Leonardo da Vinci sketched an organ gun with a fan of multiple gun barrels.
An organ gun is a volley firearm made from several barrels mounted together. Leonardo’s version, often called a 33-barrel organ, arranged barrels in a broad fan so that a group of shots could be fired in sequence or as a concentrated volley. The drawing is associated with his military engineering work in the late 15th century.
The name comes from the resemblance between the grouped barrels and the pipes of a pipe organ. Multiple barrels could increase the rate of fire compared with loading one cannon repeatedly, although the weapon would still require significant preparation, powder, and ammunition.
Leonardo’s sketch was a design rather than proof of a battlefield success. It should not be confused with a modern machine gun: the barrels were separate and the weapon did not provide continuous automatic fire. Similar multi-barrel weapons were developed elsewhere in Europe, including later systems used for defensive volleys.