The Sun.
London, England, 1864-05-07 00:00:00

EXPERIMENTS AT SHOEBURYNESS.

Yesterday the summer season at this highly scien-
tific place of destruction may be said to have been
commenced by the return of the Iron Plate Commit-
tee, after a rather long absence, to complete their
series of experiments on a target which has attracted
and deserved more attention than any that has ever
been tried at Shoebury—the target of Mr. Chal-
mers. From the fact of the discussions which have
arisen about this target in both Houses of Parlia-
ment, as well as that other important experiments
were to be tried, and that the Armstrong and Whit-
worth competition was still in progress, the experi-

ments yesterday drew a large attendance to Shoe

bury, including most of the members of the three
committees who have work in hand, and a number
of officers of all branches of the service. So much
had been said as to the powers of resistance of the
Chalmers' target, and so serious a difference of
opinion has arisen on this point between the Admi-
r4lty, who deny its merits, end the officers and
scientific gentlemen appointed to conduct these
experiments, who uphold them, that it is necessary
before refer/kg to the experiments which were
made yesterday to state britfly what has already
passed in relation to this invention. It is now little
more than 12 months since the Chalmers' system of
building ironclads was experimented on at Shoebury,
and dell the targets that have yet been tried—and
there have been a large number constructed at the
expense of the nation not worth the value of the
powder expended in shaking them to pieces—not
one has ever been shown to b 3 so perfectly satis-
factory as that of Mr. Chalmers. All inventors,
when they shake their mechanical theories against
the downright matter-of-fact arguments of the
guns at Shoebury, find that they have some-
thing to learn—most of them that they have
everything; and even Mr. Chalmers, as yet the
most successful of inventors of this kind, was no
exception to the former rule. Before the day's
firing at his target wasover last year it was admitted
to be the most successful in its powers of resistance
ever experimented on, though Mr. Chalmers and all
on the ground saw at once that, without any in-
crease in its weight, but merely by a slightly dif-
ferent arrangement of the ironwork used in its
structure, its strength could be increased, perhaps,
30 per cent.—in fact, the target could be rendered
almost periect. At the time that this target was
tried everything but the Warrior had failed in the
most conspicuous and ignominious manner to resist
shot, the worst failures as a rule always being the
targets of our moat eminent engineers. Mr. Chal-
mers, however, had made the Admiralty such a
liberal offer that they could not but accept it,
though they then believed that in the principle of
the Warrior target they bad obtained perfection,
He offered to make his target entirely at his own
expanse for £1,650, on the understanding that Hits
principle of construction was of public value, and if

it resisted perfectly the artillery ordeal to which the
Admiralty would subject it, the Admiralty were to
pay for it. If, on the contrary, it was defective in
principle or strength Mr. Chalmers was to bear the
loss, and their lordships to hear no more about the
matter. On this agreement the target was tried in
April last at Shoeburyness. The target was 13ft.
long by 10ft. broad, faced externally with hammered
armour plates 33.-in. thick. Behind these were laid
longitudinal teak beams 10in. wide by about sin.
deep, a web or flange of wrought iron '4 in. in thick-
ness passing between each beam, and being rivetted
to a plate lain. in thickness at the back. Behind this
plate, again, came another pad of teak sin. thick,
which rested against the skin of the ship—the same
thickness as that of all our ironclads, -:ths of an
inch, and behind this were the usual upright beams,
or iron ribs of the vessel. Thus it will be seen that,
though the target was apparently a light one, from
its external plates being only 34in. thick, yet, in
reality, it had, after ad, sin. of iron in it, with lain.
of teak, exclusive of the longitudinal cellular iron
webbing we have mentioned between the teak
beams, which, though not nominally called upon to
resist the shot, yet, in truth, aided the resistance
enormously, by distributing the force of the con-
cussion and giving great stiffness to the whole
structure. The theory of the target was that its
peculiar arrangement of a cellular webbing be-
tween the teak and iron plate would obviate the
evils that generally result from a hacking com-
posed of wood only, such as buckling and penetra-
tion, and would guard against the equally injurious
effects of vibration, which tell with such severity
upon the fastening bolts. The plan of its con-
struction had, therefore, been calculated to disperse
over a large area the power or work that existed
in the shot at the moment of impact, so as to give a
very large surface of resistance by the time the con-
cussion reached the inner lining of the ship's frame,
The trial to which this structure was subjected
was precisely similar to that of the Warrior, though,
as that of Mr. Chalmers was one-third amaller, it
was obviously more severe for the smaller target, as
the fire had to be more concentrated. It is sufficient
now to say here that the apparently inexhausti-
ble powers of resistance of this small and compara-
tively light target perfectly astounded everyone then
on the ground. Some three or four of the rivet-heads
(which it was admitted were made too email) were
jumped off, one of the armour bolts had been dies
placed, and the ribs gave signs of distress where
the great salvoes bad been concentrated—but this