THE SHELL GUN
The chief function of land artillery in its earlier days was the
destruction of material. The huge engines of the ancients were of
value in effecting from a safe distance what the tortoise and the
battering-ram could only do at close quarters: the breaching of
walls and the battering-in of gates, doors and bulwarks. After the
invention of gunpowder the use of artillery remained, we have seen,
substantially the same. Apart from the moral effect on horse and man of
the “monstrous roare of noise” when in defence, the offensive object of
ordnance was almost entirely the breaching of the enemy’s works. The
guns were literally “pieces of battery,” doing their slow work by the
momentum of their large projectiles.
Thus considered, artillery was not a very effective instrument.
And, just as in earlier times it had been sought to supplement mere
impact by other effects--by the throwing into besieged fortresses of
quicklime, for instance, “dead horses and other carrion,”--so, after
the arrival of gunpowder, endeavour was made to substitute incendiarism
or explosion for the relatively ineffective method of impact. The use
of grenades, hand-thrown, was discovered. And then followed, as a
matter of course, their adaptation to the mortars already in use for
the projection of stones and other solid material. These mortars, as in
the case of the early cannon, were at first made of an inconveniently
large size; and, also as in the case of cannon, they came later to
be cast of more moderate proportions to facilitate their transport
and thus render them more serviceable for operations in the field.
Artillery was now devoting its attention to the personnel. The result
of this evolution was the howitzer, a weapon whose value to land armies
was greatly enhanced by the discovery, by Marshal Vauban at the end
of the seventeenth century, of the efficacy of the _ricochet_. Under
this system the fuzed bomb or grenade, instead of being projected
from a mortar set at a high elevation, to describe a lofty and almost
parabolic trajectory, was discharged from a howitzer at a sufficiently
low elevation to cause it to strike the ground some distance short of
its objective, whence it proceeded, leaping and finally rolling along
the ground till it came to its target, where it exploded.
[Illustration]
So far shell fire had developed on land. In sea warfare the solid
cannon ball remained the orthodox missile; the use of explosive or
incendiary shells was deemed so dangerous a practice as to forbid
its acceptance by the great maritime powers, save in exceptional
cases, until the nineteenth century. Toward the end of the eighteenth
century serious consideration was given, by France especially, to the
possibilities of shell fire. Frenchmen felt restless and dissatisfied
with the conditions in which they were waging war with England. Sea
ordnance, which in the past had wrought so much by the destruction
of personnel, was becoming increasingly impotent, not only against
personnel but against ships themselves. Trafalgar came as a proof
of this, when not a single ship was sunk by gunfire. Sea fighting
was again resolving itself into a straightforward physical struggle
between the guns’ crews of the opposing fleets, in which struggle
the victory went by attrition to the side which plied its guns with
the greatest rapidity and perseverance. Élan, enthusiasm, science,
the mental alertness of the individual, were bound to be overborne
in such a case by superior endurance, physique, coolness, and sound
workmanship. Both sides had a profound belief in the superiority of
their personnel in hand-to-hand conflict. Where fighting was, as in
the earliest days of the rival navies, “man to man, lance to lance,
arrow to arrow, stone to stone,” success depended entirely upon
courage and physical strength; and in such cases, says Nicolas, the
English were almost always victorious. If, stated a French writer, sea
actions could be decided by hand-to-hand combat the arms of France
would triumph. But sea fights were in fact almost solely a matter of
artillery. If only the conditions of battle could be altered; if only
the forces of incendiarism or explosion could be summoned to put the
enemy ships-of-the-line in jeopardy, a short cut to victory might be
found or, at any rate, the superiority of England in material might be
seriously depreciated.
[Illustration]
Some time was to elapse, however, before France was to see even the
partial consummation of this fervent desire.
While the use of grenades, bombs, carcasses and other explosive
and incendiary missiles had been recognized on land for centuries,
an event occurred in the year 1788 which, coming to the ears of
Europe, should have had considerable effect in turning the thoughts
of artillerists to the possibilities of their use at sea. In that
year, some sixty-five years before the action off Sinope, a Deptford
shipwright who had risen to high service under the Russian government
fitted out for his employers a flotilla of long-boats for an attack
upon a Turkish squadron. These long-boats Sir Samuel Bentham--he was
the ex-shipwright--armed with brass ordnance mounted on his favourite
non-recoil system, and for them he requisitioned a large supply of
shells, carcasses and solid shot. At the mouth of the Liman river in
the Sea of Azov the Russians, with these insignificant war vessels,
attacked a very superior force of Turkish ships, and gained a complete
victory. The effect of the shells, fired at close range into the
Turkish ships, was startling and impressive. Great holes were torn in
the sides of the vessels, and fires were started which, in a favouring
medium of dry timber and paint and pitch, rapidly spread and caused the
squadron’s destruction.
