Evening star. [volume] (Washington, D.C.) 1854-1972, 1912-03-09
Value Of Safety Lamps.

safety lamps and permissible or quick
flame explosives each contribute to safety.
The keeping of electricity out of gaseous
mines is further wise precaution. There
are a number of other minor precautions
that are important. but all will agree
that the first essential is adequate venti-
lation. An unexpected outburst of gas
from breaking into an old gas well, or
from the smaller hidden reservoirs in the
coal itself. each contributes danger
which it has been found dlmcult to pro-
vide against in many cases, but against
which every precaution should be taken.
In quite q number of mines the danger
from gas has been reduced by an extern
sion of the entries far in advance of
ordinary working operations, and taking
the gas from the coal in advance OF the
ordinary mining work without overload
ing with 1t the ordinary return air cur
rents.
1.-THE lessons taught in the recent study
of dust explosions are that the dust from
practically all of the bituminous Goals
will explode under favorable conditions
without any gas being present. They
have also shown that a small gas eXplo-
zion Is one OF the easiest ways of start
ing dust explosion, which, il the mine
is wet. will be a local explosion, from
which many miners may escape, or, If the
dust is dry and abundant, there will be a
general explosion, extending to every
part of the mine, and killing by it's own
violence or its poisonous gases all the
men in the mine.
Zone Of the important lessons taught
by certain recent mine explosions is that
the coal dust, while thoroughly wet. will
not explode. but that with modern VEN
tilation. and especially during cold wealth
er, wet coal dust often becomes dry and
dangerous within a few hours, and that
therefore the sprinklfng OF coal dust once
a month or once a week only gives us
safer conditions for a few hours imme-
diately following the sprinkling. Indeed,
sprinkling occasionally is often a useless
and even. dangerous practice. as 1t does
little or no good unless done thoroughly
and frequently. and 1t often tends to make
us less careful in dealing with this half
dry or dry coal dust in between the pc
RODS of sprinkiing and 1t never reaches
the other unused portions Of the mines.
Wetting Of Coal Dust.
"Wetting coal dust through the intro
duction of steam along with the air cur
rent is by all means the most effective
and cheapest way of moistening the coal
dust during the cold weather. This steam
warns the innowing air and saturates it
with moisture. which moisture is in turn
deposited on and vets the coal dust In
all parts of the mine where this air pene-
trates. This method continues through
the winter season, the natural sweating
process which keeps the dust wet and
helps to prevent dust explosions during
the summer season.
LAS far as possible the coal dust should
be Kept out OF the mine. And what can
not be removed should be kept wet. either
by liberal sprinkling or turning exhaust
steam into the mine. or keeping the coal
dust mixed with fine soil dust, ashes or
stone dust.
THE influence of stone dust in prevent
ing or checking coal dust explosions is
being carefully considered in France and
other European countries. In many mines
the stone dust is considered more effec-
tive than water. In this country stone
dust has not passed beyond the expert
mental stage. but is worthy Of serious
consideration and a thorough trial"