What repeating firearm concept did Leonardo da Vinci sketch with 33 small gun barrels?

Leonardo da Vinci sketched a repeating firearm concept called the 33-barrel organ.

The design consisted of 33 small gun barrels arranged in three rows on a triangular frame. The arrangement was intended to let one row fire while another was prepared, increasing the potential rate of fire compared with a single muzzle-loading gun. A wheeled carriage was included so the weapon could be moved and aimed more easily.

The name “organ” refers to the visual arrangement of multiple barrels, which resembles the pipes of a musical organ. It does not mean that the weapon used musical technology. Leonardo’s drawing belongs to his military engineering studies in the late 15th century, when designers were seeking ways to improve artillery and firearms.

The 33-barrel organ was a concept rather than a confirmed operational weapon built by Leonardo. Its effectiveness would have depended on difficult loading, ignition, recoil, and crew procedures. It should not be confused with later modern machine guns, which use fundamentally different firing and loading systems.