What weapon design by Leonardo da Vinci used multiple barrels arranged in parallel to fire repeated volleys?

Leonardo da Vinci designed a multi-barrel cannon with parallel barrels for repeated volleys.

His military drawings include a wheeled frame carrying many small-calibre barrels. The arrangement allowed several barrels to be loaded in advance and fired in succession or as a group. The design is often called Leonardo’s “33-barrelled organ” because the barrels resemble the pipes of a musical instrument.

The device was intended to improve the rate of fire compared with a single cannon. A rotating or angled frame could help crews prepare one set of barrels while another was firing or cooling. In practice, the design would still have faced serious problems involving weight, recoil, loading, and coordination.

It was not a modern machine gun. Modern machine guns use a continuous feeding and firing mechanism, whereas Leonardo’s proposal relied on multiple separate barrels. The design nevertheless illustrates his interest in solving battlefield problems through mechanical arrangement rather than simply increasing the size of one gun.