The Hawaiian star. [volume] (Honolulu [Oahu]) 1893-1912, 1900-04-12
LIQUID AIR is EXPLOSIVE
EXPERIMENTS MADE IN GERMAN
MINES.
Effect Of Cartridges Found to BE Less
Than Dynamite, Gun Cotton or Giant
Powder.

Ever since it was demonstrated"
says Consul General Frank II. Mason
of Berlin, that liquid air could be
readily produced on a commercial scale,
it has been hoped and expected that one
of the principal uses to which It would
be applied would be that of an explosive
material for blasting purposes, partic-
ularly in mines, where the new explo-
sive would have an important advant-
agec of safety in handling and of not
vitiating the air, like gunpowder or
dynamite.
Some months ago newspaper re-
port announced that liquid air had been
formally adopted for blasting purposes
in the Government coal mines of Ger
many, but inquiry proved that this an
nouncement was at least premature
The fact appears to be that expert
ments-more or less successful-have
been made, especially by Professor
Linde, of the Polytechnic High School
OF Munich, but no formal adoption OF
the new explosive by the Government
bureau of mining industries has yet
taken place
Among the most systematic and
interesting practical experiments thus
far made in this direction, has been
the series of tests lately undertaken by
the Vienna Crystal Ice Company in the
presence of experts from the Austrian
technical committee for the War De-
partment. The liquid air used in these
tests was obtained from the Linde Com
pany at Munich and shipped to Vienna
in open TASKS, provided with the Dew
ar vacuum jacket and packed with
felt and cotton wrappings in wooden
cases, with a loose cap of felt over
the open mouth of each flask. When
put up at the laboratory for shipment
the liquid contained rs per cent oxygen
to 70 per cent nitrogen; but before it
had reached Vienna and was used in
the experiments, it had lost about half
its bulk by evaporation, and what re-
manned contained IS per cent oxygen to
! 10 per cent nitrogen. The absorbents
used in preparing the cartridges were
silicious mari (Kieselguhr) and solar
OIL and according to the report, two
methods of preparation were employed.
By one process the mari and oil were
mixed in a wooden vessel, and the
liquid air gradually added until a stiff
paste was formed which was packed
in paper shell cartridges covered with
asbestus.
BY the other plan, the mixture Of
mari and oil was put into the cartridge,
which was inclosed in a lead case with
layer of felt between, and the liquid
air then poured in until the paste was
completely saturated. The cartridges
prepared by both methods were safe
anu lGciNlly llSDOIldDlt, anu lnGlF eN-
plosive power was tested by firing at
the bottom of deep holes bored in rock
The results showed that while liquid air
| is an efficient explosive it is less eff
fective than dynamite, gun cotton, eX-
plosive gelatin, or giant powder.
The conclusions of military experts
were concisely as follows: Both meth
of preparing the cartridge were pro-
nounced wasteful, and in consequence
of the rapid evaporation of the liquid
air, they must be used Immediately af-
ter being prepared; beyond fifteen min
/ utes the evaporation will so affect the
cartridge that it is likely to miss fire
and its strength cannot be even rough
| ly estimated. On the other hand the
cartridges when freshly prepared are
powerful and well adapted to coal and
other mining, and while the large
amount of oxygen set free by the firing
of successive charges might increase
the danger of explosion in the air and
gases of the mine itself, the quality Of
the air for breathing purposes would
be definitely improved
THE net conclusion to be derived
from these and preceding experiments
in Europe, is that, Notwithstanding the
obvious advantages of liquid air as an
| explosive for mining purposes, the rap
id deterioration of the cartridges, and
| their varying an6 uncertain strength
| are obstacles so serious that, until they
| can be overcome, its value and applica-
| ton to that use will remain expert
mental and comparatively limited"