The Sun.
London, England, 1864-06-02 00:00:00

The Chalmers Target.

1, • ..• . ,
-- . er eoe. , too ohm ~t Tau 5pe11.... !armada, tat) vital
importance of our supremacy at sea has been acknowledged,
without a dissentient voice, as the best means for keeping
our shores inviolate, protecting our commerce abroad, and
upholding our political interests in various parts of the
world. In accordance with this feeling, our statesmen have
unfailingly taken good care that the fleets of England should
never run the danger of being overmatched, though it but
too frequently happened that they allowed foreign ships to
surpass ours in their seagoingof
tqualities,oir
armament. in th
With a
the
ibeautyt ol fl
ts
ou
‘eveaereddse
rod ,
oddui
fryi duringg thethat
aCrimean
great
fundamentalwar in takingb a basis this watchfulness, however, the French naval authorities
sthofe
ofiorrstsesotoep.
rity and power, by the introduction of armour plated float-
ing batteries impervious to shot; for it must be obvious to
every one that, by neutralising our means of destruction at
sea, they at once deprived us of
all the advantages inherent
to our superiority. The success that attended the first trial
of these armoured vessels against the ..
Russian forts at hen-
burn led to this plan being improved and extended to large
wascarried
frigates, which scheme out in so practical a
way, that the originators of Le Gloire may well lay claim
to the glory of having inaugurated quite a new era in the
comparison of navies and the relative position of maritime
Powers. Defensive as well as offensive capabilities at sea
could no longer be calculated
after the ratio they had borne
of monster to quantity, in the shape ships and moderate
sized smooth bores, but after that of iron dads and heavy
that rifled cannon. It followed the arm of which, in a
national point of view, we had the most peremptory need,
was slipping fast out of our hands, not through the adverse i
fate of battles—for we were the very midst of peace
—but through the simple, noiseless
agency of ingenuity,
and the resolution of
ioia promptly pushing forward
the immediate practical application
of a plan which had
proved so thoroughly
Useful and feasible. Fortunately,
however, we are living in times
when concealment and
seeresy are extremely difficult. The
success of the first iron
similar clad, and the extent to which rkfrigates were ordered
known
in the French navy, soon became and then, we
must admit, the danger was enermeticalla3, ;
time being lost in adopting the new
principledealt with, no
of
armour-
plating, and every possible despatch madotooreateaniroofleet, in unison with the traditional policy Great of Britain.
It is true that this exempla Was
_ promptly followed else-
where; in fact, most naval Powersengaged
are at present
in the reconstruction of their
fleets,
pushing on the new
system to the utmost of their abilities ; yet, with the im-
mense resources our Government can command, if wisely
used, there can be no reason to fear that we shall ever suc-
cumb in this extraordinary race, or come out of it in a posi-
tion inferior to the one we have been wont to hold.
At the time that this new invention was adopted, little
was known about the best conditions for ensuring success
with regard to the object it principally had in view, viz,,
impenetrability. It was believed that a plain slab of iron,
44 inches thick, well backed up by layers of timber, consti-
tuted a sufficiently powerful armour to resist cannon-shot
of the largest calibre, moving with the highest velocities.
This belief was not the result of a long series of experiments
undertaken for the express purpose of determining what our
artillery could do against armour, and vice versa, what ar-
mour was needed to set gunnery at defiance ; but it sprang
mainly from the impression that the thickness adopted in
France for the plating of their type ship was amply suffi-
cient, because the targets tried at Vincennes did prove
satisfactory when the iron wee of good texture and eleven
centimetres thick (equal to about four and one-third
no iron frame-work to sup-
inches), though they had
port the backing. Considering that the French me•
thod was essentially unscientific, certainly, with an
eye
to future contingencies, setae effort might have been made
towards ascertaining by what dispositions the resistance
could be increased without adding weight ; however, if we
bear in mind that the circumstance admitted of no delay,
and that our authorities were nearly in the same position
as
when they ordered a hundred 100-pounders before having
had even one tried,
we may be satisfied with the armour-
plating adopted for the Warrior, because in a relative point
of view its primitive style was superior to the equally pri-
mitive plan then carried out in the French navy. But it
soon became apparent that naval artillery was on the eve
of some radical alteration in its condition of penetration and
momentum, by the adoption of larger calibres, heavier
charges, and more suitable metal ; and from that moment
every one
could
see that the question of armour-plating had
entered on an entirely new phase. Enough had been
known of it to appreciate the value of such protection, and
save it from being abandoned as useless, if it could but be
endowed with resistance in an absolute sense--if we may so
express out selves, in view of the immense difference between
old and new gunnery—always within moderate limits of
thickness and of weight. A problem of this nature could
not fail, as a general rule, to absorb the attention of engi-
neers, and promote emulation amongst them ; but in the
present case it lots the exceptional qualification of exciting
an intense feeling of interest in the public at large, of hold-
ing out unusual promises, and lastly of opening a great field
to ambition. Never perhaps have the registers of the
Patent Office been called upon to record a greater number
of inventions in so short a space of time on one particular
object. A single hope had sufficed to instantly turn the
minds of many hundreds of men towards a career which
begins by exacting heavy payments for the grant of a natural
right, at present stigmatised as a monopoly; which opens
1 the rrity 0 /Wow, Ovinith yawl 1?y ttto grallt POPE

