THE CONQUEST OF NATURE 



bility, has made accessible many important mining 

 sites hitherto unworkable. Rich mines are now in oper- 

 ation on an economical basis which, thirty years ago, 

 were worthless on account of their isolation . When such 

 mines were situated in mountainous regions where 

 there was no coal supply at hand for creating steam 

 power, and where the only available water power was 

 perhaps several miles away, operations on a paying 

 basis were out of the question before the era of electric 

 power. 



At present, however, the question of distance of the 

 seat of power has been practically eliminated by the 

 possibilities of electric conduction. A stream, situated 

 miles away, when harnessed to a turbine and electric 

 motors may afford a source of power more economical 

 than could be furnished a few years ago by a power 

 plant supplied with fuel at the very door of the mine. 

 We need not enter into the details of this transmission 

 of power, however, since the subject has been discussed 

 in a general way in another place. Our subject here 

 is rather to deal with the application of electricity to 

 certain mining implements of special importance. 



One of the most useful acquisitions to the equipment 

 of the modern miner is a portable mechanical drill, 

 which makes it possible for him to dispense with the 

 time-honored pick, hammer, and hand-drill. But it 

 is only recently that inventors have been able to pro- 

 duce this implement. The great difficulty has lain in 

 the fact that a reciprocating motion, which is essential 

 for certain kinds of drilling, is not readily secured with 

 electric power. The use of steam or compressed air 



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