878 REPORT — 1884. 



would not so readily appreciate, and that is, how a great part of this loss is due to 

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

 paratively low limits; and he thus perceives that unless some hitherto wholly 

 unsuspected, and apparently impossible, improvement in these respects should 

 be made, practically speaking the maximum of useful effect must be far below 

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

 within the practical limits great improvements can be made, he can draw up a 

 debtor and creditor account, as Dr. Russell and myself have done, and as has been 

 done by Mr. William Anderson, the engineer, in the admirable lecture he gave at 

 the Institution of Civil Engineers in December last on The Generation of Steam 

 and the Thermo-dynamic principles involved. Furnished with such an account, 

 the engineer is able to say, in the language of commerce, I am debtor to the 

 fuel for so many heat units", how, on the credit side of my account, do I discharge 

 that debt ? Usefully I have done so much work, converted that much heat into 

 enerT. Uselessly I have raised the air needed for combustion from the tem- 

 perature of the atmosphere to that of the gases escaping by the chimney; and 

 he sets himself to consider whether some portion of the heat cannot be abstracted 

 from these gases and be transmitted to the incoming air. As was first pointed 

 out by Mr. Anderson, he will have to say a portion of the heat has been con- 

 verted into energy in displacing the atmosphere, and that, so far as the gaseous 

 products of the coal are concerned, must, I fear, be put up with. He will say, 

 I have allowed more air than was needed for combustion to pass through the 

 fuel and I did it to prevent another source of loss — the waste -which occurs when 

 the combustion is imperfect ; and he will bepin to direct his attention to the use 

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

 ton's process, as in these conditions the supply may be made continuous and 

 uniform, and the introduction of air may be easily regulated -with the greatest 

 nicetv. He will say, I am obliged to put among my credits — loss of heat by con- 

 vection and radiation, loss by carrying particles of water over with the steam, loss 

 by condensation within the cylinder, loss by strangulation in valves and passages, 

 loss bv excessive friction or by leakage ; and he will as steadily apply himself to the 

 extinction or the diminution of all such causes of loss, as a prudent Chancellor of 

 the Exchequer would watch and cut down every unproductive and unnecessary 

 expenditure. It is due to the guidance of such considerations as these that the 

 scientific engineer has been enabled to bring down the consumption of fuel in the 

 steam engine, even in marine engines such as those which propelled 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 consumption may not have been reduced, that it may be 

 even "reater, but if so it arises from this, that the travelling public will have high 

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



] 10W notwithstanding the great improvements that have been made in the forms 



of vessels — to obtain high speed without a large expenditure of power. I antici- 

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

 results are before us in those heat motors, such as the gas engine, where the heat, is 

 developed in the engine itself. Passing away from heat motors, and considering 

 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 been developed by the labours of 

 Lowthian Bell, Cowper, and Cochrane. Equally due to this application 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 the rarer 

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

 stao-e, the electrical furnace. To a right knowledge of the laws of heat and to 

 their application by the engineer, must be attributed the success that has attended 

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

 lonn - vova^e delivered in a perfect condition ; and to this application we owe the 

 economic distillation of sea water by repeated ebullitions and condensations at 

 successively decreasing temperatures, thus converting the brine that caused the 

 Ancient Mariner to exclaim, ' Water, water everywhere, nor any drop to drink,' into 



