Page:Popular Science Monthly Volume 90.djvu/832

 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

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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