On theConsumption of ~'uel in Locomotive Engines. 367

apparatus; making together, not less than six minutes delay betweeu each pair of wagons, in addition to the time occupied in their ascent. The same kind of delay would occur to the desceuding wagons, with this additional disadvantage, that in. order to raise the traveling ap- paratus between the descent of each pair of wagous, the engine musl. be kept in constant work; the same tot downward as for upward trail]e, causing thereby a considerable extra expense for coat and other requisites.

Thcre are a few other inconveniences which would result fi'om :h. change ; but those which I haw? ah'eady pointed out, being of lh<. greatest importance, and also quile sulticient to show lhat the appli- cation of the prilmil)le to our inclined plalles, is, by no means, desira- ble, it is needless ~mw to memion them.

From the preceding renmri,zs it will, I think, appear evident, that the applieatiol] o[' the atmospheric principh', to our railway in its pre- sent state, so thr fi'om b~;ing any advantage, wonId, in l'2tet, subject us not only to serious inconvenience., but to considerable additional expense, and that too, (so far as rclates to our t)rescnt traffic,) without anyeomp(?nsati~g benefit. It, however, by no means lbllows, that the principle eant~ot, under ang circumstances, l)e applied with ad- vantage; on the eol~trary, I am" of opitlion that it is peculiarl 3- al)pli- cable to the circumstances of our railway, it' properly carried out.

R~gi/,vcey O{fice, Cromford, Ju/.y Is/, 1844. Cir. Eng. and A~eh..loum.

d review of lhe circumstances which have a~'.cled lfie Coms"u mplit~ of Fuel in lhe Locomolive EJ~gi~ze.s' of/he Liverpool a~d Ala~cher- let Rclihvaff,from lhe ot)ening lo lhe prese~! IDne. 1]~} EmvAt~l, WooDs, C, E.

This is an excellent practical paper, probably the very best with which Mr. ~Veale's quarterly budget Ires y e t furnished us. The importance of the inquiry to which it is devoted, is sufficiently attested by the simple fac b that it has fi)r its object to give lhe why and wherelbre, of the consumption of fuel on the Liverpool and Blanches- ter line, having been reduced (with an increase rather than reduction of traffic,) from 12,604 tons in 1838~ to 310.-3 (!) ill 184.3. Mainly, this has been owing to at progressive increase from ~-th inch to 1 inch in the extent of" the lap, (as it is technically called) or space bY which the sliding valve overlaps at each end the steam ports (when placed exactly over them,) and to the greater rapidity with which th~ waste, or used, steam is thus enabled to escape ti'om behind the pis. Ion. The ralio~mle of this result is made exceedingly clear in th.'? following extract : - -

"Alternate]y to fill and empty the cylinder of ils contents, art: operations requiring lime. The lime allowed for the first operation, that of filling the cylinder with steam, necessarily corresponds with the duration of the stroke, whatever its duration may be. But 1his carmel be the case as regards the second operation~ the emptying of

368 Civil Engineering. the cylinder. This ought to be performed in an instant, in the twink- ling of an eye, in tile minutest fraction of the duration of the stroke, otherwise the steam would continue pent up when it ought to be liberated,--when it ought to assume its minimum pressure, the pros- stirs of the a t m o s p h e r e , ~ a n d would exert an it~jurious counter pressure against the piston, tending to increase the resistance to he overcome.

~' To (;fleet the free and rapid discharge, it is necessary ' not merely to open the conmnmieat ion to the exlmust ing pipe, hi.it to o p e t l a .~l, ide passage, a|~(t to have this (lo,~e })y the time the piston recom- mences its motion. The valve alluded to (the ohl one used until 1835.) cannot aeeonll)lish this. Its motion is gradtlal~ not inslantane- ()us. T h e passage only begins to open when the piston is on the turn~ and is not wide open mltil the piston has traveled through one-tenth of i,s entire stroke. The s team in the cylinder, is, consequent ly, re- strained from e:<:apiu:y, 1)(:i~#~ wired, 'awn it~ the passage out, and, (-ouscqtl,:.lltly, takes con.~'i(/c)vz{)[e l{~ze to assttme lho pressure of the ;tl l:I'i ()S i) [ l o r e .

+; Iu the', tn~.'~t}whi[c the new stroke, has begtm, and beet, partially completed, and xo ',i~r tl~e piston has t~ad to contend with a resistance altog~o'ttier ilI%ititna~.e, a resistance which, it1 m a n y cases, and espe- cially at high speeds;, has been etiua[ to the sum of all the other resistances put tog,eth¢.r."

