane of that orbit; and as the sun was in the focus, the position of the plane in space was completely defined. Professor Newton discussed the observed data, and showed that there were but five orbits in which the meteors could move, so as to satisfy the known conditions. One of these was an elongated ellipse, two others were almost circles differing but little from our own annual track, and the remain­ing two were ovals lying within the earth's orbit.

The problem was thus narrowed down to finding which of the five possible orbits was the one that best fulfilled all the circumstances of motion of the meteor swarm. The only further help given towards the solution of the problem was deduced by Professor Newton from a careful study of historical records, viz., that the point in which the orbit of the meteors intersects that. of the earth was not fixed, but was noticed to undergo a periodic displacement in the direction of motion of the shoal amounting to 29 minutes.

This displacement was attributed by astronomers to the disturbances which the meteoritic shoal ex­periences in passing near U ran us, Saturn, Jupiter, and the earth. Adams examined, and , with the help of his two assistants, estimated quantitatively the disturbance produced by the planets separately upon the shoal as it moved along each one of the five suggested orbits. After months of laborious computations, he showed in the Monthly Notices for April, 1867, that the elongated elliptical orbit was the only one which would account for the observed shifting of the node. Of the total disturbance he assigned 20 minutes to Jupiter,

•

7 minutes to Saturn, and 1 minute to U ranus. He found the action of the earth and the other planets to be n egligible.

\Vhen the other four orbits were similarly examined, he found that in n o case could the nodal disturbance exceed 12 minutes. This calcu­lation therefore settled on the very eccentric orbi t as the path along which the L eonid meteors travel through space.

The publication of these results increased the r eputation of the young mathematician who had solved- unknown to his great contemporary, L everrier- the mystery of the Uranian perturba­tions.

Such an achievement in 1867 by a St. John's man should have found adequate r ecognition in L ecture XVI., on " Comets and Meteors."

The last lecture of the course-L ecture XVIII. -treats of tides and their effect on the evolution and on the final destiny of planets. It is an ex­cellent epitome of the work of Professor George Darwin, and of the recent extension of the theory by Sir R obert Ball in "Time and Tide" and also in " Glimpses through the Corridors of Time." This lecture should be car efully read, as it will serve to correc~ erroneous impressions that one is likely to carry away from a perusal of those pages of L ecture ... TI. in which are explained the two laws of s~ability of the univer se given and discussed by Lagrange and La place.

The "Pioneers of S:::ience " is plentifully illus­trated with diagrams, maps, and figures, all of which will be found to afford valuable aid. There are also fine por traits of all the '' pioneers,, as well as of Carolina Herschel and Sir vVilliam Thomson (L ord Kelvin .)

---Theory of Struct1t1·es and Strength of Materials, with Dia­

(lrams, i llustrations, and Exa,mples. By M. T. BovEY, M.A., &c. New Ynrk and London: Kegan Paul, Trench, Triibner, and Co., 1893. (817 + xv. pages, and many woodcuts.)

This is a large and important treatise, so merits a pretty full notice. The work aims at the mathe­matical investigation of the theory of the d esign of structures ; the methods of calculation, both by formulro and by graphical solution, are then deve­loped, the former rather more fully ; the graphic working is , in fact, frequently n ot full enough to be sufficient of itself for the mastery of the graphic method, which r equires a great deal of practice for proficiency. A good deal of mathematical know ledge is required to read the investigations properly; in­cluding, for instan ce, some knowledge of differen­tial equations and of elliptic integrals. A good deal of space has, we think, been wasted in the detailed integration of n umerous cases of deflection, fixed beams, continuous beams, and of t he elastic curve generally ; these migh t have been condensed into a very few general cases, the solutions of w hi eh would involve certain general symbols (often simple integrals), and the values of these symbols for the particular cases might have been given in Tables. This mode of condensation is largely employed in Rankine:s works, and with the happiest effects; one spec1al advantage to the pract ical engineer is that the details of mere integrations and algebraic r eductions are thus largely got rid of. A special and so mew bat novel feature of this work is t hat the principles and methods detailed are illus­tra~ed by a. .h ost of examples (questions). H ere aga1n we thmk that the work errs in excessive fulnes~ ; there a~e, in fact, over 800 examples (questwns), covenng abou ti 140 pages, i.e., about o.ne-sixth of the book. Very few of these ques­twns are worked out. \Ve think that it would have been of more r eal help to the student if at least the leading steps of a few of the questions on each chapter had been given, and more details of gr~phic solutions instead of so many mere <] u estwns.

E xcept for (what seems to us) the waste of space as above, we have in general only unqualified praise to give of this work. It is divided into thirteen chapters, e~ch cont~ining a diatinct wide subject, or group of m1nor subJects. As a whole, the subject matter of each chapter has been well considered, and well developed. The mode in which the effects of fluctuating stress ar e. gone into (pages 145 to 166) m~! be, quoted a~ an 1nstance. After explaining 'Voh.ler s hw, w1th sketches of the experiments l;eanng thereon, Launha.rdt's, Weyrauch's and l!nwin's form~lre are detailed and applic~tions g1ven. Or, aga.1n, the very full exposition of what is known of the conditions of strength of ' ' long

E N G I N E E R I N G. pillars" (chapter viii.) may be quoted . H odgkin­son 's, Gordon's, Rankine's form of Gordon's, Euler's, and Weyrauch's formulre are quoted and discussed at length ; various American formulre and Barker's formula are also quoted. Again, after developing at some length the mathematical theories and formulre resulting therefrom, the author fairly shows the discrepancies b etween experiments and practice. One glaring instance is that of earth pressure, wherein, after many pages of development of Rankine's and Coulomb's theories, it is admitted that the uncertainties are so great that, after all, mere empirical formu]re have t o be depended on. A different sor t of instance is that of wind-pressure, as to which it is shown, after a. discussion of numerous experiments (including the recent results from the Forth Bridge), that there is the greatest uncertainty as to the maximum wind pressure over large areas ; so that the legal regulations thereon must be accepted 1J1'0 tem. as the present rule on the subject. After reading all the uncertainties here fairly put forward as to th~ r eliability of many of the fundamental experimental data upon which engineering calculations are necessarily based, one is inclined t o think that very many structures stand in spite of-not in consequence of- the calcula­tions. Nevertheless, i t is only by such tentative search after improvement, not by disguising the uncertainties, that one can hope to improve the calculations of the future. Amongst the many good points of this book, some of its practical Tables are worth special n otice-e.g., weightAJ of roof coverings (page 67) ; weights of roof frames (page 68) ; weights of modern bridges (pages 682-687) ; loads for highway bridges (page 687) . Be­sides these, there are many other useful Tables. Lastly, the print and get-up of the book are good, and there is a fair index (four pages).

---T he Book of Delightful and Strange Designs, being One

H ttndred Facsimile I llustrations of the Art of the Japa­nese Stencil·Cutter. By ANDREW W. TUER, F.S.A. London : The Leadenhall Press, Limited, 50, Leaden· hall-street, E . C.

The title explains the subject matter, and one can easily appreciate that a. study of the illustrations must be valuable to those engaged in the printing of textile fabrics. The letterpress, which is in English, German, and French, tells us that the Japanese, who has naturally a fine sense of colour and form, is taught draughtsmanship and painting in the same manner as he is taught writing-h~ copies sets which are transcribed over and over again until the pupil can draw, with absolute ease, say, a chrysanthemum of conventional shape. At­tempts have been made to discard conventionality originally copied from the unimaginative Chinese ; but it gives freedom and quickness of manipulation, w hi eh, added to the harmonious colour and delicate gradation of t ones which are characteristic of Japanese work, produces pleasing results. The Japanese stencilling system was introduced by a dyer in the seventeenth century, and enables t he women to gratify their desire to have the kimono -their loose garment with wide open sleeves­elaborately decorated. The stenciller produces two effects from a single plate, an impression in colour- indigo blue is largely used- on a white ground, and a white impression on a coloured ground. The former is by direct impression, and the latter by the impression being printed on what is termed " resist,, a pigment or substance of w hi eh rice paste is the basis, that protects the fabrics from the acti~n ?f dres. A~ter the resist has been applied, the fabnc 1s d1pped 1n the dye vat, and the resist is cleare~ ~way by washing. In many cases, too, the work 1s Improved by hand touching with gradations of colours. . As to .the des~gns, it is impossible to convey any 1mpress10n ; an1mals, flowers, allegori­cal designs, and Japanese characters peppered over the surface, all corn bine to charm.

- --BOOKS RECEIVED.

Griffin's Elecflrical E ngineers' Price Book. Edited by H. J .. J?owsrNa. London : Charles Griffin and Co. L1m1ted. '

Spon's Tables and Memoranda for Engineers. By J. T. B URST. London: E. and F. N. Spon.

Elemcntar!l L essons, tutt~ Numerical Examples, in Practical llfechantcs and Machtne Design. By ROBERT GonooN Bt.AINE, with an introduction by Professor J OHN ;I?ERRY .. New edition, revised and enlarged. \Vi th 79 tllustrat10n~ .. London, Paris, and Melbourne : Cassell and Co., Ltmi ted. [Price 2s. 6d.]

The Miners' Hand-Book. Compiled by JOHN MILNE F.R.S. London : Crosby Lockwood and Co. '

A eronautics: A n A bridgment of A eronautical Specifica-

34I

tions Filed at the Patent Office from A . D. 1815 to 1891· By GRIFFITH .BREWER and PATRICK Y . ALEXl~OER· Illustrated. London: Taylor and Francis.

Drum Armatures and CorrvmutatMs ( Theory and Practice). By F. MARTEN WEYMOUTH. London: The E lectricialn Printing and Publishing Company, Limited.

W hlite's General and Commercial Directory of Sheffield, R c,therham, and all the Parishes, Townships, Villages, and Hamlets within a Radins of Seven Miles from Sheffiela, for 1893·94. Sheffield: William White. [Price 14s.]

M echanical Engineering Materials : T heir P1·o-pcrties and Treatment in Construction. By EDWARD C. R. MARKS, Assoc. M. Inst. C. E., M. I. Mech. E. Manchester : The Technical Publishing Company, Limited. [Price 1s. 6d.l

The Coal and M etal Miners' P ocket-Book of Principles, Rules. Formulce, and Tables. Scranton, Pa., U.S.A. : The Colliery Engineer Company.

P ocket-Book of Useful Formulre and Memoranda for Civil and M echanical Engineers. By Sir GUILFORD L. MoLESWORTH and R oBERT BRIDGES MotEswonTH, M. A. Twenty-third Edition. ReviRed and enlat:_ged. London: E. and F . and N. Spon ; New York: Spon and Chamberlain.

Tke Locom,otive Catechism. By ROBERT GRIMSTIA w. New York : Norman W. Henley and Co. ; London : E. and F. N. Spon.

NOTES. THE ATLANTI C-MEDITERRANEAN CANAL.

IT is under renewed contemplation to extend or supplement the old Languedoc canal-Canal du l\1:idi- built some 200 years ago, from Bordeaux at the Garonne River to the Mediterranean, by means of a new canal, which, if completed, will have the gre~test commercial and military importance. The proJected canal-Canal des Deux Mers as it has been appropriately named-is to b~ 27 ft. deep, 140 to 200 ft. broad, and some 300 miles long. There are to be 22 locks, built as double locks, 600 f t . long and 80 ft. broad. The canal will pro­ceed from the western outskirts of Bordeaux and , follow the left border of the Garonne for a distance of ~bout ~ft.y mi.les, without encountering any very senous d~fiiculttes. At Castet it passes the old canal, wh10h ther e enters the river and from this poi~t .it has to pass through a very difficult district, unt1l1t reaches the town of Castel :::>a.rrasin where the canal crosses the river. From there the canal follows the right border of the river as far as Toulouse, this section not offering engineering difficulties of any importance. It then crosses the Garonne for a second time, and the natural con­ditions will there allow of the building of two harbours, of which one will be reserved for naval purposes. Between Toulouse and N arbonne the direction of the canal is dependent upon the gradients, and having passed Naurouse, Castel­nandary, Moux, Montredon, and Narbonne the canal enters the Mediterranean at Gruissan. 'The promot~rs of the plan ask for a ninety-nine years' conceRswn, and some financial assistance from the State.

ELECTRIC PowE:a TRANSMISSION I N BELGIUM. . The small-arms manufactory at Herstal, in Bel­

gium, a couple of miles from Liege built by the "Fa.brique Nationale d'Armes de ' Guerre, " has been bu~lt on ~he most .approved principles, and fitted ~1~h a s1ngularl:y 1nteresting electric power transm1sswn. The bUildings are on a very large scale ; the w ~ole of the pre~i~es are heated by steam . a~d hghted .by electn01ty. The motive po~er 1s 1n the first 1nstance provided by a Corliss eng1n~ of 450 horae-~ower, making 66 revolutions per ~1nute, coupled duect to a dynamo which has a capa01ty of 2400 amperes with 125 volts. The elec­tric energy ~s distrib';lte~ by means of copper ea bles, and works, 1n the sm1ths shops, two dynamos of 250 amperes (e~ch of 37 horse-power capacity); in the wood-working ~hops, one dyna~o of 143 amperes (21 horse· power); 1n the large ma.ch1ne hall, six dynamos of 143 amperes (21 horse-power) each, and four dy­namos of. 110 amperes (16 horse-power) each; in the matr1x sh~p, one dy.nat;no of 50 amperes (8 horse-power); m the pohshmg shop, one dynamo of 143 amperes (21 horse-power) ; in the jacketing ~hop, one dy?amo of 110 amperes (16 h orse-power); 1n the cartr1dge factory, one dynamo of 143 am­peres (21 horse-power). The motor for the feed­mg pumps to the boilers is a dynamo of 65 am­peres (10. h orse-power). In the wood-drying de­p~rtment 1s a dyn~mo of 23 amperes (3 horse-power). Fmally, the ma.1n dynamo s upplies electricity for 15~ arc lamps and 520 incandescent lamps. The ~aily production is 150 rifles, 20,000 cartridge Jackets, ~nd th.e sam~ numb.er of projectil~s. There 1s. a spe01al rail way hne, w1th branches to all the d1fferent departments of the works, which connects

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the fa~tory with t~e Berstal station. The buildings compnse a hall with motors, a boiler-house wood­dl1'ing appliances, a . hall with wood-working ma­chines, a large hall with the machines for the metal work, a workshop for testing instruments, a work­shop ~or the manufacture of matrices, polishing and bro~zmg sh.ops,, a hall for the manufacture of jacket tubing, smi~hs shops, a. hall for testing barrels and mechanisms, a shooting range, a testing-room for the finished arms, a cartridge factory, and finally a number of large offices and store-rooms.

THE ATLANTIC RECORD. Although anticipated, because of their great

power, the performances of the two Cunard steamers in their last Transatlantic passages are most credit­able to the designers and builders, for the one steamer beat all previous records, and the other in her first run at sea, maintained a speed not approached by any steamer on a maiden voyage. The former, the Campania, in the homeward run, accomplished the trip between racing points­Sandy Hook and Daunt's Rock-in 5 days 14 hours 55 minutes, having throughout that time maintained ~ mean ~peed of 20.94 knots. While accomplished In less time than her former best run- in May last, when 5 days 17 hours 27 minutes were needed for the sea run-the voyage does not indicate the same high mean rate of speed, for the May run was on the southern and longer route, the mean then being 21.3 knots, the best on any sea run yet made. T~e pe~formance, however, is satisfactory, and promises still better results ; and here it may be interesting to glance at the progress since the former Cunard steamers, the U mbria and Etruria, held the record before the ad vent of the New York and Paris:

Homeward. dye. b. mn. knots.

1888 . . Umbria . . . . 6 3 12 = 19.11 1892 . . New York . . 6 H) 67 = 20.IO 1993 . . Campania . . 6 14 24 = 20.9!

It must not be assumed that the U mbria's record was not broken until 1892, for not only the New York but the Paris, Majestic, and Teutonic were, in the interval, by successive efforts, bringing it down by minutes. The New York passage given shows rather the improvement made jointly by the other steamers between 1888 and 1892, while the Campania's run indicates what the Cunard Company have again done towards lessening the time needed for the voyage. The best speed of the Campania, 21.3 knots, is over two nautical miles per hour better than that of the Umbria, but there is every likelihood of it being more, while the Lucania may even eclipse her companion. In her first run to New York she completed the sea voyage in 5 days 14 hours 50 minutes, while her time from Liverpool, including stoppage at Queenstown, was 6 days 4 hours 10 minutes. The daily runs were 460, 490, 498, 516, 523, with284 miles to com­plete the run, and the improving tendency promises a record run home next week, as in the case of the Campania, since it indicates complete satisfaction on the part of the designer, Mr. Andrew Laing, who was attending the machinery, and who would not have opened out his engines unless everything was favourable.

THE REsisTANCE oF METALS AT Low TEMPERATURE . .

