The works for the defence of New Orleans will carry some two hundred and fifty or three hundred guns; they are nearly completed.
The works north of the Chesapeake cost about three thousand dollars per gun; those south of that point about six thousand dollars per gun. This difference in cost is due in part to the character of the soil on which the fortifications are built, and in part to the high prices paid in the south for materials and workmanship.
Having pointed out the character and condition of our system of sea-coast defences, let us briefly examine how far these works may be relied on as a means of security against a maritime descent.
To come to a proper conclusion on this subject, let us first examine the three or four great maritime descents attempted by the English during the wars of the French Revolution; a period at which the great naval superiority of England over other nations, gave her the title of mistress of the seas. Let us notice what have been the results of the several attempts made by this power at maritime invasions, and the means by which such attacks have been repelled.
In 1795, a maritime expedition was fitted out against Quiberon, at an expense of eight millions of dollars. This port of the French coast had then a naval defence of near thirty sail, carrying about sixteen hundred guns. Lord Bridport attacked it with fourteen sail of the line, five frigates, and some smaller vessels, about fifteen hundred guns in all, captured a portion of the fleet, and forced the remainder to take shelter under the guns of the fortifications of L'Orient. The French naval defence being destroyed, the British now entered Quiberon without opposition. This bay is said by Brenton, in his British Naval History, to be "the finest on the coast of France, or perhaps in the world, for landing an army." Besides these natural advantages in favor of the English, the inhabitants of the surrounding country were in open insurrection, ready to receive the invaders with open arms. A body of ten thousand troops were landed, and clothing, arms, &c., furnished to as many more royalist troops; but the combined forces failed in their attack upon St. Barbe, and General Hoche, from his intrenchments, with seven thousand men, held in check a body of eighteen thousand, penned up, without defences, in the narrow peninsula. Reinforced by a new debarkation, the allies again attempted to advance, but were soon defeated, and ultimately almost entirely destroyed.
In 1799, the English and Russians made a descent upon Holland with fourteen ships of the line and ten frigates, carrying about eleven hundred guns and a great number of transports, with an army of thirty-six thousand men. The Dutch naval defences consisted of eight ships of the line, three fifty-four gun ships, eight forty-eight gun ships and eight smaller frigates, carrying in all about twelve hundred guns; but this force contributed little or nothing to the defence, and was soon forced to hoist the hostile flag. The defensive army was at first only twelve thousand, but the Republicans afterwards increased it to twenty-two thousand, and finally to twenty-eight thousand men. But notwithstanding this immense naval and military superiority, and the co-operation of the Orange party in assisting the landing of their troops, the allies failed to get possession of a single strong place; and after a loss of six thousand men, were compelled to capitulate. "Such," says Alison, "was the disastrous issue of the greatest expedition which had yet sailed from the British harbors during the war."
In 1801, Nelson, with three ships of the line, two frigates, and thirty-five smaller vessels, made a desperate attack upon the harbor of Boulogne, but was repulsed with severe loss.
Passing over some unimportant attacks, we come to the descent upon the Scheldt, or as it is commonly called, the Walcheren expedition, in 1809. This expedition, though a failure, has often been referred to as proving the expediency of maritime descents. The following is a brief narrative of this expedition:—
Napoleon had projected vast fortifications, dock-yards, and naval arsenals at Flushing and Antwerp for the protection of a maritime force in the Scheldt. But no sooner was the execution of this project begun, than the English fitted out an expedition to seize upon the defences of the Scheldt, and capture or destroy the naval force. Flushing, at the mouth of the river, was but ill-secured, and Antwerp, some sixty or seventy miles further up the river, was entirely defenceless; the rampart was unarmed with cannon, dilapidated, and tottering, and its garrison consisted of only about two hundred invalids and recruits. Napoleon's regular army was employed on the Danube and in the Peninsula. The British attacking force consisted of thirty-seven ships of the line, twenty-three frigates, thirty-three sloops of war, twenty-eight gun, mortar, and bomb vessels, thirty-six smaller vessels, eighty-two gunboats, innumerable transports, with over forty thousand troops, and an immense artillery train; making in all, says the English historian, "an hundred thousand combatants." A landing was made upon the island of Walcheren, and siege laid to Flushing, which place was not reduced till eighteen days after the landing; the attack upon the water was made by seven or eight ships of the line, and a large flotilla of bomb vessels, but produced no effect. The channel at the mouth of the river was too broad to be defended by the works of Flushing, and the main portion of the fleet passed out of reach of the guns, and ascended the Scheldt part way up to Antwerp. But in the mean time, the fortifications of that place had been repaired, and, after a fruitless operation of a whole month in the river, the English were gradually forced to retreat to Walcheren, and finally to evacuate their entire conquest.