ELECTRICITY IN MINING. 



BY THOMAS COMMERFORD MARTIN. 



[Thomas Commcrford Martin, editor of the Electrical World and Engineer; born 

 London, England, July 22, 1856; has been engaged in editorial work since 1879; is the 

 expert on electricity for the United States census bureau and has lectured before lead- 

 ing learned societies of America and Europe and in principal universities; has been 

 president of the American Institute of Electrical Engineers; author of many works on 

 electricity.] 



The mining industry to-day constitutes one of the most 

 important fields for the appUcation of electric current. There 

 is hardly a country in the world and hardly any department 

 of mining in which electrical appliances are not employed, 

 and m many instances the installation and equipment are 

 of a most extensive character. The whole tendency of the 

 time is to develop mining industries along electrical lines, and 

 in fact to employ electricity continuously from the very first 

 contact with the ore to the stage at which the finished product 

 is ready for the market. It is proposed, to limit the present 

 treatment of the subject to electric mining, as both electro- 

 metallurgy and electrochemistry are distinct fields of technical 

 work, dealing with manufactured material rather than with 

 the cruder and more primitive processes of winning the min- 

 erals from the soil. 



In the United States, as elsewhere, the introduction of 

 electrical mining apparatus has been greatly stimulated of 

 late years by the high degree of perfection attained in the 

 art of power transmission. A great many mines and mining 

 camps in regions where fuel was either very costly or difficult 

 to obtain have been brought within the range of profitable 

 working through the utilization of some distant water 

 power. The single and polyphase alternating current, w^ith 

 its flexibility and high range of pressure, has made it possible 

 to transmit power from w^ater courses across valleys and 

 over mountain ranges for scores of miles, so that to-day large 

 areas, which but for the assistance of electricity would have 

 remained neglected, because unavailable, are being worked. 



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