E N G I N E E RI N G. scale. The diameter of the wire used in the ex­periments was ascertained by projecting with a microscope its shadow on the ecreen at the same time as the shadow of a standard steel gauge. The magnification used was about 300, and the diameters of the wire and the stan­dard were taken to be proportional to the breadths of their shadows. The accuracy of the method was proved to be very great, as the results thus obtained, compared with those obtained for the same wire by the density method, only differed by one part. in 2600. The range of the obsena­tions made extended from about 200 deg. Cent. above zero to more than 200 deg. below, the lowest temperatures being obtained by the evaporation of liquid oxygen, under about 14 millimetres of pres­sure, and many litres of this substance were used in the course of the experiments. For intermediate low temperatures liquid ethylene and C02 in ether were used. The resistance curves of the pure metals are nearly straight, though some are con­cave upwards and others downwards, the magnetic metals showing the most curvature. Some of the lines cross each other at low temperatures, and thus copper, which is ordinarily a worse conductor than silver, is a better one below - 100 deg. Cent. The sonorous metals, such as silver, aluminium, gold, and copper, make the best conductors. The experiments with alloys are remarkable, mainly in showing the great effect on the resistance of small impurities. Thus the resistance of copper contain­ing 3 per cent. of aluminium is enormously greater than either that of pure copper or pure aluminium. At -200 deg. Cent., indeed, its resistance is about 36 times as great.

MISCELLANEA. THE report of Mr. Ackerman, auditor of the World's

Fair, for the month of August shows a loss of 12,000,000 dols. since the Fair was opened. The additional receipts, owing to a.n increase in the number of visitors, make the report for the month of September a. more favourable one.

It is proposed to make an important rail way extension through Bechuana.land, the work to be done by a subsi­dised company, to whom the Government of the colony are prepared to a. ward a land grant of 6000 square miles, and a subsidy of 10,000l. a year, to be increased to 20,000Z. a year when the rail way 1s extended to Palapye. This subsidy is oo be for a per10d of ten years.

At Dosjobro, on the railway between Londscrona and Kjellinge, a large manufactory for smokeless powder is about to be erected for account of a substantial company. The manufacture will comprise both cotton powder and smokeless powder, and it is confidently claimed that this smokeless powder will be the best hitherto offered. It is expected that the new factory will be in full swing next spring, and a large demand from abroad for its powder is reckoned upon.

The anticipation of the Lords of the Admiralty with regard to the repair and internal reconstruction of the disabled ship Howe, now in dock at Chatham, will un­doubtedly be realised. The work is already so far advanced th9.t she will be able to be out of dock before their lordships arrive on their annual tour of inspection. In fact, the officials expect to remove her this week, and there is every probability that she will be ready for sea again in another month's time. The total cost of the repairs at Chatham Dockyard will be about 40,000l.

In a recent number of the Philosophical Maga­:,ine, Professors Dewar and Flaming publish the results of some further experiments upon the re­eista.nce of metals and alloys at very low tempera­tures. It will be remembered that their prelimi­nary observations led to the conclusion that in the case of all pure metals the resistance vanished at the absolute ztro, and this conclusion is confirmed by their more recent experiments. It is only in the case of perfectly pure metals that the resistance gives indications of vanishing at this point, and comparatively small traces of impurities seriously affect the results recorded, hence extraordinary care was exercised in o bta.ining the various metals in as pure a state as possible. One of t~e difficulties experienced was the want of a satis­factory method of measuring the low tempera­tures dealt with, which in cases sank consider­ably below - 200 deg. Cent. Finally,, howev~r, a platinum thermometer_ was used, w~Ic~ consisted of a wire of pure platmum, the variatiOns of the resistance of which formed a measure of the tem­perature. Its indications proved to be constant, and were certainly very nearly correct, though at some future time it is proposed to make an accura~e comparison between it and the true thermo· dynamic

The St. Pancras Vestry, acting_ upon the advice of their electrical engineer, Professor Robinson, have autho­rised extensions of their electric lighting installation by the addition of three 90-unit engmes and dynamos and three boilers a.t the existing Regent's Park station, with another sub-station in Regent'9 Park-road. These exten­sions will enable a further 5000 16 candle·power lamps installed to be served. The vestry have also decided to construct a second electric lighting station in combination with a refuse destructor in King's-road, which will still further increase the electric lighting of the district.

According to Professor D. S. J a.cobus, for a given tank capacity and maximum pressure, from four to five times as much power can be stored by liquid carbonic acid gas as by compressed air. If the gases are heated to 383.5 deg. Fahr. before use, a. carbonic acid compound engine would require 21.6 lb. of gas, and an air engine 14.3 lb. of air. If the exhaust of the carbonic acid gas engine is con­densed, the theoretical efficiency will be the same as that of any other heat engine working through the same range of temperature. Tbe working pressures will, however, be very high, thus giving rise to practical difficulties.

The latest long-distance electric power transmission plant in Switzerland is that recently opened at Frin­villier, the wat~r power at that place, which averages about 350 horse-power, being transmitted to a paper factory at Biberist, a diatance of nearly 18 miles. At both the generating and receiving stati9ns th~re are two continuous current dynamos connected m ser1es. Each generator supplies a current of 43 amperes at 3000 volts, so that the potential o.f the line is 6000 volts~ The .ma~n is overhea.<i, and conslSts of two copper w1res .28 m. m diameter carried on porcelain insulators fixed on poles 30 ft. high.

[SEPT. IS, I893· The traffic receipts for the week endip_g September 3 on

33 of the principal lines of the United Kingdom amounted to 1,515,44ll., which, having been earned on 18,388 miles, gave a.n average of 82l. 8s. per mile. For -he corresponding week in 1892 the receipts of the same lines amounted to 1,650,823l., with 18,199 miles open giving an average of 90l. 14s. There was thus a decreas~ of 135,382l. in the receipts, an increase of 189 in the mileage, and a. decrease of 8l. 6s. in the weekly receipts per mile. The aggregate receipts for nine weeks to date amounted on the same 33 lines to 14,330,863l., in com­parison with 15,126,139l. for the corresponding period last year ; decrease, 795,276l.

Trials of the Heilmann electric locomoti,·e have recently been made at Havre, with, it is stated, satisfactory results, at least in so far as the ease and smoothness of running are concerned. This locomotive-recently very fully described in . our p~ges -consists in .Principle . of a steam engme dn vm~ a dynamo wh1ch supphos current to motors wh1ch finally effect the propul­sion. The engine was tried on a stretch of line about li miles long, which contained curves of 250ft. ra.<iius and stiff slopes. The shortness of the run pre· vented any high speed being attained, but at speeds of from 20 to 25 miles an hour the running of the locomo­tive was remarkable. In shop trials the ma-chinery has been run at a speed corresponding to 68 miles per hour. Trials of the combined efficiency of the engine dynamo and motors were made on the ret1un of the locomotive to the shops, but the results of these have not yeb been published .

According tQ the Scientific A11U1'ican, dynamite has been used in securing a passage over an ocean bar at Brunswick, Georgia. The original passage through the bar had a. depth of 14 ft. at mean low water, and of 20ft. at high tide, but this was stopped by a wreck. The next best passage, giving a. waterway 11~ ft. deep at low tide, was also stopped by a. wreck a couple of years later. Pending an api?ropriation from Congress, which could not be obtained w1thin a reasonable time, it was decided to endeavour to clear a passage by exploding dynamite in the ba.r, and a new straight channel showing a depth of 13.3 ft. ab low tide was quickly secured. So successful has the method proved, that the operations are being con­tinued with a view to obtaining a depth of 16.3 fb. at low tide. The charges now used weigh 200 lb. each, and up to the present about 60,000 lb. of the explollive have been expended.

At a lecture delivered before the Electrical Congress at the World's Fair, Chicago, Mr. Tesla described a form of: generator by means of which alternating currents of perfectly definite frequency could be produced. The apparatus consists essentially of a very short cylinder fitted with piston and valves, and a. spring to resist the motion of the piston-rod. The piston is set in oscillation by compressed air, supplied at a. pressure of 60 lb. per square mch. Tbe valves are adjusted to produce a power­ful cushion effect in the cylinder at each stroke. This compression reaches as much as 16 tons, whilst the weight of the piston and its attachments is only 20 lb. An ex­ceedingly rapid vibration can thus be obtained, such as a rate of as much as 5000 to 10,000 oscillations per second if desired. The piston being connected to wires crossing a magnetic field, these wires are also set in vibration and a current set up in them. The apparatus is said to be both light and fairly efficient for the power developed.

Amongst the most interesting papers brought before the World's Fair Electrical Congress at Chicago, was one by ProfessorS. P. Thompson on ocean telephony. With the cables as at present constructed, ocean telephony over any considerable distance is utterlr_ impracticable owing to the retardation of the si~als. Even rapid automatic sending is out of the quest10n. This retardation of the signals is due to the electrostatic capacity of the cable, which is distributed uniformly along the whole length of the line, and cannot be corrected bycoiiJpensa.tingdevices fitted at the ends of tbe cable. A distributed remedy is wanted, and this P rofessor Thompson proposes to obtain by using electro-magnetic induction to correct the retarding effects of the electrostatic capacity of the cable. This he does by constructing the cable on a three-wire system, two of which are to form the complete circuit, whilst the third constitutes an inductive shunt connecting these two wires at intervals. Such a cable would, of course, cost consider­ably more to construct than an ordinary cable, but Professor Thompson claims that it would do ten times as much work.

The new first-class steel gunboat Speedy, 2, was de­livered to the Medway Steam Reserve authorities at SheernePs on Tuesday, on her arrival from the works of Messrs. Thornycroft, of Chiswick, who built her for the Government under the provieions of the Naval Defence Act. It will be remembered that the dimensions of this boat were such that she could only just get through some of the bridges, and her successful passage down the river must be a. source of congratulation to her builders. The ~peedy is of the same dimensions as the gunboats of the Gossamer type, but has been fitted with engines of greater power. She has a length of 230ft., a breadth of 27 ft., and a dieplacement of 810 tons. Her engines have been designed to indicate 4500 horse-power under forced draught- 1000 horse-power in excess of her sister ships -and it is anticipated she will attain a speed of 20.25 knots. Working under natural draught, the maximum power of her engines is estimated at 2500 horse-power, with a speed of 17.75 knota. The armament of the Speedy is to consist of two 4. 7-in. and four 3-pounder quick­firing guns, together with five tubes for discharging tor· pedoes, one in the bows and two on either side amidships. The total cost of the Speedy, when fully equipped and ready for commission, is estimated at 62,379l.

E N G I N E E R I N G. 343

REID'S AUTOMATIC STEAM-REDUCING VALVE.

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Fig. 1.

TnE s team- reduciug valve illustrated above is now being introduced by Messrs. vVm. Reid and Co., of 112, Fenchnrch-s treet, London, E. C. A general view of the vah·e is shown in Fig. 1, whilst the details of its construciion will easily be understood from Figs. 2 and 3. Referring to these figures, it will be seen that the high-preusure steam is admitted at A, and getting below the valve B tends to keep t his closed. At the same t ime a portion of t he st eam also passes up the bye-pass E to a small double-beat valve F. Raising this, it passes down and presses on the piston D, which, as will be seen, is fixed to the spindle of t he valve B. This piston is a very loose fit, and so cannot gain. As it is of larger diamet er than the valve B, it opens the latter against the steam pressure, thus admitting steam to the low-pressure side of the valve. F rom this low-pressure side a pipe Lis con­nected by a syphon to a water chamber M, closed at the top by a piston resting on a diaphragm of derma­tine N. lf the pressure on t he low-pressure side of the valve increases beyond that for which the spring is set, t he piston is raised by the pressure, ancl by means of the lever I closes t he small double-beat valve F, which done, the main valve of course closes automati­cally. By means of the screw and fly nut shown to the right of this lever, the double-beat valve eau be kept closed, under which conditions the vah re acts as an ordinary stop valve. It is claimed that t his valve maintains a very constant pressure on the low-pressure side, even when that on the high-pressure side varies through wide ranges.

INDUSTRIAL NOTES. TuE great coal dispute is still the one absorbing

topic in t he industrial world. It colours and affects all other questions, and exerts an influence upon nearly all trades. In some districts the excitement has quieted down, and large numbers of men have resumed work, as, for example, in 'outh Wales ; but in some other districts t he excitement has become intensified, and, unfortunately, deplorable rioting and outrage have taken place. So violent has been the attitude and the conduct of the men on strike in several districts- notably Leeds, Pentefract, Dews­bury, Featherstone, and some other places- that the military have been called into requisition, conflicts have taken place, and some ha Ye been killed and many injured in the collisions between the strikers and t he civil and military forces. Everybody must deplore these conflicts. The fact that they have taken place is proof that the presence of the military was necessary. In places where they were absent attacks were made upon workmen, houses were wrecked, offices were attacked and wrecked, the books were t orn and set on fire, t he workings were injured by wagons and other things being thrown down the shafts, the gear was cut and otherwise damaged, and stacks of coal were set ablaze in some districts. It is impossible t o defend such outrage and violence. They recoil upon the men and injure their cause. 11oreover, such conduct helps t o justify recourse being had to the military in cases of labour disputes. During the last quarter of a century, notwithstanding serious disputes in many districts, the presence of the military forces has been infrequent,

Ftg.2.

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and the policy of resorting t o them in assumed cases of need has been dying out. Under the new 1·egime there has been a return to the old, bad policy of mili­tary interference, and the blame must rest upon those who rendered such a policy desirable. The old leaders have been striving to avoid such conflicts, and they had well-nigh succeeded. A precedent has been estab­lished for the calling out of the forces of t he Crown , and t he local authorities will have t o provide the means for payment of all the costs.

In the South W ales and Monmouthshire districts t he men haYe been resuming work, the strike having practically collapsed at most of the collieries. One singular fact has contributed to this result - namely, the influx of a certain proportion of

cotch miners to t ake the places of those on strike. The Federation of Miners has not prevented this ; possibly they could not prevent it. Yet the federation is supposed to include the Scotch miners. The weak­ness of federation is that i t includes badly organised, as well as effectively organised, districts. If st renuous effor ts were made to strengthen the local organisations all along the line, the federation would be all-power­ful ; but a federation of weak unions is not really strong. Alt hough the ' Velsh miners generally have resumed work, the stoppage that has taken place, the scarcity and dearness of fuel, and the feeling of uncertainty that exists, have all combined to affect other industries, and in numerous cases have so ope­rated as to close t he works. The stoppage of t he tin­plate works has thrown idle some 5000 persons. The stoppage, or partial stoppage, of the iron and steel works has thrown out of work many t housands more. The shipping trade has ueen so far paralysed as to necessitate the docking of numerous vessels at all the ports, so that the sailors, firemen, dockers, and others are out of work. The depression in trade, which has caused the coal crisis, has now deepened into almost stagnation, which stagnation will .still further depress the coalmining industries.

The coal crisis in Durham and Northumberland may be said to be over. The men are at work, and pits which have been idle or only partially employed are busy once again. But the two counties are still more or less in a state of ferment. The federation agents are scouring the colliery districts, holding meetings and conferences, and they report enthusiastic recep­tions and gatherings in all places visited, and cordial resolution !!! of support. The federation men are strengthened in their policy uy reason of the fact that Durham and Northumberland coal is being sent into the strike districts, and thus the miners in these counties are helping to defeat their comrades elsewhere. Such competition, however, is inevitable.

In the Staffordshire districts t he impolicy of the general strike has found vent in a determina­tion to resume work at all pits where the reduction is not insisted upon. But a new difficulty has arisen. On the men declaring their willingness to re­sume work, the coalowners declared in favour of the policy of the federated owners, and asked for a 25 per cent. reduction, which they had not intimated before. This is exactly the policy which was foreseen, and was pointed out to the men. H aving struck without reason, they are asked to submit to t he full reduction demanded in other districts. This counterblast policy of the mineowners is caus~g. a good deal of anxiet y, and they are asked not to ms1st upon the reduction, at

Fig. 3 .

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least for the present. S taffordshire will now become a difficul ty when the conference meets.

In the Forest of Dean, on a ballot as to continuing at work at the pits not already s topped, the men voted for continuing at work, the "noes" numbering only 98. At a later date there were rumours of a general settle­ment being negotiated on the basis of 7i per cent. reduction, in three instalments of 2~ per cent. each on October 1, November 1, and December 1. The fact is, the Forest of Dean was all right so long as the men were supported by the federation; but as soon as the general strike took place, the resources failed, and the men were reduced to great straits. Poverty did the rest.

In the Lancashire districts the men are being assisted very generously by large donations from outsiders. The contributions are not exactly t o the strike funds, but to relieve the families in their distress. It is understood that the balloting in Lancashire will be largely in favour of resis ting the proposed reduction to the last. But perhaps they will not be so strong against arbitration. Upon this subject the agents have been reticent.

