American inventor Hiram Maxim (1840-1916) would have been much more famous if he had won the battle with Thomas Edison for credit for inventing the electric light bulb. But his other inventions were also important, at least as far as firearms of the late 19th century were concerned. Maxim first demonstrated the principle of his automatic machine gun in an 1883 patent. Several features of Maxim's weapon made it an innovation. The action was fully automatic, and the user only had to keep his finger on the trigger to fire the weapon. The recoil energy from the shot was used to expel the spent cartridge, reload, and fire automatically. The weapon had a single barrel enclosed in a reservoir of water to cool it, since it heated up when fired. It was lighter and more mobile than previous versions. The American government was not interested in buying Maxim's inventions, so he took it to Europe, where he managed to sell it to the English and Germans. Maxim became a British citizen in 1901 and was knighted by Queen Victoria. His company, Vickers, Son & Maxim, made a name for itself by selling the fearsome weapon throughout Europe, especially to Germany. The weapons were licensed and manufactured by factories in Britain and Germany, and the first Maxim machine guns were delivered to the German Navy in 1894. Both sides used them during World War I. Maxim's guns evolved over the years, becoming more efficient, and served as the prototypes for today's machine guns.