“Pitt was the greatest fool that ever existed, to encourage a mode of war which they who command the seas did not want and which if successful would deprive them of it.” [Illustration: Destruction of the _Dorothea_. From a woodcut by Robert Fulton.] Six days after the destruction of the _Dorothea_, the sea-power of France was broken by Nelson at the battle of Trafalgar. Napoleon now gave up all hope of gaining the few hours’ control of the Channel that would have enabled him to invade England, and broke up the camp of his Grand Army that had waited so long at Boulogne. With this danger gone, England was no longer interested in submarines and torpedoes. So Fulton returned to America, to build the _Clairmont_ and win his place in history. But to him, steam navigation was far less important than submarine warfare. In the letter to his old friend Joel Barlow, dated New York, August 22, 1807, in which he described the first voyage of the _Clairmont_ up the Hudson, Fulton said: “However, I will not admit that it is half so important as the torpedo system of defense or attack, for out of this will grow the liberty of the seas--an object of infinite importance to the welfare of America and every civilized country. But thousands of witnesses have now seen the steamboat in rapid movement and they believe; but they have not seen a ship of war destroyed by a torpedo, and they do not believe. We cannot expect people in general to have knowledge of physics or power to reason from cause to effect, but in case we have war and the enemy’s ships come into our waters, if the government will give me reasonable means of action, I will soon convince the world that we have surer and cheaper modes of defense than they are aware of.” Fulton had been having his troubles with the navy department. Soon after his return to this country he had made his usual demonstration of torpedoing a small anchored vessel, but it was not until 1810 that he was given the opportunity to make a test attack on a United States warship. But stout old Commodore Rogers, who had been entrusted with the defense of the brig _Argus_, under which Fulton was to plant a torpedo, anchored the vessel in shallow water, stretched a tight wall of spars and netting all round her, and successfully defied the inventor to blow her up. Even a modern destroyer or submarine would be puzzled to get past this defense. Though compelled to admit his failure, Fulton pointed out that “a system then in its infancy, which compelled a hostile vessel to guard herself by such extraordinary means, could not fail of becoming a most important mode of warfare.”