In the Nottinghamshire districts there have been scenes of violence. In one case the men on strike actually went down the pits to get out the" blacklegs." At some other places there were disturbances. The men at most of the pits declare that they will remain out for months rather than submit to the reduction. The local tradesl?eople and the religious congregations are making collectiOns in support of the fam ilies, or, at least, to afford some relief. Only one colliery replied in the affirmative to an offer of the men to return to work at the old rates ; t he others either refused or sent no reply to the let ter of the miners' officials.

In the Scotch district s the contest is virtually over. The Fife and C!ackmannan men have accepted 121 per cent. advance, in lieu of the 25 per cent. asked, and have resumed work. In other districts, in the 'Vest of Scotland particularly, the men have also resumed work on t he basis of a compromise. In the Lothians there is still some show of fight, but it is expect ed t hat there also a settlement will be effected. In the districts of Edinburgh and H addington the compromise was agreed to before the expiry of the notices so that work was not interfered with. Altogether the dispute may be said to be practically over in Scot land and with it also the stoppage of other large works. '

In Der~yshire ~here is acute distre~s, but the public are affordmg asststance, and the children are being fed. At two collieries the men were offered work on the old terms, but this was refused by a large majority of the men.

I? the Yorkshire distdcts there is the greatest exCitement and the most intense irritation. The dis­turbances have been r iotous and violent, and the leaders haYe been compelled to denounce them. But the men are out of hand for the most part . They are suffering acute distress. They can see coal brought from Durham and other places. They are the back ­bone ~f t~,e federation, ~nd in a se~se are '' fighting for dear hfe. A collapse m Y orkshl.l'e means the entire oollapse of the struggle.

The state of trade, as indicated by the report of the :Amalgamat~d So~iety of Engineers . for September, 1s very aenous m deed. Never, smce the nnion ~as formed on its present. basis, have so many of 1ta members been 1n rece1pt of donation benefit

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344 except in the months of ~larch, April, and :May in that most disastrous year , 1879. The total number on donation benefit was 6074 ; on the sick list, 1739 ; and in receipt of superannuation allowance, 2358, or an aggregate of 10,171 out of 72,892 members. The cost of maintenance per month was 4327l., or 1s. 5d. per member per week, exclusive of over 8 l . expended from the contingent fund. The cause is '' the ab­normally bad state of trade, accentuated no doubt by the lamentable struggle in the coal industry." It is p ointed out that var ious other industries are affected di~astrously by the coal strike, most of which react with direful effect upon the engineer­ing branches. \Yith all this depression, empha­sised by the miners ' dispute, the engineers express genuine and hearty sympathy with the miners in their struggle. The conclusion drawn is that Parlia­ment must do something, and that more labour repre­sentatives shall be returned, with the view of prevent­ing such catastrophes in the future. How "to prevent the recurrence of such barbarous methods of starving men into subjection " is hinted at rather than ex­plained, or even indicated. The fixiog of wages by Act of Parliament cannot be intended, and the miners, so far, have resented arbitration. Trade has declined seriously in America and Canada, the increase of men out of work and on t he funds is more than threefold. In Australia it is no better than it was, even if as good. The outlook is not cheering anywhere.

The report of the Ironfounders shows an increase of 124 on donation benefit, but a decrease of ten on dispute allowance. The number on donation, sick, super­annua tion, and all other benefits was 2610; of these only seven were in receipt of dispute pay. In all other cases there was an increase on the funds as compared with last month. The weekly outlay on all t he benefits was 849l. per week, or Is. 1 ~d . per member per week. The total number of memberg is 15,036, and the balance in hand over 39,69ll. T he details as regards the state of trade are not encouraging. I n no d istrict is it'' good," and t he intensity of the slackness has increased. The reports from America state that a large number of men are out of work , and those recently emigrating to the States from this coun try have failed to obt ain work. The dispute at Barrow has been settled. The failure of t.he federation instituted in 1891 at New...:astle, seems to have occurred by reason of a dispute in two branches of trade. But some of the causes of that disput e appear to be removed, and, t herefore, possibly the Ironfounders will again join the federation. But the Engineers also broke away, and consequently the body as originally constituted has been weakened to that extent.

The report of the Ironmoulders of Scotland. is not quite so discouraging as that of some other um~ns. It says: " While we a re not able to speak of .a.tune. of good trade, stiU, when we compare O?r pos1t10n w1th that of the other iron trades, there 1s no reason for being alarmed." The figures show that ther~ is an increase of men at work of 168 as compared w1th last m onth. The total number of members in employment is greater t han at any period this year except on the 18th of March last. The out -of-work payments have consequently been less.

- --The report of the Amalgamated Carpenters and

Joiners for September shows that there are 40,679 members of whom only 971 were returned as unem­ployed a'nd on benefit. This is most encouraging, amid so many signs of a contrary character. For mon ths past the m embers of this ut~i~n and others ~n the build ing trades have been ge.mu~g advances. 1n wages, and, in some places, a reductiOn of workmg hours also.

The cotton spinners of Lancashire, the united me!ll­bership of whose union is 16,677 persons, ar~ bus1er than for some time past, except that there 1s some trouble as to fuel. Still, very fe'Y .are on the fun~s, and the cases of dispute are very tnfimg. The associa­tion is slowly but surely recovering from t he severe s train of the late strike.

The engineering branches of trade in the Lancas~ire districts manifest li ttle change, except that. there 1s a greater difficulty in ob~aining fuel. Th1s tends t o curtail op erations, and m some cases has led ~o sus­pensions or to short. tim.e. The hea-vy statiOnary engine builders are st1ll fa1rly busy, and are n.ot badly off for orders. But, generally , the orders 1~ other branches come in slowly, and are not of ~ons1derable weight, while those on ~and are not suffi~1ent to keep the works in f ull operatwn for a long p en od.

- --Amid all the discouragements 'Volverh.ampton seems

to be on the winning side just n~w. W1th a toler~ble amount of business on hand pnor to the coal stnke,

E N G I N E E R I N G. new orders appear to have come in from outside dis­tricts at a satisfactory rate, both for crude a nd finished iron. !\I ost of t he works are tolerably busy, as the supply of fuel has not been materially diminished, owing to the sliding scale arrangements in force. The price of fuel is higher, and consequently quotations are in most cases enhanced for all k inds of material. But the outlook is not very encouraging after all, for the increased demand, here, as in Scotland, is not due to a larger aggregate trade, but mainly t o i ts being diver ted into other channels where the coal strike is not operating.

ON THE MIDDLESBROUGH SALT INDUSTRY.*

By :Mr. RICHARD GRIGG, of :Middlesbrough. Communicated through Mr. E . vVINDSOR RrcBARDSt

Vice-President. · (Concluded from page 316.)

Drilling T ools. - The tools used (Fig. 4) consist of a chisel or "bit " B, stem A, 32 ft. loog, jars J, sinker barK, 10 fb. long, and rope socket S. These are called a '' string of tools," and are altogether about 60 ft. long. They are con­nected by taper screw·joints, one of whioh is shown in Fig. 5. This joint gives great strength; a. few turns bring it home, and a.n arrangement of levers screws it up so tightly that it does not often unscrew in use, notwith­standing the vibration to which incessant blows subject the tools. The jars J, Fig. 4, are a pair of links having a vertical play of 9 in. ; they are for the purpose of freeing the tools if jammed or fastened in any way, by enabling the driller to give a succession of upward blows which loosen the tools, no matter how firmly they may be held.

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The temper screw Tis a.n ingenious contrivance for attach­ing the cable C to th~ walking beam, and enables the driller to slacken or t1gbten the cable, and to cause the tools to revolve when drilling. In Fig. 6 is shown a section of the sand pump. W~at can ~e effec~ed b.Y t~ese appliances in the bands of a htghly sk1lled dr1ller 1s l1ttle short of the marvellous. H oles have been drilled nearly a mile in depth, perfectly. straigh t and perfectly ro~nd. In Austria, indeed, a hole 1s reported to have be~n dr1lled to a depth of over 6000 ft ., but the deepest Amer10an hole, at Pittsburg, is 4618 fb.

A ccidents. - Th e driller 's only knowledge ? f th.e tools while in the bore hole is through the c:a.ble, whtch ~ts b.and never leaves while drilling. Extraordmary comphcat10ns

* Paper read before the Institution of Meohe.nical Engineers.

sometimes arise; a faulty joint may unscrew, or a tool break, the upper end of which may be driven quite aside from the line of the hole. In the effort to recover it, other tools may be lost, until :perhaps a ton of iron blocks the well. On all this a "run m " may occur, burying the whole possibly 100ft. deep and at 1000 ft . or more below the surface. ' Vith patient and wonderful skill the bole is cleaned out, t ool a fter tool withdrawn, and the cause of the mischief straightened up and got out. Or the hole may collapse, burying the tools, and "sticking" the jars. Then the cable is cut at the lowest accessible point ; the hole is lined with t ubes, which follow the tools down; the burifld tools are got hold of, and by the action of jars are drawn out inch by inch. ::>ometime~, though rarely, holes have to be abandoned as the result of such accidents.

Sinhng and Lining of Middlesbrough Wells.-The diameter of the ~Iiddlesbrough wells is 8 in. After con­struction of the rig, the first process is to drive down 10·in. tubes, furnished with a strong shoe, through the surface clay, sand, gravel, &c., to a depth of from 80 ft. to 130 fb., till the sandstone is reached, for which purpose the rig is temporarily transformed into a clumsy-lookio~ but efficient pile·driver. After this the drilling begms. Thicknesses of from 300 fb. to 700ft. of water-bearing red sandstone are passed through, then red marl down to the white stone overlying the salt, then r~tten marl, and then the ealt bed; the drilling stops at the bottom of the salt. The 8-io. hole is then lined, either throughout from top to bottom, or else only through the b<:>ttom 200 ft., ~vhicb. i3 the region of falls _of marl. For th1s bo~tol? port~on ~·to . tube is used of 5~ m. bore. If the bole ts hoed b1ghe~ up the tubes are i in. thick and 6~ in. bore; at the co.uphngs they are then 7~ in. in diameter outside. In F1g. 7 1s shown a section of a brine well at Port Clarence. The tubes are perforated at A to permit ingress of water from the sandstone; and again at Bat the top of the salt bed, to let this water flow over the rock salt. They are also perforated at C at the bottom of the bed to permit ingr~ss of brine to the pump tubes D. The latter are ! m. thick and 4 in. bore from the surface down to 250 ft. depth, as far as the pump barrel E ; and thence 3~ in. bore below, down to the bottom, where tbe.y are perforated at F through a length of 4ft. to adro1t the brine. The pump is ~~ in. bore with 4 ft. stroke, is connected by iron rods to the walking beam, and pro­vided with a stuffing-box and brin~ outl~t at. surface.

P umping of Brine.-As soon as the well 1s bored, the pump tubes in pla~e, and the PU'f!lP rods attached., the small cavity occupied by the woll1n the salt bed w1ll . be filled with fully saturated brine; and the pump bemg started at the normal speed of twel ve to fourteen strokes per minute, the first d1scharge will be water, until the brine, passing up the suction pipe, appears in a muddy stream. It quickly clears, and as quickly becomes weak, through the exhaustion of the contents of the cavity, which is as yet small. Water is found in the sandstone within 20ft. of the surface, and, standing in the annular space, balances the column of brine so far as the difference io their specific gravity permits. A column of water 1200 ft. supports one of brtoe having a heig.ht of nea~ly 1000 ft.; the pump therefore has really to hft the brme only about 200ft. A new well, if working properly, in­creases daily in yield as the cavi ty in the salt bed becomes enlarged through the removal of salt and thereby presents a larger area of salt surface for solution. Owing to its greater specific gravity, the strongest brine is always found at the bottom of the well ; and if the pumping is considerable, brine of decreasing strength, or even fresh water, will occupy the upper part of the cavity. The solvent power of the water, of course, steadily becomes less as full saturation is approached, until it ceases alto­gether. T he resulb is that more salt is removed from the top of the bed than from lower down ; and thus the shape of the cavity should become that of a fiat funnel or shallow inverted cone, depending somewhat on bow the well is pumped, whether so fast as to yield weak brine or not. This has proved to be what really happens. Wells bored ab from 40 to 60 yards distance from old wells have found the cavity already formed and of a depth which, considered in relation to the salt removed, con­fi rmed this theory. In another case a fall of rock broke the well tubes. The fallen stone was drilled through, and fresh tubes inserted to the cavity beneath it. A fter the pumping had been resumed, the stone slipped down H ft., breaking the tubes again. lb was again pierced and the process repeated until the stone was lowered 6ft., showing that solution of the supporting side of the funnel had allowed the stone to slip down. The pumper confessed defeat, and now pumps from the top of the atone ; but be bides his t ime in the l>elief that scHmce will eventually provide an explosive which shall oreate a sufficient disturbance in the very heart and vitals of that obdurate ston~. Last, but perhaps not least, an abandoned cavity at Nancy having been pumped dry was entered, and found to be of the shape m~ica~ecl. I~ is obvious that the funnel shape of the caVIty ts an Im­portant matter, and an unfortunate one, for pumping, because it removes support from the neighbourhood of the tubes where it is most needed; and heavy falls of marl and rock ~ccur, which break the tubes, no matter how strong they are, althoughlightfalls maybe resisted, and areknown only by the discoloration of the brine; i·in . ateel lining tubes are used; and with this thicknes3 the worst bent and broken tubes after a fall have, with great strain and diffi­culty, been so far stra.i.ghtened as .to be got o~t by~ steady pull with two 50 ton JS.CkS j but 1D a well Wlth r·tn. steel tubes the bend wa~ such that withdrawal was impossible, and the well bad to be abandoned. After a fall, weak brine or water is obtained ; the in valuable rig is detached from the pumping gear, and is used to withdraw the tubes above the break, generally leaving from 60 ft. to 100 ft.

SEPT. 15, 1893·] in the well. The tools are then strung up, and a.n attempt is made to drill down b~ the side of the old tubes and to pub fresh tub?s in. 'Ibis operation is often attended with endle R perplexities and difficulttes ; nevertheless wells h:we been repaired in this way many t imes. Tools are often lost in this cleaning-out process; in one instance a string of tool!i, cable and all, went down a cavi ty, and remain there; and yet the well is work ing still. 'l'he number of wells which have been pumped and afterwards abandoned for various reasons is beheved not to exceed ten.

Y ield and St,·ength of Brine. - Well3 vary considerably, b )th in yield and in strength of brine. This may be due to the existence of earthy matter, which may cover the salt with a coating of mud, and thus check solution, or it may be due to defect ive couplings or tubesJ which would psrmit dilution of the brine by the entrance of water into t he pump tubes from the annular space surrounding them. A well pumping ten hours per day, and yielding 200 tons of salt in brine per week, would be considered doing good work.

Sur face S ulJs idence.- The question of possible subsidence of the surface has naturally excited a. good deal of interest in :Middlesbrough. In Cheshire the flooding of old rock­salt mines and the subsequent pumping, as well as the removal of the mineral from the course of the "runs, u

have led to serious subsidence and to extraordinary behaviour on the part of houses, roads, streams, and bridges ; but at ~Iiddlesbrough the depth of the salt bP,d is so much grea.t~r, and the character of the strata so d ifferent, that it does not follow the same results will ocour. It is believed that great arches will form them· selves over the funnel-shaped cavities in the rock salt, from point to point of support; or that the interstices left by broken masses of fallen rook will equal the bulk of salt removed, and will so support the S"Urface. On the other hand, it is the opinion of experienced persons in Cheshire that subsidence will ultimately take place ; and t o this result the experience of mining engineera seems to point. All that can so far be said with certainty is that no sign of subsidence has yeb shown itself.

F iltration and Evaporation of B rine.-On reaching the surface the brine is conveyed in pi pes to a. filter bed, con­structed on the pattern of ordinn.ry water works sand filter . These act well, and pass a. clear bright brine to the r~servoir, whence it is pumped to the pans for evapo­ration. Notwithstanding the fact that endless efforts have been made to iruprove the method of evaporation, and that a. large number of plans have been devised for this purpose, yet to-day, just a.s 1800 years ago, open pans are used, having beat passed under them. 'l'be only d ifference is that the R omans used pans made of lead and not more than a. few feet square, while to-day much larger pans made of steel and iron are employed. The ordinary size of common salt-pans is 60 ft. by 24 ft. by 1! ft. deep, as shown in Figs. 8 and 9. The pans are set

.Ft.g. 8. Hvrdle Salt Pan Hvrd/~

upon longitudinal walls, which form flues to convey the products of combustion from fireplaces at one end of the pan to the chimney at the other. As the water is driven off by evaporation, the Ealt crystals form on the surface of the brine, and gradually sink to the bottom ; thE'y are drawn by rakes to the side of the pan, a nd lifted out and deposited npon decks or "hurdles," from which the adhering brine drains back into the pans.