As was to be expected in a case like this, men of all
classes come forward, and, of course, all sorts of ideas were
brought to the surface—some feasible, others absurd. Of
the former, many were characterised by an endeavour to
attain resistance at the expense of the backing, the plate
alone being looked upon as the element of impenetrability.
Many of our most eminent engineers adhered to this plan,
forgetting, strangely enough, the mechanical principles
which cause the blacksmith to give the anvil an elastic
foundation of wood in solid blocks—which enable the cob-
bler to hammer leather on his knees, by using a thick and
heavy stone as a cushion—and permit railroads successfully
to bear enormous weights. Now, on referring to Sir Howard
Douglas's work on Naval Gunnery, we find that a plate of
iron, 6ft square and Bin thick, standing in an inclined posi-
tion against a wall, was broken up by twelve 681 b shots,
fired with the ordinary charge, at an average distance of
500 yards. We likewise know that the 42-inch plate of the
vertical Warrior target will bear any amount of such pound-
ing. In the first instance, irrespectively of the favourable
inclination, the resistance is as 64 ; while in the second,
exclusive of the backing, it is as 20'25. Surely, then, it
could not require much ability to see at once that the back-
ing was endowed with a latent force, which came out on
impact, and contributed most usefully to the resistance of
the plate. This force, which might be called reactive force,
is due to the elasticity of the backing, coupled with suffi-
cient rigidity. It supports the inert matter of the plate,
enlivens its resistance, spreads the concussion over a sur-
face which increases with depth, and, lastly, it acts directly
against the projectile, to the prejudice of its penetration.
With all this, the Admiralty countenanced many plans
which, though backed by great names, were sadly deficient
in the very elements of this valuable force, and of course
the penalty had to be paid, in the shape of repeated de-
feats ; whence they eagerly declared that there was nothing
better than their first child, the original 44-inch armour.
The Minotaur target was a kind of compromise between
some of the anti-backing plans and the 'Warrior, being a
thicker plate (siin), with only 9in of wood behind ; yet,
notwithstanding such extra thickness, it was pierced and
literally destroyed by 7501bs of metal thrown; while
the Warrior stood 4,0001ba comparatively well —at
least, its skin was not broken. There is nothing won-
derful in this ; the more you diminish your reactive
force, the more you facilitate penetration. Fer instance,
in the Warrior, the resistance of the iron being as 20'25,
that of its 13-inch backing as 324, the total of the reactive
force might be represented by the area 20.25 X 324 6,561;
while in the Minotaur the resistance of the iron was 3025,
that of the 9-inch backing ss 81, giving an area as 2,450 ;
wherefore, when the 300-pounder, fired with 501bs of
powder,
sent its cast-iron round shot into the former, leav-
ing five inches of timber and the skin unbroken, it could
easily be foreseen the same gun fired under similar condi-
tions would sweep " clean through the Minotaur target,
carrying plate, backing, skin, frame, and all before it."
The 11-inch plates tried without backing were broken
through at the first round of the 300-pounder, though the
iron resistance was as 121, six times greater than that of
the Warrior; but there was no reactive force, so the shot
only encountered inert matter of great tenacity. With a
little care, how easy it would be to save the country of a
vast amount of wanton expenditure I

