Up: Glassmaking
Coal: 16 of 25
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A rotary dump
We too must go back to the surface. First we
ask our guide about the timbers we see. Do they keep the mine roof
from falling down on the miners' heads? "No," he says, "the timbers
overhead merely help to keep loose pieces of rock and coal from falling
down." (The hard, light helmets the miners wear often save them from
being hurt by such falling rock or coal.) Huge posts or pillars of
coal twenty or thirty feet thick have been left to hold up the roof
until the rooms are "worked out" and the miners are ready to leave
that part of the mine and let the roof fall.
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