Salt.-Fine sa.lt is obtained from salt which is boiled, the fineness of grain depending upon the temperature a.t which the brine is evaporated; the higher the tempera· ture, the finer the grain ; the lower the temperature, the larger the crystals. Block salt or "squares, are obtained bv drawing off boiled salt a.t short intervals into moulds ; the squares are afterwards dried by surplus beat from the pans. Table and dairy salt are obtained by grinding squares. Common salt is drawn every other day from brine kept at about 190 deg. Fa.hr. ; fishery is drawn every seven or fourteen days, according to grain, from brine kept a.t about 100 dig. All these processes are very simple, yet the salt manufacturer is not without his diffi­culties and perplexities ; and a certain degree of skill and good management is essential to the successful prosecu­tion of thiCJ, as of every other industry.

CoKE I N G&RMANY.-The German coke syndicate decided to reduce production in AugYst to the extent of 25 per cent. Tbe reduction in the production in July "as a.t the rate of 30 per cent.

E N G I N E E R I N G.

THE MANUFACTURE AND TESTING OF PORTLAND CEMENT.*

P ORTLAND cement consists of a. chemical combination of lime, silica, and a.lumina with iron in certain well de­fined proportion~, together with alkalies, magnesia, &c. , which enter in a minor and less essential degree into it:t composition.

The lime may vary from .. . 58 to 64 per cent. The silica , . . . 18 , 24 , The alumina. and iron . .. 8 , 14 ,

the three together a.mountinEf to about 05 or 96 per cent. of the wholo, and the properttes of the cement produced will depend on the proportions which these ingredients bear to one another. Tbe magnesia., alkalies, and sul­phuric anhydride affect its properties in a minor degree.

A hydraulic lime contains a. larger percentage of lime than a P ortland cement, and consequently its nature is such that it requires hydrating before use, whereas P ort­land cement is fit for use without previous hydration; this diffE'rence being due not only to the difference in composition, bnt also to the degree to which calcination is carried.

The processes of manufacturing Portland cement consist, in the first instance, of obtaining a. perfectly mechanical admixture of such raw materials as are suitable and avail­able, subsequently reducing this mechanical admixture to a chemical one by calcination, and afterwards grinding the clinker so produced.

Given any materials which contain amongst them the lime, silica., and a.lumina, and which may by proper ad­mixture in definite proportions, produce the components of a Portland cement, then P ortland cemenb may be pro­duced from them, but in many cases the cost of produc­tion may be prohibitive.

Those materials which are capable of reduction by water are not only the most economical to reduce, but are al o capable of producing the most perfect mechanical ad­mixture, and the more pE\rfect is then thb chemical com­pound produced by c1.lcination. The chalks and clays from which Portland cement ie produced on the Thames and Medwa.y in England, and tbe chalk and clay which are used at Yancton, Dakota, U.S.A., at the works of the Western P ortland Cement Company, are examples of materials whi<'h lend themselves easily to disintegration and reduction by water .

Other raw materials which are not capable of reduction by water have to be ground t o powder and then mixed, and with suitable machinery the extra. expense need not be great. Examples of such ma.terials are to be found in the blue lias formation, from which many cement works in the Midland Counties of England derive their supply of raw material. In this case the stone and the shale which separate the beds of stone, are both used in the production of cement, the proportion of shale to stone used being determined by the chemical composition of each, but as both are capable of being ground as brought from the quarry, they are generally ground in their proper proportions together, the grinding and subsequent pugging effecting the mixing.

Another modification in the means of obtaining a mechanical admixture of two materials, is where one is capable of being reduced by water and the other is not, as, for instance, a. hard limestone and a clay. Such an instance, among many others, is found a.t J:>arahyba do Norte, Brazi l, where a bard limestone is used in conjunc­tion with a ri ver mud, and the admixture is produced by grinding the limestone, dryin~ and then grinding the mud, and then weighing and mtxing them in their proper proportions.

For the further treatment of materials which are reduced and mixed by water, there are two well-known processes, both p_rocE.'sses being subject to many varia­tions in detail. The first, and the oldest, and probably, all things considered, the most satisfactory, except in the matter of economy, is to wash the chalk and clay together in a wash-n1ill with a very large qua.nti~y of water. Tbe slip so produced runs away by an overflow, and id con­ducted by proper channels into large reservoirs or backs, where the solid particles in the slip gradually sink to the bottom, and the clear water is drawn off by weirs and sluices. When a. back or reser voir is full, and the slip has attained sufficient solidity to be removed in barrows, it is laid on the drying floor, and subsequently loaded into the kiln. This process, it will be readily understood, produces the most perfect mechanical admixture of the two materials which it is possible to attain. The second well-known method is to wash the chalk and clay in a wash-mill as before, but with considerably less water, and instead of taking the o'"erflow, the slip produced is simply allowed to pass through a g rating, and, consequently, it is not reduced in the wash-mill to that same degree of fineness to which it is in the previously described pro­cess. In order, therefore, to obtain that required fineness, the slip, as it pa.€ses through the g-l'ids of the wash-mill, is conducted to a. pair of ordinary millstones and ground, from whence it passes direct on to the drying floors, and is dried ready for calcination. As will be seen, these two processes lend themselves to many modifications, in accordance with exigencies of the site, &c., and the fancy or whim of the manufacturer. When dealing with materials which are reduced by grinding, there are two well-known methods. The one is to mix it in a. pu~­mill with a fairly large quantity of water, reducing 1t into a kind of stiff slip, which may be dried on a. drying floor; the other is to mix it with a. small quantity of water and make it into bricks in any of the well-known dry brick machines, which bricks are then dried in the ordinary way previous to calcination.

*Abstract of paper read by Mr. H enry Fa.ija, M.I.C.E., at the International Engineering Congress, Chicago.

345 The difference in the two processes does not seem very

great, but there is perhaps more difference between them than is apparent at first sight. \Vhen mixed into a stiff slip there is possibly from 25 to 30 per cent. of water to evaporate from it before it is suffi ciently dry to load into the kiln; at the same time the dr!ed slip has the advantage of being more or less porous, and consequently is fairly easy to calcine. In the process of compressing the slip into dry bricks, or briquettes, the amount of water to evaporate is perhaps only 12 or 13 per cent., but owing to the density of the brick it is difficult to eva.po· ra te this water, and the dried brick does not lend itself readily to easy and regular calcination in the kiln.

The means adopted for drying the slip, slurry, or bricks, are various. The oldest and perhaps best known is that of having ordinary tiled floors with flues under­neath, through which the combustion from coking ovens is passed, the slip being laid on the top of the tiles; by thts means the slip is d ried, and a. certain quantity of coke is produced which is used as a supplementary supply to that which is required for the calcination of the cement in the kilns. Other floors are of iron plates, under which free steam is passed, and again there are many drying floors which are constructed like ordinary brick drying floors, witboub any pretension to economy. But the mosb advanced method is to construct the <hying floor at the level of the top of the kiln, and to use the waste heat from the k iln for drying the slurry or bricks for the next load-• m g.

'fbe requirements of calcination are: That the calci­nation should be stopped just short of vitrifaction ; that the proper degree of calcination should be effected rapidly, and that the clinker should be burned, nob baked; that the product of a. kiln should show an e~en and regular degree of calcination throughout ; and lastly, that these results should be obtained with due £conomy with respect to fuel, and the kiln which best satisfies theee requirements is the one to be adopted.

On drawing a. kiln, all ligbb burnt portions should be picked out, and only the thoroughly burnt clinker passed to the crushers for subsequent grinding, and it is u~ua.l to put the light burnb on the top of another kiln for further calcination, or in some works small subsidiary kilos are used for its further calcination.

The calcination of a. Portland cement has hitherto been carried out in intermittent kilns; the difficulty of altering this and adopting a continuous or running kiln has been the difficulty of obtaining a sufficiently refractory material to form the lining of the kiln- not so much on account of the beat in a cement kiln being greater than that to which fi rebricks are subjected in many other manufactures, but to the presence of the lime in the cement acting on the silica. and a.lumina in the bricks. causing them to flux and enter into combination with the slip of the cement.

The economical grinding of cement has attracted the attention of a great number of inventors. The two princi~les which have perhaps attracted the greatest attentton are those of edge-runners and ball mills, and the economy in power by both these principles over ordi­nary millstones is very considerable, and the cost of repairs and maintenance is also, in most cases, consider· ably reduced ; but whether the grinding is as efficient, is another question altogether. Mere fineness does not satisfy the question, as a cement may be ground to an equal fineness in two different mills, and yet one will be all grit and the other all flour · and the more floury a. cement is, the better will be the results obtained with ib, both in the testing-room and in actual practice ; and undoubtedly no grinding machine that has as yet been invented will produce the same percentage of flour on equal ~inding, as the ordinary millstone. Mills on the ball pnnciple give better results than those on the edge­runner principle, but are not so efficient as millstones. The power consumed by the several principle~, reduced to the production of one ton of cement per hour, may be approximately stated to be as follows :

For millstones... .. . . . . 30 to 32 indicated

Ball principle ... ... ...

Edge-runner principle ...

horse - power per ton per hour.

16 to 18 indicated horse - power per ton per hour.

12 to 14 indicated horse · pow<:r per ton per hour.

In each case the c£:ment being ground to a fineness of about 6 per cent. residue on a. 50 by 50 sieve, and it will thus be seen that the power required is propor­tio~a.t~ to the_ amount of flour produced. The great obJeCtion to mtllstone~, from a. manufacturer's point of view, is the great expense entailed in dressing them, as in a. burst of four pairs of stones, one pair will always have to be up being dressed, and there is, therefore, not only the expense of dressing, but there is the increaEed capital charge in requiring four mills to do the work of three. It seems possible, though the author has not had the opportunity of trying it, that by giving the millstones a fine dress with a. considerable depth of fac~. the first grinding of the cement might be effected in one or other of the grinding machines and finished only in the mill­stones.

Very few cements are fit for use immediately they are ground, and all cements are improved by judicious and careful warehCiusing.

The obj£ct of testing cement is to obtain a. k~owledge of the material which is about to be used, and the author maintains that that knowledge can best be obtained by gauging a. ce~ent by itse~f. with the addition only of water, and w1thout theaddttlon of sand or other material~ as these themselves by variations in their composition • form, and nature, introduce an element of error, inde~

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pendently of any good or bad qualities in the cement; also that the results obtained in the testing-room and labora­tory, are infinitely superior, so far as strength is concerned, to any that can be obtained in actual practice ; ~nd that it is the object of the manipulator m the testmg­room to obtain the very best results which his knowledge and skill enable him to.

A very true knowledge of the value of a cement may be obtained by determining the following properties :

1. The time which a cement takes to set. 2. Its soundness or freedom from blowing. 3. The fineness to whi<;h it is ground. 4. Its tensile strength at three or seven days. Of tb(;Se the most important is of course its soundn~ss. The setting properties of a cement may be d~ter~n~.ed

by taking a few ounces of the ~ement and mlX~ng it with the very smallest quantity of .water wh1ch will allow of its being worked up with a trowel into a t enacious mass that will retain the form ~nto which it is made . This should be shaped up mto a pat of about 3 in. long by 1! in. wide and ! in. thick, and placed on a non-porous slab, and it may be con­sidered '' set hard " when the J?ressure of the. thulJl~­nail will no longer mark it. Or, 1f the thumbnail test ts considered t oo primitive, a Vica.t needle may be u~ed ; the needle having a flat point with a diameter of 0.1 m., and loaded with a weight of 3lb. The needle _should be allowed to remain on the pat for about one mmute, and when on removal no mark is left, the cement. may be ~n­s idered set hard. There itJ, .boweve~, an :p.t~!J?lediat~ s tage wbi<;h should be noted, vtz. , the ttme of . tmttal.set, and this is of more importance than the ttme. w_h10h a cement t akes to finally set. A cement when It IS first worked up into a pat, has a glossy, wet _appear~nce due to the excess of water w~ich. was us.ed . m ~augtn~, remaining on the surface, and It wtll rem am m tht~ condi­tion until the setting commences. The water w1ll then leave the surface and become absorbed by the cement as it sets or orystaU{ses. When once this pr<><?8ss has co~­menced any disturbance of the cement will destr? Y Its constru~tive value· hence it will be seen that the time of "initial set " of a~ment, or the time that elapses between the first addition of water and the commencement of setting, defines the time whic~ may be ta~en fo~ tbe_pr? per manipulation of the cement m the work m which 1b IS to

b e used. · k tt' Cements may be di vide_d into t_wo classes, qmc se mg

and slow setting. A quick settmg cement m~y hav,~ an "initial set" of seven or eight minutes, a_nd wtll be set hard " within the hour; i J? a slow se~tmg cement the time of initial set is sometimes very dlffiou_lt to define, but it may be set hard in from from two to s1x hours.

(To be contin ued.)

D uTCII CoAt.-It appears that 96,144 tons of coal were raised last year in Holland.

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~~-...... ·~~(< E N T R AN C E 0 F A I R

TO BE HEATED

I

i= I=

EXPERIMENTS ON ''SERVE '' TUBES IN MARINE BOILERS.

Some E xperi?Mrtts on the Combination of I nduced Draught and H ot A ir, A pplied to Marine Boile1·s Fitted with "Se1-ve " Tubes and R etarders.*

By J. D. ELLIS, Managin~ Director, Messrs. John Brown and Co., Ltmited, Sheffield.

• • I N these days of triple and quadruple expansiOn engmes and high speed for ships, I tr~st some rem~rks and res~lts of experiments on the ~conom!cal and efhCie!lt prod~ct10n of steam for marine bOilers wtll not be unmtfilrestmg to the members of this Institution.

The combined use of strong artificial suction draught, " Serve " tubes and retarders, and furth er utilising the beat of the gas~s when they have left the boiler, seem to me the natural outcome of the requirements of the. day.

The engine power demanded by the present ships has advanced by leaps and bounds, and tw? o! the latest built have reached a power of over 30,000 mdwated horse­power each. lb has, therefore, beC?me an urge~t neces­sity to obtain more work per cubtc ~oot of. boiler _than hitherto, not only without loss, but, tf posstble, w1th a gain of economy. .

The hei6'ht of smokestacks for natural draugh~ has m ­creased w1tb the increase in the size of the shtps, and thus a vacuum of about ~ in. of water has bee~ reached, being nearly twice as much as had bee'!l <?btamed only three or four years ago in the great maJOrity of vessels with natural draught. In other v~ssel~ ~he draught has been artificially increased by blowmg atr m to an OJ?en or closed stokehold or closed furnace. Mr. M ar t m has worked in the direction of e~hausting . th~ gases by_ fans in the funnel instead of forcm~ the au m to the bo1lers. Jets of s team: or compressed a1r in the funnE\1 have been tried to obtain an increase of draught . . ~r. Howden has, in addition to his forced drau~bt, ut1l~sed so~e ?f the beat of the waste gases by heatmg the a tr, makm~ 1t pass round a nest of short vertical tubes through wb10h the waste gases go from the smokebox ~o the funnel. In other cases t he air has been heated shgbtly by th~ ~eat wbioh would otherwise have been lost _by ra~1at10n . R etarders have been used by Mr. Ho~den m p~am tubes with forced draught t o bring the swtft~y passmg gases into better contact with the bee.t-absorbmg B!lr~ace, and have thereby, as well as to some extent by rad1at1on, been a source of economy.

The advent of the" Serve " tubes haR marked another important era in the history of boilers. The heat-absorb­ing surface of the "Serve " tube is. muo~ greater than that of a plain tube of the same outside dtameter, and a retarder placed in the centre of the "Serve" tubes makes, for a draught of ~ in. and over of water pressure or

* Paper read before the Institution of Naval Archi· t ect a.

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vacuum, the most efficient and economical combination I know at present.

Having ascertained in ordioary sinfile-ended Scotch marine boilers the value of the "Serve tub~ and of ~b~ t·etarder with different rates of draught, wtth l\1artm s induced draught with cold air, and H owden's fo_rced drausht with heated air, it seemed to me that a. consider­able rmprovement was possible over ~xisting practic~ by combinmg and extending the best _features. of the var10~s systems, and the accompanying IllustratiOns show th1s combination as it has been at work for over twelve months at the Atlas Works in boilers Nos. 7 and 8.