No evidence can be quoted, it must be admitted, to show that
contemporary opinion realized how portentous was this sea action;
no stress is laid on the event in histories relating to that time.
Nor does another event which occurred at this period appear to have
caused the notice it deserved: the firing, at the suggestion of a
Captain Mercier, 35th Regiment, of mortar shells from the British
long 24-pounders, from Gibraltar into the Spanish lines.[100] Nor
was Lieutenant Shrapnel’s contemporaneous invention,[101] of a
shell containing case shot explodable by a small bursting charge,
developed or the possible adaptation of its use for sea warfare fully
appreciated. Or, if authority did discern the eventual effect of these
innovations, a wholesome dread of their extension and development
in naval warfare appears to have dictated a policy of calculated
conservatism in respect of them, a suppression of all ideas and
experiments which had in view any intensifying or improvement of
our artillery methods. “So long as foreign powers did not innovate
by improving their guns, by extending the use of carronades and,
above all, by projecting shells horizontally from shipping; so long
it was our interest not to set the example of any improvement in
naval ordnance--the value of our immense material might otherwise be
depreciated. Many of the defects which were known to exist, so long
as they were common to all navies, operated to the advantage of Great
Britain.”[102]
Apart from this consideration, however, it is remarkable how small a
value was set by English opinion, even at a late date, upon explosive
as compared with solid projectiles. The obvious disadvantages of
hollow spherical shell--their smaller range, more devious flight and
less penetrative power--were emphasized; their admittedly greater
destructive effect (even taking into account the small bursting charges
deemed suitable for use with them) was rated at a surprisingly low
figure.
The French, on the other hand, showed great eagerness to explore the
possibilities of shell fire in fighting ships. Addicted to science,
they searched unceasingly throughout the revolutionary wars for some
development of naval material which would neutralize the obvious
and ever-increasing superiority of the British navy under existing
conditions, even if it might not actually incline the balance of
power in their favour. To this end they courted the use of incendiary
projectiles. Our own authorities, partly from a lively apprehension
of the danger believed to be inherent in their carriage and use in
wooden ships and partly from a feeling of moral revulsion against
the employment of what they genuinely believed to be an unfair and
unchivalrous agency, limited the use of fuzed shells, carcasses and
other fireworks as much as possible to small bomb vessels of special
construction--and inferior morals. But in ships-of-the-line the use
of such missiles was strongly deprecated by naval opinion, and even
the use of hand-grenades in the tops was forbidden by some captains.
Time justified this cautious attitude. The French suffered for the
precipitancy with which they adopted inflammatory agents; fires and
explosions were frequent in their fleets; the history of their navy in
these wars--“la longue et funeste guerre de la Révolution”--is lit up
from time to time with the conflagrations of their finest ships, prey
to the improperly controlled chemical forces of their own adoption. One
example alone need be cited: the _Orient_ at the battle of the Nile.
Even if the French flagship was not set on fire by their direct agency,
small doubt exists that the spread of the fire which broke out in her
was accelerated by the presence of the combustibles which, in common
with most of the French ships, she carried. Throughout the wars fuzed
shells, carcasses, stinkpots, port-fires, proved far more terrible to
friend than foe. And the foe doubtless felt confirmed and fortified in
his opinions that such substances were quite unsuitable for carriage
in warships. As to the ethics of explosives even the French themselves
seem to have been doubtful. For, shortly after the battle in Aboukir
Bay, some of their officers accused an English captain of having been
so “unfair” as to use shells: an audacious manœuvre on their part,
for, on some of the shells in question being produced and the gunner
questioned as to whence they came, “to the confusion of the accusers,
he related that they were found on board the _Spartiate_, one of the
ships captured on the first of August!”[103]
Continuous trials were carried out in France with shells fired
from guns. In 1798, following a series of successful experiments,
trials were prosecuted at Meudon by a special commission, who caused
24-and 36-pound shells to be fired at a target representing a
ship-of-the-line, at ranges of 400 and 600 yards. The results were
impressive, and the report rendered to Bonaparte such as to confirm
his personal conviction in the value of shell fire. Less than a year
later, we may note in passing, the Consul was himself the target of
shell fire: being subjected, at the siege of Acre, to the unpleasant
attentions of a 68-pounder carronade from the English fleet. In 1804,
with the avowed object of keeping our cruisers at a distance, he had
long howitzers cast and placed for the defence of Toulon and other
ports. And hardly a year passed but some trial was made of horizontal
fire of shells from guns and mortars.
