Mance: Quarry Industry of Southern Indiana 15 



to loosen it is pulled over by means of a derrick and is then split 

 up into the desired sizes for quarry blocks, by means of drills 

 and wedges. x\fter it is worked up to the desired sizes it is loaded 

 on cars for transportation to the stone mills. 



Swing-back channelers and gadders are machines resembling 

 the common channeler and drill but differing in that they are 

 arranged to cut in any plane, while the common machine can cut 

 only a vertical channel. The fact that the strata in the Oolitic 

 limestone district are in a horizontal position makes their use 

 unnecessary. 



If the quarry floor tends to fill with water in times of heavy 

 rains, it is emptied by means of pumps, the single stage centrifugal 

 pump being most commonly used. 



The derricks at present in use thruout the district are handled 

 by steam or electrical power, usually the former. The wooden 

 derrick of a few years ago is slowly giving way to the steel derrick, 

 and the hand-turned derrick has been almost entirely displaced 

 by the power-swung type. Electrical power is far better adapted 

 to handling stone derricks than steam power on account of its 

 speed and easy control. The electric motor can be placed nearer 

 the work than a steam-power plant, thus facilitating its control. 

 I have seen quarries in which small steam power plants for derrick 

 handling have been located close to the workings, when set up, 

 but as the workings have been extended the operator thought 

 it cheaper and less trouble to extend the lines than to move the 

 power plant closer to the work. As each extension was made the 

 ropes were lengthened until at the present time some derricks 

 are operated on as much as 1,000 feet of rope. This causes a 

 very great loss of power, and, in addition to delaying the work, 

 is a constant menace to the workmen in the quarry. All this is 

 unnecessary where an electric motor is used, since its position 

 can be changed in a very short time without in any way inter- 

 fering with the work or causing any great delay in the quarr}^ 

 operations. 



The Stone Mill. The milling of stone entails considerably more 

 work, and the operations involved are much more varied than in 

 the quarrying of the stone. The stone mills give work to more 

 men than the quarries, and the labor is on the average more 

 skilled. The fact that the mills run longer and pay higher wages 

 than the quarries makes the mill the more attractive, and less 

 trouble is experienced in getting men than in the quarry. 



The first operation on the quarry block when it arrives at 

 the mill is sawing. The block is removed from the car by means 



