The Sun.
London, England, 1863-03-30 00:00:00

) •

EXPERIMENTS AT SHOEBURYNESS.

On Friday the members of the Ordnance Select
Committee and the Ironplate Committee, with
several officers of the Artillery and Engineers, made
some novel gunnery experiments at Shoeburyness
both with cannon and forms of projectiles. The
first was made by the Ordnance Committee entirely,
and consisted of trials to ascertain how far a method
now rather in favour among French artillerists,
by which a series of holes, about an inch in
diameter, are bored through the substance of the
cannon near its muzzle, in order, by permitting a
quick escape of gas, to diminish its recoil, affects the
services of the piece as to range and accuracy. The
experiments were made with two brass nine-
pounder ordinary smooth-bore field pieces, which
were loaded with the usual service charges and
spherical shot. Five rounds were fired from each gun
in GUCCt ssion, the recoil of both being carefully mea-
sured after each discharge. They were then shifted,
so that each occupied the platform which had been
used by the other, when again more rounds were
firm The minute official results of the experi-
ment are not likely to be made out for some days,
but the general merits of the performances of each
gun could be seen at a glance, and were exactly
what were anticipated before a shot was fired. The
recoil of the ordinary gun was, in round numbers,
just twice as great as that which had the holes
bored round the muzzle, while the range and accu-
racy of the latter were scarcely more than half as
good as that of the common piece. The lateral
escape of gas and flame through the side holes of the
French gun, it we may so call it, was very great
indeed, so much so as to prove at once that even if
the gun otherwise possessed the most transcendent
merits it could never be used either on shipboard,
in casemates, or even at embrasures. In the open
air on Friday the trigger had to be pulled by a
laniard nearly 20 yards long. One half of the
force of the explosion evidently escaped through
the sideholes before the force of the powder was ex-
pended on the shot, and virtually therefore the
barrel of the gun is shortened by as much of its
length as is thus perforated. As a general rule, the
recoil of the gun is always in exact proportion to
the force it exerts in propelling the shot, and any-
thing which takes off from this recoil, by allowing
the gas generated by the explosion to escape before
it has done its work, just diminishes by so much the
range, and, therefore, the accuracy of its fire. The
results obtained with this curiously bored gun on
Friday were enough apparently to satisfy the Ord-
nance Committee that it would be a waste of time
to continue the experiments further.
Some experiments were then made with the Arm-
strong 110-pounder service-gun, loaded with steel
shot, against a box target faced with 43-inch plates
and lined inside with teak and an iron skin
like the Warrior. The only interest of this ex-
periment was to test the penetrative power of
the projectiles, one of which was prepared by
the Ordnance Committee, weighing 651 b. and
fired with a 161 b. charge of powder. The immense
superiority of this projectile over the cast and
wrought iron shot, which, as the standards or units
of penetration, were fired at the target before, was
at once apparent. Its indentation was nearly 50 per
cent. deeper than either the wrought or cast iron
missiles. The next shots tried were those of a pecu-
liar kind of steel made by Makin and Sons of Shef-
field. Friday was the third time that steel shots
supplied by this firm have been tried at Shoebury-
ness, and always with the same result—that their
metal, both for toughness and hardness, is superior
to any other kind that has yet been experimented
upon. A conical-headed shot of this kind, of which
the cone was small and sharp, with a very small
shoulder, weighing' 651 b., and propelled by only
141 b. of powder, smashed its eone completely
through the plate, damaging the backing and break-
ing a rib behind—the greatest result that has ever
been obtained with so light a shot and so small a
charge. It was evident that only the very full form
of the shoulder beneath the cone, part of which was
sheared off, prevented the whole going completely
through the target. A second shot of the same kind,
the same weight, and fired with the same charge,
struck the upper plate of the target on an uninjured
part, and about 12in. from its edge. It completely
smashed away a piece about 15in. deep by 18 or 20
wide, splintering and ripping up the backing be-
hind. One piece of the plate, of considerable weight,
was carried far behind the target, where it fell with
the shot itself. An examination of the shot showed
a part of the cone broken off, but otherwise it was
little injured, though the injury to the target was
very great, in spite of the hard, rather than tough,
character of its metal. The trial seemed to show
that to pierce the plates almost as much depends
upon the metal of the projectile as upon either the
gun or charge of powder which fires it. Certainly,
the result seemed quite to upset the notion that a
flat-headed shot is essentially necessary to punch
armour plates, and, on the other hand, to strengthen
the belief that the best form for this purpose may,
after all, and with proper metal, be found to be
the conical form adopted by Sir William Armstrong.