The first attacks on a ship by an underwater vehicle are generally believed to have been during the American Revolutionary War, using what would now be called a naval mine but what was then referred to a torpedo. Even so, various attempts to produce submarines had been made prior to this. In 1866, British engineer Robert Whitehead invented the first effective self-propelled torpedo, the eponymous Whitehead torpedo; French and German inventions followed soon thereafter. The first submarine with a torpedo was "Nordenfelt I" built in 1884–1885, though it had been proposed earlier. By the outbreak of the Russo-Japanese War, all the large navies except the Germans had acquired submarines. Nevertheless, by 1904, all powers still defined the submarine as an experimental vessel and did not put it into operational use.