't'he. m(ri t of first g,.~tlin{,g rid of this i l legitimate resistance is ascribed lo Mr. l)cwmtmc~, o[ the: i~iverpooi aml Manchester l i t ; e : -

" The next i~t,.l)olt:mt improvement in the vah;es is due to Mr. ., 27.s l)e\vranee~ al>[ was s . ~ e . . t e d by him ear ly in the ,,.ear 1S40. I l ls

principle was, t!mt th(; exhaust ing passage, instead o{" being only par- tially open at the moment of eom}fleti~g tim stroke, as was, more or less, the case with the engines before named, should be mmrly wi,.h; open, which was to 1)e accomplished by making the ~lap ' of the valve eqtml to tl~e width of' the steam p o r t ; ~ m o r e o v e r , that the trave[ of the valve should be made proport ionate to tile increased lap, so as to allow tI~e s'ame area, or Ihe s:uno amoun t of opening of' the s team t)ort tbr ti~'.' a,,tmission of" steam. A fiavoral)le opportuuit 3, occurred for earryit:g out these ideas, both as regarded iimreased lap and in- creased travel, from thc circumstance of two engines requir ing exten- sive repairs, which would allow thno ibr the. needflfl alterations. One inch !~ [) was giveq to the Ra])id's valve, which was now made to travel . i '~inehe~:. Thc result of this a r r a n g e m e n t was, that the ex- haust ing pz~:~'~aT;e was ore.' inch open at the end of the slroke, arid that, suppo:dn{," the slrok.e of the piston divided into 100 eqnal paris, the s~eam was cut oil" at '79; it expanded from 79 to 95} at 9.5 it began to l~c rt h :~c 1, and was escaping into lhe a tmosphere from 95 ~o 100. The L'eq)id's Nroas average consumpt ion of coke, whell running sixty-fbur trips of a0 miles each with coach trains, before the alteration, was ,3(;.3 lbs. per mile, and o.8.6 lbs. per mile immedia te ly ~ l e r the aheration. Thus we have a measure of the effect produced ~ a savb~g o f o~ze-fi~urlh oJ' lhe fue l . "

Mr. W o o l gives the following valuable summary of the work

On the Consump t ion o f F u e l in Locomot ive Engines . 369

done , coke c o n s u m e d , a n d loads ca r r i ed , by the s eve ra l c lasses ot eng iue s on this l ine for the last f o u r years . I t de se rves , and , w e doub t not, wi l l r e c e i v e the e a r n e s t a t t e n t i o n o f al l o the r r a i l w a y compan ie s .

a a o s s Co~'sv .~vTm~ OF coxE. -Passer,get E~gines . Coke.

Tons. ewt. qrs. Pe r mile

,~ ) ,ear e n d ' g

y e a r e n d ' g

y e a r e n d ' g

J t m e , 1840 3463 Tr ips , 30 mi les 1523 16 3 ~ 3 2 . 9 1 b s . l ) e c e m b e r , " 3596 " ~ 1276 9 1 = 2 6 . 5 ,hme, 1841 3493 " ~ d 1036 15 3----22.1 I ) e c e m b e r , " 3496 " o eo 958 19 0 ~ 2 0 . 5 J u n e , 1842 3655 " ~ ~ 853 3 3 ~ 1 7 . 4 D e c e m b e r , " 3526 " ~ o ¢ 684 9 2----14.5 J t l l le , 1843 32.13 " ~ ~-- 646 1 1 = 1 4 . 9 D e c e m b e r , " 3555 " ~ 717 2 2-----15.1

l O, O • r e

,lune~ 18.t0 1925 " 1160 12 3--~45.01bs. l ) c e e m b e r , " 1653 " ~,7 867 9.3-----39.2 J u n e , 1841 1640 " ~ ~ 749 0 1 = 3 4 . 1 l ) e c e m b e r , " 1370 " ~ e~ 531 17 1 ~---29.0 J u n e , 1842 1604 " . ~ 559 2 2~--.26.0 D e c e m b e r , " 1521 " ~ o~ 421 17 2 = 2 0 . 7 June, 1843 1588 " ~ c~ 441 7 2 = 2 0 . 7 Dceember~ " 1605 ~ 451 12 2 ~ 2 1 . 0

y e a r e n d ' g

.Bank ,Engines.

June, 1840 349 Days . 486 11 3 D e c e m b e r , " 353¼ ,, 369 10 0 .Iutle, 1841 349~ " 343 3 2 D e c e m b e r , " 341~ " 251 11 0 J une~ 1842 361 " 174 6 3 D e c e m b e r , " 363,~ " 143 13 3 J u n e , 1843 45°¼ " 162 8 3 December, " 517~ " 183 12 2

Coal a n d

J u n e , 1840 D e c e m b e r , " J u u e , 1841, l ) e c e m b e r , " J u n e , 1842, D e c e m b e r , ,' J u n e , 1843~ l ) e e e m b e r , "

I n the y e a r 1838, 1839~ 1840, 1841, 1842, 1843~

Bal la s t Engines . 43(1¼ " 489 4 0 370 " 344 17 3 .~ 334 " "o .-. ~ ~' o ~ o 4 2 ~ = 351-~ " 312 4 2 ¢z ~¢n 407 " 313 3 2 ~D 44 :~ ,, 243 3 3 ~ -2 306~ " 226 5 0 < 398¼ " 274 13 3

Genera! Resul t . ,

12604 tons o f coke c o n s u m e d . 11754 - • 6518 " 4508 " 3393 " 3103 "

Mechanics' Mag.