The labor argus. [volume] (Charleston, W. Va.) 1906-1915, 1908-02-20
EXPLOSIONS
in COAL MINES.
Their Causes and Remedy-A Paper Read Before
The Chic Engineering Society by Andrew Roy
at Columbus An Able and Instructive Paper

ence of any quality I, f fire damp in
the air, produce as fatal and desl
ructive explosions in dry an,.
dusty mine as that of fre-damp.
Following Mr.. Galloway's re-
searches the governments of France.
Germany and Great Britain each
appointed special commissions of
scientific men to investigate the
cause of explosions in coal mines.
The French commission concluded
that coal dust alone could only
give rise to local explosions of
limited extent. The English com.
mission were almost unanimous in
the opinion that coal dust itself
IS lnfiamable to any serious extent,
and no instances had come under
their observation of explosion be-
ing caused by coal dust alone; but
that while coal dust could not
OF itself cause an explosion it
lntenslfies its power and ex-
tent. The German commission, by
its tech nical committee, made a
series ofeXperiments under circum-
stances more clostly resembling
mining conditions than those made
by either the English or French
commissions.
In stone drift 167 feet in length
several small cannon, the bore
holes of which resemblad the drill
hole made by II miner in coal
mine, was taken into the face of
the drift. The cannon were pro
tected by heavy blocks of masonry.
The committee were also protected,
and watched the results through
small but thick glass windows in
serted i'll cast-iron frames. The
guns were fired by electricity. The
length of the flame of a gun tamped
with clay was ten feet: with small
coal tamping the flame extended
nineteen feet. A layer of fine coal
dust an inch and half thick of
poor quality was strewn along the
floor of the drift; d cannon tamped
with clay produced Il flame is
feet; with small coal dust tamping
the flame extending 81 feet. With
coal dust from the ploto mine in
Westphalia, which had been the
scene of several great fire. damp
catastrophies, the flame from the
cannon extended 100 feet-23 feet
beyond the month of the drift
The Pluto dust was very high in
combustible volatile matter, ex
ceeding 40 per cent.
In the spring of 1885 ! collected
sample of fire coal dust from every
minlng district in the state, and
also a sample OF dust from the
Pocohontas mine in Virginia, where
the great explosion occurred the
year before, and took them to Pro-
fessor n. w. Load, the talented
chemist i'll Ohio State University,
and was present when he made ex-
periments with the various dusts.
The apparatus used consisted of
d pipe seven inches in diameter,
and two and Il half feet long. The
pipe was set on end, air holes
having been previously made at
the bottom. A lighted gas jet was
placed in the pipe. Dry pulverized
coal dust, collected in Il mine which
by analysis contained 40 to AZ per
cent. of cumbuStible volatile mat
ter, was placed in a sive and shaken
over the top of the pipe, the dust
falling on the light. The dust in
stantly inflamed and filed the pipe.
.imuiar experiment were made
with all of the samples of dust, but
none of them would intlame. Two
per cent. of common street gas was
then mixed with the air i'll the pipe,
and the dust shaken over the top
as before. Every one Of the dust
inflamed eXcep in the case of the
PocohontaS dnSt; instead of flame
the pipe became filled with red
sparks about an inch in length.
The Pocohontas coal, as all know,
belongs to the family of semi
anthracite Goals, and contains
about 10 per cent. of com mbustble
volatile matter.
Now, every coal mine makes
fire-damp in a greater or less de
gree, even the most harmless Civ