Frostburg mining journal. [volume] (Frostburg, Md.) 1871-1913, 1876-12-02
The Ventilation Of Mines.
BY ANDREW ROY.


sites because the pressure of the at
mosphere in both shafts is equal but
if one of the shafts is sunk in higher
ground, and is consequently deeper
than the other, there is always nat
ural motion of the air. provided tenn
perature of the mine and that of the
surface is of different densities In
winter, when the air of mines is rarer
and lighter than that of the surface,
The current flows down the lower
opening and up the higher one; and
in summer these conditions are reyer-
sed, because the cooler column Of air
is then transferred to the higher open
ing At certain seasons of the year,
when the atmosphere above ground
and that OF the mine approach each
other in density, there is again no mo-
ton, except what may be produced by
the action OF the cages in the shafts, CT
the movement of the cars along the
galleries of the mine, or the direction
md force Of wind on the surface. In
the language Of the miners, the pits
fight the ventilating current some
times going down one shaft, and in a
few minutes reversing itself and going
down the other; but in such cases it
is weak and languid, and often as
sumes a state of rest. The unassisted
forces of naturs at such seasons of the
year are wholly insufficient to create
a current of air for the supply of oven
the smallest mines.
In very deep mines, where the in
creasing heat Of the rocks maintains
the temperature of the mine all the
year round above the summer heat of
the surface, the natural flow of air is
constant in one direction, entering the
lower opening and discharging itself
at the higher one. 1t is of course,
very feeble in summer and very
strong in winter. Hetton Col!iery, in
England, has been found to produce
one hundred thousand cubic feet of air
per minute on cold winter day, bv
the naturAl forces
The powers applied for the purpose
Of creating and maintaining constant
and necessary current Of air in mines
when the natural forces fail, are many
and various The earliest means used
for renewing the air Of mines, we are
informed by PIiny, was by diligently
shaking a piece of cloth at the en-
trance Of the mine. Fans and air
pumps We're in general use in Agrico-
las time, and are described at length
by that author. Some of these ma
chimes were capable Of extracting the
foul air from passages quarter of a
mile in extent. Waterfalls were for
lnerIy employed in coal mines to give
motion to the air, A stream of wa
ter was poured into the downcast shaft,
but as it had to be pumped out again
it was let on very sparingly, and was
a very expensive method. Steam jets
We're proposed by Sir Goldsworthy
Courtney, in the year 1913, ard for
numLer Of years after We're in high ia
vor as the danger in fiery mines of an
explosion OF Gred4inp was avoided by
the foul return current passing over
the furnace. and they We're believed
to produce better results than the fur
mace. But after an elaborate series of
experiments, instituted by some Of the
ablest mining engineers of Great Brit
ain, they We're found to be greatly in
terior to the furnace as ventilating
power, and are now very generally
gone out of practice. Since the intro
duction Of steam pumps to discharge
the waters Of mines, exhaust steam
is frequently used to promote a cur,
rent Of air, although wholly made
quate to produce a vigorous ventila-
ton, it is, in shallow mines, a great
auxiliary to the furnace, and can be
applied without any expense what
ever.
Exhaust fans have long been the
favorite ventilating power on the Con-
tinent Of Europe and they are now
coming into practice in England and
the United States In Belgium the
law forbids the use of a furnace in a
fiery mine, and since the passage of
the mines inspection law of Pennsyl-
vania, which followed the Avondale
catastrophe, the fan has become quite
a fayorite in he anthracite coal region.
This accident, by which one hundred
and nine human beings 10 their lives
rno,,l al frC,, NO f,,,,,oo ooI4:.z- e