Imatges de pÓgina
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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 be 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 detence 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 erclusively. 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 sourcc, 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, formed 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

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 flect, may be an overmatch for any small force upon which it should be concentrated.

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At the same time, therefore, that there is the less liability to heavy attacks, there will be, in the batteries, the greater capacity of resistance to others.

It must not be urged, as a reproach to fortifications, that, in the case we are considering, they are obliged to call in aid from other sources, so long as these aids are cheap, efficient, and of easy resort. By the mode we have suggested, the defence will undoubtedly be complete, every chance of success being on the side of the defence; that is to say, if any confidence is to be placed in the lessons of experience. How, on the other hand, will the same security be attained by naval means? Only, as before shown, by keeping within the harbor a fleet or squadron, or whatever it may be, which shall be at all times superior to the enemy

In a naval defence there will be no advantage in obstructions of any sort, for there can be no lessening of the array of guns in consequence of such obstructions ; because, if these obstructions are under the fire of the floating defences, the enemy will first subdue that fire, and then remove the obstructions at his leisure. If this fire prove too powerful for the enemy, the obstructions will have been unnecessary, and will serve only to shut up our own fleet, preventing the prompt pursuit of a beaten foe.

4. There is a fourth class, consisting of harbors, or rather bays or estuaries, of such expanse that batteries cannot be made to control the passage. These have been before spoken of. If the occupation of, or passage through these must be defended, it must be by other means than batteries upon the shore. The reliance must, from the nature of the case, be a floating defence, of magnitude at least equal to the force the enemy may bring. The complete defence of each of these bays would, therefore, involve very great expense; certainly, in most cases, greater than the advantages gained. The Chesapeake bay cannot, for instanee, be shut against a fleet by fortifications; and if the entrance of the enemy is to be interdicted, it must be by the presence of a not inferior Heet of our own. Instead of such a system, it will be better to give up the bay to the enemy, confining our defences to the more important harbors and rivers that discharge into the bay. By this system, not only will these harbors be secure, but the defences will react upon the bay itself, and, at any rate, secure it from predatory incursions ; because while Hampton roads and the navy yard at Norfolk are well protected, no enemy would proceed up the bay with any less force than that which could be sent out from the navy yard.

In certain cases of broad waters, wherein an enemy's cruisers might desire to rendezvous in order to prosecute a blockade, or as a shelter in tempestuous weather, there may be positions from which sea-mortars can reach the whole anchorage, although nothing could be done with guns. A battery of sea-mortars, well secured from escalade, would, in such a case, afford a good defence, because no fleet will lie at anchor within the range of shells.

In thus distributing the various exposed points of the sea-coast into general classes, according to the most appropriate modes of defence, we do not find that anything can be substituted for fortifications, where fortifications are applicable, and we find them applicable in all the classes but the last; and in the last we shall find them indispensable as auxiliaries. In this last class there are, no doubt, some cases where naval means must constitute the active and operative force ; and it is probable that steam batteries may, of all floating defences, be the most suitable.

It must not be forgotten, however, that the very qualities which recommend this particular kind of force will equally characterize the steam vessel of the enemy; nor must it be forgotten that, whether steam vessels or sailing vessels, or both, are relied on, unless there are well-secured points on the shore, under which they can take refuge, they will themselves constitute an object inviting the superior force of an enemy;

If, for example, we were to deem one of the open harbors of such importance as to assign eight or ten steam batteries for its protection, we should thereby place within reach of the enemy an object worthy of the efforts of a squadron, or twelve or fifteen vessels of the same description. Even, therefore, in the cases where naval means must be resorted to for defence upon the water, there should be works upon the shore behind which, if overpowered, they can retire.

It has been before remarked that the steam batteries are in no way more formidable to shore batteries than sailing vessels are: armed with Paixhan guns they would be less so. And they would be less formidable, also, on account of their comparatively small number of guns; for there is no reason why the firing should be more accurate than from ships; and the chances of inflicting injury would be in proportion to the number of missiles.

The only material effect the introduction of this description of vessel ean have upon a system of defence by fortifications is, that owing to their les draught of water, it will be necessary to secure channels that, not being navi gable by vessels of the line and frigates, might otherwise be left unguarded. Some of these channels may have the draught of water lessened by an artificial ridge of stones, so as to be impracticable even to steam vessels; and this may often be done at small expense, and without detriment to the harbors; others will need additional fortifications. But the instances are not numerous where any such shallow channels exist.

In opposition to an opinion not uncommon, that modern improvements in steam vessels will tend to lessen the necessity for fortifications, we here see that the tendency is rather to increase their number.

