Robert Fulton the "Nautilus", the first practical submarine in history. Fulton is also credited with inventing some of the world's earliest naval torpedoes for use by the British Royal Navy. Fulton became interested in steam engines and the idea of steamboats in 1777 when he was around age 12 and visited state delegate William Henry of Lancaster, Pennsylvania, who was interested in this topic. Henry had learned about inventor James Watt and his Watt steam engine on an earlier visit to England. Robert Fulton was born on a farm in Little Britain, Pennsylvania, on November 14, 1765. He had three sisters –
French submarine Laplace steam propulsion was abandoned and the ships were instead equipped with diesel engines. Measuring long, with a beam of and a draught of , "Lagrange"-class submarines could dive up to . The submarine had a surfaced displacement of and a submerged displacement of . Propulsion while surfaced was provided by two diesel motors built by the Swiss manufacturer Sulzer and two electric motors. The submarines' electrical propulsion allowed it to attain speeds of while submerged and on the surface. Their surfaced range was at , and at , with a submerged range of at . The ships were equipped with