What repeating firearm did Leonardo da Vinci design with 33 gun barrels arranged in rows?

Leonardo da Vinci designed a 33-barrelled organ, a repeating firearm with gun barrels arranged in rows.

The weapon used three groups of eleven small-caliber barrels. The rows could be loaded in advance, and the frame could be raised or lowered so one group fired while another was prepared. Its nickname comes from the parallel arrangement of barrels, which resembles the pipes of a musical organ.

Leonardo’s design aimed to increase the rate of fire compared with a single muzzle-loading gun. It was not a machine gun in the modern sense: the barrels did not fire continuously from a single ammunition feed, and each discharge still required separate loading.

The design belongs to Leonardo’s military engineering work in the late fifteenth century. It is often grouped with volley guns, weapons intended to release many projectiles in a concentrated burst.