The Express.
London, England, 1864-06-27 00:00:00

[stamped, Id. Additional,]

TRIALS OF THE ARMSTRONG AND
WHITWORTH GUNS.

The most important test to be applied to the 70-
pounders in the firing against iron plates was
commenced on Thursday and Friday last. The
guns have been tried for range and accuracy, as the
12-pouoders have been ).but it would be premature
to my more of this part of the inquiry, which has
not yet gone beyond the elevation of 60, than that
the three guns have so far been fired rather more than
100 rounds at the two elevations of 5 and 6 degrees,
with a considerable advantage in range for the
Whitworth gun. This may be roughly stated at
about 200 yards at the higher elevation over the
shunt gun, and 500 over the wedge breechloader,
the ocimparison being made between the greatest
ranges attained. The guns all maintained a toler-
ably equal regularity of range, that is to say, the
shots all pitched within a space of ground that
meastued much the same for midi gnu. But in the
respect of range and accuracy, while the guns all
performed well, the Whitworth so far wan allowed
to have the advantage, in a marked manner as
to range, but as to accuracy the guns were all
very close. With regard to the methods adopted
in estimating the relative range and accu-
racy ,WP h,. amid
of .yi?jak,
be partake more or tees lallacy 4.04
we venture to offer a word upon the point, in '
the hope of affording an explanation of a subject
which is simple when simply considered, but be-
comes complex when technical terms, such as
" rectangles," " parallelograms," to., are sin-
ployed. In firing without aiming, and when the ,
guns are laid by quadrant, the shots pitch on the
ground, and if the points marked by the shot which
went furthest, and by those two which went widest, ,
were bounded by a line drawn through these points,
a sway( ground would be enclosed, which with
another line at the gun would give this much die..
cussed " parallelogram." At first eight it would •
be thought that the area thus enclosed would re-
present the figure of merit of the gun ; but this is ,
not so, as the area of two parallelograms—one long .
sad narrow the other short and broad—might be
precisely the same, and thus a short range wide ,
shooting gun would appear to be as good as the
long range close shooting gun. This is where •1
fallacy lies in such a calculation, and we imagine
the only way to represent range and accuracy by a
geometrical figure of merit would be to mark upon
the parallelogram, which in that case should be
squared to a scale, the precise spot where each shot
struck the ground. If it is required to show the merit
in numbers, a centre may be chosen in the group of
bits as in rifle shooting, and the sum of the devia-
tions would represent the aocuracy of the gun. At
any rate it is clear that the sum of the areas of the
parallelograms cannot truly represent range and
accuracy.

In the firing with the 70-pounders, the Armstrong
breech-loader, which is rifled precisely like the
service gun, was found to work well with its two-
wedge breech stoppem and the tin dish which help'
to close completely the bore of the gun ; no accident
happened to the wedge, and altogether the gun was
considered to answer the expectations formed of it.
The Armstrong shunt, however, got into serious
difficulties after firing about twenty rounds; there
was so much fouling of the grooves and bore that
the shot, with its projecting studs, could not be
forced home without repeated heavy blows, such as
would have been dangerous, if not impossible to
use with percussion shell. Sir William Armstrong's
ingenuity was somewhat taxed to invent an efficient
instrument for cleaning the bore of the shunt gun,
but we believe this did not act satisfactorily, and
eventually the Committee allowed a suspension of
the practice while an oil wad wasadapted for the gun.
The trials for range and accuracy will then, as we
understood, proceed.
We come now to the most important service
which is demanded of these 70-pounders, that of a
broadside gun for the iron-plated ships. All these
guns are within the weight which is considered
easily manageable by the ordinary crew of a gun •,
the Whitworth is 76 cwt., the Shunt 75 cwt., and
the Breech-loader 60 cwt., while the old 68-pounder
is 95 cwt. Then they all carry rather heavier
metal, and much more powerful shell. When,
therefore, it was known that another Warrior
target was to be attacked by these guns, we
naturally recalled the experiments made in the
summer and autumnof 1862, at Shoeburyness, when
the Whitworth gun of this calibre (5.5) sent a
shell at 600 yards through the plate, and burst in
the backing of the Warrior target. The larger
gun of 7-inch bore did far more in sending its shell
completely through the Minotaur plate of 5 inches
fixed on the same backing, and into the ship.
It is necessary, as will be seen presently, to refer
to these results in connexion with the trials of
these guns against a similar target, as they gave a I
standard two years ago, from which, as it would
seem, either our artillerists have fallen off or the
armour-plate makers have advanced. However
this may be, one thing is certainly shown by the
experiment we are about to relate, that Sir W.
Armstrong has, since that remarkable result was
achieved by Mr. Whitworth, got the right kind of
steel for his shot and shell as well as for his
guns, and has now brought the competition to
very close quarters.
The firing at the iron-plated target, which is a
veritable Warrior, and we suspect something better,
was commenced ou Thursday at a range of 806
yards. At this point the three guns were to have
been all fired, but we found that the breech-loader
had been withdrawn from the contest as not being
considered up to the work. The Whitworth and
the Shunt, therefore, entered the lists alone, two or
three trial shots being fired at a dummy target, in
which the Whitworth shot aceuratelv at once, while
the Shunt could with difficulty be got to hit the
small 6 ft. target, in consequence of throwing its
shot too high and running off the platform.
The srst shot from the Shunt missed
the iron target, and the two others very
narrowly escaped the same mishap, one
striking the top part of the upper plate, and the
other the extreme upper left-hand corner carrying
away the piece. The gun evidently surpiised those
who had to work it with this tendency to throw higher
than the sights indicated. In accordance with the
programme each gun was to fire two shot and one
she! L The Whitworth gun used throughout a
charge of 121b5., the Armstrong one of 1411 s. of
powder, increased with the steel round shot to
181ba.

The first shot from the Whitworth gun struck
just below the bull'reye, passed through the plate,
and buried itself in the wood backing, the rear of
the shot breaking off about three inches from the
face of the plate. 8o that the total penetration was
about inches, as the shot measures 14. No
damage was done to the skin of the ship. The
second shot struck well, buried itself again, and
knocked off three boltheada behind the skin.
The first shot from the Shunt missed. The second
bit, as we described above, upon a bolt and rib, re•
bounded after driving in a piece of the plate which
remained about four inches from the Laos of the
target, and no damage was done to the target The
third shot, to make up the number of hits pre-
scribed, struck the corner of the target, and flew
away to seaward. These shot were spherical-
beaded, and measured 11 inches long. The Whit-
worth shell, after penetrating the middle plate
and bursting in the wood backing, or rather against
it, scattered some of its fragment. in front of the
target, others lying in the opening, which was about
4; inches in depth. Very little effect was observable
in the heck of the target The bunting charge of
this shell was 11b.

Tb. Armstrong obeli 'Wm& the centre of the
lower plate, made a dent of 2+ inches, and wee sop-
posed to bare broken up • but on the next day it
was discovered in the ditch, at a distance et more
than 500 yards, where it bad rebounded after
bursting upon the target. It was " set up" and the