I have preferred artificial "suction " draught to "forced" draught,, because ~t s~~med the, natural w_ay of increasing the effi01enc~, ~emg natural draught mten­sified, produced by arttfiCial means, merely because the equivalent height of smokestack cannot be used at s.ea. Seeing that in any caRe, _whetb~r the draught be suct10n or forced, a given quantity of a1r must pas~ through the boiler at a certain sl?e~d to prod u.ce a gt ven com bus­t ion and being of opm10n that suctiOn draught was less likeiy to produce trouble in the combustion ~hamber th~n forced draught at the high rate of combustton _I . bad •.n view the best means applicable at sea of obtammg this kind' of draught bad to be considered. S team jets in the funnel could not be entertained because of the loss .of the water. Air jet s were doubtful. Fans ~ad been tned for exhausting the gases, and the beat bad. g1 ven trouble even wh~n burning at rates ~ar ~elow those mtend~d by me ; or t o avoid the gases passmg m to the fans ab a bt.gh t.empera­ture the tubes bad to be made very small m d iameter, wer~ therefore liable t o choke readily, and red1:1ced gre.atly the amount of coal which could be burnt w1th a gtven rate of draught compared with o~dinary-si z~d tub_es. Besides this, the crowded tubes Impeded circulatiOn within the boiler. I knew the "Serve " tubes a~ re­tarders would reduce the heat of the ~ases appreCiably within the boiler itself; but, as I desu ed to b~n at the rate of 45 lb. to 60 lb. per square foot of full -stze grate, therefore three or four times the rate of ordi.nary natural draught, the t emperature of the g~ses esc_apmg from the boiler into the smokebox would still be htgb, and would require t o be further a~sorbed for the ~ouble .purpose of preventing d ifficulty w1th the fans and mcre~mg ~be effi­ciency per pound of fueL A nest of short vertJCal au-heat­ing tubes, as in the Howden systAm, w~uld do good, but I desired something more, becau~e I wtsbed to bu~n at a h igher rate. Thus I came to horizontal t~bes, which are more effective than vertical ones, and whiCh can be used of greater len~th. '1;~e ulti~ate combination an~ exten­sion is shown m the tllustrat10ns above, the leadmg fea­tures of the boiler being tberefore-

1. Suction or induced draught. 2. The utilisation of the waste gases for beating the

air before it passes into the furnace. 3. '' Serve " tubes. 4. Retarders in the tubes. The principal dimensions of the boiler! are as follow '

EPT. I 5, I 893.] E N G I N E E R I N G. 347

TABLE I.- RESULTS OF EXPERIMENT MADE "\VITH "SERVE, TUBES AND INDUCED HOT-AIR FEED ON A~GUST 2~, TO 27, 29 TO 30, EPTEMBER 1 TO 2, 2 TO 3, 1892, ATLAS WORKS, SHEFFIELD. NOS. 7 AND 8 MARINE BOILERS. SERVE TUBES 'VITH RETARDERS AND INDUCED HOT-AIR FEED.

..., ... ~ ~ a..QI "d ... ~ ~ ... ... . . ~- .... ~- ~ CID CID Q) -- GICISO c c ... • 00 ~ ~~ ... ~ ... c =' 0 Q) a~ os Oc:S eo aS Ql • Q1 ..., =<'4 • s:l-GiaS .... . ... aS - ., ~ =' aSGi s;l. s;l. s;l. ~ Q1 > ., ... CID>-, CID - ~ .. ~ t: 0 ='~ ... CSQI aS .. • en

=' c ~ - o=' c+> ..., • - aS rile en Ql~ CS .... = .,. > H,; .... Oc 0 c =' CS ~=Q er aS CID ~- =' c > "d ,..='., I=QO• < Q1 eo ..cl 0 ... Ul aS =' ... ... .i; ~ai • Q)~-QI 0 ... ....s .. CSO c ~ .s aS ~oen ... QICID a~oc -~ =' - ·- Q1 • e ... 0 aS H =' ... ., .... ., ~-ell a~ - ... ~ ::cc Q) ... .... $:1. ... I=Q Ql c:S c - ~cs aS 0 0 o ·- 0 • s~ 0~ ~ .... ~ ~ s;l. c >aS='~ aS .• 8QI= ..cl

Qlx Q1 ...... > .... aS a~ c ... =' • "d ... 0 < en • - oc .... ... =' o..,

~~e Gl en Ql {) .,.c ~ aS ~ s;l. CID ... 0 00 ,...u o - ,.. o ~ .a ... ~ . ... .... o .- . Date. 0 ll>O .. Q) ... c

8i:t cCP - ~ . ~~ .... ell 0 ...... =' ..0 > aS '- aS+> UlQI CID 0~ ... ... ell c: tn • ~~ .;. s;l. 0 .... CISQI ='> :::1'- =' aS .... p:l ::S os:l< Q) CID

"d .... ..... -; ~0 ~ Q) 0 » Cl) ='=' c 0 • ... "0

~ .5 > c oo~~ 0 "d.!: ~ O='s:l< CISil> aS .!Id 8 ~ . 0 c ~., Ql ... '.3 Cl) () Q1 ~..0 0 C) CII ='c Q1 er ~> .. o a E Ss:i !Ill=' aS ~ :; ·;:: ~ 0 • CID ~ .... CID "d aS =' alll) Q1 ... c .. .... ::.Lil> ::lC c

. ... CID '0 c:Q=' :::> 'Oc::"d ~ ., .... Q Cl) Ul Q) Q1 Ql~ a~e =' . =' ='e ~ ::S ed ~ ::a Cl ~ aS Cl) • .... .... s;l. .!Id .... .. _c: 0 _., ..... '0 ~ s;l.CI) "d- .. (1).c Ob.O 00, c='~ ... t'S::S aS::S -~ (1$11> _s::s C ::::) QICIS ccG - c,..aS p.I=Q P.en ='f =' ='·- ~ :;:l~ Q/ aS .. ... ~ Q)Git> ;;.. c 0 =' er·- G> a..o - ='o ., ~ =',..CISC') 8:g 8 .., ~c O CIS 0 t> ..Q (.)- ~ ... 11) ~ ~ > .. c ... -"' 0 gc

Ql ... .... CIS O o o ..... ='CP._ ciiS Q ;?: ~~ ·- ..cl o en A s:l< ::S:Il Oll,c =' oCIS >~ .ell.c~P. 0 P.:.> C') 0 p.(!) Qlen ~aS aS~ aS aSo P.:!) p. ... 0 < ~ ..... < 8 0..

Q 8 o·- ~ 8 .. .... 0.. p.. 8 8 8 '- > > > > Ul < - - - - -- I

• • de g. de g. deg. • • • ft. deg. lb. 1n . m. 1n. 1n. 10.

189~ Fahr. Fabr . Fahr. Q1 541 i 3 12.6 ugust 23 to 27 96 123,tH8 12ss 1 ... 1,102,800 11,487.5 8.91 10.29 40.25 263 393 656 .48 4.68 1207 87 44 ·f •• • •

! 13.89 .... 3.37 1451 76 46 463 l 29" so 24 3t,6r,2 1439.6 ..cl 303,700 12,654.1 P.78 10.24 44.98 305 386 653 .39 • • • •

if 13.51 .. ~~ 81 45 525 i September 1 t o 2 24 32,805 1366.8 295,500 12,312.5 9.00 10.45 42.71 262 3 6 618 . 77 1.16 4.56 • • • •

1372 1 .. 5.05 79 45 671 i t 13.68

2 " 31 2! 3:?,928 0 297,000 12,876 9.10 10.48 42.87 294 891 692 .65 . 72 • • •• .. ~

A

• August '13 to 27.-In this experiment all bars were cleaned and tubes swept before starting ; fires were cleaned every twelve hours alterna~ely ; the tubes were not swept dunng t he whole of

t his t rial. In this test all bot ai~ was passed above t he fires, and cold air underneath, the bottom doors being half open to allow admittance of cold au. . . August 29 to 30.- In this expPriment new firebars were put in, and tubes swept before starting ; tires were cleo.ned every four hours ; the t ubes were not swept dunog the whole of the t r1al.

In this test o.tl bot o.ir was pa.ssed above the fires, and cold o.ir underneath, the bottom doors being half open to allow admittance of cold air. . . . September 1 to 2.-In this experiment all bars were cleaned and tubes swept before star ting; fires were cleaned every six hours ; the tubeR were !lot swept d~rmg the whole of lhts tnal. In

this test the hot.air feed was both top and bottom, but underneath the bars the bot air was diluted with cold air h E>ing admitted throug h sevent y holes 1n eQ.Ob ashp1t door ; there was also a second perforated plate behind tha ashpit door, for the purpose of mi xing the air thoroughly . The temperature of air under grate was o.o o.verage of about 150 deg. Fabr. . . . .

September 2 to 3.-In this ex periment all bare were cleaned nod tubes swept befot'e star ting; fires cleaned every six bou1·s; the tubes were. not ~wept dunoa- the whole of t h1s tr1al. In th1s test all hot air was paBSed abo\'e the fi res. and cold o.ir underneath ; t he bottom doors being E hut, the oold ai r passed through seventy boles dnlled m eo.ch door fo r the purpose ; area of these boles, 124 square inches, i.e., 62 square ior hes in eaob door; area for pas3age of air over both fi res, 220 square inches.

TABLE II. - RE ULTS OF EXPERIMENTS MADE WITH "SERVE " TUBES AND INDUCED HOT-AIR FEED ON AUGUST 15 AND NOVEMBER 5, 8, 15, 17, AND 18, 1892, ATLAS WORKS, SHEFFIELD. NOB. 7 AND 8 MARINE BOILERS. "SERVE '' TUBES WITH RETARDERS AND INDUCED HOT-AIR FEED.

•

Date.

Q c - ·--aS .... .. 8

-0 -aS c 0 . 0 • 0~

1·- 11) .... ~ ... ... aS::! _ ... ... 0 cS::l .... 0 ~~ ~p.

c ·-... =' 0 = .. Q) Q.

"d Q1 .... aS ... 0 s;l. cS > ~

----- -- ___ , ________ , ___ ---- --- -- --

1892 Nov. 6 . . 4

11 15 . . .. 17 . .

Aug. 15 . .

7! 5 7

4,969

8,018 5,632 7,443

Nov. 8 . . 48 67,268

.. 18 . . 7 10,192

c cS

1242.25 .~ ... 47,550 1069.06 ~ Q1 72,500 1126.4 I ~ 52,600 1063.28 -Cl) ~ 68,900

c be. c 1401.41

1456 z ~ 99,800

11,887 6

9,666.66 10,520 9,842.85

12,493.76

14,185.71

9.56

9.04 9.83 9.26

8.91

9.74

11.28

10.63 11.02 10.83

10.5

3S.82

33.4 35.2 33.22

43.79

11.44 46.5

246 246 j00

311 265

331 336 290

442

374

Cl) Q1 fD aS 0 -0

11 .. 442 deg. F.

{ M~tted } ZIOC

11

(I) ... aS .. "

in.

• •

.88

.91 1.07

••

• CID Q1 ... .. (I)

> 0

8 =' ::s t> aS > in.

.6 1.2 1.27 1.64

.62

. 78 1.3

--00 Cl)

(I)QI Cl)..c aSO ~=QC .....

• 1n.

4.08

4.35 4.97 2.65

6.18

4.87

~

I ~ 0 ~ > 0 .a cS

• lD .

.26

.36

.35 • •

.33

.36

1902

2176 2404 I

1~~9 I 2658 I

ft.

486

1249 12:?0

• •

508

1141

deg. Fahr.

~5

66 51 • •

64

67

d eg . Fahr.

65

66 59 72

66

67

49

45 43 45

49

45

Grate Bars.

• CID Q1

~ Q, 00 ... ·-< • 10.

605 { F ront t } Back!

498 ! 490 l 382 i 634 i 648 i

• 10.

13.04 1().61 11.54 10.8

13. '/ 1

15.67

REMARK .-In these experiments with Welsh and American coal, t.he best results were obtained by putting all the hot air under the grate with the ashpit doors closed, the hot ai r being diluted by the cold o.ir being admitted through the boles in asbpit doors. Fires kept a moderate thickness. Durin~ the 48 hours' test the mode of admitting the air was tried in various ways, but the best results were obtained as above stated . This experimenting with the ,·alves accounts for the apparently low evaporat-ion. The 6rebars in this test were partly cleaned every eight hours ; but in the others t h ey were not cleaned during the whole of the tests. Melting point of lead, 630 deg. Fabr. ; of zinc, 700 deg. Fahr.

TABLE IlL- RESULTS OF EXPERIMENTS MADE WITH AND MARCH 15, 1893, ATLAS \VORKS, SHEFFIELD. INDUCED HOT-AlR FEED.

"SERVE, TUBES AND INDUCED HOT-Affi FEED ON FEBRUARY 24, 27,

Date

1893 Februaf5' .. March 1 5

24

27

••

.. ---<IS -.. H

-0

c 0 • . ... CID ~ ... CIS=' ... o ='~ Q

7

7

7

c .. ::s ... 0 ....

c = ... ... =' (I)

P=l p. • - +>CID

ell Q"d 0 • ... c oco ='=' -o l:QO .... c ~ cS ::l -.... o cSC op.. o ·-

E-4 0 . - -

9,632 1376

10,304 1472

10,192 1456

I

1· - ·- I I • .. o..s. aS ... .... 0 ~ ~ ~o cS 8.o · eo 1 $:1. p. e11 0 ~. CIS O bi .. ..,: cS > - ... > Gl ::s > ~ ~ o p.! ~oo l ::~:~(; g ~ a) Q1 • ... ., 8 aS ... 'Ce-1 0~ ..,m -o eii'C 11> c~e: a~ c .... (;~ ,..c .. c ~ :I ~ ::s C') ... a.=' O::s e11 0 ~ cS 0 o a~

P.o ~P,.-GI ~p.~ O~p. .... o • CIS~ :~ ~ CISGI a! a..

!l';c - ... ::s~ - .. ., .... ::s aS Ql rile! OCP..., O(l)c 0 I=Q CID .... .... al s;l. (.) ...., CID p. cS CO !if ::> ~ ,.. .. "d "d CS 0 '0 'i '0 (I) (;.S ~ =' c::~ 11> c 8 c,..~ -~ .. 0 ::s +>aS ~ ::r: ='~~~ ='~0 =' Gl .. 0._ ~ ... tS ..., ~ .. .!: ~ P.O ~ E-4 ::::

~ - 88,100 12,685.71 9.14 10.81 43 ~

~ ~ 96,600 13,800 9.37 11.18 46 ~ Ql 92,300 13,186.71 9.06 10.66 45.6 1 z

No. 7 MARINE BOILER. "SERVE " TUBES WITH RETARDERS AND

..,. CID fD ~ .... Cl) .... ...... ..c~ • • ~ a.. CID "d Grate Bars. .. ..,. Q1 aS cCI) Q1 Ql ..... OGI Q1 »GI ct,QI ... Gl-c) c ~et() Cl) • (1) aS ..cl ..... 'OP.. ::SQI ~~ ::s - s;I.GICIS .... • .. c ell ... aS>. CS .. (1) (.) =' c., or:. - 0=' ... !I: 't: .... oa. c 0 • ...=' < llD Cl)c ::SGI aS ~0 c c Q1 0 .. c .... H .. • CS Cl)-~ -e .. CS .,.. Q) .c .... < ~ P....C - - .. ·- I=Q ... r:.. ... CID P..· 8 0 ~ - ... 0 0 o .- 0 Ql ~

Q) -~:r 8~ 0 ciiS

..cl • c > ·- c .. a~ oc aSc.S ....

i:t(;bG ~ . Cl) o I ~X ~ ... .... 0 ~·- .... ..0 Q)~ ~ ... 0 a~ ... a.. CID ,.. ... o c Ql ... ..0 CID ~ =' . a.. as H aS .. Cll CID oc= ::sal =' .... ::s ..O =' > CIS aS E-4~ • •

_ .. =' 11> ~ en ... c 4ioof ~ . ..... • ..,> .... o .._.GI • 0 ..... ... 0 >,a.. oaS - ~=' ~t:r: QICIS 0 Q) CD .e- aS (I) as .!Id a~(l) ~ ... =' • Cl) ='=' .. aS

~:X ..o 8 s d- 8d I=Qai 0 c·S ~ ~ ~Q) () Q1 Cl) (I) ..0 0 a.> Q)e - ~bO CO ~ t~«='O' ='c tS Q =' • =' ::ss aS ::Sed ~~:I "d.-::a cS~Ul s;l. • I., = ·.: ::r: P.Q> s:l<CQ s;l.Ul ='f p..c CS ~ -·- .!Id«< =' =' ·-at ='~ Ql~ .. .. ~ 0~ en s ='~ .. S:g 8~ ~"

~eiiQ s·.: .. 4.1 ... 0 ... OCIS (.) o .c .... ~-Cl) .. ... Q1 (I) ~ ~ ... CII > c ... . .. cS .. ~- Q> Glen ~aS .ell~ aS aso 0 ~0~ $~ p.. ~ ~ >- ~~ ~ ~~ ... ..cl !X) o en A s:l< 8 8 8 '- , > > >0 8~ <0 ~ < 8 P4

-de g. de g. • • • in. de g. de g. • • lD . 1n, 10. 10. 10. Fahr. Fabr . Fahr . Fahr.

