Page:Popular Science Monthly Volume 90.djvu/832

This page needs to be proofread.

Coal Mining Machinery Has Increased Our

Four cars of coal are unloaded every minute on the rotary dump. The coal falls into a conveyor which leads down the mountain to the tipple house. There it passes over shaker screens and is graded according to size

At left: A modern mining machine for un- dercutting coal. It is driven by electric cur- rent and the teeth or picks travel on a chain around the cutter bar. The first cut is al- ways made at the level of the ground

Press lUus. Serv.

Mountain women come to the mining camp to trade their eggs, butter and chickens for coal and other merchandise. Traveling is done on horseback and with pack-mule since the mountains are too rugged for wagon roads