

5Y/? WILLIAM SIEMENS, F.R.S. 133 



mperature of the blast exceeded 500 or 600. Now, how- 

 i-vrr, ironmasters saw the advantage of raising the temperature of 

 the lilast from G(>> to 800 or 1,000 ; and in using this regenera- 

 tive stove, the temperature had been raised as high as 1,400, 

 without any deterioration of the quality having been observed. 

 At the same time, there were ironmasters of high intelligence who 

 asserted, that though the quality of the metal was maintained, yet 

 that there was very little or no economy whatever in increasing the 

 temperature of the blast above 1,000 ; but although this view had 

 been gravely advanced lately, in discussions that had taken place 

 before another Institution, he felt convinced that the conclusion in 

 question was based upon a misapprehension, and would share the 

 fate of the former objections to the introduction of hot blast 

 generally. 



In inquiring into the chemistry of the blast furnace, it would 

 be difficult to separate carefully the operations going on at each 

 stage within the vast mass of incandescent matter ; but if the 

 problem was to decide upon the goodness or the efficiency of a 

 mechanical contrivance for transmitting power, consisting of a 

 number of wheels, cams, and differential pulleys, there would be no 

 very minute inspection of the effect produced by each crank, wheel, 

 or pulley ; but the conditions of power applied to the machine 

 would be taken, and the power judged by the motion of the load 

 at the other end, taking it for granted that, according to the law 

 of the conservation of force, nothing could be added or taken away 

 except by friction. In the same way he looked upon blast furnaces. 

 It was known that carbon, fluxing material, and ore, consisting for 

 the most part of sesqui-oxide of iron and of silica, were put into 

 the furnace, and atmospheric air was blown in at bottom. It was 

 known that atmospheric, air on coming into contact with carbon in 

 a state of incandescence formed one of two combinations viz., 

 carbonic acid if the combustion was perfect, and carbonic oxide 

 if the combustion was imperfect. It was known that when a 

 pound of carbon was burned into carbonic acid 14,000 units of 

 heat were liberated ; whereas if carbonic acid was formed, only 

 4,000 units of heat were liberated. It depended, therefore, entirely 

 upon the composition of the gases resulting from the combustion 

 in the blast furnace what would be the effective duty performed. 

 Analyses of the gases issuing from the top of the furnace proved 



