from the Public Advertiser (New York), March 11, 1807.
A gun-boat, carrying heavy metal, is a movable fortification; and there is no mode or system of defense the United States can go into for coasts and harbors or ports, that will be so effectual as by gun-boats.
Ships of the line are no ways fitted for the defence of a coast. They are too bulky to act in narrow waters, and cannot act at all in shoal waters. Like a whale they must be in deep water and at a distance from land.
Frigates require less room to act in than ships of the line; but a frigate is a feeble machine compared with a gun-boat. Were a frigate to carry and discharge the same weight of metal and ball that a gun-boat can do, it would shake her to pieces. The timbered strength of every ship of war is in proportion to the weight of metal she is to carry, and the weight of metal she is to be exposed to. The sides of a frigate are not proof against the weight of a ball that a gun-boat can discharge. The difference between two ships of war is not so much in their number of guns as in their weight of metal.
I remember the late Commodore Johnson saying in the British House of Commons at the commencement of the American war, that “A single gun in a retired situation would drive a ship of the line from her moorings. I mention this (said he) that too much may not be expected from the navy.”
A gun-boat can carry a gun of the same weight of metal and ball that a ship of an hundred guns can carry; and she carries it to the greatest possible advantage. The shot from a gun-boat is a horizontal shot. The gun is fixed in a frame that slides in a groove, and when the man at the helm brings the head of the boat to point at the ship, the gun is pointed with it. When a ship fights with her starboard or larboard guns, she presents the whole broadside of the ship to the object she fires at. A gun-boat fights only with her head, that is, with the gun at her head, and when she fires at an object she presents only the breadth of the boat to that object. Suppose, then, a boat to be ten feet broad and two feet out of the water (I spake here of boats intended for the defence of the coast, and of towns situated near the coast, and to carry a gun of the same weight of metal and ball that a ship of the line carries) such a boat will present a space to be fired at equal to twenty square feet, that is, ten feet horizontal length (being the breadth of the boat) and two feet perpendicular height, being the height of the boat out of the water. Suppose, on the other hand, that a ship be an hundred feet long and ten feet high out of the water, she will present a space to be fired at equal to one thousand square feet, that is, a hundred multiplied by ten. It is probable that a ship, in firing at a gun-boat, would fire one of her bow guns, because in so doing she apparently shortens about one half of her length; but she can fire but one gun at a time in this angular position.
But the gun-boat has other chances in her favor besides what arise from the different dimensions of the two objects. If a shot from the ship, though in a straight line with the boat, passes more than two feet above the water at the place where the boat is, it will pass over the boat without striking it. But a shot from the boat that is too high to strike the ship, may strike the mast and carry it away. It is by this means that masts are carried away. The shot that does it passes clear above the ship, and spends its whole force upon the mast. Again, if a shot from the ship pass an inch or two wide of the boat, it can do her no injury. But a shot from the boat that passes five or six inches wide of the body of the ship at the stern, may unship or carry away her rudder. This, and the carrying away a mast, are the two most fatal accidents that can befall a ship; yet neither of them can happen to a gun-boat.
Of the number of men killed or wounded in a ship, the greater part of them are not by cannon balls, but by splinters from the inside of the ship that fly in all directions, but the sides of a gun-boat not being thick like the sides of a ship, a ball would pass through without splinters; and as an effectual way to prevent splinters, should any happen or be apprehended, the sides of the boat on the inside should be lined with a strong netting made of cord, which the men can make themselves. The cabins of French ships are frequently lined in this manner.
Musquetry can be used by ship against ship in close action, but cannot be used against a gun-boat, because a gun-boat drawing but little water, not more than two and a half or three feet, and depending upon pars, can always keep out of the reach of musquetry. The proper distance for a gun-boat to fire at is point blank shot. (Point blank musket shot is 250 yards, point blank cannon shot varies according to the size of the cannon.) The men should be frequently exercised at firing point blank shot at banks of earth on shore, or against the high perpendicular shores of rivers, like the North River, or against the bulk of old ships that are to be broken up, the man at the helm to point the boat and give the order for firing. A gun-boat should not carry a less weight of ball than twenty-four pounds. A frigate would not chuse to expose her sides to such shot.
The first gun-boats built in the United States, were for the defence of the Delaware, in 1775 and ’76. The Roebuck man of war came up the Delaware within a few miles of Philadelphia, and the gun-boats went and attacked her. The ship fired broadsides without striking any of the boats, and as the deep water the ship was in, was but narrow, the re-action of the broadsides forced her into shoal water, and she got aground. The man who commanded the gun-boats, a suspected character of the name of White, gave orders to the boats to cease firing, and when the tide rose the ship floated and made the best of her way to sea. White afterwards joined the British at New York.
When General Howe sailed from New York, in 1777, to get possession of Philadelphia, he avoided coming up the Delaware, where the gun-boats were, and went to the Chesapeak, where there were none, and marched by land from the head of Elk into Pennsylvania. No cause can be assigned for this circuitous route of several hundred miles, but that of not exposing his ships and transports to the gun-boats. There were at that time a fortification on Mud Island, a few miles below Philadelphia, and another at Red Bank on the Jersey shore opposite; but Howe could have landed below those, and out of the reach of their shot, but he could land no where on the Delaware shore, nor be any where with his ships in the Delaware, out of the reach of the movable fortifications, the gun-boats. After Gen. Howe got possession of Philadelphia by land, the gun-boats quitted their station below, and came above the city.
