1901.] 



on Metals as Fuel. 



503 



a small piece of magnesium wire, which serves as a kind of wick if it 

 is placed in a little heap of calcium sulphate and aluminium. Such 

 a mass will now be lighted, and you see intense heat is produced. 

 [When the operation was conducted in accordance with the above 

 iudications, the theatre was brilliantly illuminated by the intense 

 light produced. A mass of metallic chromium weighing about 100 

 lbs. reduced to the metallic state as above described, was exhibited.] 

 The aluminium abstracts oxygen from the oxide of iron, and a 

 sufficiently intense heat is produced, not only to melt the iron which 

 is liberated from its oxygen, but to melt up the slag and, further, to 

 leave a considerable surplus of heat, which is available for doing other 

 work. No known pyrometer will enable the heat to be measured. 

 I believe it to be about 3000° C. The aluminium plays the part of 

 a fuel, and this table show r s the advantage aluminium possesses as 

 compared with carbon for the particular work required of it.* 



The Reduction of Fe,0, to Iron by Alumixium and by Carbon. 



On the aluminium side some 750 calories (units of heat) are 

 available to do work (3456 — 2706 = 750 calories). On the carbon 

 side there is a deficiency of no less than - 1026 calories. As re- 

 gards the crucibles, they may be made of alumina, the solid product 

 which is the result of the combustion of aluminium. They may also 

 be made of magnesia or mended with magnesia. I shall have more 

 to say about the solid product of the combustion subsequently. The 

 practical application of the process is as follows. The ignited and 

 molten mass in the crucible is so intensely hot that it may be made 

 to unite surfaces of steel that require to be joined, such as the ends 



* These data are from a paper by Prof. Kupelwieser, of Leoben, ' Oester- 

 reichische Zeitschrift fur Berg- und Huttenwesen,' vol. xlvii. 1899, pp. 145-149. 



