air-drill

“The most satisfactory electric drill produced has been the Temple drill, which is really an air-drill driven by a small electrically-driven compressor placed near the drill itself.”

Principles of Mining Valuation, Organization and Administration

“This trench is cut with a hammer and moil, or, where compressed air is available and the rock hard, a small air-drill of the hammer type is used.”

Principles of Mining Valuation, Organization and Administration

“The actual work performed by the standard 3-3/4-inch air-drill probably does not amount to over two or three horse-power against from fifteen to eighteen horse-power delivered into the compressor, or mechanical efficiency of less than 25\%.”

Principles of Mining Valuation, Organization and Administration

“Compressed air has a distinct place for minor pumping units, especially those removed from the shaft, for they can be run as an adjunct to the air-drill system of the mine, and by this arrangement much capital outlay may be saved.”

Principles of Mining Valuation, Organization and Administration

“I want you to turn on them the air-drill pipe as soon as they break through.”

Ridgway of Montana (Story of To-Day, in Which the Hero Is Also the Villain)

“He doesn't know the difference between an adit and an air-drill.”

Rimrock Trail

“Casey was in jail, naturally; but he didn't care much about that so long as he owned a head with an air-drill going inside.”

The Trail of the White Mule

“Beyond that he was good-naturedly willing to talk of the stupendous undertaking over which he was presiding, expatiating enthusiastically upon air-drill performance, porphyry shooting, the merits of various kinds of high explosives, deep-mine ventilation, and the like.”

Branded

“Brawny, half-naked forms were already wielding pick and shovel amid the masses of rock just loosened, a powerful air-drill was being placed in position for another attack upon the wall of tough rock, and”

The Copper Princess A Story of Lake Superior Mines