{ Melted } 279 408 1.01 1.17 5.06 .375 2464 1167 61 47 673 (l i bismuth 61 13.81 tl

281 392 .. .93 1.24 4.62 .375 2098 1332 61 60 47 510 I i 15.14 { Melted } 276 390 1.25 1.67 5.42 .375 2586 1570 65 66 49 567 i i 14.47 lead

-RB\IARRS.-February 2 & : Lo this experiment all the hot a ir w11s p~sed above the fire~, and cold air underneath, the bottom doors being shut, the cold ai r pn.ssed through seventy boles drilled in u oh

door for the purp~se. February 27 and March 16: In these expenments all the bot atr was passed under the fires, but wn.s diluted with cold air, admitted through seventy holes in each ashpit door. In the abo"·e expenmeots the ftrebars were cleaned and tubes swept before starting. The 6 reba.rs were not cleaned again during the whole of the seven hours' t est. Melting point of bismuth 493 d eg Fahr. ; of lead , 630 d eg. Fabr. • •

TABLE IV.-RESULTS OF EXPERIMENTS MADE WITH ATLAS WORKS, SHEFFIELD. No. 7 MARINE BOILER.

''SERVE" TUBES AND INDUCED HOT-AIR FEED, MAY 5 AND 8, 1893, "SERVE, TUBES WITH RETARDERS AND INDUCED HOT-AIR FEED.

- I . -c c ... • .. ..... . 0<0 .. .... ~ Cl) CID ~ -- .... .c~ ::s 0 ceos p.o eo ..... • • Ql a.. a> "0 ... Grate Bare . ... .... ~ ·- .... Q1 aS Q1 Ql 00 ~ ~~ bG ~ C UI s;l. ... Gl"d ea~ GlaSO 0 p. > Cl) tS 0 bi. ... ...: (1) • CID aS - 'O P.. ::s ~ l'il~ ~ ::r: aS ,~-g8 .~-Q)~~=' .. cd>. aS .. tn .. =' ::c ces:l< $:1.~(1$ - .... c., 0~ ell > "

• =' ...,

0=' =-c "d < (!) Cl C) CO ~~ ... =' - ~ai • =' '0 OQ 0 0 c en .c 0 =' ~ a..c: aS I=Qo c ... ;:; .. .. QICI) .. - ... "d 0~ Q1

Cll ·- 8 ... • ~ =' ... '0 ......"0 ~OCIS~ ll>cC')~~ - -s .... .. aS(.) ... ~ ..Q .... < ~ ~..cl aS ~-en

I=Q Q1 asc 0 .. ~ I=Qc Cll ... ,

-~ p.,; 8 () ~ ~ - ... 0

" 1 ceP4 .E~ :d ='C:: o ~ o .... 0 Ql 0 p.. ... =' ..cl • ...... • ~ aS ... =' X ~ ... .... Q oc 8~ c-c Da.te. ...

~0 00 ~ .. c.> .... :;~..., O f~ ~ . a. o ~0 c ... 0 ~ ·- a.. .a Q) ~ Ql- G' C.,.. 0 ·"" ~~bl 0 - ...,

~0.. ... Cl) Q1 ~c ..0 <~$ ~.... bO • ~p. ... ... ..0 E-4"' o c aS CCID • Q) aS 0 aS cS $.., ='QI =' .... =' ~ aS ·- fD .. aS .. Cl) Cl) c

0 '0 -Q. Q)- ... -oo='"' ..,> .a~ aS ... =' ~ ~ • ... o.- . ... ~ ~Q > .:>0 0 >. -CIS :I m a.. c~ Ql ::1 O ai ::se ~ ~ .s o "d ~ .. o Q) c crl:Q d - ~= ~ cS 0 CID 0~~ ... 0 • Cl) ,..aS CIS~ aS.!-4 e ~ . o~ ..... ooc (.) Cl) ='=' '0 I=Q=' ..... CID Q1 ~ ::S CO ~ C1S ~ Ul .. o 8 8 Be G>"d l a~ .. ::l:.:; a) aS _eo ::> ~> t(1) ~ o c.- ~CO

Q1 CID (I) _a 0 ..... _c 0 _-o ..... "d.... .... '0-c) ~ Q,(l) p.CIS a~e =' • =' ='8~ ::SaS ~ .s ~ 't:l ·~ ~ t!QGI bot=' er =' ..... Q. Q ~ :r.: ::r: aS::l d=' -ll.o - ce<~~ 11>=' c c:S .-...s Ca~8 c ..., 8~ P.en ='f =' ::s~

p..c aS~ aS :en - ::: Ul ..!&:Sai a..o ...... o gc Cl) ~~ .. 0 ='~ga; ::s~o ::s~f 8:9 ~c

:::3 .... ....- ~ c:S C ~ a.. s·.: ... ~ .. a~ a.. O-o C 0 .. c='~ ... ::s:x: ::s o CIS "'= O CIS 0 0 ..C CIS ~- ~ ... .... Q) ~ Q) 41 ~ .. Q1 > c ·- ... o o.. o P.O Q. o ~ .!: o :::. ':.!) (I) en ~ .. aS IX) CIS cS o~ >- ·- ·- ell ::s 0"'- ~

~ 8 o ·- ~ t-4 .. ~ 8 "' £0 ::111 ~~ p.. ~~ > 0.. s;l. ~ aS :a < ..Cp::) OcnAa. P4 0.. p.. H 8 '- > > > >0 8 .... <0 ""( ~ 8 ~ - - - -dPg. deg. • • . • d eg. 10. 10. 10. m. de g . • •

lll. m. 1893 Fahr. Fabr. Fahr . Fo.hr .

r~-Alo.y 6 7 11,228 1604 9l,GOO 13,035.71 8. 15 0.46 60.12 300 416 { Melted } .99 1.22 4.68 .376 2445 1160 83 82 46.6 542 i • • lead i 14.36 g 8 107,200 2 7 13,293 1899 15,314.2 8.06 9.46 I 59.34 ! 293 43-t 11 •• , .93 1.26 4.58 . 376 1981 1448 ss 70 46 644 i ~ 16.81 oo I ..

• • R;E'l ~RKS .. - May 6, 1893 . In the seven hours run. the fires were not cleaned for the whole of the seven hours . The fi res were kept very thick, and all the hot air put on top of fi re t he cold air Cloly be10g adm1tted under grate. May 8, 1893 : In th1s test of Sc~to~ coal, the bars were again not cleaned during t he whole of the run, but the fires were very thin and the whole of 'the air b tb bea.ted and cold, was passed under the grate. The results were, 1t w11l be eeen, much better even than on May 6. Melting point of lead, 630 deg. Fa.br, ' • 0

Boiler

Alr-buting bo •

Futt ar.d enaiou

( Diarntttr of l>o1ltn .. .. 1 Length , , . . • .

•• Pu" u" ftuee In fiLch hoi ltr .. loaide dianaettr of ftuo . . .. l..enl(th Of fUIII I

I :rotal nu m her c,f tub (" t r \ t:-:.; ',uta rle diameter of tub• 1 Tbickne of ordioarv tub .. . .. .. Nu.m~r of tt.a) t ube .. .. Tbtckot • • • • • • Pi tch of tub 1 from centre to

centre .. • • • • • • Total heat·•btorbing eurfaco of

tubtt .. .. .. .. Heat · di trlllutln.r eurface of

tu bel . . . . . . . • llut · dletrtbulloi eurface of

furnacu .. .. . . . . H u t. · dl trihutl n~t aurface of ~mlJu tlon chambers . . . .

Tot I h. at-di trl\mling eurface per lJoaler . . . . . . . .

Area of a-rate eurrace . . . . L ng\h of gratt• . . . . . . Dart, S to . deep, In. t.hlck, utd

I in. •lr tpa<'e Proportion or grate to total

heat io.r aurface . . . . . . lo the heu alJ orlJiog chamlJen

tbere ar~ .. .. .. .. Diameter of tulJes outeiJe .. LtniCth of tu~• .. .. .. That'koe 1 of tubt .. .. Total but ab10rblng aurfae~ .. Fan to each bo1lt'r . . . . Diameter of fan O\ er llpe of

hlad .• . . . . • . . . Wid th c.f fnn . . .. .. Diameter of eneine cy lindert

(t•·o C) lloden) . . . . . . Stroke .. .. . . ..

10 ft. 6 io. 10 " 6 "

2 2 ft . lO! In. 7 .. 6. "

ll Sl m. uu "

u .lU io.

•t " 13)3.0 q. ft.

7U .. i6 .. 05

" 9 11 .. 3•) - " 0 ft . 8 lo.

1 to 28. "

0 tul;ea (pi&Jo) 3 In.

U ft. 4 in. . 11 61 n.

900 .. l ft . 1

6 ft . 61n. 1 " 0 "

7 In. 6 "

. It will be fl e n that the boiler itself is ~n ordinary aaogltH.·ndPd ootch type marine boiler, with " Pur\ ea , furna<'ee and " n e •· tubes. The combuff tion chamber i• fairly large for the ize of boiler. The tubes 3! in out.did_e diameter, are llpaced somewhat furthe; apart than 11 customary n ow, and good c irculation of water and r~y e cape of s~am ar~ thereby facilitated. In eelectmg !oJO large a du~meter of tubes- instca.d of the usual small diameter11- for high rates of combustion, I wu not concerned as to the amount of heat " diatribut­ing " aurf&("e within the boiler, and this finally came out at the proportion of 28.4 quare feet to one square foot of grate aurfacc. mall plain tubes have been n ecessary previou 1y for the aake of obtaining the utmo t heat­abeorbin~ e~rface; but by u ing the "_Serve " type of tu~, I obtamed much m ore hcat-a.b orbmg s urface wit.h the Rmn.ller numb. r of 3!-in. tubes widely spaciOd, than eou_ld be done w1th. a large number of small diam ter platn tubee clo ely pttchNi. The advantages are obvious: ancreued section for the pa.ssage of the gase ; increased beat-absorbing urfaoo, and better circulation of the water and escape of team. };vents have pro\1 ·d that in th~ e boilel'8 prolonged evaporation can take plaoo, with­out trouble, and from coal feed, at unprec d ented rate for thi class of boiler.

The Rrate is in two len~ths-tbe bar are ord inary wrought-iron bal'8, 2ft. 10 10. long by 3 in. deep, :J in . thick at top by i tn. at bottom. spaced S in. apart. The only departure from ordinarr practice is that the gra.te for h igh rate of oombu t10n. say, ov~r 35 lb. , r i s towards thA back (2 in. in 5 ft . in. total I ngth), inatead of falling about 2 in. a i u ual U p to 35 lb. per squ&r foot the grate may be hori zontal. I did not arri,·e at thie c-oncluaion wtthouo consid erable exper iment. At one time it seemed as if I hould require to ha' e recour e to a tubular grate with air or water passing through the same : but, realising th objections to such grat , I per· aeven.<J, after having repeatedly burnt down in half an hour a new wrought-iron grate composed of bar aa above eloping d o wnwartls. The gradual raising o f the back end to :! in. alxwe front f'nd ha.s resulted in our being entire ly r eli6ved of all an xi ty as to the g rate , ' en when burning at GO lb. per quar foot .

E GI E ER I G.

we u now metals o r whi<·h th m lting point i well k~own, in prefert·!"oo to any kind of pyrorn t.ei'l'. Th~ tr1 1 onmtn •nco w1th the 6rt "' lmrnt down to a minimum, and 6m"b• as n taar a po 1ble. w1th th am· h igh t u f fir and m€' oondition. Th T bJ "'how how th• t m· J rature of th g is greatly r ucro for they r a h the fan~, and the he~t uttli •d by the htgh wmperatun of the aar, and th att fa<:tory \'aporation per pound u f en al. L~aky tube ends are unknown, and coke n ta ha'

hPen found. to .occur only with coal froiJl certain m in . The heat·dlltrtbuting s urface evidently do th ir \\ Ork well. on u rquar foot of b~ating urface having '·apo­ratcd u much a Hi. lb. of cold wa~r (i O d ~.) pPr hour ( Tabl No. IV.) with ootch co.J for ,. n hour without cleaning the grate, a veraging o\·er th whol period & combu tion of 59.34 lb. per quare foot of ~rat .

In our exper imen ts we ha\'e already uaed u tb \VaJ Newe&;Stle, South Y ork!hire, , cotch, Lancashire, P no~ 8flvaDtan, and Australian coal, and it. is intended to con tmue the ex.pcrim~nts until all the different kind prinf'i· pally u ed m our m E:'rca.nt1le navy havo been tried and tbo comparath1e r ults ascerta in d. '

I am well aware that these exper imen ts ha,·e ~n mad on land, and with a comparativ ly low pr Wf' ol ~am. but I am u nabJo to a any :rufbcient reason why imtlar ad\antage: and re ulta s hould not beobtaioedat (a i f th y~tem be adopted, provided ~re i taken to k' p th

boilers reasonably free from otl an:! solid matter. Oo ship thu 6t.t d is working sati factor ily and se\· raJ othf rs will be running shortly. '

.B id s the principal advanhg of h igh evaporation Wtth ~00my and safety, t her br l'edUCing the OUffiOOr o~ botlers (~naequently the botl r 8pace and weigh t h1therto requared ) • . the following further ad \'an tag · appear to me not u01mportant :

Cool ~tokebold or engine·room, if the air supply is taken from the latter instead of the atmosphere.

Clean t.ok ehold, the oo~l d us t being sucked in to th boil en.

Absence of r isk of burns to fi remen, the flame at. all times being ucked away fro m th m .

Con venience to firem('n, there being no ,la)ves to hut or open, when opening or d o in~ the d oor a..

. moke with ~nskilful firing 1s gr 3 tly reduced, and wttb careful fi rmg need not oocur at all, with any kmd of coal.

G reat elaatici ty of power under ready control. Greatly reduc d quanti ty of clink rand r idue. In making publ ic the re. ults of the combination I

d ire to C'\ pre my indebt d ne to the t-min ent Fr n'cb engineer, [r . . J. en 'e, for hi faluable sugg t ions, and to the atafi at the Atlas W orks.

LAUNCHES AND TRIAL TRIPS. T HE new fint-cl a-u nboat R nard. which was built

and cngined by L trd Broth~l'!l, of Barkenh &d was ub­jf'Cttd to a full-power trial of h r macbtoery 'at a on \\T edn day, the 6th imt. Tbe trtal w conducted und r natural draught, and wu of ·~ht hou • d uration. tbo r u1ts attained ooing COD id r d \' ry sati factory. \V1th a s~am pr ure of H !l.6 lb. , and th ·ng-in working 2L9 revolutions pcr minute, a mean of 2~ .6 hon!.e-power was regi tered, with a speed of 1i.6 knots. The \'es e l is pre­paring for her forced-draugh t trial.

Oo aturday. the 9th in t • there WM launched from th (> hiJ~yard ~f i r W . . Arm tr;ong. M itch lJ, and ., at El wtck, Newca tle, a new cnuser for th Ch1lian R -public, nam d the Blanco J.: oca.Jada. The v 1 i 3i0 ft. 10 length ; 4fi ft . 6 in. in bi'E'adth; draught, 1 ft. 6 m .· d i p lacement. 4400 tons; ind ica d hor -pow r, 11,600: speed under foi"CE'd draught, 2-.?j knots. The armament i heavy, oon~i ting of two 1 -in. br ·hloading gu na, ten 6-in. quick -fi ring gun , tweh·e 3· pounder guns, tw h 1-pouoder gun ; aDd five torptdo tu~. Th ves 1 i& to be command d by Commander J oaquin ~(unoz.

