WILLIAM SIEMENS, F.K.S. 179 



;uil its freedom from the deleterious effects of gas in heating and 

 polluting the atmosphere in which it burns, and it seems not 

 improbable that it will supersede before long its competitor in many 

 of its applications. For lighthouses, for military purposes, and 

 for the illumination of large works and public buildings the elec- 

 tric light has already made steady progress, while for domestic 

 applications the electric candle proposed by Jabloschkoff, or 

 modifications of the same, are likely to solve the difficulty of 

 moderating and distributing the intense light produced by the 

 ordinary electric lamp. The complete realization of all the advan- 

 tages of the electric light remains, however, a problem to be 

 solved, and it would be extravagant to expect from applications on 

 a small scale such as have hitherto been made anything like the 

 amount of relative advantage indicated by theory. 



The dynamo-electric machine has also been applied with con- 

 siderable success to metallurgical processes, such as the precipita- 

 tion of copper in what is termed the wet process of smelting. The 

 effect of one horse-power expended in driving a dynamo-electric 

 machine of suitable construction is to precipitate 1120 pounds 

 of copper per 24 hours, equivalent to an expenditure of 72 pounds 

 of coal, taking a consumption of 3 Ibs. of coal per horse-power 

 per hour. 



Electrolytic action for the separation of metals need not be 

 confined however to aqueous solutions, but will take perhaps an 

 equally important development for the separation while in a state 

 of fusion of the lighter metals, such as aluminium, calcium, and 

 of some of the rarer metals, such as potassium, sodium, &c., from 

 their compounds. Enough has been shown by Professor Himly, 

 of Kiel, and others, to prove what can be done in this direction, 

 although there remain practical difficulties (chiefly the rapid 

 destruction of the vessels containing the fused masses), the removal 

 of which will require patient perseverance, but is not likely to 

 prove of an insuperable character. 



In an inaugural address which I had occasion to deliver to the 

 Iron and Steel Institute a twelvemonth ago I called attention to 

 another application of the dynamo-electric current, that of convey- 

 ing mechanical power, especially the power of such natural sources 

 as waterfalls, to distant places, where such power may find useful 

 application. 



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