Leonardo da Vinci sketched an organ gun, a rotating weapon with multiple cannon barrels arranged in parallel.
The design placed several small guns on a wheeled frame. Its name comes from the resemblance between the grouped barrels and the pipes of a musical organ. The barrels could be loaded together, allowing a concentrated volley of fire before the weapon was repositioned or reloaded.
Leonardo studied the device as part of his broader work on military engineering. The arrangement addressed a major problem with early firearms: slow loading. Multiple barrels could increase the number of shots available at once, although the weapon would still have been heavy and difficult to operate.
The organ gun should not be confused with a modern machine gun. It was a manually loaded artillery concept, and Leonardo’s drawing does not prove that a successful battlefield version was produced.