of the vessel required and as to the best position for the propeller, difficulty in accommodating the early long-stroke steam engine to drive direct an under-water propeller shaft; inertia, prejudice and vested interest, all seem to have played a part in delaying the adoption of what, when it did come, was acknowledged to be the only suitable form of steam propulsion for war vessels. [Illustration: PETTIT SMITH’S PROPELLER] In 1825 a premium was offered by the Admiralty for the best plan of propelling vessels without paddlewheels; and a plan proposed by Commander S. Brown, R.N., was deemed sufficiently promising for trial: a two-bladed screw propeller placed at the bow of a vessel and actuated by a 12-horsepower engine. But though exhibiting advantages this form of the invention did not survive. The history of the screw-propeller may be said to date from 1836. In that year two capable inventors obtained patents: Mr. Francis Pettit Smith and Captain Ericsson. So little attention had, up to that time, been given to the subject that the two proposals “were presented to the public in the character of novelties, and as such they were regarded by the few who had curiosity enough to look at them.” Smith’s patents were for the application of the screw to propel steam vessels by fixing it in a recess or open space formed in the deadwood; and, says Fincham, “the striking and peculiar merit of Mr. Smith’s plan appears to consist, _chiefly_, in his having chosen the right position for it to work in.” Trials were carried out with Smith’s propeller in a 6-ton boat on the City and Paddington canal, and then between Blackwall and Folkestone, with encouraging success; the boat, encountering heavy weather off the Foreland, demonstrated the advantage derived from the absence of paddlewheels, and showed the new form of propelling machinery to place no limitations on her qualities as a sailing vessel. She returned to Blackwall, having run over 400 miles at a mean speed of 8 knots.