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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 diamond-drill. In
French Excavator (From Lieutenant Kimball's Government Report).
September, 1883, the director-general of the works. Dingier, gave an address in Paris upon the then condition of the enterprise, in which he says:
For the great cutting we have made a large number of American soundings. The Americans in this special matter have made considerable progress, and have rendered us very great service.
Ordinarily, when soundings are made, the yield is brought up in a pulver-
