574 Professor George Lunge [March 15, 



powder, almost instantaneously, converted into its oxide, alumina, by 

 substances capable of giving off oxygen. In the case of thermite, a 

 mixture of finely powdered aluminium and ferric oxide is, when lighted, 

 decomposed instantaneously into molten iron and aluminium oxide. 

 The heat produced thereby far exceeds that produced by coal in any 

 conceivable way ; it is equal to that of the electric arc. One of the most 

 important applications of this agent occurs in the welding of the ends 

 of railway rails, when already laid down, into one continuous rail of 

 any length required. And yet the total energy of thermite is only 

 450 thermal units per kilogram, or in other words, about one- 

 twentieth of that of the best coal. But, whereas it takes a good deal 

 of time to burn a pound of coal, during which process there is a great 

 loss of heat by radiation, and the heat is spread over a current of gases 

 which we call the flame, a pound of thermite burns off in about one 

 second, and, as there are no gaseous products formed, all the heat 

 generated remains within the molten iron and the alumina, which 

 accounts for the extreme degree of heat to which these are brought. 



Electricity has often been invoked to produce the most important 

 of all inorganic products, iron. If this problem could ever be solved 

 in an economical way, it would bring about a perfect revolution in 

 the position of the leading nations. On the one hand, the enormous 

 quantity of coal now consumed in the production of iron and steel 

 (which is probably at least a quarter of the entire output of coal) 

 would be set free for other uses, and the exhaustion of the coal-fields 

 would be put off to a corresponding extent. On the other hand, the 

 production of iron would pass over into the hands of those nations 

 which command the largest amount of water-power, and which, 

 therefore, can produce electricity most cheaply. Of the three 

 countries which now produce between them the bulk, that is seven- 

 eighths, of the world's iron. Great Britain and Germany would go to 

 the wall, and the United States, which already produce more iron 

 than these two countries put together, would become omnipotent in 

 that field. Sweden, Italy, and some other countries would, at any 

 rate, greatly increase their present production. But this radica] 

 change is, as yet, far off. No proof has, so far, been given that pig- 

 iron, or the ordinary descriptions of wrought-iron and steel, can l)e 

 generally produced by electricity at anything like the price at which 

 it is now done by coal in the great industrial centres. Where a 

 certain success has been scored in the electrical metallurgy of iron, it 

 is for the refining of ordinary iron into a superior grade of steel which 

 fetches an extraordinarily high price, and in the production of certain 

 alloys of iron with chromium, nickel, and the like, whereby so-called 

 special steels are obtained. But if at the present moment we do not 

 see our ])last furnaces and Bessemer works threatened l)y the com- 

 petition of electrical iron, who can tell how soon this may not be the 

 case ? 



The limits of my time have been too nearly reached for me to 



