Leonardo da Vinci designed an organ gun with multiple rows of barrels for repeated cannon fire.
An organ gun is a volley weapon made from several small barrels mounted together. Leonardo’s famous design places many barrels in a broad fan-like arrangement, allowing a crew to fire a concentrated burst across a wider area than one cannon could cover. The name comes from the resemblance of the barrels to the pipes of a musical organ.
Leonardo’s proposal belongs to his military studies in the late fifteenth century. It was intended to improve the rate and breadth of fire, not to create a single giant cannon. A crew could prepare one group of barrels while another was firing, at least in the concept.
The weapon was not the same as a modern machine gun. It still required separate loading and firing of gunpowder weapons, and surviving drawings do not prove that Leonardo’s exact model entered service. His design shows experimentation with salvo fire and battlefield logistics.