Leonardo da Vinci designed an organ gun with many barrels arranged in a row.
Leonardo’s multi-barreled gun design placed a group of small cannon barrels on a frame. The arrangement resembles the pipes of a musical organ, which explains the weapon’s name. Multiple barrels could be loaded and fired in sequence or in a coordinated volley, increasing the rate of fire compared with a single muzzle-loading cannon.
The design addressed a major problem in Renaissance artillery: reloading a cannon took time. A row of barrels allowed another loaded barrel to be brought into action while other barrels were being prepared. Leonardo’s drawings show that he was thinking about both firepower and battlefield handling.
An organ gun is not the same as a modern machine gun. Its barrels were separate artillery pieces, and operation still required manual loading, powder, and ignition. Leonardo proposed the arrangement as military engineering, not as an automatic weapon with continuous fire.