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 a 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 so 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 S-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 surrounded 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 clement 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 other wise 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 establishments, 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

could find no spot within in which he could safely prepare for operations ulterior to the mere forcing an entrance.

In this class are to be found objects that are, in every sense, of the highest value. On the one hand, accumulations of military and naval material, and structures for naval accommodation, that could not be replaced during a war, which are of indispensable necessity, and of great cost; and, on the other hand, the untold wealth of great cities. As these objects must be great in the eyes of the enemy-great for him to gain, and for us to lose-corresponding efforts on his part must be looked for and guarded against. If he come at all, it will be in power; and the preparations on our part must be commensurate.

The entrance to the harbor, and all the narrow passes within it, must be occupied with heavy batteries; and if nature does not afford all the positions deemed requisite, some must, if practicable, be formed artificially. Batteries should succeed each other along the channel, so that the enemy may nowhere find shelter from effective range of shot and shells while within the harbor, even should he succeed in passing the first batteries.

Provided the shores admit this disposition, and the defences be supplied with an armanent, numerous, heavy, and selected with reference to the effects on shipping, the facts we have quoted from history show that these defences may be relied on.

If the mere passing under sail, with a leading wind and tide, one, or even two sets of batteries, and then carrying on operations out of the reach of these, or any other, were all, the enemy might perhaps accomplish it; but our present supposition is, that with this class his ulterior proceedings, and finally his return, are to be subject to the incessant action of the defences.

3. This brings us to consider a third class, consisting of establishments of importance situated at a distance up some river or bay, there being intermediate space too wide to be commanded from the shores. In such cases the defence must be concentrated upon the narrow passes, and must, of course, be apportioned in armament to the value of the objects covered. When the value is not very great, a stout array of batteries at the best positions would deter an enemy from an attempt to force the passage, since his advantage, in case of success, would not be commensurate with any imminent risk. But with the more valuable establishments it might be otherwise; the consequence of success might justify all the risk to be encountered in rapidly passing in face of batteries, however powerful. This condition of things requires peculiar precautions, under any system of defence. If, after having occupied the shores, in the narrow places, in the best manner, with batteries, we are of opinion that the temptation may induce the enemy, notwithstanding, to run the gauntlet, the obstruction of the passage must be resorted to. By this is not meant the permanent obstruction of the passage; such a resort, besides the great expense, might entail the ruin of the channel. The obstruction is meant to be the temporary closing by heavy floating masses.

There is no doubt that a double line of rafts, each raft being of large size and anchored with strong chains, would make it impossible to pass without first removing some of the obstructions, and it might clearly be made impossible to effect this removal under the fire of the batteries. Such obstructions need not be resorted to until the breaking out of a war, as they could then be speedily formed, should the preparation of the enemy be of a threatening nature.

There would be nothing in these obstructions inconsistent with our use of part of the channel, since two or three of the rafts might be kept out of line, ready to move into their places at an hour's notice.

The greatest danger to which these obstructions would be exposed would be from explosion vessels; and from those they might be protected by a boom, or a line of smaller rafts in front.

From what has just been said, it will be perceived that, when the inducements

are such as to bring the enemy forward in great power, and efficient batteries can be established only at certain points, we are not then to rely on them exclusively. In such a case, the enemy should be stopped by some physical impediments; and the batteries must be strong enough to prevent his removing these impediments, and also to prevail in a cannonade should the enemy undertake to silence the works.

The conditions these obstructions have to fulfil are these:

1st. They must be of a nature to be fixed readily, and to be speedily removed when there is no longer occasion for them; and, to this end, they must

be afloat.

2d. They must have adequate inertia to resist, or rather not to be destroyed or displaced by, the shock of the heaviest ship; and, in order to this, they must be held by the heaviest and strongest cables and anchors.

3d. They must be secure from the effects of explosive vessels; and, if in danger from this source, must be covered as above mentioned.

We do not say what are the exact circumstances in which all these conditions will be fulfilled, though we think the idea long ago presented by the board of engineers will, with modifications, embrace them all.

The idea is this: Suppose a line (extending across the channel) of rafts, separated from each other by a space less than the breadth of a ship-of-war, each raft being about 90 feet long, 30 feet wide, and 6 feet deep, forined of strong timbers, crossed and braced in all directions, and fastened together in the strongest manner. A long-scope chain cable is to proceed from each of the four corners, two obliquely up stream and two obliquely down stream, to very heavy anchors; and there should also be a very strong chain cable passing from one raft to another. Suppose a ship, striking one of the rafts, to break the chains leading down the stream: in doing this, she must lose much of her momentum. She has, then, "under her fore foot," the raft connected by a strong chain with the rafts to the right and left; on being tightened, this chain will throw the strain upon the down stream cable of that adjoining raft towards which the ship happens to tend. If we suppose it possible for these chains also to be parted by the power still remaining in the ship, or by impulses received from succeeding vessels, there will be other chains still to break in the same way. After the down stream chains are all parted, the rafts will "bring up" in a new position, (higher up the channel,) by the anchors that, in the first instance, were pointed up stream. Here a resistance, precisely like that first overcome, is to be encountered by vessels that have lost most of their force in breaking the successive chains, and in pushing these great masses of timber before them through the water. Should there exist a doubt as to the sufficiency of these remaining anchors and chains, or should it be deemed most prudent to leave nothing uncertain, a second similar line may be placed a short distance above the first.

The best proportions and dimensions of the rafts remain to be determined ; but as there is scarcely a limit to the strength that may be given to the rafts themselves, and to the means by which they are to be held to their positions, and to each other, the success of a well arranged obstruction of this sort can hardly be doubted.

The expense would not be great in the first instance, and all the materials would be available for other purposes, when no longer needed for this.

It may be repeated here, that such expedients need not be resorted to, except to cover objects of the highest importance and value, such as would induce an enemy to risk a large expedition. For objects of less importance, batteries would afford ample protection. It will be remembered that this last power is. when once established in any position, a constant quantity; and, although it should be incompetent to effect decisive results when diffused over a large fleet, may be an overmatch for any small force upon which it should be concentrated.