Which Leonardo da Vinci weapon used several barrels to fire repeated volleys?

Leonardo da Vinci designed a multi-barreled cannon to fire repeated volleys. The arrangement placed numerous small cannon barrels on a rotating or fan-shaped support, allowing one group to fire while another was prepared.

The concept addressed a major weakness of Renaissance artillery: guns took considerable time to reload. Multiple barrels could increase the rate of fire and maintain pressure on an opposing force. Leonardo’s studies included several military machines, and his weapon drawings show how he applied mechanical organization to battlefield problems.

This design is sometimes loosely called a machine gun, but that modern term suggests automatic firing that Leonardo’s mechanism did not provide. The barrels still required manual loading and ignition. Its historical importance lies in the attempt to combine many artillery pieces into a coordinated weapon system.