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
O 19-class submarine O 19-class submarine The "O 19" class was a class of two submarines, built for the Royal Netherlands Navy by "Fijenoord", Rotterdam. The ships were designed as submarine minelayer for operations in both European and colonies waters. The class comprised "O 19" and "O 20" and were the first submarines in the world to be equipped with a submarine snorkel that allowed the submarine to run its diesel engines while submerged. The submarines diving depth was . These units were very similar to earlier Polish , with a reduced torpedo battery and 10 vertical mine tubes fitted on each beam.