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THE POPULAR SCIENCE MONTHLY. 



mechanisms used have been brought to a state of efficiency — one could 

 not say perfection — never reached in the case of any other undertaking. 

 In attempting to trace how this has been brought about, we may begin 

 with one of the first of the new processes introduced, the American 

 method of boring to test the strata and use of the dianaond-drill. In 



<i^^ ^ 







September, 1883, the director-general of the works. Dingier, gave an 

 address in Paris upon the then condition of the enterj)rise, in wliich 

 he says : 



For the great cutting we liave made a large number of American soundings. 

 The Americans in this s])ecial matter have made considerable ])rogress, and have 

 rendered us very great service. 



Ordinarily, when soundings are made, the yield is brought up in a jjulver- 