Other plans, on the contrary, laid great stress on the part
played by the backing; in fact, they took a line diametri-
cally oppposite to that followed by the former, their origi-
nators having evidently understood the lesson conveyed by
the comparative superiority of the Warrior with regard to
a system based on the use of thicker plates and thinner
backing. They may not have seen what constituted the
secret of impenetrability, but it was apparent to them that,
by :improving the rigidity, and at the same time the
elasticity of the backing, they would increase the resistance
to compression, and proportionately diminish the plate's
tendency to buckle and give way before the shot. One
would have thought these principles plausable enough to
merit fair consideration, or novel enough to excite
official curiosity. Such, however, was not the case in
any way; the Admiralty being either unable to
appreciate the scientific features, or determined never to
depart from their own favourite ideas, right or wrong. Be
this as it may, we find that amongst the persons who sided
with the backing a certain Mr. Chalmers distinguished him-
self especially for hie perseverance in bringing the question
into notice, and at the same time for his faith in the prac•
tical success. Early in 1562 he became convinced that ar-
mour needed three essential conditions, viz., more support
behind the plate, an elastic medium to check the vibration,
and fastening bolts better proportioned. In the first and
third conditions we fully concur. We likewise concur in
the second—but not as to the purpose it is intended to fulfil.
In August, 1862, he submitted his plans to the Admiralty;
they, of course, refusing to give them a trial. Upon which
he proposed (September 22) to furnish a target at his own
expense—the conditions being that in case of failure it
should remain his property, whereas in case of success
further trials were to be made, preparatory to the general
introduction of the system, in the armour-plating of new
iron-clads. On the 15th October their lordships refused
over again, characteristically referring Mr. Chalmers to
their "former answer on the subject of his proposal to con-
struct a target;" but there had been no " former answer"
to the proposal based on the risk of the projector. So Mr.
Chalmers immediately reiterated his offer, reserving to him-
self the right of reimbursement up to £1,650, on condition
that, first, his plates should neither buckle nor be pene-
trated, on being tested in the same way as the Warrior ;
secondly, the armour should afford protection to the skin
against the Whitworth projectiles, which had succeeded in
penetrating the Warrior; thirdly, plates 3! inches thick
should afford better protection than 4i-inch plates backed
by wood only. Failing in these conditions, he claimed the
right of removing his target ; succeeding, he left himself en-
tirely in the hands of their lordships with regard to compen-
sation. Two days later, the Admiralty were pleased to sig-
nify their adhesion to this proposal, declaring beforehand
their intention not to enter into engagements " as to future
remuneration, or costs ;" and there is every reason to be-
lieve that this answer satisfied Mr. Chalmers in spite of its
vagueness ; for the target was at once commenced by the
Millwall Iron Ccmpany, the work being completed suffi-
ciently in time for the first trial to come off on the 27th of
April last year.

On examining the system one could see that the outer
armour-plate was 31 inches thick; that the first backing
was composed of alternate layers of wood and iron about
11 inches deep, the iron ribs being equivalent to about an
additional thickness of nearly half an inch to the plate;
that this backing was supported by an inner armour plate,
1 inch thick, resting against a cushion or second backing
from 3 to 4 inches deep ; the whole being firmly bolted to a
frame representing the side of an iron ship. The target
weighed as much as the Warrior per square foot. The pro-
gramme consisted of 27 rounds, of which 8 were from the
68 pounders-4 solid shot and 4 shell—with 16 lbs of
powder ; and 9 were from the 110 pounder Armstrong
(12 solid, 6 shells, and one steel flat-ended)—the charges
being respectively 141 b, 121 b, and 101 b. Without going
into the various details of the firing, we may at once say
that the result was far more satisfactory than in the case of
the Warrior, thanks undoubtedly to the greater amount of
reactive force located in the cushion, and the peculiar con-
struction of the cellular backing. Great hopes were im-
mediately founded on this good achievement ; but they
eventually made way to bitter disappointments, despite
words uttered in the House of Commons, and which seemed
to be an acknowledgment full of promise for Mr Chalmers,
as well as for the friends whe had so heartily given him
their support. On the 4th of May two more rounds were
fired at this target from the 10.5-inch shunt Armstrong,
with spherical cast-iron shot, and 510bs, of powder, result-
ing in two belts and a few rivets broken, one of the ship's
ribs being bulged inwards a few inches; still, the inner
plate was not pierced. Unfortunately, however, Mr.
Chalmers consented to the firing of a 3001 b. steel shot, with
no less than 451bs, of powder : it effected complete penetra-
tion, and thus he himself enabled his adversaries to turn
the result against his own work ; not with much good
faith, we grant—for we have yet to learn where the Admi-
ralty has the target able to stand such a shot at 200 yards,
especially after 29 rounds—but nevertheless with that
superficial show of reason, which was wanted for waging
war on bad grounds.
Contrary to their expectations, the Admiralty had been
taught a valuable lesson. They had been forcibly shown, not
by deep science, but by plain practical results due to sound
instinct, that backing hag more to do with resistance than
they had imagined ; wherefore, according to the usual rules

followed between masters and pupils, one would have ex-
pected them ready to acknowledge the service done. But
official institutions cannot adapt themselves to vulgar
usage, so it was decided to pay for the tangible outlay--
that is. for the target furnished by the Milwall works—and
not to reimburse the master the small amount due for per-
sonal expenses and for time expended during the manufac-
ture of the target. Moreover, acting after the same pro-
pensities which tempted them to build the slow Orontes as
an improvement on the swift Himalaya, they determined to
try another target on their own favoured plan, embodying
A shadow of the principles which had succeeded in tte
Chalmers ; and again they had the deep mortis ation to
witness its failure, in the presence of a large assem-
blage, the first round the 10.5-inch gun send-
ing the whole Concern Vto ruin. A succession of
disasters was a matter not to be tolerated, for the sake of
official fame ; so one more effort was made to secure at least
a semblance of triumph in another target called the Belle-
rophon, by adhering as closely as possible to the most
essential features of the Chalmers : in fact the backing eon-
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