Nicholas Roosevelt (inventor) 74-gun ships. In 1797, with Robert R. Livingston and John Stevens, he agreed to build a boat on joint account, for which the engines were to be constructed by Roosevelt, and the propelling agency was to be that planned by Livingston. The experiment failed, the speed attained being only equivalent to about in still water. On September 6, 1798, Roosevelt described and earnestly recommended to Livingston a vertical wheel, which is the first practical suggestion of the combination that made steam navigation a commercial success, although four years later Robert Fulton believed that chains and floats were alone to be
Claims to the first powered flight a steam-powered aeroplane which took off from a ramp with a sailor on board and remained airborne for a short distance. This has sometimes been claimed as the first powered flight in history but the claim is generally rejected because takeoff was gravity-assisted and flight was not sustained. It is however credited as the first powered take-off in history. Ten years later in 1884 the Russian Alexander Mozhaysky achieved similar success, launching his craft from a ramp and remaining airborne for 30 m (98 ft). The claim that this was a sustained flight has not been taken seriously outside Russia.