Mance: Quarry Industry of Southern Indiana 



13 



the drills just described the drill bar is fastened to the piston rod by means 

 of a clutch. This means that the whole drill bar reciprocates with the piston. 

 For light work another arrangement is used by the Sullivan Company in 

 their hammer drills. In this drill the bit is held against the rock and the 

 piston strikes the hardened end of the steel. This drill is rotated by hand. 



A combination electric air drill is manufactured by the In- 

 gersoll-Rand Company. In the electric air drill the bit is driven 

 by pulsations of compressed air created by a pulsator actuated by 

 a standard electric motor. The air is never exhausted, but is 

 simply used over and over again, playing back and forth in a 

 closed circuit. This is simply an electric drill in which the com- 

 pressed air is used as a spring and cushion. This drill can be 

 driven on about one-fourth the power consumed by the ordi- 

 nary steam or compressed air drill. It seems to be the best 

 fit«ted for ordinary quarry work where electric power is available, 

 and is sure to be adopted widely in this quarry district. 



After the quarry floor is leveled the tracks are put in position 

 for the channeling machines. The channels cut by these machines 

 are about 2 inches wide and from 6 to 10 feet deep. The first 

 machine of this type was made by J. Ward well in 1863, and 

 the first Wardwell machine was bought in Indiana in 1873 by 

 John Mathews. This machine was essentially the same as the 

 Wardwell channeler in use today. It cost approximately $6,000, 

 but at the present time can be purchased for about $2,000. 



G. P. Merrill, in his work on Stones for Building and Decora- 

 tion (p. 404), describes the channeling machine as follows: 



The channeler is essentially a locomotive machine driven by power, 

 moving over a steel-rail track which is placed on the quarry bed. 

 It carries a single gang drill on one side, or two such drills — one on each side. 

 These are raised and dropped by a lever and crank arrangement. The 

 gang of cutters forming the drill is composed of 5 steel bars, 7 to 14 feet 

 in length, sharpened at the end and securely clamped together. Of the 5 

 cutters, 2 have diagonal edges; the other 3 have their edges transverse. 

 T'he center of the middle largest extends lowest, so that the five form some- 

 thing like a stepped arrangement, away from the center. The drill, lifted, 

 dr»ps with great force and rapidly creases a channel in the rock. The 

 single gang machine is operated by 2 men, the double by 3. As it runs 

 backward and forward over the rock the machine is reversed without stop- 

 ping, and as it goes the cutters deliver their strokes, it is claimed, at the 

 rate of 150 per minute. The machine feeds forward on the track half an inch 

 at each stroke, cutting half an inch or more at every time of passing. The 

 single machine will cut from 40 to 80 square feet of channel per day in marble 

 or limestone and at a cost of from 5 to 20 cents per square foot. The double 

 machine will do twice the amount of work. A good workman by the old 



