Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-09-10

explosion. Some of the dust in the Pitts
burgh cylinder was so fine that 1t passed
ings to an inch. This exploded when
there was only a small proportion of 1t
in the air
The bureau OF mines advises that the
coal dust should he frequently washed
from the timbers and the mines be kept
wet. They say that a dry mine Is
dangerous mine and that the finer the
dust the more water required Under no
conditions should coal dust be used for
tamping the holes filled with other ex-
ploSives.
DIR. Holmes tells me that many explo
sions of coal dust have occurred in and
about coal bins and that similar explo-
sions have happened in coal crushing
rooms There were some explosions OF
that kind last year at st. Louis and there
was one in a cement plant in Colorado.
In the latter case nine men We're so
badly burned by the flaming dust tina.
they died
1t must not be thought that coal dust
is the only kind of dust that will ex-
plode without infammable gas The
dusts of flour, starch and sugar, all of
which contain carbon, will do the same
thing. This is we'll known in the -four
milling centers, many of the mills having
been blown to pieces by such explosions.
One such instance occurred at Minneap-
oils in 1878. and another at Granite City,
H., in 1910. Other mineral substances
than coal have dusts that will explode.
This is of srahamite and gilsonite,
both Of which contain carbon. Last
December violent explosion which was
. due to dust occurred in one of the
asphalt mines of Oklahoma.
The business of making explosives is
an important one We have $50 different
plants engaged in it and their output is
something like 5DO,GO0OOO pounds a year
? Thay- nT II doc nd en-
dangerous that many people are killed by
them. In their transportation alone sew
eral million dollars worth of property is
annually destroyed. The government is
making tests of the various kinds. the
work being done by Prof Charles r.
Munroe of the George Washington Uni
versty, who is noted as an expert in the
science, and by MIR. Clarence Hall of the
bureau of mines These men have issued
An Explosives Primer for Miners and
they have tested II number OF explosives
in the great Pittsburgh cyclinder, which
has been filled with gas and mixtures OF
gas and dust and of coal dust alone for
this purpose. The gas and other mix
lures are set off by electric decorators. If
the explosive passes the test, 1t is mark
ed permissible The permissible ones
are now we'll known to the miners and
mine operators, and the latter are glad to
use them To avoid the blame and damages
that might arise if other unapproved eN-
plosives were used. 10 say nothing OF their
desire for the good of the miner.
So far we have no laws requiring
the use of approved explosives only.
1t is different in Europe. Germany,
France, Belgium and Great Britain
have long had commissions studying
and testing the various explosives.
and they have prohibited those known
10 be dangerous. There are about
nifty different kinds which are safe.
and some of these have been found
incapable of igniting mixture of
hre damp and air. even with charge
forty times as great that of the
Old explosives, which invariably caus-
ed an explosion. Belgium restricts the
amounts of the materials that may be
used. and the safety powders there
are rapidly driving out the dangerous
plack powders of the past.
Belgium, France and Germany ne
.qnire all mines to furnish arrange
nents for speedy aid 10 the injured,
and each must have rescue devices
There are penalties for both operators
and miners. and also mine inspectors
who may close the mines by injunction
II the laws are not complied with. As
result the accidents are few aver
aging much less per million tons of
coal than with us. AS it is now we
are killing six men for every million
tons of coal we get out
The bureau of mines has number OF