In general terms, it appears from the above-mentioned report, that the number of guns actually brought into action by the floating force, (counting only one broadside of the ship,) amounted to ninety-four guns, besides four heavy sea-mortars; that the whole number so employed in the fort was only nineteen, including the smallest calibres; that these guns were generally so small and inefficient, that their balls would not enter the sides of the ordinary attacking frigates; the principal injury sustained by the castle was produced by the explosion of powder magazines injudiciously placed and improperly secured; that the castle, though built of poor materials, was but slightly injured by the French fire; that the Mexicans proved themselves ignorant of the ordinary means of defence, and abandoned their works when only a few of their guns had been dismounted; that notwithstanding all the circumstances in favor of the French, their killed and wounded, in proportion to the guns acting against them, was upwards of four times as great as the loss of the English at the battle of Trafalgar!

St. Jean d'Acre.—The narratives of the day contained most exaggerated accounts of the English attack on St. Jean d'Acre; now, however, the principal facts connected with this attack are fully authenticated. For the amount of the fleet we quote from the British official papers, and for that of the fort, from the pamphlet of Lieutenant-colonel Matuszewiez. These statements are mainly confirmed by the narratives, more recently published, of several English and French eye-witnesses.

The fortifications were built of poor materials, antiquated in their plans, and much decayed. Their entire armament amounted to only two hundred guns, some of which were merely field-pieces. The water fronts were armed with one hundred cannon and sixteen mortars, those of the smaller calibre included. ([Fig. 38.]) When approached by the British fleet, the works were undergoing repairs, and, says Commodore Napier, "were fast getting into a state of preparation against attack."

The British fleet consisted of eight ships of the line, carrying six hundred and forty-six guns; six frigates, carrying two hundred and thirty-six guns; four steamers, carrying eighteen guns; and two or three other vessels, whose force is not given. "Only a few guns," says Napier, "defended the approach from the northward," and most of the ships came in from that direction. The western front was armed with about forty cannon; but opposed to this were six ships and two steamers, carrying about five hundred guns. Their fire was tremendous during the engagement, but no breach was made in the walls. The south front was armed in part by heavy artillery and in part by field-pieces. This front was attacked by six ships and two steamers, carrying over two hundred guns. The eastern front was armed only with light artillery; against this was concentrated the remainder of the fleet, carrying about two hundred and forty guns. The guns of the works were so poorly mounted, that but few could be used at all; and these, on account of the construction of the fort, could not reach the ships, though anchored close by the walls. "Only five of their guns," says Napier, "placed in a flanking battery, were well served, and never missed; but they were pointed too high, and damaged our spars and rigging only." The stone was of so poor a quality, says the narrative of Colonel Matuszewiez, that the walls fired upon presented on the exterior a shattered appearance, but they were nowhere seriously injured. In the words of Napier, "they were not breached, and a determined enemy might have remained secure under the breastworks, or in the numerous casemates, without suffering much loss." The accidental explosion of a magazine within the fort, containing six thousand casks of powder, laid in ruins a space of sixty thousand square yards, opened a large breach in the walls of the fortifications, partially destroyed the prisons, and killed and wounded a thousand men of the garrison. This frightful disaster, says the French account, hastened the triumph of the fleet. The prisoners and malefactors, thus released from confinement, rushed upon the garrison at the same time with the mountaineers, who had besieged the place on the land side. The uselessness of the artillery, the breaches of the fort, the attacks of the English, all combined to force the retreat of the garrison, "in the midst of scenes of blood and atrocious murders."

We will close this account with the following extract of a speech of the Duke of Wellington, in the House of Lords, Feb. 4, 1841: "He had had," he said, "a little experience in services of this nature; and he thought it his duty to warn their lordships, on this occasion, that they must not always expect that ships, however well commanded, or however gallant their seamen might be, were capable of commonly engaging successfully with stone walls. He had no recollection, in all his experience, except the recent instance on the coast of Syria, of any fort being taken by ships, excepting two or three years ago, when the fort of San Juan d'Ulloa was captured by the French fleet. This was, he thought, the single instance that he recollected, though he believed that something of the sort had occurred at the siege of Havana, in 1763. The present achievement he considered one of the greatest of modern times. This was his opinion, and he gave the highest credit to those who had performed such a service. It was, altogether, a most skilful proceeding. He was greatly surprised at the small number of men that was lost on board the fleet; and, on inquiring how it happened, he discovered that it was because the vessels were moored within one-third of the ordinary distance. The guns of the fortress were intended to strike objects at a greater distance; and the consequence was, that the shot went over the ships that were anchored at one-third the usual distance. By that means, they sustained not more than one-tenth of the loss which they would otherwise have experienced. Not less than five hundred pieces of ordnance were directed against the walls, and the precision with which the fire was kept up, the position of the vessels, and, lastly, the blowing up of the large magazine—all aided in achieving this great victory in so short a time. He had thought it right to say thus much, because he wished to warn the public against supposing that such deeds as this could be effected every day. He would repeat that this was a singular instance, in the achievement of which undoubtedly great skill was manifested, but which was also connected with peculiar circumstances, which they could not hope always to occur. It must not therefore be expected, as a matter of course, that all such attempts must necessarily succeed."

