What firearm concept did Leonardo da Vinci draw with 33 small barrels?

Leonardo da Vinci drew a thirty-three-barrel organ gun.

The design arranged 33 small gun barrels in three rows on a wheeled frame. The barrels were intended to fire in sequence or in a coordinated volley, producing a concentrated burst of projectiles. Its nickname comes from the resemblance of the rows of barrels to the pipes of a musical organ.

Leonardo’s proposal belonged to his military engineering work in the late fifteenth century. The multi-barrel arrangement could reduce the delay between shots, while a carriage made the weapon easier to move than many separate guns. However, the design’s practical battlefield performance is uncertain, and it is not the same thing as a modern machine gun.

The organ gun concept has older precedents, but Leonardo’s drawing is one of its best-known Renaissance examples. Surviving sketches show a proposal rather than proof of successful mass production.