Of the two great maritime powers, Britain had contributed more,
perhaps, towards the building up by actual practice of the system of
artillery which was shortly to come into vogue. Shell fire from mortars
had been used with far more effect by her forces than by those of her
great enemy. The invention of the carronade was in itself almost a
solution; and, though it did not lead directly to the shell gun, yet
it undoubtedly induced the weapon which most strongly resembled it:
the medium ship-gun, as designed by Congreve and Blomefield, which was
something between the carronade and the long gun, and which for a time
was mounted in our two-decked ships for the purpose of preserving unity
of calibre.
But the French, free from the bias against change of method and
material which operated in this country, seized on the possibilities
of existing elements, and combined them in such a way as to form a
complete solution of the shell-fire problem. To General Paixhans,
the eminent officer of artillery, the credit for this solution is
undoubtedly due.
§
The experiments of M. Paixhans, carried out in order to confirm the
theories on which his new system was founded, extended over several
years and resulted in the publication of two books--the _Nouvelle Force
Maritime et Artillerie_, 1822, and _Expériences faites sur une Arme
Nouvelle_, 1825.
In these works[104] the author developed in detail the scheme of ship
armament which was to win adoption, in the course of time, in the
French navy; whereby our own authorities were also gradually forced to
abandon methods and standards of force by which the British navy had
grown great. Two principles formed the basis of this scheme:--(1) unity
of calibre, embodying the maximum simplification of means; (2) shell
fire, embodying the maximum augmentation of effect.
On these two principles M. Paixhans reared and elaborated in minutest
detail the revolutionary system with which his name is associated.
No new element or discovery was necessary for giving effect to his
designs. Indeed he expressly disclaimed having introduced any novelty:
“Nous n’avons donc rien inventé, rien innové, et presque rien changé;
nous avons seulement réuni des élémens épars, auxquels il suffisait
de donner, avec un peu d’attention, la grandeur et les proportions
convenables, pour atteindre le but important que nous étions proposé.”
It may be said, in fact, that unity of calibre had been an ideal sought
for years before M. Paixhans’ time; while shell fire, the New Arm of
1822, was almost the logical consequence of Robins’ discoveries in
the principles of gunnery, extended as they were by the researches
of Doctors Hutton and Gregory. In particular, mention is made by M.
Paixhans himself of two of the results brought out by Dr. Hutton’s
experiments: one, that the length of the bore of a gun has but a
small effect upon the range of its projectile, the range varying as
the fifth root of the length; two, that the muzzle velocity may be
considered to be independent of the weight of the gun.
As to the lack of novelty of shell fire on ship-board, M. Paixhans
gives a significant extract from French naval annals. In 1690, it
appears, a M. Deschiens had invented a means of firing bombs from long
guns horizontally, instead of parabolically as from mortars. This
secret was of great use to him; for, falling in with four English ships
at sea, he so surprised them by this new invention that, fearful of
being set on fire, they drew off and did not attempt to renew battle.
This same French captain at a later date attacked two Dutch ships more
than a match for him, and, by means of these horizontally fired bombs,
sank one and disabled the other. But M. Deschiens died and his secret
with him; though, as M. Paixhans remarks, this “secret” would have been
easy to find if anyone had looked for it.
A whole chapter of _The Genuine Use and Effects of the Gunne_, written
by Robert Anderson and published at London in 1674, concerns “the
shooting of Granados out of Long Gunnes.”
Briefly, the grand idea of M. Paixhans consisted in the establishment
of a fleet of steam vessels armed with guns designed to project
charged shells horizontally at considerable velocities. But as this
consummation could only be attained by degrees, he proposed that in
the meantime the existing French fleet should be re-armed in such a
way as to give to each ship a maximum of force combined with unity of
calibre. This part of his scheme was applicable to solid shot (_boulets
massifs_) as well as to shell (_boulets creux_). But the former he
considered too ineffectual for use in future sea engagements. Although
they might be the most suitable projectiles for the destruction of land
works, the breaching of ramparts and the battering of stone walls,
yet hollow shot, filled with powder and other combustible material,
were far better adapted to rend and set fire to defences of wood,
impregnated with tar, and, in time of action, replete with every
species of inflammable substance, and crowded with combatants. No, M.
Paixhans hoped to make solid shots entirely obsolete, by adopting,
in combination with small steam vessels, or, for the present, in
combination with the existing fleets of sailing ships, an ordnance
specially dedicated to shell fire, and to shell fire alone. By its
means the enormous superiority of Great Britain would be effectually
eliminated, or transferred into the hands of France; her material
would be rendered suddenly obsolete, her maritime power would shrivel;
and the power of France would be augmented to such a degree that the
defeat of these islands might at last be encompassed.
