A/A' WILLIAM SIEMENS, F.R.S. 



267 



suddenly and effect a temporary reduction of temperature in that 

 manner. 



With regard to that point of your paper, sir, on which I took the 

 liberty of differing from you at the last meeting, I must say that 

 I still hold that the increase of temperature in the blast would 

 produce a beneficial result, and the beneficial result would rise 

 fully in the proportion of the increase of temperature. I think 

 the chief point of difference between us on that occasion was, 

 that you, Mr. Chairman, referred the result to a unit quantity 

 of ore, whereas, I referred it to a unit quantity of blast ; and I 

 cannot help thinking that the latter is the correct way of taking 

 it. The quantity of heat supplied depends upon the temperature 

 to which we heat the blast ; and if I can show that, for every 

 unit of heat added to the blast, you produce an equal saving of 

 heat in the blast furnace, then, I think, it is proved that increase 

 of temperature benefits you to an unlimited extent. But I would 

 go farther, and say that the benefit goes on in an increasing 

 ratio ; and I think we can show it from the facts which you 

 have brought before us in so complete a manner. Your own 

 figures prove that the higher the temperature of the blast, the 

 lower is the temperature at which the gases issue from the top 

 of the furnace. Therefore, this is no longer a question of a certain 

 bank of heat which you can draw upon to the extent of its 

 debit and no more ; but your bank of heat is an increasing one, 

 because, in the first place, the gases escape at a lower degree of 

 temperature, and, in the second place, the higher the temperature 

 of the blast, the greater is the proportion of carbonic acid es- 

 caping from the furnace ; which signifies that more heat is gene- 

 rated within the blast furnace, inasmuch as every pound of fuel 

 burnt into carbonic acid produces, roughly speaking, three times 

 the number of units than is the case when carbonic oxide is pro- 

 duced. These are two reasons, therefore, why the bulk of heat is 

 very much increased by raising the temperature of the blast. 



Tlie Chairman. You are now referring to the Consett furnaces. 



Mr. Siemens. Yes, and to the other examples that have been given 

 to the same effect. With regard to the very ingenious argument 

 which you put before us just now, regarding the negative effect of 

 increased temperature at the boshes, I am disposed to admit it 

 fully in the abstract, and I am pleased to see such clear proportions 



