264 THE SCIENTIFIC PAPERS OF 



by the 62'04 cwts. of hot blast at 1000 Fahr. would be 62'04 x 

 112x1000x0-267 = 1,855,244 units of heat, leaving a small 

 excess of 182,295 units of heat brought in by the blast per ton of 

 iron made, which was probably not more than would cover the 

 loss of heat by radiation from the furnace. 



The actual work done in one of the Cleveland blast furnaces 

 represented therefore a consumption of between 19 and 20 cwts. 

 of coke per ton of iron made, supposing the ironstone to contain 

 only 40 per cent, of iron when calcined, and the blast to be 

 delivered into the furnace at a temperature not exceeding 1000 ; 

 and under these conditions he believed no blast furnace could be 

 constructed to work with less than that quantity of coke, 

 although with richer ores and higher temperatures of blast there 

 would of course be a considerable margin for further economy in 

 consumption of coke. Practically speaking he thought that 

 22 cwts. of coke per ton of iron made would be the best result 

 that would be obtained under these circumstances ; and this 

 would be independent of the capacity of the furnace, which might 

 be increased indefinitely without improving upon this estimated 

 minimum consumption. 



In the discussion of the Paper 



" ON THE DEVELOPMENT OF HEAT, AND ITS APPRO- 

 PRIATION IN BLAST FURNACES OF DIFFERENT 

 DIMENSIONS," by I. LOWTHIAN BELL, 



ME. C. W. SIEMENS,* who was received with applause, said : 

 I have listened with great interest to this paper, which, founded 

 on practical information, deals with blast furnaces as an economi- 

 cal question. I think, in all operations, we should endeavour 

 to look at the ultimate results we might possibly obtain, and 



* Excerpt Journal of the Iron and Steel Institute, 1869-70. pp. 124-125 

 and 220-222. 



