878 



UBPOKT — 1884. 



at 

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would not so readily appreciate, and that is, liow a groat part of tliia loss is due to 

 the inability of materials to resist lemperatnre and pressure beyond certain com- 

 paratively low limits; and he tiuis perceives that unless some hitherto wbolK 

 imsuspected, and apparently irapossibh', improvement in these respects slmulil 

 be made, practically speakincr t\w maximum of useful effect must he far bel<m- 

 that which pure science would say was possible. Nevertheless, he knows that 

 within the practical limits frreat improveineiits can be made, he can (h-a\v up a 

 debtor and creditor account, as Dr. .Kussell and myself iiave done, and us lias Ijecu 

 done by Mr. William Ander,son, the enirineer, in tiie adiniral)le lecture lie pave 

 the Institution of Civil J'lnfrineers in December last on The Generation nl'Stt-i 

 and the Thermo-dynamic; principles involveil. Fiu'uislied witii sucli an arcount. 

 the eiif^ineer is able to say, in the lannuiii>e of commerce, I am debtor to tlic 

 fuel for so many heat units, liow, on tlie credit side of my account, do f disciiaii'e 

 that debt ? Usefully I have done so much work, convtsrted that mucli ln'at intii 

 enerfry. U.selessly l havt^ raised the air needed for combustion from the tens 

 perature of th(! atmosiihert^ to that of the jrase'i escajnnjj by tlie cliimncy; nml 

 he sets Iiimself to consuler wlietlier some portion of the heat cannot be alis'tracti'd 

 from the.se pases and ]w transmitted to tlie incoming' air. As was tirst poiutcil 

 out by 3Ir. Anderson, ho will have to say a portion of the heat has been con- 

 verted into energy in displacing tlie atmosphere, and that, ,so far as the frn?mb 

 products of the coal are concerned, mu,«t, I ffar, be ])ut up with. lie will sav. 

 I have allowi'd more air than was needed for combustion to pass tlirniifrli tie 

 fuel, and I did it to prevent another source of loss — th»^ waste which occurs wlun 

 the combustion is imperfect; and he will begin to direct his attention to die um' 

 of gaseous or of liquid fuel, or of solid fuel reduced to fine <lust, as by Cramp- 

 ton 'a process, as in lliese conditions the supply may be made continuous ami 

 uniform, and the introduction of air mny lie cusily regulated with the greatest 

 nicety. He will say, 1 am ol)liged to jmt umong my credits — loss of heat bv con- 

 vection and radintioji, loss by carrying particles of water over with the steaiii, lo.v 

 by condensation within the cylinder, loss l)y sti'auLrulation in valves and pa.ssaL'i'S 

 loss by excessive friction or by leakage; and he will as steadily a])ply hiniscll'to tin' 

 extinction or the diminution of nil sucdi caiisos of loss, as a prudent Ohaiicfllor oi' 

 the Exchequer Avould watch and cut down every unproductive and uinuwssnrv 

 expenditure. It is due to the guidance of ,'«uch considerations as these that tlu' 

 scientific engineer has been enabled to bring down the consumption of fui>l in the 

 steaiu engine, e%'en in marine engines such as those which projudled the ship that 

 brought us here, to less than one-half of that which it was but a few years back, 

 It is true that the daily consum])tiou may not have lieen reduced, that it may be 

 even greater, but if so it arises from this, that the travelling public will have hi^'li 

 speed, and at present the engineer, in his capacity of naval architect, has not seen 

 bow — notwithstanding the great improvements that have been nuide in the forms 

 of vessfds — to obtain high .speed without a hirg(> exponditnvc of power. I antici- 

 pate from the application of thermal science to practical engineering, that great 

 results are before us in those heat mot(n's, HU(di as tlu; gas engine, where the heat is 

 devel.iped in the engine itself. Passing away from heat motors, and considerinfr 

 heat as applied to metallurgy: From the time of the hot blast to the regenerative 

 furnace, it is due to the application of science by the engineer that the economy of 

 the hot blast was originated and that it has lieen developed bv i' labours of: 

 Lowthian Bell, Cowper, and Cochrane, h'qnally due to this applicanon are the 

 results obtained in the regenerative furnace, in the dust furnace of Crampton, and 

 in the employment of liquid fuel, and also in operations connected with tlie rarer 

 metals, the oxygen furnace and the atmospheric gas furnace, and, in its incipient 

 staple, the electrical furnace. To a light kudwledge of the laws of heat and to 

 their application by the engineer, must be uttriluited the success that lias attended 

 the air-refrigeratinfr machines, by the aid of which fresh meat is at tlie end of a 

 long voyage delivered in a perfect condition ; and to this application we owe the 

 economic distillation of sea water by rep(>ated ebullitions and condensations at 

 successively decreasing temperatures, thus converting the brino that caused the j 

 Ancient Mariner to exclaim, ' Water, water everywhere, nor any drop to driul;,' into j 





