The wooden screw was the least successful of the various appliances. An attempt was made in 1776 to annihilate H.M.S. _Eagle_, then lying off Governor’s Island, New York. The operator apparently tried to drive his screw into iron, and quite naturally failed. Writing to Thomas Jefferson on the subject, Bushnell suggests that had the operator shifted the submarine a few inches he could have carried out his operation, even though the bottom was covered with copper. Two other unsuccessful trials were made in the Hudson River. Owing to ill-health and lack of means, the inventor then abandoned his submarine, though in the following year he attempted to ‘discharge’ one of his magazines from a whaleboat, the object of attack being H.M.S. _Cerberus_. It failed to reach the British frigate, and blew up a prize schooner anchored astern of her. Washington was fully alive to the possibilities of Bushnell’s invention, but was evidently of opinion that it was too crude to warrant his serious attention. Writing to Jefferson, he says: “I thought, and still think, that it was an effort of genius, but that too many things were necessary to be combined to expect much from the issue against an enemy who are always upon guard.” Incidentally this was a remarkable testimonial to the men on look-out duty on the British vessels. Keen sight is still a recognized weapon against submarine attack. In 1797 Robert Fulton, also an American, brought his fertile brain to bear on the submarine, possibly on hearing or reading of David Bushnell’s boat. One would have anticipated that the era of the Revolutionary and Napoleonic wars would be propitious for the introduction of new plans and methods calculated to bring a seemingly never-ending state of hostilities to an end. Novel propositions were certainly brought forward; few were utilized. Fulton, an artist by profession, simply bubbled over with ideas connected with maritime operations. Moreover, he had extraordinary tenacity and enthusiasm. Set-backs seemed to give him added momentum. He tried to do business with Napoleon in France, with Pitt in England, with Schimmelpenninck on behalf of Holland, not always without success, before returning to the United States and running the steamer _Clermont_ at five miles an hour on the Hudson.