Such was the amiable intention of M. Paixhans.
The arguments which he employed in favour of his revolutionary
proposals are of sufficient interest and importance, perhaps, to merit
consideration. The past histories of the two navies showed, he argued,
that the introduction of improvement or of innovation into either navy
was shortly afterwards followed by its introduction into the other;
so that there was never any important change in the relative naval
strength of the two nations. It followed, therefore, that the only
means by which power could be wrested from the possessor of it, must be
such a change of system as would render useless the existing means by
which that power was sustained. How could this be accomplished? Foreign
nations had always felt the innate strength of England, residing in the
race of splendid seamen (a highly specialized profession) who formed
so great a part of her population. France especially had felt her own
weakness in not possessing a reserve, a nursery of seamen, such as
England had. If only seamanship could be discounted----! M. Paixhans
proceeded to show that the coming of the steamer was itself an event
which would go a long way to discount a superiority in seamanship. The
accursed English “devil boat,”[105] which had begun to spread its pall
of smoke over all the northern waters, might be, in truth, a potent
friend to France. Steam vessels required only a small and unskilled
personnel to man them, instead of prime seamen. Steam vessels could
always outstrip sailing ships, and thus could choose their own range
and accept or decline battle as occasion required. Moreover, the
effect of shell fire would be to upset completely the balance of power
existing between big ships and little ships, as such. Instead of size
being a measure of power, it would be a measure of vulnerability. The
larger the ship the more she would be endangered. Costly three-deckers
would cease to exist, and in their place small steam vessels, fast
and heavily armed, easily manœuvred and perhaps encased in armour,
would hold power. Thus the great obstacle to the acquirement by France
of a large naval force--the necessity for a numerous and experienced
personnel--would be easily removed. In short, the adoption of his
scheme would in any case be most favourable to France. Even if it were
simultaneously adopted by Great Britain its adoption would at least
ensure that in future the naval power of the two states would be in
proportion to the strength of their _whole_ population, instead of only
that part of it familiarized with maritime affairs.
Considering first the conversion of the existing French navy, he
examined and enlarged upon the various inefficiencies inherent in
the usual disposition of ship armaments; in the manner in which the
unit and the number of units of artillery force were selected for any
individual design of ship; in the variety of the units, and in the
lack of system observed in the various proportions between the gun,
the charge and the projectile. He observed that the constant tendency
of development, both in the French and in the English navy, was in
the replacing of smaller by greater calibres, by which process the
diversity of calibres was diminished and the effective force of the
armament increased. Continuing this process, it appeared that the
ideal armament would be reached, the maximum degree of force would
be attained, when unity of calibre was achieved. When the calibre
of the largest-sized cannon carried on the principal gun deck of
ships-of-the-line was adopted as the sole calibre used, the maximum
of force would be attained: the greatest possible destructive effect
combined with the greatest possible simplification of means. These
remarks applied equally to a solid shot and to a shell gun armament. If
for some reason it were decided not to adopt shell fire, nevertheless
it would be of advantage to re-arm the French sailing fleets on this
principle, with guns of one calibre.
M. Paixhans proposed as the unit the French 36-pounder. He explained
the advantages to be derived from arming existing ships-of-the-line
with 36-pounders all of the same calibre but of different weights on
the respective decks. The guns on different decks would take different
charges and would therefore project the shot with different muzzle
velocities. They would be disposed, the heaviest on the lower deck;
a lighter type (reamed out from 24-pounders) on the main deck; still
lighter guns on the upper deck, and 36-pounder carronades on the
quarter-deck and forecastle would complete the armament.
The employment of solid shot was not favoured by him, however, and
he claimed the results of various trials as showing the superior
offensive value of shells, when compared with solid shot. Comparing a
solid shot and a shell of the same external dimensions discharged with
the same muzzle velocity, the former, he said, had only the advantage
in superior range and penetrative power. The latter, while having a
range greater than those at which sea actions were invariably fought
and sufficient penetrative power to effect a lodgment in a ship’s
timbers, required less powder to propel it, a lighter and therefore
more rapidly worked gun from which to discharge it, and it had a
destructive effect enormously greater than that of the solid ball.
The complete proposal therefore involved the adoption of shell guns
exclusively, new guns being made and old guns being reamed out as
necessary to enable each ship to carry pieces of one calibre alone. The
calibre proposed as unit was the long French 48-pounder. And, as an
example of the way in which M. Paixhans would convert armaments, the
case of the French 74-gun ship is here taken. This, with an existing
armament of:--
28 36-pounders,
30 18-pounders,
14 6-pounders,
14 6-pounder carronades,
a total of 86 pieces throwing 2250 pounds of solid shot, he would
convert into a ship armed with:--
28 48-pounders (reamed from 36-pounders),
30 48-pounders (of same weight as 18-pounders),
28 48-pounder carronades;
eighty-six pieces throwing 3010 pounds of charged shell weighing 35
pounds each.
