I Stephen Decatur having examined the model of a Machine, invented by Robert Fulton, for cutting cables under water; and a piece of 15 inches Cable, which was cut by him 12 feet below the Surface; which effect was produced, by firing a Sharp piece of iron, from a gun 2½ feet long, one inch caliber, with 2 ounces of powder, which powder was ignited Said 12 feet under water, with a water proof lock invented by Said Fulton, and the experiment made at the Navy yard near New york, in the year 1810, in the presence of Commodore Chauncey and many other Gentlemen; which demonstrated the practicability of firing a gun under water with Sufficient force to cut cables.

Having also examined a yellow pine plank, four inches thick, through1 which, the Said Fulton did on the 27th day of April, fire a lead ball one inch diameter, the gun and plank being 3 feet 6 inches under water, and the plank one foot from the muzle of the gun.

And having heared his account of a third experiment, in which he inserted a loaded gun, of the before mentionned length and caliber, into one end of a water hogshead, near the bottom, and filled the hogshead with water, leaving out the bung; the Gun was fired, the bullet passed through three feet of water, the opposite end of the hogshead, and Six inches into a post of white pine. These experiments presenting a flattering hope of farther success, and the Said Fulton now preparing to try, to what distance a 6 pound Shot and balls of greater diameter, can be fired under water to useful effect, either with the gun totally immersed in water, or its muzle in water and breech in air. as though the muzle passed through the Side of a Ship 6 or more feet below the water line, and the breech inside, and he having Shewn me the Drawing2 of a piece of mechanism, by which a loaded cannon, can have the muzle passed through the Side of a Ship, at any depth below the water line, and there fired, will recoil into the Ship without letting in any inconvenient quantity of water, and can be loaded and fired as often as need may3 require.

I have deliberately considered these experiments, and give it as my opinion, that Should Said Fultons future essays prove, as he hopes they will, that 36 or 42 pound Shot, or columbiads of 50 or 100 lb., can be fired from 15 to 20 or 50 feet, through water, and from 3 to 10 feet under the Surface, with Such force as to pass through the Side of a Ship of the line, no vessel can be Saved after a broad Side well directed of only four or Six Such guns; For as the bullets would pass through her from 6 to 10 or more feet below the water line, where the pressure is great, the water would rush in with a rapidity, that could not be cleared by the pumps and She would Sink in a few minutes. The practice then Should be, to run along Side as near as possible, fire one broad Side and retire. the act would be that of a few minutes, and the risque to the assailants little compared to the present mode of combat. Thus, thick Sided Ships of 3 or 4 hundred tons, with 4 or 6 guns on a Side, from 3 to 9 feet under water, could destroy vessels of ’100 guns, as they are now constructed. And I perfectly agree with Mr Fulton, that Should his experiments prove, that the above mentionned weight of metal can be fired as he contemplates, and as I have much reason to believe, this new mode of Maritime warfare must4 anihilate the present System, by rendering Small vessels equal to large ones, for both must Sink if attacked in a like manner. Hence I feel it a duty which I owe to my country, to Solicit the Governement, to prosecute of these experiments and the practice of them to their utmost extent.5

Signed Stephen Decatur