The trial o f the new oi l-carry ing teamer J>otomac were carri d out on ~Inoday and T uesday, t.h 4th and 5th in t. The teamer ha been con trocted by ~1£ re. A . and J. Ingli , Poiotho~ , for the Anglo-American 11 ompal\y, of London and X w York under tbe d ire tioo of ~fr. J ohn D. Jami n: a m mber of the L ondon board. and i of the fol · }owing dim n ion~, viz. : ~ngth betw n per pend i­cu~rs, 34:> ft . ; beam, 44 ft. : d pth to upper d eck, 31 ft. 6 in . ; . nd h i proJlf"lled by ngin of about 3000 indicated hor a-power . The speed of the Potomac w rtained to bo 13.05 knot.!, " hich indicates a uffi ­ci nt margin of power to contend with winur gal in the N orth Atlantic, and at thi apeed n o ~brataon w perceptible in the officers' saloon.

propelling ngin &re u _tantia1ly of th, n 1 t rn the of th• oth •r ' 1 of the la! . Th c kt! ·,

•l in. ! a nd th tri~l w mad it.h th n in ho up to :l.l l D. :t'ht I' " !'r of th tr.odi6oo ( rrit lth" L J , ha' mg a dtam t r of 1, fr. and a m n 1 i h, f }!-i fL !» 10. Th ap ndoo tabl bo t.h r ol of tb o r a i n1 fort h halr· h ur mP.d :

D)il r Jndi t.ta<J R ·,lu-Pr u re. l (or Puwer. taoo .

lb. H 11,347 1Q.3 lfJ() 11,5 0 HH H U 11, 2:J. lfl' 15i ll,-4f 114

' •l . '-'•

151 11,~:!-\ lfH . ;~ 1a l 11,6~ H • .G!J 1&7 1l,l)f,J lU:J .'i Hi 10, I 10'.? . ~ 1

Th fo~lowi'!g m ana w r au equ nt.ly work d out : team tn bot len~, H . s lb. ; ,. uum, 2i. ; r 'olutaon ,

103.2 starboard and 103 port; m an prc .... ur h• h 52.37 and 5~. 73; 1ntt:rm diate, :?11.00 and ~ti 3.r,'. lo•' 12.51 and 12.3.): mdtcat !d ho ·po\\ r high ti49 and 17i3; tn~rmodtatc, 1, '~and 19".! ; Jow,' _ :!& 'and :. atu; total tndtoat.ec.l hone-power, 56f tar board and 54_,11 port.. T le coil ti \ e in di t d hor -pow r wu con :!qU ot.Jy 11,379. or 3i 9 hon · beyond the oont:r& t a u)t " hich wa obt:am~ with aoon umptionof ru l (lbrri ·,dt; p· ~a nav1gat.ton) amountmg to :?.4 lb. pt-r indi too hor ~· pow r per h our, and an air p r • ur 10 th atokt.•holde t'<)ual to .G3 in . , or only a t.ntle 10 of th &\ ra u od for natu ra) draught. Th m an peed r aJi d dot iag th fou.r hour~. me ured by " h rub" J , w 17.92, the t•mated a . d und r agoing condit i n beiog Ji .0 knot.a. Tb eng1n w re aft rw rd t ted fvr tf'Jppinlf and tarting, wilh the ft,IJowing r nl : From full f*-00 ahoad to top, i nd ; full peed t. rn, G l oondrt ; full peed a tern to full peed ahead, j ~ nd1 · and aJ..o

und r various condition of cut-off. Th truu 'w ta . factory in e,~ery pect.

Th lu~e tool crowa~amt-r R oland, which hM been built for the Norddeutsch r Lloyd, o f Bren1 n, by )( . ir ,V, G. Arm trong, ~Ittchell, and Co., Limited, w talcen out to a on ""r ·do ay . • \ ugust 30, for ht>r tnal trip The d imeo ions ar u follow : Leo~th, 3.Ji ft. : br adtb~ 4~ ft. ; and d E>pth, ., ft . 3 in. The R oland 1 th pion Pr hip of one of tb Xorddeut: her Lloyd ' n ew d partu~

and i nrranged for the tran port o f migr nt.i and carg~ from Brem rha,en to X w Y o rk. nth trial th Roland attained a speed of O\er 13 k not.9 " h1ch w ruid f\:d ~trem ly sat i factory, and the ~al consumption whi<.-h

was mPa."!ured during five hour ' oontinuou run~ing at 12.25 knota, cam out at 1.5 lb. per indicated ho t-pow l' pe_r h our . Th m binary was ~upplicd by th \Valb nd Sltpway and Engi~ r ing Com(l6DY, Limit . A me­what DO\•e} £ ature ID the m hiD ry d partm nt i the o:>ee aah ~jector. A mall hopper in th tok bold is con ­nect~ to th~ hip'~ id abol' t h wa~r lin by a ntJy lopmg ro;st·•ron pape. At the bottom o f t h ptQe a j ·t

of team 1 allowed to ntn wh r tt m t:4 a t am o f water, upplied by a pump. Tbo am &C'llon tak place a in the ord inary btlge ej ctor, and t.he tr am of wat r fl:l8h tbro~gh th lJo tt.om of the hopper, throuab th d1 charge ptpe, and ou t at the hip' ad at an normou-i ''~locity. Th hee are poured in to th hopJ>Qr and d1 -charged through tbe tde by the tre m o f w r wtth

u<:h force as to throw t hem a CODBid rable d tan from the 11hip' id .

---Th o ffic ial for :d-d raught tri 1 of th fiNt ·d tM-

pedo gunboab Leda " u .., fulJy c rr1 d out on th 11th in t . , off b rn 11, tho dockyard ~Jog n pr ott d by ~Jr. P atl i. on, wb iJ Mr. Sa mu 1 R cxk r pr nt tb Admiraltr, . and l-1~. J . P . . H all the ·ng10 r con · tractors. Tha ~.:~ tbe thtrd or tha cl of , cl n~in ~ by M n . . John I on and on , Lim1t d, and all b ,. e~ ded oootr t n qu1 r m~nts. T h n~in w illu -trated and d " ·r ibcd ID Est... J~E££li!'G \ ol lv r :? . The machinery i requtred to d ' '·lop 3500 md1 ttd bor -powH w1th not nlor t han :l in. of a1r pre ..... ur m the tok bold : tb L !da obtainro a m n of !«;01 ho"" . power with an M rag t am 1.J nr in boal " of 11 lb; \acuum. 27.5; ~,·oJution11, :!46; m an tr pr ur in stokehold~. 2 2l in. The speed of tbe ' 1 w~ 1 . 3 knots. The foUowing d tails bow th p ow rs for th ix half-hours a.s tak n :

Half- Indi ted IIo H ours. tarbo&rd.

1 17( 9 () liil _, 3 17ii G 4 19:r,. l

e -P ow r . P ort.

176.3 1 11 2 11 .... ] , 5

'\JVU ti \ ta. Indi t !d

Uo Pow r. :l!>Ji.i 3.): . 0 3562..0 37Ul.6

For OOD\ ~ni nee o f admi ion of the air in proper quan· titi ·s abo,·e or below th gra~, I u e the ca.st-tron mouth­pi introd uce<! by Mr llov.~deo, aod have modifi d them to my requir~ments. The H o wdeo mouthpiece has one ,·alve O\er th fire, and two at the side for the air to pa under the grate. I ha' e added two vah O\ er the fire, aa I found the usual practice ga"~ incomplete com ­bu. tion with certain cl es of coal, because 1t did not admit suffici nt air ov r the grate. In our boiler the three top val v ~.re wide open, and the two aid \'ah shut, for smoky I, and t.·tu t·tr,J for n on · moky coal A number o f mall hol in the bottom furnace doors allow a cer tain quantity o f cold a i r to be drawn in under the gratt-, and it i only th heated a ir which i put aome­times ov r, ..omet im und r the grate, according to the nature o f the coal. Thus we have found e \- ry sort of ooal can be burned with econ omy without amok . The R lotion, a first -cl a battl hip of the R oyal

The Tabl of perimenu (reprodu ·d on the pre- vereign cl , built and ngin d by l.I rs. Pa1mer a nd

5 G

lHOl 9 17 ' J G

17Gi. 1 1iti9 G

'l:.•·(· 0 ~, ... 3:~l.l

cooing page) gtve th r . ults of ,-arioua cl o f eo., of Jarrow, wen t on Thur .. day, Augu t 31, for a COD· coal, moderate and h igh ra.td of combu tion, hort and trac tors' four hour ' full power trtal, und~r what i long trialfl, and gra cle ned at gr-eat and small r officially d tgnau.-d modified foi'CE'd d raught. The intenalt'. These resulu, I tru t, ar indiHdually and ditr 1'\:D\: bctw n th i and e treme forced draught may c ,uecth·~ly int rest ing. I ha\6 tmdea,oured to t:l1mi- be conci .. Jy tated to be tbi • that wher the n~ in

---~le n indi tOO hor~ pow r forth

thr h .>u ... ... •. .. ~~ 01 2 Th fuma of t he boil r-, hich are of th marm looo­moti ' e ty~, are corrugated on the 11d and top on t.b princtp1e of ~lr. }'. \V. \\. bb, of tb L od n and X orth · W t rn Rathray, nd the fi box end1 of th tubee w r fitted wttb ftrrul on tb Adntira.lt.y plan. n aminattoo aft r th~ triaJ-. the 'X>i1 " were found to ba' e u tainld no ill cff£ct from th applicati n of forced draught.

nat all circum tanc which m ight mak tb r ulta und r the form r condition are contracted to d ev Jop a d oubtful. F or experiments. th water ie taktn from m an of at ll t 13,000 horte , und• r the latter oondi t ion hokA mad of C'&lt-iron plates planed to t mpJo.~. th~ contrac t i for 11,000 horses. Tb ·r w a hght wind The in ide dimen ion are 4 ft . .J in . by 4 ft. 4 ~ io. 1 tbrou~bout the day, with a perfectly mooth • The bv 9ft. high. One inch d pth of water equal l U gaJJon trim of tb ~hip W&8 23 ft. 10 in. forward and 25ft. sin. ~ 100 lb. The quantity pumpe.J m to the bot len can be aft, gh iog a m n irnmel'8ion of 24 ft . in .• or 3ft. 10 in . read off at any t ime by th 1 d gaug gl . Th 1 than herd i$rned load draught. T he battl hip ~ot coal i~t w ighP.d out car fully as the tria1 p ~. M er· und r wav at ~1ght o'clock, ring a dtrect coune for I~m.\~ PIM'ROL.n.Y.-The di oovery of a rit b trol um cury tb~rmomt•tel'8 are used for temperat.aree to GOO deg. Be by H ad for the pui"J)OfEe o f obtaining a run in d ·p field i r pvr~d in t h A m d ' trict, Brit• h nd ia . A } .. ahr. Only on e indication noed the means of m aaua -~ wat r. and '"hortly ~fore nin o' lock everything w company und r th titl of th am 011 ~rndi te i.a iog a higher tt>mperature- viz.., the "~mokebox. For thiA t"l>ady for tb haJf-hoarly obaer\ations to be~n. T he . about too n up the oil r u o f tb i'f'8't"n..

" ENGINEERING,, ILLUSTRATED PATENT RECORD.

COMPILED BY W. LLOYD WISE. SELECTED ABSTRACTS OF RECENT PUBLISHED SPECIFICATIONS

UNDER THE ACTS 1883-1888. T~e number (lf views given in the Specification Drawing8 is stated

ttl ~eh ca~e ; where n one are ·mentioned the Specification i8 not 1ltmtrated. '

Where l nventioM are communicated from abroad the Names &~ .• of the Co~mu?ticators are given tn i talics. • '

Coptes of SpecijtcattoJt,Q m11y be obtained at the Patent Office Sa~ Branc?t, 38, Cursitor·Btreet, Chancery·lane E. C. at the un;fono, pnce o/8d. ' '

The dCf~<' o.[ th_e ~dvertisement of the acce1)tance of a complete soecl)Wttton ts, t.n each case, given after the abstract, tmlus the Patent has been. sealed, ·when tlLP- date of sealing is given.

~nu person ~ay at a~y time within two m onths .front the date of 1/~e ad ve~ttaeme~t oj the acceptance of a complete specijication, gtve noltce at the Patent O.Oice of oppo8ition to the grant of a Pate>lt on any of tlte o,·ounds mentioned in the ~et.

E LECTRICAL APPARATUS. 17,246. T. J. D. ltawllns, Lymington , Hampshire.

Electric ~ri~ar~ Batteries. [4 .F igs.] Septem ber 27, 1892.- In th1s m veot10n t he carbon or negati ve electrode is made disc-shaped, .and suppor ted upon an axle a rranged to be r evolved, a port10o only of the electrode dipping into the

F~ 1. Fig .3. ,

. ._.

• • • ; • ,I : • • ~ '',,.. ./ ~ ... .. .... 0 ... • • ... :

. I ··········-·· ........... .-....... "'

Pig.2.

•

h f'xl'iti ng ft uid. The car bons are car ried upon a spindle E insu lated by a. covering of gutta-percha F. T he carbon discs for eac ce11 a r e placed io electr ical contac t by a core G. To connect th t \VO elictrodes together, a mercury t rough J is used electricall c?noect.ed t<? th.e zinc; aod connect ed to the ca rbon is a coppe d:sc whtch dtps ID the m ercury. (~ccepted August 2, 1893).

e y r

GAS, &c., E NGINES.

• d

18,020. J. Southall, Worcester. Gas, &c., E ngines [~ Figs.] Oot~ber 10, ~892.-Tbis inven tion r elates to gas an otl motor eogmes. K ts par t of t h e combustion space of th cy linder into which opens the vahre. This vah'e ha.s attache to i t a. ring forming a. slide valve gover ning the exhaust por M, th6 air s upply port N, and the port 0 for supply of gas or o vapou r. When the working piston of the engine commences it exh'lust stroke, t he face of the cam Y causes t he end of lever Z t press oo t he eod of the spindle E, lifc.ing t he valve sufficien tl to allow of the exhaust gases passin~ into the por~ M ; at th ?Om!Jlencemeot of the next outstroke of the piston, the ,•ah· 18 still fur ther raised by t he ac tion of the cam face uot il the r in closes the port M and uncovers ports 0 and N for the suppl of gas and air to the cylinder ; when the piston makes its instrok

e d t

tl ~

0 .) e e g y e

r

''·'lt

compressi ng the charge the val ve ia closed. At the end of this compr( S3ion ~troke t he lever Z, operated by another cam faoe Y2, d raws back the spindle E, open ing the val ve A, which allows some of the compressed explosi\re charge to pass by the passage J to t he ig niter , thus igniting the charge to actuate the next outstroke nf the piston. The lever Z is operated by t he sliding cam Y, d riven by a pin in t he motion shaft B, this shaft being driven by ge:ning o n the c rankshaft at a. s peed of one r evolution for two of the c rankshaft. The one end of the lever Z wor ks between t he two cam faces, which act on it so as to cause its other end , which works in an eye on the spindle E, to impart to the valve the necessary for ward movements for supply and exhaust, and to the small valve A the required li ft fo r ignition. ( A ccepted .4ugtl8t 2, 1893).

17,277. B. B. Andrew, A. R. Bellamy, and R . Garslde, Reddish, Stockport. Governing the Speed of Gas, &c., Engines. (6 Figs. ) ~eptember 28, 1892.- This invention relates t o means for govermng th t> speed of gas, &c., engines. The sleeve f ot a centrifu~al governor is connected by rods g, li to the end of . a. shor t le\'er i mounted on a shaft j, sup·

Jv . 111n

ported on the engine frame so t hat the movemen t of the go,·eroor c:1.used by irregularities io the speed of t he engine causes the lever to oscillate upon it3 stud. To the boss of this lever is a lso s •cured an arm. the end of which is shaped so as to keep the s t riking finger k out of con tact with the hir.·and-miss mo tion ,

E N G I N E E R I N G.

whe~ the speed of the engine is too g reat. Means are provided fo r cau~mg the go,:ernor to t hrottle the supply of gas when the engme ex~eeds 1ts normal speed before the bit·and-miss mo ve. ment, whtch operates the gM admission valve, ca.o come into pll.y. (d ccepted .Augttst 2, 1893).

15,417. J. E. W eyman, G~lldford, Surrey. P etro­~eum~ &c., E n gines. (10 F l.£lS.] Au~ust 27, 1892.-This mven~l(?n r elates to P.etroleum, &c., engmes, in which t he vapor1stng chamber c 18 constructed so as to contain a cer tain amount of oil, which is maintained at a uniform dept h and heated by c~nductors d, e, t he beat being transmitted tbrouf?h these to the 011 from the combustion chamber b or cylinder a or from tbe waste gases of combustion conveyed tbro~gh th e exhaust ports, &c. , arranged to pass through the vaporising ch amber , and the

. .

/J 411

heat t hrough the ext er nal conductors e being generated from an exter nal lamp; t his vapor iser for ming a separate chamber in t he cylinder of the engine. Tbe ai r to supply combustion in the cylinder is ~rawn through the com bustion ch~mber or the po!ts, &c. , so that 1t can be heated, aod at t he same ttme the vaporismg vessel pre,·ent ed from becoming too hot.. Ao automatio feed er is provided by m eans of which the supply of oil is r egulated aod the le\'el maintained in t he \'apor ising Clhamber . (Accepted .4. UJ U8t 2 I 1893).

GUNS, &c. 15,223. T. Perkes, London . B reechloa d ing Small

Arms. (4 Figs. ) August 24, 1892.-Tbis invention relates to t.he ejecting and lock mechanism of breechloadiog small a rms. The spr inJr is operated and compressed by the knuckle or the gun or a movable p rojection in it such as a rod, aod is made self­cocking , thus remo\ ing the resistance to the closing of the gun. In t he lock mechanism the spring is operated by the fore end, the compression for firing being g iven by the fore end on closing lbe

Fig.2.

F '

gun, and the expans ion being allowe d on opening, Lhis ex pansion operating to cock the tumbler. A is tbe extract or leg, A' the bent, D tbe ejecting lever in which is a r ecess to take the free eods of the spring- C, which ha.s a tongue C1 at t he turn eo d. D is t

• I

t r

be d etent taking into a slot cut io the extractor . E is a rod working from and photed to the hammer , and capable of opera t­ng the sprinct C on the fall of the latter. The main spring F of b e lock mechanism is pivoted at F1 and i ts free ends work io a ecess in t he hammer . ( A ccepted .dugust 2, 1893).