Throughout this whole discussion the argument has turned on the relative efficiency of fixed and floating defences. The great relative economy of the former, we suppose, will be conceded. If not, we would ask, as conclusive, w at least as leading to calculation entirely satisfactory, that the following information be obtained from authentic sources, namely: the first cost, when comiplete in all respects, of the frigates United States, Constitution, and Congress, and also the entire expense of each of said vessels up to this time; specifying, as to each, the year of the several expenditures and the amounts thereof, under the heads, as far as practicable, of first cost, repairs or rebuilding, and impritëments and alterations, and distinguishing-1st. The expense bestowed na the hull. 2d. The expense bestowed upon the masts, spars, sails, anchors, cables, and rigging. 3d. The expense bestowed upon the armament; and 4th.

The expense bestowed upon all other matters, (as boats, ballast, tanks, paint, &c.,) necessarily connected with the preservation or the ordinary service of the vessel.

Before we proceed to describe the several positions on the coast requiring fortifications, we have something still to say on the general subject, though on another branch. We now refer to the kind of fortifications, or rather to their magnitude and strength. That this particular topic should be embraced by ou remarks is the more necessary since views hostile to the system of works now in progress have been urged from a high source.

The present system is founded on this principle, to wit: that the fortifications should be strong in proportion to the value of the objects to be secured. The principle will not, we suppose, be controverted, but only the mode of apply. ing it.

There will hardly be a difference of opinion as to the mode of guarding the less important points. There being no great attraction to an enemy, works simple in their features, requiring small garrisons only, containing a moderate armament, but at the same time inaccessible to the dashing enterprises that ships can so easily land, and which can be persevered in for a few hours with much vigor, will suffice. Circumstances must, however, materially modify the properties of these works, even when the points to be guarded are of equal value. In one, the disadvantage of position must be compensated by greater power; in another, natural strength may need little aid from art; in another, greater width in the guarded channel may demand a larger armament; and in a fourth, peculiar exposure to land attack may exact more than usual inaccessibility. But all these varieties lie within limits that will probably be conceded.

As to the larger objects, it has been contended that there has been exaggeration in devising works to cover these, the works having been calculated for more formidable attacks than they will be exposed to. It is easy to utter vague criticisms of this nature, and it is not easy to rebut them without going into an examination as minute as if the criticism were ever so precise and pertinent.

But let us look a little at the material facts. What is the object of an enemy? What are his means ? What should be the nature of our defences ?

The object may be to lay a great city under contribution, or to destroy one of our naval depots, or to take possession of one of our great harbors, &c. It was estimated that in the great fire in the city of New York, in the year 1835, the property destroyed within a few hours was worth upwards of seventeen millions of dollars, although the fire was confined to a very small part of the city, and did not touch the shipping. Is it easy, then, to estimate the loss that would accrue from the fires that a victorious enemy could kindle upon the circuit of that great city when no friendly hand could be raised to extinguish them? or is it easy to overrate the tribute such a city would pay for exemption from that calamity? Can we value too highly the pecuniary losses that the destruction of one of the great navy yards would involve, and the loss, beyond all pecuniary value, of stores and accommodations indispensable in a state of war, and that a state of war can hardly replace ?

But what are the enemy's means ? They consist of his whole sea-going force, which he concentrates for the sake of inflicting the blow. In the language of the critic: “From the nature of maritime operations, such a fleet could bring its whole strength to bear upon any particular position, and, by threatening or assailing various portions of the coast, either anticipate the tardy movements of troops upon land, and effect the object before their concentration, or render it necessary to keep in service a force far superior to that of the enemy, but so divided as to be inferior to it on any one point."

We have, then, objects of sufficient magnitude, and the means of the enemy consist in the concentration of his whole force upon one of these objects.

With the highest notion of the efficiency of fortifications against shipping, these are not cases where any stint in the defensive means are admissible. Having, therefore, under a full sense of the imminent danger to which the great objects upon the coast are exposed, applied to the approaches by water an array of obstacles worthy of confidence, we must carefully explore all the avenues by land, in order to guard against approaches that might be made on that side in order to evade or capture the works guarding the channels. But before deciding on the defences necessary to resist these land attacks, it will be proper to estimate more partieularly the means that an enemy may be expected to bring forward with a view to such land operations.

History furnishes many examples, and the expedition to Flushing, commonly called the Walcheren expedition, may be cited as peculiarly instructive.

From an early day Napoleon had applied himself to the creation of a maritime force in the Scheldt, and, in 1809, he had provided extensive dock yards and naval arsenals at Flushing and at Antwerp. On his invasion of Austria this year, he had drawn off the mass of his troops that had before kept jealous watch over these naval preparations, relying now on forts and batteries, and on the fortifications of Flushing and Antwerp for the protection of the naval establishments, and of a fleet containing several line-of-battle-ships and frigates, and a numerous flotilla of smaller vessels.

The great naval establishment at Flushing, near the mouth of the Scheldt, and of Antwerp, gome sixty or seventy miles up the river, with the vessels

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