What Leonardo da Vinci weapon design combined 33 small cannons on a rotating platform?

Leonardo da Vinci’s 33-barrel organ was a rotating weapon design carrying 33 small cannons.

The design is commonly described as an organ gun or organ cannon. Leonardo arranged the barrels in three rows on a triangular or fan-shaped frame. The platform could be rotated so that one row was aimed and fired while another row cooled or was reloaded. This arrangement addressed a major problem with early firearms: slow reloading and overheating during repeated firing.

The name “organ” comes from the visual resemblance between the parallel barrels and the pipes of a musical organ. It does not mean that the weapon used musical mechanisms. Leonardo’s drawing belongs to his military-engineering work for Renaissance patrons, but there is no firm evidence that he built and deployed this exact model.

The design should not be confused with a modern machine gun. Each barrel was a separate firearm, and the weapon still depended on manual loading, aiming, and ignition. Its importance is as an early attempt to organize multiple barrels for sustained fire.