The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-04-07
AIR AS AN EXPLOSIVE.
Liquid Atmosphere Used for Mining
Instead of Dynamite.
From the Philadelphia Record.


From the Philadelphia Record.
Now that liquihed air can be produced on
a commercial scale, Investigators are turn
ing their attention to the utilization of this
achievement. Prof. Linde, who was the
first to devise a method of producing Ii
quilted air in large quantities, has discov-
cred that liquifed air can be used in the
manufacture of an explosive of high pow
er, comparable in action and power to dy-
Mantle. Prof. Ewing, in a lecture before
the English Society of Arts, recently de-
scribed the method of manufacture of this
explosive. He states that liquid air, enrich
ed by the evaporation of a large part of its
nitrogen, when mixed with powdered char
coal, forms a powerful explosive, which
Possesses properties similar to those of dy-
Mantle, among others being capable of ig-
milton by the use of detonator. To make
the explosive, DIR. Linde pours the liquid
containing about 10 or so per cent of oxy-
gen, on fragments of wood charcoal, rang
ing in size from one TO four cubic milli-
meters. These are kept from scattering by
the ebullition of the liquid by mixing them
into sort of sponge with about one-third
of their weight of cotton wool.
When liquified air is allowed to stand
the evaporation is extremely rapid, but
the nitrogen constituent of the liquid
evaporates much more rapidly than the
oxygen, so that, after standing a time,
the liquid becomes more richer in oxy-
gen than the true proportions of air would
ind Co tba iva
evaporation is constantly going on and
the liquid which remains is, of course,
richer in oxygen than that which is orig
inally applied, and when the mixture is
allowed to stand for any considerable
length of time the liquid evaporates, and
the explosive power of the mixture dis
appears.
The cotton waddng impregnated with
coarse charcoal powder, can take up more
than enough of the liquid to supply oxy-
gen for its complete combustion, and
when put quickly into thick insulating
cases made of paper, it retains its full cx-
plosive power for 10 or Is minutes. After
an interval of from Is to 30 minutes, &c
cording to the size of the cartridge, Gil
explosive power is lost.
One would imagine that this would pre-
clude the new explosive from being Of
commercial value, but in reality this feat
ure is a decided advantage for some pur-
poses. The process has had practical trial
in some coal mines in Germany, and found
to be satisfactory. The temperature pro-
duced by the explosive is lower than that
required to ignite fire-damp, which is an
extremely valuable feature in an explosive
for mine blasting.
The L.inde apparatus for the liquifaction
of air could readily be set up in a mine
and operated as desired, so that there
would be no danger from the presence
or handling of large quantities of eXplos-
ives in storehouses or the accidental or
premature explosions. Probably some
method of preventing the rapid evapora-
ton win be devised, or, at least some
method of prolonging the period so that
explosive powers of the cartridges could
be kept for days, or even weeks, where
desirable. With ordinary liquids, to pre-
vent evaporation is a comparatively sim
pie matter, and only requires hermetcal
sealing, but liquified air changes so ma
terially the physical properties of the sub
stances with which it comes in contact
that the problem is much more difficult.