Leonardo da Vinci arranged 33 barrels in his proposed organ gun.
The design placed many small cannon barrels in a broad, organ-like array. The name “organ gun” refers to the visual resemblance to the pipes of a musical organ, not to a musical function. The arrangement was intended to let a gun crew fire a volley of projectiles in rapid succession.
Leonardo’s design belongs to his military engineering studies in the late 15th century. It addressed a practical problem of early artillery: guns often took considerable time to reload after firing. Multiple barrels could provide concentrated fire before reloading was necessary.
The weapon was not a modern machine gun, because the barrels still required separate loading and firing. It is also distinct from Leonardo’s giant crossbow, which used a bow rather than gunpowder artillery.