By way of securing maximum public exposure, as well as obtaining additional funding for his experiments, he made arrangements to conduct the Submarine Battery demonstration directly off Castle Garden, a popular open-air theater located in venerable Castle Clinton on lower Manhattan, the scene less than two years earlier of a demonstration of "Cochran's Bomb Cannon," another transient ordnance phenomenon of the era.To his delight, his experiment received generous notice, the New York Evening Post relating that "an interesting experiment with Colt's sub-marine battery created much attention, and was witnessed by many thousands with great satisfaction. An old hulk was moored off Castle Garden fitted with temporary masts, from which were displayed various flags, with piratical devices, immediately under which the battery was placed, and the effect of the explosions was tremendous. The vessel was shattered into fragments, some of which were thrown two or three hundred feet in the air, and there was not a single piece left longer than a man could have carried in one hand."In preparation for his second major New York demonstration, held off Castle Garden on 18 October 1842, Colt acquired an extensive amount of insulated cable, including at least three reels lent by Professor Samuel F. B. Morse, who was concurrently conducting tests of his magnetic telegraph system, in the immediate vicinity, employing copper cabling similarly insulated with tarred thread.
At precisely twelve o'clock a salute of thirteen guns pealed forth from the fort on Governor's Island--which was echoed by the war frigates North Carolina and Columbia and returned by the British razee, Warspite, lying off the Battery. A few minutes after the last gun had roared from the Warspite a small craft, moored between the North Carolina and the Battery, was taken in tow by a boat from the former, and had scarcely moved from her position when a monstrous jet of muddy water was thrown up high in the air, and when it fell the craft had utterly disappeared. Not a fragment of it larger than a billet of fire-wood was any where to be seen. It was the triumphant result of an experiment made by Mr. SAMUEL COLT, at the expense of the General Government with an engine of destruction he has just invented. The vessel on which the experiment was tried was an old gunboat from Lake Champlain, filled with rubbish. The magazine contained some two hundred pounds of powder and was placed directly beneath the gunboat at a depth of 12 or fifteen feet. A wire extended from this to the deck of the North Carolina, two or three hundred yards distant. At the appointed moment, Mr. Colt, who conducted the experiment with Professor [Samuel F. B.] Morse and Dr. Fisher, brought the plates of his voltaic pile into contact, and quicker than thought the old gunboat vanished into thin air. The experiment was completely successful and was witnessed by tens of thousands from the Battery. In harbor defenses the invention promises to be of essential service: certain it is that if an enemy's vessel will allow one of the utensils to be sunk under her, the place that once knew her will be apt to know her no more. . . . ("The Celebration of the Fourth," New-York Daily Tribune, 6 July 1842, page 2)