THE CONQUEST OF NATURE 



by Mr. W. B. Clarke. In one coal mine, where an 

 electric pump is located in a worked-out portion of 

 the mine, the circuits are so arranged that the pump 

 is started from the power house, some distance away. 

 Near the pump is placed a telephone transmitter con- 

 nected to a receiver in the power house. To start the 

 motors, or to ascertain whether the pumps are working 

 properly, the engineer merely listens at the telephone 

 receiver, without leaving his post." 



ELECTRICITY IN COAL MINING 



In coal mining the effect of the use of electrical 

 machinery has been revolutionary in recent years, par- 

 ticularly in the development of electric coal cutters. 

 The old method of picking out coal by hand, where 

 the miner labored with the heavy pick, working in all 

 manner of cramped and dangerous positions, was sup- 

 planted a few years ago by the " puncher" machine, 

 worked by steam or compressed air. With these ma- 

 chines the coal was picked out just as in the case of 

 the hand method, except that the energy was derived 

 from some power other than muscular. So that while 

 these machines worked more rapidly than the hand 

 picks, they utilized the same general principle in apply- 

 ing their energy. 



Within recent years, however, various coal- cutting 

 machines have been devised, with which the coal was 

 actually cut, or sawed out, these machines being pecu- 

 liarly well adapted to using the electric current. 

 The most practical and popular form of machine is 



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