The Sun.
London, England, 1865-06-29 00:00:00

TIMES.—The recent experiments at Shoeburyness
have revived some important questions in the pro-
gressive science of artillery, and have called forth
two interesting letters from the representative pens
of Sir William Armstrong and Capt. Coles. One
day last week the Admiralty produced a new target
for trial. It was called the Hercules target, as being
exactly equivalent to a section of the Hercules, a
new ironclad, designed on new principles by our
chief constructor, Mr. Reed. The broadside thus
represented was actually 4ft. 2fin. thick, and of this
thickness 11-1-in. were iron. The target representing
the Warrior, which long defied our best guns, was
but Ift. 10in. thick; nor did the Bellerophon target,
which succeeded it, contain more than 2ft. 6in. of
wood and iron together. By way of more complete
comparison we may add that, while the total weight
per foot of the Warrior target was 3471 b., and of
the Bellerophon target 3891 b., that of the Hercules
target is 5201 b. ; and yet Mr. Reed undertakes
that his vessel shall be a good and buoyant
sailer. It will surprise nobody to hear that when
our largest service guns were tried against this
newly combined mass of wood and iron they failed
to penetrate it. Behind the Hercules target, in fact,
the whole assembled company might have stood in
perfect safety throughout the firing, and ithe
ship, therefore, claimed a victory over the guns.
We must, however, explain that the guns
employed on the occasion were only 300-pounders
—specimens of ordnance which would, indeed, have
been thought monstrous five years ago, but which
have been surpassed, and, as it is supposed, super-
seded, by cannon just twice as .big. Sir William
Armstrong has built a 600-pounder, and proved it
to be an effective gun ; so it was very naturally ob-
served that if guns of that calibre had been used
against the Hercules target last week, instead of
guns only half as heavy, the shot might once more
have carried the day. That remark brings forward
Captain Coles, who improves the occasion by argu-
ing that, as nothing but 600-pounders will now
pierce the sides of first-rate ironclads, and 600-
pounders can only be carried by turret ships on his
principle, it follows that his principle should have
immediate trial preparatory to immediate adoption,
concessions which he thinks the Admiralty are not
sincerely disposed to make. Side by side, however,
with his letter appeared another from Sir William
Armstrong himself, the manufacturer of the 600-
pounder, depreciating the power ascribed to it, and
doubting whether the result would have been mate-
rially affected by the employment of his tremendous
gun. We think we can simplify this controversy
considerably. The real question is whether, in es-
timating the effectiveness of a gun against a ship,
we must necessarily consider power and size as con-
vertible terms. Captain Coles evidently thinks
that we must ; Sir William Armstrong suggests that
we should not. The object of the defence--that is,
of the shipbuilders—is to make a vessel impregnable;
that of the attack, or, in other words, of the artil-
lerists, is to pierce a ship's sides. If this can only
be done by augmenting the weight and calibre of the
gun in proportion to the thickness and strength of
the target, then Captain Coles's argument may hold
good, for there is certainly a growing belief, though
not yet a universal conviction, that cannon above
a certain magnitude must be carried on some
species of turn-table, and not as broadside guns.
But are we not jumping too readily to the first
conclusion ? It is a self-evident truth that a large
gun is unnecessary if a smaller gunwill do the work,
and it is, to say the least, not yet decided that a
lighter gun than the 600-pounder will not do all
that the 600-pounder has done. Mr. Whitworth is
known to rely upon other conditions than that of
bulk alone, and Sir William Armstrong now leads
us to conclude that the effect of a gun depends not
upon the actual magnitude of the shot, but the pro-
portional magnitude of the charge. He thinks, for
instance, that on the occasion referred to his 600-
pounder, loaded with 701 b. of powder, might not
have produced a greater effect than was produced by
the 300-pounder with its charge of 601 b., and his
calculation is that the power required for piercing
the Hercules target at 1,000 yards range could not
be generated by a less charge of powder than 1201 b.
