ALUMINUM. 725 



neering, gilding, and silvering alumiuum are minutely described in 

 Kichards's work on the subject. 



The aluminum industry is on a firm footing, both in Europe and 

 America. There have sprung up two distinct lines of manufacture; 

 the one a chemical process, and the other strictly metallurgical. The 

 former^ produces pure aluminum, and continues to be a complicated 

 process demanding skill and patience. The latter produces only the 

 alloys of aluminum, and has been made extremely simple by certain 

 methods not necessary to be here described. 



ALLOYS OF ALUMINUM.* 



By J. n. Dagger. 



Deville's method, modified in detail, is still the chief of the chemical 

 processes for the production of aluminum, and is dependent upon the 

 cost of metallic sodium. The greatest value of aluminum is however 

 in its alloys, and the successful application of the intense heat of the 

 electric arc to their production on a commercial scale marks a depart- 

 ure in electro metallurgy of which we can not overestimate the impor- 

 tance, rendering it possible to })roduce rich alloys of this metal at half 

 the cost of any other method, and so widening the field of their appli- 

 cation to an extent hitherto unknown. 



At the works of the Cowles Comi^any, Lockport, New York, there are 

 in operation fourteen furnaces, the electricity for which is generated by 

 three dynamos, capable of supplying a current of 3,000 to 3,200 am- 

 peres, and E. M. F. of 55 to 60 volts. These furnaces can produce 2,500 

 pounds of aluminum bronze (10 per cent.) and 1,800 pounds of ferro- 

 aluminum (10 per cent.), or a total yield of 430 pounds of contained 

 aluminum per twenty-four hours. The English works of the company 

 at Milton, Staftbrdshire, contain twelve furnaces with a500-horse power 

 dynamo, built by Messrs. Crompton, and said to be the largest machine 

 in England and probably in the world ; it furnishes a current of 5,000 

 to 6,000 amperes, with an E. m. f. of 50 to 60 volts. The production of 

 these works is 2,301) pounds aluminum bronze (10 per cent.) and 1,800 

 pounds ferro-aluminum (10 per cent.) per twenty-four hours, or -llO 

 pounds of contained aluminum. 



The furnaces are rectangular in form and are of fire-brick ; into each 

 end is built a cast-iron tube, through which the carbon electrodes 



'Abstract of a paper read before the Chemical Section of the British Association, 

 A. S., at Newcastle, September, 188t). {Report of British Association, vol. Lix, pp. 

 r>:?8-540.) 



