1873 - Old Forge Coal Mines

INSPECTORS OF MINES. 189
mense heaps now to be seen everywhere, would be left in the mine in the
future. The gangways would be more secure, having a good substantial
pillar of coal unbroken by schutes for 25 to 50 yards in length. There
would be do such thing as a squeeze, from the fact that the roof would be
allowed to settle down gradually as the coal was extracted from the loose
end next the fallen rock, until all the coal was taken down to the gangway
pillar, where the fallen rock and slate would close in and settle, so that any
future time the gangway pillar comprising about one-tenth of the available
coal of the lift could be mined out before the lift was abandoned, thus securing
from 80 to 90 per cent, of the coal, instead of from 20 to 30 per
cent, by the present mode of mining the Mammoth vein.