For the new shell gun he proposed a design of iron howitzer in which
the distribution of metal was so adjusted as to give a sufficient
factor of safety at every section, while at the same time allowing
the total weight of the piece to be reduced to a minimum. This
_canon-à-bombe_ was to be mounted on a stable form of carriage, made
without trucks but fitted with running-out rollers and directing bars
to control the line of fire and the direction of recoil.
To those who were inclined to regard with feelings of horror this new
use of explosive missiles, this progress in the art of destruction,
the inventor put the question, whether experience had not proved
that the perfection of arms had not had the effect of making warfare
actually less bloody; whether it was not a fact worth consideration,
that, while in days of old the destruction and loss of life in battles
was enormous, the loss of English seamen by gunfire in the numerous
combats of three long and bitter wars of recent times amounted to
less than five thousand killed. And would not, therefore, further
development of arms be a positive benefit to humanity?[106]
One other feature was put forward to complete this scheme of
re-armament, the importance of which it is unnecessary to emphasize.
M. Paixhans explored the possibility, by the sacrifice of a tier or
more of guns, of rendering all classes of ships invulnerable by casing
their sides with iron plates. Although rejected at the time, and as
the result of trials which he himself carried out, this suggestion was
destined to be carried into effect in startling fashion some thirty
years later: with what consequences to naval architecture we shall
presently see. In connection with the scheme of re-armament outlined
by M. Paixhans in 1822 the suggestion was important in that there was
implied in it an admission of one of the two weak features of the
inventor’s system. The shell gun would lose its superiority over the
shot gun, and might indeed be reduced to absolute impotence if, in
imitation of France, the enemy also cased his ships of war with iron.
The solid shot gun would once again have the advantage; in fact, that
very equilibrium of relative values which M. Paixhans was endeavouring
to destroy would once more obtain between the navies of the two rival
powers.
For this reason, presumably, and because the shell gun system
contained, though in a less degree, the disability inherent in the
carronade system--inferior ranging power, enabling a clever opponent
armed with long solid shot guns to fight at a range which was too great
for shell--the Paixhans scheme was not adopted in its entirety by the
French government of the time. But the principle of unity of calibre
was acclaimed and approved almost immediately, applied to solid shot
guns. The French 30-pounder was chosen as the unit. In 1829 guns of
this calibre, made on several different models to suit the various
decks and classes of ship, were mounted in their fleets.[107]
In the meantime M. Paixhans had made further progress toward perfecting
the details of his shell gun system. A _canon-obusier_ of 80 pounds
was made to his design, a chambered howitzer of the same weight
(about 72 hundredweight) as the French 36-pounder truck gun and of 22
centimetres calibre. This was designed to project a hollow shell of
the same size as the French 80-pound solid shot, but weighing, when
its cavity was filled with a charge of 4 pounds of powder, 56 pounds
French (62½ pounds English). The shell gun itself was of a distinctive
shape. The characteristics of short chase, large bore, a chamber, a
small propelling charge, and a scientific elimination of all useless
metal, resulted in a form of ordnance quite different from that of the
long-accepted smooth-bore cannon. It was easily recognizable by its
straight muzzle, smooth lines and the absence of the usual ornaments
and reinforcing rings. When, eventually, the New Arm was adopted by
other powers, their shell guns too, though independently evolved, were
found to exhibit the same external features: the features of what came
to be known universally as a “Paixhans gun.”
The terrific effect of charged shell, fired from this form of gun
with sufficient velocity to find a lodgment in a ship’s timbers, was
demonstrated at Brest in 1821 and 1824; in the latter trials the target
being a frigate, the _Pacificateur_, moored in the roadstead. High
range and accurate shooting were obtained. The incendiary effect of
the shell was prodigious: so impressive, indeed, that in spite of a
strong opinion in the French navy against further carriage of bombs in
ships-of-the-line, the Commission recommended “that _canons-à-bombe_ be
adopted, even in ships-of-the-line, but in small numbers.”
But though the principle of the shell gun was accepted by experts,
public opinion was not yet ready for the change. The Commission had
shown a sage circumspection in regard to the extent of the change
proposed; but public opinion was not yet satisfied that the new arm
was sufficiently safe. The scheme suffered a long postponement. In the
meantime several further trials were held. The design of the piece
was again modified; a larger chamber was arranged and a support was
cast, at the commencement of the chase, for carrying a sight. Tests _à
outrance_ were made to find what maximum charge such a shell gun would
safely stand; and at last, in 1837, the principle of shell fire was
accepted by the government, the Paixhans gun being assigned a place
in the prescribed armament of the fleets of France. To the impairment
of the unity-of-calibre principle, lately achieved, shell guns of 22
centimetres were admitted as part-armament of ships the greater number
of whose pieces were 30-pounders firing solid shot.
[Illustration: A PAIXHANS GUN]
§
In England the arguments in favour of a new and more scientific
adjustment of ship armament had not until this date been clearly
formulated. Of the tendency to a single calibre there certainly had
been many demonstrations in the last decades of the eighteenth century:
a tendency favoured by the replacement of the smaller long guns of the
fleet by carronades. Sir Howard Douglas, in his _Naval Gunnery_, the
first edition of which was published in 1820, had demonstrated the
advantages of large calibre, the inefficiency of random broadsides, and
the high importance of the deliberate aim of single guns. And in 1825,
before the French began to remodel their ordnance, Colonel Munro, of
the Royal Artillery, submitted his project to the naval authorities
of arming our ships solely with 32-pounders, of different classes and
weights to suit the various circumstances. But no radical revision
of armament was made in the British navy until some years after the
French had made the great stride of 1829, already described.
Unity of calibre, then, was no novel idea on the part of M. Paixhans.
“No project,” says Dahlgren--“no project has proved more attractive to
naval men than that of having a uniform calibre throughout the entire
fleet. It has been proposed from time to time without success, until
adopted for the French navy in 1829.
“In the promptness with which the example was followed by England and
the United States, may be recognized the general convictions of the
profession in regard to the serious mischief inseparable from the chaos
of calibres that prevailed, and the urgent necessity for some measure
that would simplify the complex economy of naval ordnance.
“In a three-decker might be witnessed the extreme phase of the evil:
long 32-pounders, 18-pounders, and carronades, requiring three sizes of
shot and four classes of full charge, with as many reduces as caprice
might suggest. All this variety of supply was to be distinguished and
selected in the magazines and shot-lockers--circulated with perfect
exactness in the confusion and obscurity of the lower passages, to
a particular hatchway, then up to the deck where was placed the
gun for which each charge or shot was designed: and this was to be
accomplished, not with the composure, deliberation, and attention
that the nature of the operation itself demanded, but amid all the
excitement and hot haste of battle.”[108]
The plans of M. Paixhans, in particular those for the adoption of shell
fire on a large scale, were viewed with much misgiving in this country.
But, as already noted, Great Britain moved very cautiously in the
counter-measures which she took in view of the policy then under review
in France. It is probable that the publication, in 1828, of a memoir
by Captain F. A. Hastings, R.N., commanding the Greek steam vessel
of war _Karteria_, had great effect in encouraging the authorities
to countenance shell fire. From this memoir it appears that Captain
Hastings was led, by arguments similar to those which influenced M.
Paixhans, to consider the possibilities of discharging at an enemy
something more devastating in effect than the solid sphere of iron
in general use. His navy was inferior in numbers to possible rivals;
he expressed the opinion that this inferiority might be nullified by
the use of shell, but he “got well laughed at for his pains.” Soon
afterwards, however, he came across Paixhans’ work. Acting on his
ideas, he applied shell fire with great success in action, and at once
became an enthusiastic advocate of the new arm. One great objection
to its adoption he almost laid to rest: the increased danger due to
the carriage of shells. He denied that there was any increased danger.
On the contrary, he considered charged shells less dangerous than
powder in cartridges, if properly packed. They were less dangerous,
he argued, because their use involved bigger and therefore fewer guns
than an ordinary ship would carry. Therefore there was less confusion
in action, less jostling, more working spaces, and fewer cartridges and
projectiles to be handled. In support of his opinion he could point to
an entire absence of accidents during his commission in the _Karteria_.
In 1829 a general increase of calibre was obtained by the inexpensive
expedient of boring out guns to their next larger calibre; in which
operation the opportunity was taken to arrange for a reduced allowance
of windage for the guns thus altered, and thus to secure a double gain,
of increased calibre and improved discharge. Experiments were made
with shell fire _à la Paixhans_. Tentative designs of shell gun were
produced by the ordnance department, and guns of 8-inch, 10-inch and
12-inch calibre were made; one of which, an 8-inch, mounted in H.M.S.
_Phœnix_, made very effective shooting at San Sebastian in the year ’36
and gave thereby an advertisement to shell fire.
And then, in 1837, came the French decision to adopt a shell gun
armament generally.
The result was a complete and corresponding reorganization of British
ship armament.[109] By 1839, the authorities being at last convinced
of the necessity of meeting the French innovations with similar
innovations on our part, Colonel Munro’s proposal of 1825 had been
adopted, and various classes of ship were equipped with six different
patterns of 32-pounder long gun. With these were associated, in small
numbers, 8-inch shell guns of fifty-three and sixty-five hundredweight.
Thus this country by a single move countered the two moves made
by France in ’29 and ’37 respectively, and denied to M. Paixhans,
for a while at any rate, any considerable change in the relative
strength of the two navies. As in the French navy, shell fire was only
introduced as an auxiliary to the solid shot. Thus the great ideal
of unity-of-calibre, so long sought and at last almost attained, was
found incompatible with the other ideal, shell fire; and was therefore
sacrificed. No doubt was felt, at this time, as to the necessity for
two types of gun. The superior power of shells was dreaded, suspected,
half-acknowledged; but the superior range and penetration of solid shot
fired from long guns made the latter indispensable to ships’ equipment.
So shell and large-bore shot guns were mounted in ships side by side.
Old guns and carronades were “scrapped” in large numbers to give
place to the new ordnance; and an official announcement was made, in
justification of the Admiralty policy, that “the changes were not made
until they had been adopted by foreign powers.”
§
Shell fire was at last accepted. The perils associated with the
carriage of shells in wooden ships were found to have been exaggerated;
experience soon confirmed that, if special precautions were taken, no
danger was inherent in their use.
Even after its introduction into our fleets the shell gun was regarded
by many as of doubtful value. For some years previously the opponents
of shells had agitated the question of a compromise: viz. the use of
hollow shot uncharged, instead of solid balls. And when M. Paixhans
had published his great scheme they had held that more advantages
would have been offered by it if he had stopped short at charging the
shot with powder, and had advocated merely hollow shot, which by their
larger size would give the advantages of heavier calibre. But the
argument for hollow shot was finally demolished in 1837 by a writer
whose views carried great influence. Incorrectly attributing to M.
Paixhans himself the proposal to use them, Captain Simmons, R.A. proved
clearly and conclusively their comparative uselessness. The adoption
of hollow shot, he showed,[110] would be tantamount to a reversion
to the use of stone or granite projectiles; it mattered little, for
practical purposes, what the projectile be formed of, so that its
density be what was desired: whether hollow iron or solid granite.
Except the Turks, who still guarded the Dardanelles with granite-firing
cannon, all nations had abandoned granite in favour of the heaviest
metals, and no one questioned the vast improvement thereby obtained,
“except the inventors of the carronade and the promoters of this same
system, improved by M. Paixhans.” As a matter of fact the carronade was
designed for the special circumstances in which hollow shot were not
without value. And M. Paixhans, as we know, never intended to forego
the use of a charge of powder in the cavity of his _boulet creux_.
But the arguments of Simmons sufficed to kill the advocacy of hollow,
uncharged shot.
Doubt was cast, too, on the capacity of the shell gun to project its
shells to a sufficient range and with sufficient striking velocity in
action. In the case of the first shell guns cast, a strict limitation
had to be placed on the powder-charges which could safely be used;
and this involved a limitation of range, apart from the reduction
due to the lower specific gravity of the projectile. Both French and
English shell guns suffered in this respect. For this reason they had
been deemed by the French specially suited for use in steam vessels,
which could by their locomotive power attain the desired range. But,
it was said, steam gives the power of avoiding, as well as of closing
to action; and steam, it was foreseen, was a giant which would one day
haul even ships-of-the-line into position for battle. Might not future
actions be fought at considerable ranges? And for close-quarter work,
could not our powerful long guns, double-shotted, be used with greater
effect than shell guns?
Then, again, the flight of shells was not nearly so certain as that of
solid shot. The effects of eccentricity, which in the case of solid
shot had always militated against accurate shooting, were in the case
of shells considerably enhanced. The varying thickness of the shell,
the lack of homogeneity of the metal, the presence of the protruding
fuze, all tended to produce eccentricity and give a bias. The centre
of gravity of a shell was seldom at its centre of figure; and this
eccentricity was the cause of deviations in flight, in range and
direction, which made the trajectory of a shell not easily predictable.
Savants and artillerists, both here and in other countries, discussed
for years these deviations, and on the relationship between range and
eccentricity numbers of trials were made and theories were propounded.
