Leonardo da Vinci sketched an organ gun with 33 parallel gun barrels arranged on a rotating platform.
The design is often called a multi-barrelled cannon or a 33-barrel organ. Its barrels were arranged in three rows of eleven, giving the weapon an appearance similar to the pipes of a musical organ. The platform could be aimed and reloaded as a unit.
Leonardo’s concept belonged to a period when military engineers were exploring ways to increase the rate of fire of early gunpowder weapons. Firing many barrels in sequence or together could create a concentrated volley, although practical problems included weight, recoil, ignition, and reloading.
The weapon should not be confused with a modern machine gun. Leonardo’s drawing describes an early artillery concept, not a self-loading firearm. It also should not be confused with his mechanical musical instruments, despite the organ-like arrangement of its barrels.