Evening star., 1903-07-22
LYDDITE's TERRIBLE POWER.
How Shells Are Filled With the Ex-
plosive at Woolwich.

From the London Chronicle.
For a long time after its first discovery
picric acid which is the foundation Of lyd-
dtte was used in the arts chiefly as dye,
and was often stored in large quantities,
without any idea of its terrible power. A
number of years ago fire occurred in
building in Of the large manufacturing
towns where large amount OF picric acid
was stored. During the progress of the fire
a terrible explosion occurred. the cause of
which could not be explained. After Il time
experiments showed that pcric acid when
rapidly heated and burned in confined
space appeared to undergo process of de-
composition, which transformed it from an
inert substance into one of the most ter
rrible of explosives.
NJ Turpin "A French chemist. recognizing
the possibilities of the substance, invented
the preparation of 1t, which he named after
NJ Meline the then French premier, and it
was adopted in the French military serv
ice Our own office some years after
ward followed suit. only their adaptation of
Dicric acid named not after a promt-
nent politician. but after the Gunnery
school at Lydd, in Kent, where the first eX-
periments with it were carried out by Brit
ish artillery experts. Lyddite melts at
temperature of 1929 centigrade. a degree
of heat about 40 degrees Fair. hotter than
boiling water, when it assumes the form
of a pale yellow liquid The method of fill
ing shells, with 1t IS to melt the lyddite and
pour it into the shell. which is then allowed
to cool. If ignited in the open air 1t burns
away harmless!y with a smoky flame To
develop its explosive quality 1t must be fired
by a detonat1ng substance, such as fulmi-
nate of mercury when 1t instantly resolves
itself into gas at terrific pressure.
In the filing sheds at Woolwich arsenal
the Shells after being filed with lyddite
are left to cool in the shed. When quite
cold the fuse hole in the nose Of the shell.
through which the charge was poured. Is
closed with wooden plug, driven in with
a lead hammer so as to avoid risk OF
sparks, and the shell Is then placed in
store No shells in our own service of a
larger calber than ten inches Of a
smaller size than At inches are at present
filled with lyddite. Those Of a larger or
smaller size filed with ordinary gun
powder in the form Of what is known as
pebble powder, from its bulk and shape.
Lyddite shells are always fused at the
point so as to avoid the risk of premature
explosions in the bore of the gun when the
shell is fired. If this accident happened no
gun would be strong enough to resist the
pressures that would be set up. Indeed a
premature explosion of this nature did oc-
cur some years ago in one Of our warships
when at practice in the North sea- The
gun in which it took place was cut off at
the point Of explosion as cleanly as If 1t
had been done with a lathe. Fortunately
the burst occurred in that portion of the
gun which was outside the side of the ship
so that there was no fatal result
The inquiry which has been ordered by
the war office into the dreadful accident
last month at Woolwich may disclose the
cause, but this is extremely doubtful If.
as is the accepted theory, one of the 10
inch shells burst. detonating the others
near it, it is possible that the accident was
caused by a particle OF C1it On the wooden
plug with which the filing hole is closed.
This may have caused a tiny spark that
fell on and ignited the lyddite charge within
the she'll.
The man who drove in the plug could
not of course. notice this as the plug
would prevent him seeing 1t, and the charge
would burn quietly for second or two, un-
til the pressure and temperature rose suffi-
GENTLY high, when the whole contents of
the shell would instantly detonate. Be that
as it may, the fact that lyddite is exceed
ingly safe to manufacture and to handle
is proved by the fact that a quantity of
the explosive which was in melting pot
in shed near that destroyed was quite
unaffected by the explosion.