The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1898-03-24

plosive known. In one Of the naval intelli-
gence publications ii is stated that the
English government tested the safety of
gun cotton containing 90 per cent. moisture
by burning bonfires in TWO lots of ton
each. In one case the explosive was in
disks in closed tank, and i'll the other 1t
was divided among eighty closed packages.
In both cases the gun cotton burned away
without explosion.
special kind of primer or detonator must be
used consisting of disk of dry gun cot
ton, and this dry gun cotton is exploded
by a illuminate of mercury fuse fired by
electricity. These disks OF gun cotton may
be made any size Usually they are about
four inches in diameter and an inch thick,
with q hole in the center Several disks of
gun cotton are placed one over the other;
near the top IS put one layer or disk of dry
cotton then the electric primer is lowered
into the charge through the hole. and the
entire cartridge is carefully sealed up with
water tight head through which the cleo
trio wires lead. which are to be spliced to
the wires leading to the firing battery. 1t
is of the utmost Importance to keep this
dry gun cotton dry. Should ii get wet the
fuse would be imperative. When gun cot
ton is used to charge the war heads of tor
pedoes, the gun cotton is usually nodded
to tit the form of the chamber designed to
Gun cotton is not so extensively used for
commercial submarine operations some
of the nitroglycerin compounds. mainly be
cause of the difficulty of preparing it for
hiring. Nor is 1t so terrible in its explosive
action as some of them. A form of gelatine
seems to be more generally preferred. One
of these now on the market is called Re
pauno gelatinc. 1t is described as a high
plosive powder, having gelatinous consist
ency 1t is therefore, sticky and very dense
or heavy-two very advantageous features
in certain classes of work. The higher
grades have extraordinary disruptive pow
er. 1t is decidedly plastic This, with its
density. renders it particularly suitable for
submarine work, where the flow of water is
strong because it will adhere firmly to-
gether even should the coverings of the
charges get damaged or removed, and it is
not disintegrated by water.
Another high explosive in our market is
forcite. 1t closely resembles explosive gela-
tine cellulose, being used instead of nitro
celulose. Some forcite contains 50 per cent.
OF nitroglycerin, and other grades less, in
corporated with a mixture of nitrate of
soda. sulphur and wood tar, with a little
wood pulp added 1t burns in the open air,
eXpiodes in confined places, and water has
no action on it.
STRENGTH OF HIGH EXPLOSIVES.
There are many other explosives suitable
for submarine use, some of them of a
greater explosive strength than dynamite,
others less. Some years ago General Alb
bot, of the United States army, carefully
investigated the properties of several kinds
of high explosives and gave as the results
of his experiments the following relative
strengths under water of certain ones of
them per pound, assuming dynamite No. /,
that described above. as 100: Blasting gela-
tine. 142; forcite gelatne, 133; gun cotton.
wet, 81; nitroglycerin, 81 gunpowder 20 to
81. There We're some other interesting data
reported by General Abbot concerning high
explosives. His experiments led him to be-
leve that in order to wound the bottom of
a man-of-war of 5000 tons. armored with
nine inches of iron, an explosive must pro-
duce a pressure of $500 pounds per square
inch;, that $500 pounds would be fatal to an
ordinary double-bottomed ironclad. How
ever all scientific investigators in this eli
rectlon as well as in other theoretical mat
tiers pertaining to the force which high ex-
pioslves exert are not by any means in
agreement Referring to some of the re-
suits of the researches of Colonel Bucknill,
or england, into the relative strengths of
nigh explosives, it is noticed that he gives
the following relative horizontal distances
ana charges necessary to inf1ict a fatal
blow on a modern ironclaG: