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injury was done the fort, since it is certain that there were no less than six other similar magazines situated on the rampart, in different parts of the work, not one of which was shell-proof. The surrender, after these explosions, was a very natural event, with a governor and garrison who seem to have known as little about the proper preparation for such contests as about the mode of conducting them. The second explosion must have satisfied them, if the first did not, that they had introduced within their own precincts much more formidable means of destruction than any it was in the power of the French to send from gin or mortar.

The important points to be noticed in this contest are these:

1. The French took such a position that their 94 guns were opposed by the equivalent of 10 or 12 guns only.

2. In proof of the inefficiency of the Mexican guns generally, it may be stated that although the three French frigates were struck in their hulls about three hundred times, they lost but thirty-three men in killed and wounded. The Iphigenie was hulled 160 times, and yet had but thirteen men hurt. Very few, therefore, of these 160 balls could have passed through her sides.

3. It appears that very few, if any, of the guns exposed to the direct action of the French broadsides were dismounted or silenced by their fire.

4. The narratives of the day contain exaggerated statements of injury inflicted on the walls by shells fired from guns; the professional report, above quoted, of the chief engineer of the expedition, neither speaks of nor alludes to any such injury. After deducting from the parts of the work said to be most injured—the cavalier and also battery No. 5, in each of which a magazine exploded—there remain, as having suffered most, the quarters of the officers and bastion No. 2. As to the first, if it was elevated above the walls, as is probable, it would of course suffer severely, because the walls of mere barracks or quarters are never made of a thickness to resist shot or shells of any kind; and if not elevated above the walls, but covered by them, the injury resulted, most probably, from shells fired at high angles from the sea-mortars, and not from shells fired nearly horizontally from the Paixhan guns. Whether the injury sustained by bastion No. 2 was the effect of shot and shells upon the face of the walls, or of shells falling vertically within the bastion, is not stated. It was probably due in part to both. If there had been any extraordinary damage done by the horizontal shells, we may reasonably suppose special mention would have been made of it, because it was the first time that this missile had been tried, in a large way, in actual warfare. That anything like a breach could have been effected with. solid shot, at that distance and in that time, we know to be impossible; but it “is neither unreasonable to suppose, nor unlikely, that many of the heavy vertical shells may have fallen in the bastion and caused much injury. Whatever may have been the cause of the damage, or its amount, it did not, we have reason to believe, extinguish the fire of any of the five 16-pounders that were pointed from the bastion against the ships.

5. So far as effects were produced by the direct action of the French armament, whether guns, bomb-cannon, or sea-mortars, it does not appear that there was the slightest reason for the submission of the fort. There is little doubt that the 8,250 shot and shells fired at the castle must have greatly marred the surface of the walls, and it is not unlikely that three or four striking near each other may have made deep indentations, especially as the stone is soft, beyond any material applied to building in any part of the United States. But these are not injuries of material consequence, however they may appear to the iner. perienced eye, and we should risk little in asserting that, abstracting the effects of the explosion, the castle was as inaccessible to assault after the cannonade as before it; that, so far as regards the levelling of obstacles lying in the way of a sword in hand attack, the 8,250 shot and shells might as well have been fired in the opposite direction.

6. The explosion, however, of two deposits of powder in the castle, one of which is reported to have buried sixty men in its ruins, showed the defenders that, although they might evade the vertical fire, and their works might cover them from the horizontal fire of the French, there was no protection against, no evasion of, the dreadful ravages of exploding magazines. With this ruin around them, and a sixfold greater ruin likely, at every moment, to burst upon their heads, it is not surprising that a garrison, found in circumstances so unmilitary, doubted their power of protracted resistance.

7. It must be borne in mind that these explosions have nothing to do either with the question of relative strength or with the peculiarities of the French attack. No defences, with such management, can be effective, and no attack can fail. The French, not dreaming of such culpable, such inconceivable negligence on a point always receiving the most careful attention, entered upon the cannonade with no other purpose, as is avowed, than that of somewhat weakening the defences and dispiriting and fatiguing the garrison, before proceeding to an assault, which was to have followed at night, and for which all preparations had been made. Had the Mexicans thrown all the powder of these eight magazines into the sea, or had they transported it to their barracks, and every man, making a pillow of a keg, slept through the whole cannonade, as might have been done safely, in their quarters in the curtain casemates, the castle of St. Juan de Ulloa would, we doubt not, have been as competent to resist the projected assault as it was when the French first arrived before it

8. The number of killed and wounded in the French vessels, in proportion to the guns acting against them was, for ten guns, more than twenty-seven men, being upwards of four times as great as the loss sustained by the English at the battle of Trafalgar.

In concluding this reference to facts in military history, we will add that we do not see how it is possible to avoid making the following deduction, namely: that fixed batteries upon the shore are capable of resisting the attacks of ships, even when the armament of the latter is by far the most numerous and heavy.

There are several reasons for this capacity in batteries, of which the principal may be thus stated; and these reasons apply to vessels of every size and every sort

, to small or large, to vessels moved by wind or steam. This ship is everywhere equally vulnerable, and, large as is her hull, the men and the guns are very much concentrated within her; on the other hand, in the properly constructed battery it is only the gun itself, a small part of the carriage, and now and then a head or an arm raised above the parapet that can be hurt, the ratio of the exposed surfaces being not less than fifteen or twenty to one. Next, there is always more or less motion in the water, so that the ship-gun, although it may have been pointed accurately at one moment, at the next will be thrown entirely away from the object, even when the motion in the vessel is too small to be otherwise noticed; whereas, in the battery the gun will be fired just as it is pointed, and the motion of the ship will merely vary to the extent of a few inches, or at most two or three feet, the spot in which the shot is to be received. In the ship there are, besides, many points exposed that may be called vital points; by losing her rudder, or portions of her rigging, or of her spars, she may become unmanageable and unable to use her strength; she may receive shots under water and be liable to sink; she may receive hot shot and be set on fire; and these damages are in addition to those of having her guns dismounted and her people killed by the shot which pierce her sides and scatter splinters from her timbers, while the risks of the battery are confined to those mentioned above, namely, the risk that the gun, the carriage, or the men may be struck. That the magazines should be exposed, as were those of the castle St. Juan de Clloa, must never be anticipated as possible.

While on this part of our subject, it is proper to advert to the use of horizontal shells, or hollow shot, or Paixhan's shells, as they are variously called,) it having been argued that the introduction of these missiles is seriously to impair the utility of fortifications as a defence of the sea-coast.

We fully believe that the free use of these shells will have an influence of some importance on the relative force of ship and battery, but that influence must be the very reverse of such predictions. How are the batteries to be affected by them? It can be but in two ways: first, the ship-gun having been pointed so as to strike a vital point that is to say, a gun or a carriage-the shell may explode at the instant of contact. This explosion may possibly happen thus opportunely, but it would happen against all chances, and if happening, would probably do no more than add a few men to the list of killed and wounded. For reasons that will soon appear, it is to be doubted whether the probability of dismounting the gun would be so great as if the missile were & solid 32-pounder shot. Secondly, if it be not by dismounting the guns or killing the garrison, the effect anticipated from these missiles must result from the injury they do the battery itself

. Now, we are perfectly informed by military experience as to the effects of these shells upon forts and batteries, for the shells are not new, although the guns may be som-the 8-inch and the 10-inch shells having always been

supplied in abundance to every siege-train, and being perfectly understood, both as to their effects and the mode of using them.

Were it a thing easily done, the blowing away of the parapets of a work, (a very desirable result to the attacking party,) would be a common incident in the attacks of fortifications ; but the history of attacks by land or water affords no such instance. The only practicable way yet discovered of demolishing a fortification being by attaching a miner to the foot of the wall, or by dint of solid shot and heavy charges fired unremittingly during a long succession of hours upon the same part of the wall, in order not only to break through it, but to break through in such a manner that the weight and pressure of the incumbent mass may throw large portions of the wall prostrate. This, the shortest and best way of breaching a wall, requires, in the first place, perfect accuracy of direction, because the same number of shots that, being distributed over the expanse of wall, would merely peel off the face, would, if concentrated in a single deep cut, cause the wall to fall; and it requires, moreover, great power of penetration in the missile—the charge of a breaching gun being for that reason one-third greater than the common service charges. Now, the requisite precision of firing for this effect is wholly unattainable in vessels, whether the shot be solid or hollow; and if it were attainable, hollow shot would be entirely useless for the purpose, because every one of them would break to pieces against the wall, even when fired with a charge much less than the common service charge. This is no newly discovered fact; it is neither new nor doubtful. Every hollow shot thrown against the wall of fort or battery if fired with a velocity affording any penetration, will unquestionably be broken into fragments by the shock.

After so much had been said about the effect of these shells upon the castle of St. Juan de Ulloa, it was deemed advisable, although the result of European experiments were perfectly well known, to repeat in our own service some trials touching this point. A target was therefore constructed, having one-third part of the length formed of granite, one-third of bricks, and the remaining third of freestone. This was fired at by a Paixhan gun and by a 32-pounder from the distance of half a mile, and the anticipated results were obtained, namely:

1st. Whether it was the granite, the brick, or the freestone that was struck, the solid 32-pounder shot penetrated much deeper into the wall, and did much more damage than the 8-inch hollow shot; and

2d. These last broke against the wall in every instance that the charge of the gun was sufficient to give them any penetration.

The rupture of the shell may often cause the explosion of the powder it contains, because the shell, the burning fuse, and the powder are all crushed up together, but the shell having no penetration, no greater injury will be done to the wall by the explosion than would be caused by the bursting of a shell that had been placed against it.

From all this it appears, incontrovertibly, that, as regards the effects to be produced upon batteries by ships, solid shot are decidedly preferable to hollow shot; and the ship that, contemplating the destruction of batteries, should change any of her long 24 or 32-pounder guns for Paixhan guns would certainly weaken her armament. Her best missiles, at ordinary distances, are solid shot; and, if she can get near, grape shot to fire into the embrasures and over the walls. The best shells against batteries are the sea-mortar shells, fired at high elevations; which, being of great weight and falling from a great height, penetrate deeply, and containing a considerable quantity of powder cause material ravage by their explosion. Such shells, however, can only be fired by vessels appropriately fitted.

The use of these same hollow shot by batteries against vessels is, however, an affair of different character. The shells do not break against timber, but penetrating the bulwarks they, in the first place, would do greater damage than hollow shot, by making a larger hole and dispersing more splinters; and having, as shot, effected all this injury, they would then augment it many fold by exploding

In all cases of close action between ship and battery, the shells will pass through the nearer side, and if not arrested by some object on the deck, will probably lodge and explode in the further side; causing, by the explosion, a much greater loss among the crew, and greater injury to the vessel, than by their mere transit across the vessel. As before suggested, the vessel would suffer less injury were her sides made so thin as not to retain the shell, permitting it to pass through both sides, unless fired with a small velocity. It is not impossible that an extensive use of these horizontal shells may lead to a reduction in the thickness of ships' bulwarks.

In the facts quoted above, there is no illustration of the effects of hot shot, except in the case of Gibraltar. In that attack the floating batteries were made proof against cold shot, and, as was thought by the constructor, proof against hot shot also; and so, indeed, for a time, it seemed. It was conceived that the hot shot, when buried deep in the closely-jointed timbers, would scarcely communicate flame; and that it would not be difficult, by the use of the fire-engines provided, to subdue so stifled a combustion.

By making these floating batteries impenetrable to shot, it was supposed they had been rendered equal, in perfectly smooth water, to land batteries, gun for gun; and so they might then have been, nearly, had the incumbustibility of the latter been imparted to them. But now resistance to fire would not suffice; these floating batteries must either repel these horizontal shells from their bulwarks, or, if that be impossible, permit them to pass through both sides. Nothing can be better calculated to exhibit the tremendous effects of these shells than a vessel so thick-sided as to stop every shell, allowing it to burst when furrounded by several feet of timber; and there can be no greater mistake than supposing that by thickening the bulwarks of vessels-of-war, or fitting up steam batteries with shot-proof sides, the effects of land batteries are to be annulled, or in any material degree modified.

We will sum up this branch of our subject with the remark that the facts of history, and the practice of all warlike nations, are in perfect accordance with the conclusions of theory. The results that reason anticipated have occurred again and again. And so long as, on the one side, batteries are formed of earth and stone; and, on the other, ships are liable to be swallowed up by the element on which they float, or to be deprived of the means by which they move; so long as they can be penetrated by solid shot, set on fire or blown up by hot shot, or torn piecemeal by shells, the same results must, inevitably, be repeated at each succeeding trial.

But, after all, it may be urged that the general principle herein contended for, namely, the superiority of batteries in a contest with ships, might be admitted ; and still it would remain to show that batteries constitute the kind of defence best adapted to our peculiar wants. This is true; and we will now proceed to consider, severally, the cases to which defence must be applied.

It may be well, however, first to recall the general scope of the preceding argument. It has been contended that floating defences should not be relied on, not because they are actually incompetent to the duty, but because they cannot fulfil this duty unless provided in inordinate numbers, and at a boundless expense; and we have endeavored to show that this remark is generally true, whether the defensive fleet be made up of sea-going vessels of floating batteries, or of steam batteries. We have next urged the point that properly planned and constructed batteries are an overmatch for vessels-of-war, even when greatly inferior to them in armament-sustaining our opinion by many striking examples, and explaining satisfactorily the only instances that have cast any doubt on such contests. If the facts and reasonings we have presented do not convey the same strong convictions that sway our own minds, it must be because we have obscured rather than illustrated them; for it would seem to be impossible that facts could be more unexceptionable, or reasons more beyond the reach of cavil. However that may be, we now leave them to candid and dispassionate revisal, and proceed to examine the mode of applying these defences to our own coast.

It may be well to divide these into several distinct classes :

1. There will be all the smaller towns upon the coast, constituting a very numerous class.

At the same time that no one of these, of itself, would provoke an enterprise of magnitude, it is still necessary to guard each and all against the lesser attacks. A small vessel might suffice to guard against single vessels that would otherwise be tempted by facility to burn the shipping and exact a contribution; but something more than this is necessary, since the amount of temptation held out by a number of these towns would be apt to induce operations on a larger scale. It might often happen, moreover, that our own vessels-of-war would be constrained to take refuge in these harbors, and they should find cover from the pursuer.

Although the harbors of which we now speak afford every variety of form and dimension, there are few, or none, wherein one or two small forts and batteries cannot be so placed as to command all the water that a ship-of-war can lie in, as well as the channel by which she must enter. While the circumstances of no two of them are so nearly alike as not to modify the defences to be applied to them severally, all should fulfil certain common conditions, namely: the passage into the harbors should be strongly commanded; the enemy should find no place, after passing, wherein he would be safe from shot and shells; and the works should be inaccessible to sudden escalade—that is to say, a small garrison should be able to repel such an assault. With works answering to these conditions, and of degrees of strength in accordance with the value of their respective trusts, this class of harbors may be regarded as secure. We cannot, however, here avoid asking what would be the mode of defence, if purely naval, of these harbors ? Suppose the circumstances are deemed to require the presence of a frigate, or a steam frigate, or an equivalent in gunboats; would not two hostile frigates, or two steam frigates, infallibly arrive in quest? Could there be devised a system more certain to result in the capture of our vessels, and the submission of our towns?

2. Another class will consist of great establislıments, such as large cities, naval depots, &c., situated in harbors not of too great extent to admit of good defence at the entrance, and also at every successive point; so that an enemy

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