Having completed our examination of the ability of land batteries to cope, gun for gun, with a naval force, let us consider, for a few moments, the objection which is sometimes made to the use of fortifications for the defence of the sea-coast, viz.: that our maritime cities and arsenals can be better and more economically secured by a home squadron.

We have already alluded to the impossibility of substituting one means of defence for another. The efficiency of the bayonet can in no way enable us to dispense with artillery, nor the value of engineer troops in the passage of rivers, and the attack and defence of forts, render cavalry the less necessary in other operations of a campaign. To the navy alone must we look for the defence of our shipping upon the high seas; but it cannot replace fortifications in the protection of our harbors, bays, rivers, arsenals, and commercial towns.

Let us take a case in point. For the defence of New York city, it is deemed highly important that the East River should be closed to the approach of a hostile fleet at least fifteen or twenty miles from the city, so that an army landed there would have to cross the Westchester creek, the Bronx, Harlem river, and the defiles of Harlem heights—obstacles of great importance in a judicious defence. Throg's Neck is the position selected for this purpose; cannon placed there not only command the channel, but, from the windings of the river, sweep it for a great distance above and below. No other position, even in the channel itself, possesses equal advantages. Hence, if we had only naval means of defence, it would be best, were such a thing possible, to place the floating defences themselves on this point. Leaving entirely out of consideration the question of relative power, position alone would give the superior efficiency to the fort. But there are other considerations no less important than that of position. Fort Schuyler can be garrisoned and defended in part by the same militia force which will be employed to prevent the march of the enemy's army on the city. On the other hand, the crews of the floating defences must be seamen; they will consequently be of less value in the subsequent land operations. Moreover, forts, situated as this is, can be so planned as to bring to bear upon any part of the channel a greater number of guns than can be presented by any hostile squadron against the corresponding portion of the fort. This result can be obtained with little difficulty in narrow channels, as is done in most of the other works for the defence of New York, the works for Boston, Newport, Philadelphia, Baltimore, Charleston, Savannah, New Orleans, &c., and an approximation to it is not incompatible with the defence of the broader estuaries, like the Chesapeake.

But we will suppose that there are no such points of land, in the inlets to our harbors, and that we rely for defence upon a naval force exclusively. Let us leave out of consideration the security of all our other harbors and our commerce on the high seas, and also the importance of having at command the means of attacking the enemy's coast, in the absence of his fleet. We take the single case of the attack being made on New York harbor, and that our whole fleet is assembled there. Now, if this fleet be equal in number to the enemy, the chances of success may be regarded as equal; if inferior, the chances are against us—for an attacking force would probably be of picked men and of the best materials. But here the consequences of victory are very unequal: the enemy can lose his squadron only, while we put in peril both our squadron and the objects it is intended to defend. If we suppose our own naval force superior to that of the enemy, the defence of this harbor would in all respects be complete, provided this force never left the harbor. But, then, all the commerce of the country upon the ocean must be left to its fate; and no attempt can be made to react offensively upon the foe, unless we can control the chances of finding the enemy's fleets within his ports, and the still more uncertain chance of keeping him there; the escape of a single vessel being sufficient to cause the loss of our harbor.

These remarks are based upon the supposition that we have but the single harbor of New York; whereas Portland, Portsmouth, Boston, Newport, the Delaware, the Chesapeake, Charleston, Savannah, Pensacola, Mobile, New Orleans, and numerous other places, are equally open to attack, and therefore must be equally defended, for we know not to which the enemy will direct his assaults. If he come to one of these in the absence of our fleet, his object is attained without resistance; or, if his whole force be concentrated upon one but feebly defended, we involve both fleet and harbor in inevitable ruin. Could our fleet be so arranged as to meet these enterprises?