A forerunner of the machine gun, invented in 1861 by Richard J. Gatling (1818–1903) and first used during the American Civil War, that had six barrels mounted around a central shaft. It was hand-cranked, each barrel in turn reaching the firing position, firing a single shot, ejecting the spent cartridge, and loading a new round. It then had a short time to cool before being fired again. The ammunition was fed into the breach by gravity from a box and each barrel had its own firing mechanism.