If we except the small vessel tested by J. Stevens[143] between Hoboken and New York in 1804, the _New Jersey_ was the first screw-propelled vessel practically used in America, numerous experiments with the screw having been previously made without success, and she certainly was the first used for commercial purposes. The importance of the screw as a propeller having now been fully admitted in America, 150 vessels of a similar description were in less than ten years from that time employed in the United States; most of which continued to be in active operation in the carrying trade, returning large profits to their owners, particularly those employed on the great North American Lakes. Indeed, in 1848, thirteen screw-propelled vessels were employed on Lake Ontario, and only nine paddle-wheel steamers. [Sidenote: Superiority of Mr. Woodcroft’s “varying-pitch” propeller, 1832.] It is not my province to decide to whom the honour of the invention of the screw is due. It had engaged, as has been shown, the attention of various men in different countries for more than a century before it was applied to any useful purpose, and, like most other great inventions, has evidently been the production of many minds. I can, therefore, only deal with it as has been done in the case of the steam-engine itself, in its application to marine propulsion, by inquiring who it was that first, by practical tests, showed its superiority to the paddle-wheel, and that, for the purposes to which it has been applied, it could maintain such superiority over all other modes of propulsion. As this appears to me to be the only way in which this question can be fairly treated, I shall venture to state that, if Robert Fulton of America and Henry Bell of Glasgow are entitled, as I think they are, to be considered the first who put the paddle steamer into practical and _continuous_ employment (I hold that James Watt and Robert Symington were its true inventors), it may, with equal justice, be said that to Captain Ericsson, Mr. Pettit Smith, and Mr. Woodcroft, the credit is chiefly due of having put the screw into working order so as to show how it could be profitably employed for the purposes of commerce or of the arts of war, though, at the time when Smith and Ericsson were practically illustrating the power of the screw, in their respective forms, that of Mr. Woodcroft, though well known, had not then been tried. In fact, his invention bears date antecedent to that of either of the others,[144] and proved equal, if not superior, when tested; indeed, it must have been considered so by the Admiralty, as it was fitted in the royal yacht _Fairy_, which, with the exception of the _Rattler_, and the _Bee_, of thirty tons, was the first screw-propeller in Her Majesty’s Navy: it was also about the same time applied to H.M.S. _Dwarf_. Mr. Woodcroft’s “varying-pitch screw-propeller,” patented by him in February 1844, of which the