The Sun.
London, England, 1867-08-20 00:00:00

The late experiments at ShOeburyness have been
fertile interest. We_ itav4 sue- ,j it!) 1-inch
American gun with American powder and American
shot defeated by a.'target which has been repeatedly
pierced by an English gun of less than two-thirds
its weight, firing shells with a smaller charge of
powder. We have also seen one of these same
English 9-inch guns endure more than 1,000 rounds
with battering charges, and remain perfectly sound
only requiring to be revented once. Our artillerists
have found a remedy for the one great danger to
rifled guns—the danger of destroying the grooves by
high charges; for by placing a thin papier mache
wad between powder and projectile the windage is
closed and the gas, with its burden of solid particles,
can no longer dash itself against the edges of the
grooves, so that the life of a rifled gun will for the
future be prolonged to a considerable extent. We
know that the spherical shells, which can alone be
fired from smooth bore guns, have no power what-
ever against iron plated targets of very moderate
thickness, and as for putting in higher charges and
risking the awful effects of a burst gun in a turret,
no officer would be mad enough to affront so ter-
rible a ruin with its attendant demoralisation to the
crew for the sake of one penetration. Grant that
the shot perforates the opposing vessel, how many
chances are there to one that it does so at a spot that
will cause a leak? And i lane did cause a leak, are
there no such things as pg to close it? People
frequently talk nowadays as if ships must be abso-
lutely invulnerable, and sailors are for the future to
lead charmed lives. We seem to forget the host of
resources which seamen have for keeping water out
of a wounded ship. A square hit from a ram must
be destruction, but a warship may float and fight
effectively with a good many holes in her sides.
Demoralise her crew if you can by a stream of pro-
jectiles, especially shells poured constantly into her,
and they must haul down their flag or be driven
from their guns ; but even were :she lying like a log
on the water it would take many rounds of artillery
fire to sink her.
A great deal has been said about "racking," but
whatever may be the action of a shot, it cannot be
considered as effective if, like the American gun
the other day, it leaves the inner skin without a
single hole of any sort.
There is another argument in favour of the Eng-
lish system which has been strangely neglected.
Suppose that the big smooth bore fires its big shot
and makes its big hole between wind and water.
Suppose that the crew neglect to plug this big hole
and that the ship sinks. An enemy's vessel has gone
down and is of no further use to anybody. But if
the rifled guns succeed in turning the batteries op-
posed to them into a slaughterhouse no longer ten-
able the enemy surrenders and one more man of
war is added to the victorious navy.
Another experiment was made lately at Shoe-
buryness which is more interesting in its deductions
than in its details. It has long ago been proved that
different plates of equal excellence will, if unbacked,
oppose a resistance to shot nearly proportional to
the squares of their respective thicknesses. But, be-
sides the well-kno cannot beact that
worked so after a certaievenlyn thick-
as
ness large plates
thinner ones, few people can have supposed, and
certainly experiment has never demonstrated, that
the same proportion will hold good if the thin plates
be placed in support of each other, and thoroughly
riveted together. The one solid plate will always
have an advantge if really well made, but not to the
same extent as if the thin ones were attacked sepa-
rately. The trial referred to was as follows :—Three
masses of iron, each 7in. thick, were exposed to the
fire of the 7- inch muzzle-loading rifled gun. Nothing
was put behind the iron as a backing. The thinner
plates backed each other.
The first target was a sold 7 inch plate, the second
was formed of two 31- inch plates, the third of threo
21 inch plates, well bolted together. Had the empi-
rical rule of the squares of the thicknesses been ap-
plicable under the conditions of the case, the ratios
of resistance, taking the inch as a unit, ought to
have been for the solid plate 49, for the two 3f inch
about 24, for the three 21 inch plates about 16. But
what really declared itself as the result of the day's
work may be shown very simply as follows :
To pass an ogival-head Palliser shot through the
solid plate required 15}1b. of powder.in the 7 inch

gun.
To perform the same feat upon the two 31 inch
plates needed 141 b ; upon the three 21 inch plates
131 b.
The energy of the projectile was in the first case
61 foot tons per inch of shot's circumference ; in the
second 57 ; and in the third 52.
These ratios are manifestly very different from ,
those deduced on the rule of the squares, and show
that considerable strength may
never equal the re-
built up target, though it will ne be obtained in a
sisting power of a soli
reatd pla
for the Go-
The subject is one of g imtp°oorfta
cry is already abroad
to build iron forts with, and
a
a su
vernment asks Parliament forpplementary sum
immense. thickness are re-
that solid plates of an
plates 21ft. long by sft.
quisite to keep out thetprrroeiseecnta:cpsrforporonsencr
fdorertnheriifiroedn
artillery. Thep lan a
them a row of vertical
bisihienienccdhtion, and behind them again
laidfart: e
shisio:6lTiZnOl.lanbttyftrilYinn, t.
plates 16in. by sin. laid horizontally. To
similar p
support this structure in rear there ate a number of
iron uprights which have a section of 12in. by sin.
They are placed two and two, with an interval of
2ft. Sin. between each pair and next. Strong bolts
pass from the front through all the plates, and bind
every pair of uprights tightly to the armour by
clamps and nuts. There can be no question that
the compound structure is far cheaper than the solid
iron plate. The only doubt is whether sufficient
strength can be obtained. So far experiments tend
to show that it can, and before criticising too sharply
the War-office designs it would be well to know what
is proposed in exchange for them. There is a general
tendency to insist on invulnerability for forts and
ships, and men argue as if an enemy could lay his
ships close alongside a sea fort and bombard it at
leisure. War is a very different affair from that,
and it is time some understanding should be come
to on such subjects. Fortifications are not intended
to act as impregnable caves into which soldiers may
creep and cower for safety ; nay, such conduct
would surely induce demoralisation, but rather as
obstacles to arrest or delay the advance of an enemy
who has a specific object in view.
The element§ of the cme aro not quite the saute