[revolver] The Tranter revolver was a double-action cap & ball revolver invented around 1856 by English firearms designer William Tranter (1816–1890). Originally operated with a special dual-trigger mechanism (one to rotate the cylinder and cock the gun, a second to fire it) later models employed a single-trigger mechanism much the same a... Found on http://en.wikipedia.org/wiki/Tranter_(revolver)