15,613. C. B echls, T urin, Italy. F irearm s, [15 Figs.)

t August 31, 1892.-T his invention relates to means for facilitating he use of firearms at night, and consists in t he employment of lectric lamps with a storage battery in order to illumine the ights of riftes, &c. T he electric accum ulat or is inclosed in a mall sheet-metal box A arrangfd under the barrel. T wo h oles re provided in the lid for the ter minals, and a spr ing is attached

e 8 8 a.

b 0

to the box by a screw at one end, a stud carrying a platinu m poin t ei ng provided at the other. The application of a. cer tain amount f p ressu re oo t he spr ing causes the point to make con tact with a

' r;=~ Ji'ig . J. Fig . 4 .

0

IS lO

pl atinum plate, and close the ci rcui t of t he lamp, which then uminates the sight. The box is attach ed by a small spr ing

atch worked by a p rees b utton , so that the lamp, contained a r ing embracing the barrel, can be readily placed in front of

nd abo ve t he sight or any other position. The direction of the y of light from the lamp is io t hat of the axis of the gun, so as enable the line of sight to be determined wh en th e surround­

g dar kness is complete. Mechanical means a re provid ed for utt ing the lamp into aod out of action. (Accepted July 26, 93).

ill c • tn

a ra to • m p 18

STEAM ENGINES AND BOILER S.

s 15,068. M. H . Robinson, Thames Ditton, Surrey. team, &c., Engines. L6 Figs. ) August 20, 1892.-This in · ntion r elates to the constr uction of siogle-aoting steam enginet~. is the steam cylinder and B the valve cylinder , in which work e steam and valve pistons 0, C respectively . At th e top of the roke s team enters the cylinder A from th e cheet D by ports E

ve A tb at

t he cylinder B, aod forces the piston G downwarrls, and with the val\•e piston C. At a ce r tain p oint this p iston covers the

ports E io the valve cylinder B, aod cuts off t h e steam, wh ich t h en

. lU

it

•

349 expands io the steam cylinder. Near t h e end of the stroke the piston Q uncovers the ports F , and, during its passage to t he bottom of the stroke and back again to t his poin t, steam exhausts. During the remaind t r of the \lpstroke until t he por ts E are again uoco,·ered by t he p!ston C, the steam io the cylinder A abo ve the

piston is con1pressed. The governor (Fig. 2) is applied by means of a. sl eeve H sl:ding on the outside of the cylinder B aod con­nected by a spi!Jdle passing through a gland in the top of the steam chest wttb a gover nor capablf' of moving it up and down, so as to contract and enlarge the por ts E. (Accepted July ~U 1893). •

16,845. J. and A. Pren tlce, Westown, Thankerton La~ark~ • . Eng~ne Governors.. [3 F'igs. J September 21: 1892:-Th.IS rn vent1on relates to eogme goverl tors d escr11Jed in spectficatton No. 1620 of 1892. The ftuid is drawn from the closed chambe~, the s.uppl~ to wb:ch is regulated, and, if t he speed of the mato engtO(S 1 n~reases abnormally , the suction from, is greate r than t~e ftutd supply to , the tank , a vacuum being the_reby c reated: 10 the dosed chamber , and t he piston, agaitJst the act~on of a s~mng, s i ~ks under atmospher ic pressu re into the cyhnder .. A t8 t.he flUid tan.k forminct t h e foundat ion of the ap . paratus, lll the ~tdes of whtch are ai r holes a. Al is the tank cover ; B, Bl, C, Cl, the pumps ; D t he cylindr ical "sue t ion" chamber , on the to, of which the <'ylioder E is fi tted and from t he top of which a pipe F leads to the bottom of the tank A, t.bis pipe

.Fig. 1.

8

8 '

. ·-• • • ...

Fig .2.

A

A

o·

• • • • ' I • • • ·-·

ha' iog a controlling cock. H, Hl, I , 11 ar e J·ipes \vhicb cc.m· municate, respec tively, '' i tb the suet ion chamber D and t he pumps B Bl, aod C, 0' . Pipes connect the pumps B, Bl aod C, Cl with the tank, and L, Ll, M, Ml a re the pump plung ers connected by Jiok cross h eads 0 , 01 to the pins of t h e c ranks Q, Q1 on the c ross s haft R. S are t he bear ings ot t h e shaft, and T a belt pulley. bare stuffing· boxes. Tbe ball va lv€:8 c, c1 a re fitt ed in the val ve CD.f ings d , d' . e is a piston workin~ io t he cylinder E. e' is a colla r on the piston , between which and the top of the cylinder a spr ing g is interposrd. The piston e is so connected to t he va lve for cont rolling tbe supply of motive fiu id to the main engin~s that its inward motion sh uts and its outward motion opens t he valve, the sprin g g normally tending to press outwards the piston e, and, thE>refore, to keep open the supply valve of the engines. (.Accepted J 11.ly 26, 1893).

16,326. J. S. Starn es, London. Stuffing-Boxes, &c., of Steam Engines and P umps. (4 Figs.) September 12, 1892.- I o this in vention ao additional member is provided to the packing gland, and eer ves as a !!plit cyli ndrica l sleeve D provided at the upper end with ftao~es a, b. There is a space between the

ftanges a and c sufficiently deep for the introduction of a series of nuts a rranged circumfer entially between t he two, and opera ted by a spanner, and t h ereby caused to screw up and down fix ed bolts E seoured to the flange of the to p of the s tuffing-box, and passing through a, to the ftange of the stuffing-box gland c. (Accepted J uly ~6, 1893) .

15,817. W. and A. W. Sisson, Gloucester. Steam Boilers. (5 Figs.) September 3, 1892.- In this inYenbion the firebox is constr uc ted with rows of tubes crossing it from side to side in t hree different directions, each row of tubes lying to a plane inclined to the horizontal suffic iently to cause an adequate cir culation of water to be set up t hrough the tubes, the axes of which lie up and dow n the incline. T he boiler is eonstru c ted with an internal fi rebox 2, within the upper por tion of wh ich !lr e a rranged three series of water tubes 3, 4, and 6 conn eoted to the fi rebox, and arranged to extend in t hree different d irections. ThE\ tubes in each of the g roups a re in two planes one above th e other, and each slightly inclined to t h e hor izontal, so as to cause an · effective circulation of water and steam to be set up through t hem when they are exposed to the heat of t he fire within the fi rebox.

350 To enable access to be gained to the tubes tor cleaning or renew­ing them, the boiler shell is constructed in two parts adapted to be connected and disconnected to and from each other and to

I 2

and fcom the uptake 7 from the firebox. For t his purpose to the exterior of each of the adj acent ends of the two parts 1, la. of the boiler shell is r iveted an angle iron forming a circular flange 8. (Accepted ~ ug1tst 2, 1893).

16,145. A. Shlels, Glasgow. Water Gauges for BoUers. [5 Figs.] eptember 9, 1892.- This invention rebtes t1 water gauges tor boilers, and it has for its object to so construct the gauge that whilst i t , under normal conditions, allows a perfect blow throuj:th, the steam and water ways are closed automatically in the event of the gauge-glass breaking. Fitted in the interior of the glass tube e is a ver tical spindle h, which has a small piston valve ion it at its upper end, and a disc valve j, of larger area than the piston valve. screwed on its lower end. The extreme upper end of the spindle passes through a guide hole l, bored in a bridge 1n secured to the ring- seat of the piston valve. This seat has a central hole for the reception of the piston i , and is fitted into a washer o secured in the brass fitting a. of the gauge. Sruall p rojections pare fitted to the vah·e seat, and catch in correspond­IDg recesses in the screwed washer o. When the nut is taken out, the bridge m can be easily turned round in the one or other direction, so as to screw the washer up or down, and thereby

Fig . 2 .

P~ . 1.

adjust the valve se:1.t to any desired position. Th~ diameter of the water valve j is such that when the gauge-~las~ 1s b~oken t~e rush of water lifts it up off its rest t and forces 1t up a~amst a cn·­cular seat in the fitting b, so as to close the waterway, th1s valve n_or ­ma.lly resting on four triangular suppor ts made on the upper_ s1~ e of the hollow cylindrical rest t , which has passage ways cut 111 1t, covers over opening w leading to the blow-off cock. The hole made through its top serves as a guide for the lowt-r end of the spindle h. If the gauge-glass is b~oken the w~ter rush~s through cook g , and lifts up the water valve;, togeth_e!Wlth the spmdle hand the steam vah•e i and as the water valve; 1S of greater area than the steam valve i ,' the upward pressure forces the valve i tightly into the hole made in seat and so cuts off the escape of steam, at t he same time as the wa.t~r val ve closes tight up against its seat 1· at the bottom of the gauge-glass and cuts off the escape of water. When the gauge is in proper working order the Yalves fall down and leave a free passage. (.Accepted ~ugust 2, 1893).

8317. A. Miller, London. Heatin~ 'Yate~ Supply of Bollers. [6 Figs.] April 25, 1893.-Th1S mven~10n has for its object the beating of t?e.fee~ supply of steam hollers before it enters the main one as 1t 1s d1soharged from the feed pumps. The feed is forced by the pump through pipes to the check valve

Ft:g .2.

A

A, and as it accumulates in the boiler , escapes ~Y ~h e valve B into the main boiler . The beat from the furnace 1mpmges on the roof aud sides of the firebox, and if fitted wit h tu~es acceler~tes the raisi ng of the temperature of the feed before 1t escapes mto the main boiler. (Accepted ..August 2, 1893).

14 890. A. Bratoluboft', Moscow. Produ~i':lg su 'erheated Steam. [2 Figs.] August 17, 1892.-Th1s l-ll· ven~on relates to means for the production of ~upe~eated s.team and for applying it to steam engines, and cons1sts 1~ a senes of tubes a arranged in the heating chambers I .• II.! wJ:nch art: s~pa-

t d by brick arches b and the lower part of whtch 1s also d1vt~ed ~:o~ the upper by a thin brick arch c, channels fo~ conveym~ the hot gases being thus formed. Steam comes b) the tube d provided with a regulating cock e into the first tube of the upper row arranged in the upper chamber 11. Th_e ste_am passes con­secu tively through the tubes of the two rows1n th1~ cho.mber, and comes down into the first tube of the upper row 10 the chamber directly beneath if there are more t ha.o two chat;nbers, _and so on until $he lower chamber I. is rea~hed, the steam 1n <;omm~ out _of the end tube of the lower row in this ch!'-mber bemg led to tts

E N G I N E E R I N G. destination by a. pipej provided with a cock and a thermometer g. The products of combustion take a dire<'tly opposite path to that of the steam by entering into the upper portion of the lower

. 1.

-14.890.

chamber, and then into the upper par t of the next one imme­diately above, and so on, leaving by the chimney after having passed through t he upper par t of the highest chamber of the apparatus. (.A ccepted ..Attgust 2, 1893).

13,954. T. Shepherd, Manchester, and M. Ollver, Salford. Piston Packing Rings. [2 F igs. ) August 2, 1892.-This invention relates to packing rings for pistons, and consists of metallic r ings made U -shape which fit side by side into a corresponding recess in the piston, with their free ends working against the sides of the cylinder. The body of t he piston is formed in two halves, and the recess formed to recei\·e the rings is slight Jy less than the width of the two

Pig.1. Fig.2.

ri ngs, a space being thus left between the two halves. This space is filled in by a series of thin discs of material such as brass, surrounding the piston-rod. The rings are cut through at one place to allow of their expansion and ~ontraction, and are fitted with "steam bits " at this place to prevent the passage of steam. The rings readily give on being compressed between the two halves, this allowing them to become elongated, and so com­pensate for the wear. (.&ccepted .Augttst 2, 1893).

MISCELLANEOUS. 16,927. W. B. Thompson, Dundee, N.B. Plate·

Bending Machines. [2 :ltigs.) September 2-e, 1892.- In this invention all t he drivin~ gear is concentrated atone side A. The gable at the other side B consists of a base 3 carryine- the bearings 4 of the lower rollers 5, those of the upper and adjustable roller

Ftg 1

8 7

F~ . 2

3

7 being suppor ted by a cross beam maioto.ined by strong columns 9. Ey thts construction half a plate can be bent, then with­drawn, turned end for end, and the operation completed . Means are provided for bending plates of great length without with­d rawing and turning them. (..4 ccepted July 26, 1893).

16,140. T . Thorpe, New Basford, Notts. Winding Machines. [2 F igs. ) October 7, 1892.-This invention re-

Fig.2.

Fig 7 .

16140

la tea to a winding or spooling machine i~ which a rot~ry_ moti_on of varying speed is communicated to the sp!ndles a by fn_c~10n d1scs b secured to the tormer, and disce c carrted by the dnvmg shaft cl

fS EPT. I 5, I 893.

and capable of being reciprocated laterally. A le,·er lt h2 com· munic'ates the movement of the lever k to the shaft d. When the yarn is being' wound on the thick part of the spool it revolves more slowly, but more quickly as it nears the thin part. (Accepted July 2G, 1893).

16,549. s. Alley and J. A. MacLellan, Polmadle, Renfrews., N.B. Making Moulds for Casting. (4 Figs.) September 16, 1892.-':.~is inven tion has for its object to provide means for making castings of large size, and consists of a box, upon which is t emporarily secured the flask, in which " half mould is to be form ed, this box having at one side or end of it brackets hinged to fixed standards, so as to allow of the box and flask being turned completely over for the purpose of depo· si ting the flask with the mould in it upon a truck, the turnmg over being effected by hoisting appa1·atus, a chain from which is connected to a. swivelling shackle at the end of the box furthest from the binges. The flask A, in which a balf mould is to be formed, is temporarily secured to a. cast-iron box B of a rectan­gular form. On one side of the box B are formed brackets C, bing-ed to fixed standards D, to allow of the box and the flask beina­turned completely O\'er. The flask A is connectEd to the box B

F¥J .1

Pig .2

• Jar )O( • •

•

•

•

by shackles F, which engage with studs Yl, fixed in bosses F'l in the ends of the box. The shackles F are jointed to rods G, pass­ing through lugs on the box, and these rods are adjustable by means of disc nuts screwed on their ends. Springs H are applied between the shoulders of the rods G and the outer part of a wooden bedpiece J, fixed on top of tbe box B, through which the rods pass before going throug h the 1 ugs, so as to keep them from dropping " hen the shackles are disconnected from the studs cf the ftask. For the flask A, in which the flanges and inner side of a. segmental plate are to be moulded, s lides K, L, .M ar~ fi~ted a.t the sides and ends of the box B, and are adapted to the mchna­tions of the flanges to be moulded, and to which the flange pat­terns are fixed. 'I he sliders are arranged in guides, and move out or in when external hand wheels are turned. (Accepted J uly 26, 1893).

737. J. s. Starnes, London. Stern Tubes of Steam· ships. (7 Figs. ) January 12, 1 93.- Tbis invention has for its object to provide means for preventing leakage or rush of water from the stern tubes of screw .steamers. a and lJ are respecti ''ely the top and bottom hat ves of the vah·e· box, with flanges al and bl, by wh1ch the.y are bolted together_around t~e. shaft. in _th~ valve­box is contamed the vah•e d havmg a sem10u cular prOJection dl, which fits upon the shaft e like a saddle. The valve d is raised or lowered by means of the screwed spindle e carried upwards through the stuffing-box/, and actuated wben required by the handwheel h. Tbis bandwheel his formed around its periphery with indentations into which takes the pawl o, which is pivoted to the standards p bolted to the \'alve-box cover, and serves to hold

~

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the valve securely in any fixed position by the interposition of a pin q through the standards and pawl. 'l.'he fore par t l of the valve-box may be formed as a stuffing-box, and t he old gland from the stuffing-box of the stern tube is made use of for it, so that the packing and support of the tail shaft and stuffing-box are douhly secured. To affix this shut-off vah•e and valve-box to the stern t ube the gland is drawn out of the stu ffing-box of the stern tube a suOicient distance to allow of t he introduction of the two bah·es a and b of the valve- box, which are bolted together around the tail shaft through their longitudinal flanges. The box then is slid along the shaft. and the spigot i enters the stuffing-box of stern tube and take9 the place of the gland re­moved from it. (A cceptecl.Auow,·t 2, 189a).

UNITED STATES PAT.ENTS AND PATENT PRACTIOF. Deecriptions with illustrations of im•entions paten ted in t he

United States of America from 1847 to the present time, and repor ts of trials of patent law cases in the United States, may be con ulted, gratis, at t he offices oi E xotNBERHiO, 35 and 36, Bed lord­street, Strand.

LA YISH DECORATION.-The dome of the Colorado ea pi tol is now approaching completion . It is proposed to CO\'er it with a heavy plating of silver. Colorado, it will be remembered, is a great silver State.

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