Spons' dictionary of engineering, civil, mechanical, military, and naval; with technical terms in French, German, Italian, and Spanish (1871)
Spon, Edward, Byrne, Oliver, Spon, Ernest · London, New York : E. & F.N. Spon · leaf 208
derable distance in the mine : the machine is worked at a distance of as much as a mile from the shaft. In a trial of this machine, it was found that a pick of 75 lbs. weight, cutting a groove to a depth of 24 in. in from the face, gave about 74 blows a minute. At the colliery the coal was got by… … undercutting a length of 56 ft. was twenty-five minutes, including all stoppages for clearing the rubbish out of the hole and for backing the machine when the pick occasionally made an incomplete stroke. The machine was then run back to the starting-point, and set to work again with a longer pick…
Engineering
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