Which is the more strange, seeing that Robins had placed on record
an almost complete solution. Briefly, the effect of eccentricity may
be explained as follows. Just as a stick held vertically by a thread
receives, when struck at a point in it other than the centre of
percussion, a tendency to motion not only of translation but also of
rotation round that centre of percussion; so a spherical shell whose
centre of gravity lies away from its centre of figure receives, from
the pressure of the powder gases acting at its centre of figure, a
rotary motion about its centre of gravity in addition to a motion along
the bore. If the centre of gravity lies below the centre of figure this
rotary motion is in such a direction that, as the shell approaches the
muzzle, points on its upper surface are moving towards the muzzle,
points on the lower part are moving inwards. And this rotation,
maintained during flight, has the effect--as was demonstrated by Robins
with the musket ball--of giving the sphere a vertical deviation in a
downward direction; i.e. of reducing its range.
It follows, then, that an artificial increase of range could be
obtained by placing the sphere with its centre of gravity _above_
the centre of figure? This is precisely what was done; and by many a
measured eccentricity was considered a desideratum, as giving a higher
range than could be obtained without it. With such a system, however,
the deviations still remained large and flights still more irregular.
And the best opinion held that the most satisfactory solution lay
in reducing the errors of flight as far as possible by the use of
perfectly concentric shells. This ideal was difficult of attainment.
Sir Howard Douglas has described at length experiments with shells
the axis of whose eccentricity was found by floating them in mercury:
experiments which revealed that not one shell in a hundred of those
supplied was perfectly balanced. For this reason misgiving was felt as
to the effectiveness of shell fire when carried out at considerable
ranges against solid shot, and efforts were continuously made to
correct all shell before issue.
Nor were the Americans inclined to view the shell gun with much favour;
remembering, doubtless, what they owed to their long and powerful guns
when they were opposed to our light guns and carronades in the war of
’12 and ’13. America was more cautious even than this country. But in
’41 the 8-inch shell gun appeared in American ships as an auxiliary
to the long guns: four or so on each gun deck. And four years later
the types of guns in their ships were limited to 8-inch shell guns, in
combination with 32-pounder long guns of various patterns; in fact,
their system of armament was assimilated to that of the French and
British.
Whatever the relative value of shell and solid shot might be,
experience showed that increase in size favoured the former. Though
medium-sized solid shot might be more efficient than medium-sized
shells, yet it was widely accepted that large solid shot would probably
be of less value than large shell. Strong tendencies were at work,
making for such increase in the size of artillery. It was in 1837 that
a writer already quoted showed the direction in which the arguments of
M. Paixhans were leading. Citing Sir Howard Douglas on the advantages
of large calibre and the inefficiency of random broadsides, Captain
Simmons put forward the argument that, if these statements were
accepted, it followed that all ships of war should be armed with a
few long guns of the maximum calibre and giving the maximum muzzle
energy which the ship could safely carry, with other guns on other
decks of the same calibre but of varying weight and range. “Instead of
determining the armament of a ship from the length of her decks and
crowding as many guns together as possible; determining the number
by the extent of the battery, and subjecting their nature to their
number--making, in fact, the weight and type of gun depend, not on the
service demanded, but on the quotient arising from dividing the total
deck-weight by the number, previously fixed on; it might be safer to
place on board a few of the most powerful guns which her construction
would admit, and then regulate the total number carried by their
aggregate weight--making the _number_ and not the _nature_ of the guns
depend on what is inevitably fixed: the capacity of the vessel?”
The English writer went farther than M. Paixhans had gone. His argument
foreshadowed the evolution which was so largely influenced by the
coming of the steam vessel, with its large paddle-wheels and small
crew, and with its deck space necessitating the concentration of its
armament into a few guns of the largest calibre; it foreshadowed the
supersession of the broadside by the pivot gun, and the enormous
expansion in the size of ordnance which took place after the Crimean
War.
* * * * *
The evolution of the shell gun was at this partial stage when the
Crimean War broke out. In 1854 both types of projectiles were still
struggling for ascendancy, though large shell guns were by this time
acknowledged as the superior armament for steam vessels. Both friend
and foe were now literally “stormed at by shot and shell”--of which
the shell proved on the whole the more effective missile. No decisive
superiority could be claimed, however, by one type over the other; and,
as we shall see later in surveying the evolution of the ironclad, it
was only gradually that the inherent superiority of the shell gun came
to be recognized.
Soon after the close of the war a new step in the evolution of armament
made its supremacy decisive. The rifled cannon at last materialized.
The cylinder superseded the sphere. The increase in volume gained by
the adoption of this form of projectile, and the enhanced range and
striking velocity which it was possible to impart to it, set all doubts
at rest as to the military value of the _Arme Nouvelle_.
[Illustration: THE _SPEAKER_, A SECOND-RATE OF THE COMMONWEALTH
From Fincham’s _Naval Architecture_]