The Asia man of war, of 60 guns, Capt. Vandeput, got aground in New York harbour, three or four miles below the city, in the spring of ’76. General Lee commanded at New York at that time, and had there been any gun-boats, they could have taken her, because they could have raked her fore and aft, and obliged her to strike. A man of war aground is like a bird shot in the wing; it can make no effort to save itself. As to the guns on the point now called the Battery, they could do nothing. The ship was out of the reach of their shot.
The gun-boats built in France for the descent upon England are numerous and formidable, being more than two thousand. They were began in the year ninety-six. Those which I have seen, being both convoy and transport, were about sixty feet long, sixteen feet broad, drew about 2 1-2 feet water, carried a 24 or 36 pounder at the head, and a field-piece in the stern, with a flap by which to run the field-piece out as soon as the boat touches ground ashore, as they run a waggon out of a scow. Each boat carried an hundred men, and rowed with twenty-five oars on a side. They have since built a much larger sort called praams. These also are flat bottomed, draw three or four feet water, and are from four to six hundred tons burthen, and carry several very large cannon, not less, I suppose, than 48 pounders at least.
The British men of war have made several attempts against the French gun-boats at Boulogne, but were always defeated. The last attempt was by fire arrows, which might be formidable against ships, because of their sails and rigging, but is ridiculous against gun-boats.
A great deal has been said in Congress and in the New York newspapers about fortifying New York. Mr. N. Williams, in a speech in Congress, Jan. 23, said, “The gentleman on my right (meaning Mr. Smilie) meets the proposition for fortifying New York with a most formidable objection. Expend, says he, what money you will, it is impossible to erect fortifications that shall prove sufficient to defend the harbour and city of New York. He (Mr. Smilie) calls upon us for a plan, and tells us, that if it can be defended, to produce our plan.” “I do not (continues Mr. Williams) pretend to be very wise upon this subject myself, but I have been told that the ablest engineers have examined the position, and have given it as their opinion, that an effectual mode of defence is practicable. But if defence is impossible, I call upon the gentleman (meaning Mr. Smilie) to shew wherein the peculiarity of the situation of that place (N. Y.) consists, to render it so. For surely the pretence of impossibility would not be made use of here, unless the city and harbour of New York were different from all other places in the world that were ever defended.”
I now come to reply to the demand Mr. Williams has made. I shall do this as concisely as the limit to which I confine myself will admit, but what I say will serve to sow seeds of thought in the minds of others upon this subject, and may prevent millions of dollars being wasted in vain.
Fortification is founded on geometrical principles, and where the condition of a place is such that those principles cannot be applied, that place cannot be fortified to produce any effect. A place that cannot be enclosed in a polygon, cannot be fortified on any principles of fortification, unless there be a part so strong by nature, as to be inaccessible to a besieging army. The fortified parts are then sections of a polygon. New York cannot be enclosed in a polygon, and therefore cannot be fortified; neither is any part of it strong by nature. It is approachable in every part by land or water, and besides this, it can be bombarded across the East River from Long Island.
It is absolutely necessary in fortifying a town that all parts of it be equally strong, or an enemy will attack only the weakest part. New York cannot be made equally strong in all its parts, and therefore it is money thrown away to attempt to fortify it. — Those who wish to know more on this subject may consult any encyclopedia, or any dictionary of arts and sciences under the head of FORTIFICATION. They will there find plans of fortified places by Count Pagan, Blondel, Vauban, Scheiter, &c. But the plans and drawings are all on the same principles. They are all polygons.
Some of our New York papers have talked of fortifying New York with “impregnable fortifications.” There never yet was an impregnable fortification, nor ever can be. Every fortified place can be taken that can be approached. All that a fortified place can do is to delay the progress of an enemy till an army can arrive to raise the siege. Bonaparte takes every fortified place he goes against, but he fortifies no places himself. He trusts to the open field for when you are master of the field (and the militia of the states are numerous enough to be master of the field against an enemy) fortifications are of no use. The population of the U. States when the revolutionary war began was but two millions and an half. It is now nearly six millions, and surely the people are not grown cowards, whatever the fed. and tory faction may be. It was cowardice that made them tories at first. The British impostor and emissary Cullen, Alias Mac Cullen, Alias Carpenter said in one of his papers that a single frigate could lay the city of New York under contribution. This shewed the extreme ignorance of the man. Two twelve pounders, or heavier metal if it can conveniently be had, taken to the water edge would soon oblige the frigate to quit her station. I saw this done in the revolutionary war to two frigates; the Pearl frigate and another with her. It proved commodore Johnson’s opinion to be correct.
The lower a gun is to the surface of the water the more certain the shot is. — This is one of the cases that gives a gun boat an advantage against ships. If a shot from a ship strikes another ship between wind and water, it is always a chance occasioned by the heeling of the ship that is struck. — But the direction of a shot from a gun boat is so nearly between wind and water, that it generally strikes there or thereabouts. As to land batteries that are elevated, they have but little chance of striking a ship, as their fire is always in an oblique or sloping direction; whereas from a gun boat it is a horizontal line. Fort Washington was built to prevent British ships going up the North River and it never struck one of them; but it killed three men by chance medley coming down the river in Gen. Washington’s barge, and this was the only vessel it ever struck.
When all the plans that can be devised for fortifying the narrows are examined, for there is no fortifying the city, it will be found that half a dozen gun boats carrying twenty four pounders, will do it more effectually than can be done by any other method.