The sun., 1885-07-05
High Explosives in War.

In the current number Of tho journal of
the Military Service Institution, eut.-Col. Fl.
L. ABBOT OF the Corps OF Engineers. who
commands the School OF Application at Will
let's Point, discusses, under the title Of
Recent Progress In High Explosives and
their Uses in War" subject in which he is
an admitted expert OF tho highest order.
This subject is OF special interest just
now, rs within the last year experiments
in this country havo shown the pos
sibility OF firing dynamite shells with small
charges Of gunpowder from ordinary can
non: The Dracticability Of discharging
dynamite rockets from compressed air guns
had already been shown. Other high explo-
sive projectiles for mortars and also for
cannon, are awaiting trials. While disad-
vantages impede the free use OF some Of
these, and while thcre seem to be limits to
the charges that can thus far be used with
safety, yet those obstacles are likely to be
overcome In time. Other uses Of the high
explosives In war are suggested by the great
military balloon now in process of construc-
ton. and intended for dropping them on hos
tile forts, armies, or fleets. To these coming
uses OF high explosives, both on the earth
and in the air, the submarine gun Is seeking
to add their employment in projcctiles in the
waters under the earth.
But before drawing upon the essay Of Col.
ABBOT, it may be well to briefly recount the
history OF the high explosives. They all date
since the outbreak OF our civil war; and
though familiar to the engineer, contractor,
and chemist, they signify to most people only
some terribly shattering compound, without
discrimination between the varieties Of these
explosives and their different properties.
Blasting oil, or nitro-glycerine, was dis
covered in 1S47 at Paris. In the laboratory OF
PELoUzE, by A. SoBRERo. But ALFRED
NOBEL, Swedish engineer, first had the
courage to produce 1t in great quantities, In
1858; and that Same year Sir F. ABEL rem
dered gun cotton, Still older high ex-
plosive, safe to handle in large quantities.
NOBEL founded a factory at Stockholm and
another at Laucnburg; the former blew up
in 1864. At Aspinwal, Sydney, San Francisco,
and elsewhere. like accidents occurred, and
Sweden and Belgium outlawed the new ex-
plosivc. NOBEL went on, aud, having sue
ceeded in absorbing nltro-glycerine in porous
substances to make 1t safer, and calling the
product dynamite, he at length. in 1866 saw
1t for tho first time used for blasting.
A fundamental characteristic of tho high
explosives Ia that they explode instan.
tanoously, while the low explosives, like
gunpowdcr, explode by combustion or pro-
grcssively. A cartridge OF gunpowder an
inch in diameter and two hundred feet long
requires eighteen seconds to consume; but
In O like cartridge OF dynamite all the parts
decomposc simultaneously. When nitro-gly-
cerine is poured into drilled hole, tho blast
gives bstter results than whom enclosed
In 1i-inch tin cartridge A violent blow
or great heat explodes 1t, but not gradual
pressure; and most valuable property OF
nitro-glycerine is that 1t burns with diff
Guilty. 30 that 1t may bo consumed before
reaching Its exploding temperature, though
In large mass set on fire the unburnt por-
tion might be heated to that temperature.
The force OF blasting oil compared with gun
powder Is as Is to according to volume, aud
as to according to weight.
Dynamite or giant powder consists, as has
boon said, OF somO absorbent combined with
nitro-glycerine. Kioselauhr. or infusorial
earth, Is OF special excellence, because 1t
holds the oil by capillary attraction. 1t be-
longs to the class OF chemically inactive ab-
sorbents, the other class being the cheml-
cally active. which themselves take part in
the explosion. Both the mixing Of the
ki0selKuhr with tho oil and the filing of
cartridges with the edynsmits are dangerous.
Dynamite can bo exploded by cap or a
heavy blow, or by contact with red-hot
metal, though II simply lighted by match
or fuse II will burn without exploding. like
damp powder.
Turning now to Col ABBoV's record OF re-
cent progress and OF Investigations at Will
let's Point. we may note that special atten-
tion has been given thcre to measuring the
relative Intensity OF the new high explosives.
Tho method Is that OF submergng In deep
water powerful charges OF the samples suit
ably sncased and centred In vertical ring
holding rlgidly In position six pressure
gauXes OF a peculiar pattern. The records Of
.hcso gauges after tho explosions show
the relative tatspsitiss. Most persons will