Evening star. [volume] (Washington, D.C.) 1854-1972, 1907-06-01
Life-Saving Apparatus.

ing severe explosion.
Life-saving Apparatus.
An apparatus which when worn by men,
bers Of rescue party enables them to ex-
plore a mine filled with gas or smoke was
studied by Mr.. Hall while in Europe and
Will be used by him in the miniature mine
to be erected by our government. 1t Is
a canvas jacket equipped with cylinders of
compressed oxygen, connected with the
wearer's mouth by a flexible, rubber-lined
metallic hose. The oxygen supply is varied
by pressure gauge and the breath of the
wearer passes out through Jumps of potas-
SUM hydroXlde, which absorb all of the
carbonic acid gas given off by the lungs.
The exhaled breath after being thus puri-
ned Is then refreshed with oxygen and
breathed over again repeatedly. Wearing
such Jacket rescuer could enter mine
Immediately after an explosion and I'M
doubtedly save many lives. If these tests
prove as satisfactory here they have
abroad mine owners will be urged to keen
supply of the jackets always ready in the
mines, as well at convenient places
above ground. Up to date such apparatus
does not appear to have been adopted by
any American mine owners. Smoke and
fume helmets manufa ctured however
IN this country and some of our coal mines
are equipped with ambulance cars while
In many more the miners are drilled in first
aids to the tnjured-in producing artificial
respiration, methods Of carrying the dis
abled, bandaging wounds. etc.
The miniature mine wherein these rescue
experiments are to be made will have
drifts headings, rooms and ladders. After
1t has been filled with smoke miners will
be instructed to enter these compartments,
as if searching for injured companions
Testing Miners Safety Lamps.
Many mine explosions caused by de-
fects of miners safety lamps. In the
lamp-testng gallery of the new station
all safety lamps now used in this country
will be tested. not only for their candle
power. but for their relative safety In the
presence of fire damp. Some of these
lamps safe in rapid currents of air
filled with gases. provided these currents
are horizontal. but are quite unsafe when
such draughts are vertical or oblique in
which latter cases they explode the sur
rounding fire damp in a few seconds. In
the testing gallery various lamps will be
subjected to different velocities of explo-
sive mixtures of gas pulled in different
Observation-Disclosures. vertical and oblique.
In Belgium Mr. Hall witnessed such a test
In which the lamp used mostly in the mines
of the United States behaved the worst and
ignted the gas each time. A self-gnit
ing lock-lamp made in Germany made the
most satisfactory showing. The gas used
for the tests at the Belgian station is OBJ
tanned from abandoned coal mine of the
COmpagnie de CharbOnnageS, which owns
mines containing the highest percentage of
fire damp to be found in the world.
Testing Power Of Explosives.
The relative powers Of different mine
explosives will be tested in the explosive
laboratory" another interesting adjunct of
the new station. A standard quantity Of
each explosive will be fired from a mortar
and against the face Of large pendulum
Weighing several tons. The distance of the
pendulums backward swing caused by the
force of the explosion will be recorded
by scale. Each standard sample of an
explosive will next be placed in a cavity
in the top of cylinder Of lead eight inches
high and eight inches in diameter. The
explosive will be ''tamped' with sand and
moist clay and exploded by electricity, after
which the resulting pear-shaped cavity pro-
duced In the lead will be filled with dis
titled water kept at standard Temporal
ture and afterward measured. The larger
the cavity the greater will be the volume
of this orffice There will be delicate ap-
paratus for measuring also the pressure
and heat generated by each explosive and
for Analysing the products of each explo-
sion.
Flashes from different explosives will be
photographed at night just as are light
ming flashes, and this test will be for the
comparison of lengths of flames. The
camera will be posted at a standard dis
lance and the different explosives fired into
the air. always from the same mortar and
the same angle The duration Of the flame
will, at the same time, be measured by an
electrical apparatus. Thus it will be seen
to what fine points the science of explosives
new station will be under the direction of
DR.. ]. A. Holmes. chief of the technologic
branch, geological survey.
JOHN ELFRETH WATKINS.