Report of the Bureau of Mines of the Department of Internal Affairs of ...

408 REPORT OF THE INSPECTORS OF MINES. Off. Doc.
many of the refuge holes were obstructed by slate.
mine later, I found the condition much improved in all respects.
On visiting the
The
link chain electric type of machines are used to undercut the coal in
one part of the mine, and mining is done by hand labor in the other
I^art. The hauling is done by the head and tail rope system and a
furnace is used to produce ventilation.
Quantity of air passing near
the face of the entries, when last measured, G,5()0 cubic feet per
minute and 18,100 cubic feet, was measured at the outlet.
Summer Hill.—This mine was also in poor condition during the
early part of the year, but when last inspected I observed quite an
improvement. The main return airway had been cleaned up and
enlarged. A* main overcast had been built and some of the doors
dispensed with, so that the air currents were conducted to the face
of the workings much better than formerly.
Quantity of air in the
different entries near the face of the workings varies from 4,500 to
10,000 cubic feet per minute, and 52,000 cubic feet was measured at
the outlet. About 'SO per cent, of the air volume is lost by leakage
and is of no benefit to the working parts of the mine. The coal is
undermined paiily by machinery and partly by hand labor. The
link-chain type of machine is used, which is driven by electricity.
li-foot Brazil fan is used to produce ventilation and the hauling is
done by the head and tail roi^e system.
Bower Hill.—AVas found in reasonably good condition, both
in regard to ventilation and drainage. I measured :?(J,000 cubic feet
of air per minute passing at the outlet, and about 6,000 cubic feet was
measured near the face of the various entries. The system of working
is that of double entry. The coal is mined by hand labor and is
hauled from the mine to the tipple by animal power. A furnace is
used to produce ventilation.
Bridgeville.—This mine is being developed on the treble entry system.
The chain link type of mining machine, deriving its power from
electricity, is used to undermine the coal, and it is hauled from the
mine to the tipple by an electric locomotive. The ventilation is produced
by a l()-foot Vulcan fan. Quantity of air at outlet, when last
measured, OO.OOO cubic feet per minute, and about 0,000 cubic feet
was passing near the face of each entry. A squeeze had overran one
j)art of the mine, but the section of workings affected are nearly
worked out, and on account of the squeeze being local in extent, the
operations in
the main body of the mine will not be retai'dcd.
Hastings Sloi)e.—This mine was not in good comlidon during the
early part of the year. The ventilation was inadecpiate and the aircurrents
were not properly conducted to the face; of the workings.
10-foot Brazil fan was erected last spring to produce ventilation, and
on my last visit, the condition was satisfactoi'y. Qnaiility of air
passing at the inlet, 20,00(1 cubic feet jK'r minute, and S,(MHI cubic feet
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