Ikre, however, we miss a link in the argument of
our correspondent, for if it is the proportional
rather than the actual magnitude of the charge
which determines the effect, we are left to doubt
whether a smaller charge with a smaller projectile
might not do all that was required. Suppose, for
example, we inquire what charge of powder would
suffice to send a 701 b. projectile through the Her-
cules target, and then what sized gun would suffice
for carrying that charge ? It is because of the un-
certainty attaching to this point that we are dis-
posed to question the conclusiveness of Captain
Coles's rejoinder to one of the official " objections"
with which he has been favoured. We think he,
and the public, too, had a right to expect that his
design for a man-of-war should have been brought
to a fair, full, and honest trial long ago, but we must
say the Admiralty are justified in refusing to take
it as absolutely proved that guns of 22 tons weight
will in future be indispensable to the armament
of a fighting vessel. It is certainly not yet
" clear" that such guns are necessary, and at
the time these "objections" were framed it was
quite true that " guns of half that weight
had been found to pierce the thickest plates
yet put into a ship." Last week's experiments
demolished that assumption, no doubt, for the 300-
pounders did not pierce the Hercules target ; but it
is still not clear that the work might not be done by
something short of a 600-pounder, and almost as
doubtful, according to Sir W. Armstrong himself,
whether the 600-pounder would do it. We have no
wish to prejudice the discussion either one way or
the other, but it certainly appears to us that if a
701 b. shot or shell could be driven from:a 70-poun-
der gun through the Hercules target, the effect
would be sufficiently destructive to answer all the
purposes of the attack. A projectile of that size
may seem light and insignificant in comparison with
the ponderous balls which American practice has
made familiar to us, but if it really be sent through
a ship's broadside, we should think the hole would
be quite large enough to let life out and water in.
The only question is as to the degree in which
weight must necessarily be combined with velocity
to produce the momentum required. Of course the
weight must be considerable, but the Americans, we
fancy, have increased this ingredient to excess, and
we suspect that some of our own projectors have
been carried away by their example. Nothing, how-
ever, can be plainer than whatever is superfluity in
this matter is also inconvenience, and inconvenience
of no slight importance. Let us have 600-pounders
if w e must have them, and can get them ; and let
us have the vessels which will carry such ordnance
best ; but, if the object of a ship's battery can be
answered by smaller guns, it would be sheer folly
to cumber ourselves with this race for bigness.
POST.—The civil war being at an end, the Ame-
rican Government have now ample time to devote
themselves to the pleasant duty of punishing the
leaders of the insurrection, and the more profitable,
but„rather more difficult task, of reconstructing
the republic on a new basis. Mr. Jefferson Davis
still remains in prison, and, although a grand jury
has indicted him for treason, the authorities do not
yet seem to have made up their minds whether he
shall be tried before a civil or a military tribunal.
Generals Lee and Longstreet, though they laid
down their swords on the express stipulation that
they should be paroled as prisoners of war, are also
to be placed in jeopardy of their lives on a charge
of having conspired against the State, and in their
case, as in that of the late Chief Magistrate of the
Confederacy, a grand jury has been found to lend
its aid towards carrying into effect the obvious de-
sires of the Government. To dispassionate observers
on this side of the Atlantic, the policy pursued by
Mr. Johnson towards the Confederate chiefs seems
quite unaccountable. Mr. Davis is no pretender to
a throne whom motives of political expediency
might induce the present occupant to deprive of
life ; nor are his generals crafty and able conspira-
tors attached either to a particular individual or his
family, whom it would be dangerous to leave at
large to renew, under more favourable circum-
stances, plots similar to those which have now been
successfully frustrated. 'Whether the leaders of the
secession movement were in truth guilty of treason
to the Government of the United States we shall
leave to be decided by American lawyers, although
we may observe in passing that they only gave ex-
pression to sentiments which had been repeated
again and again by every American who filled the
Presidential chair from the time of George Wash-
ington down l o that of Abraham Lincoln. But it
must be manifest to all that the question, if raised
at all, should be decided on other than merely legal
grounds. As for Lee and Longstreet, they were
officers acting under the orders of a Government
which, though not officially recognised, had never-
theless as real and as tangible an existence as that
which gave commissions to Grant and to Sherman.
Had the Confederacy been triumphant, surely nothing
would have been more preposterous than for Mr.
Davis to have placed the Federal generals who
might have fallen into his hands upon their trial forj
an attack on the independence of those States which