What Leonardo da Vinci weapon concept used multiple barrels fired in sequence?

Leonardo da Vinci’s 33-barrelled organ was a weapon concept using multiple barrels fired in sequence.

Leonardo designed the device as a field artillery system with three rows of eleven small cannons. The barrels were arranged on a frame resembling the pipes of an organ, which explains the nickname. The frame could be angled, and the rows were intended to be fired one after another.

Sequential firing could maintain a more sustained attack than discharging every barrel simultaneously. While one row fired, another could be loaded or allowed to cool. This addressed practical problems that affected early gunpowder weapons, including slow reloading and overheating.

The 33-barrelled organ is often called a multiple-barrel gun, but it was not a modern machine gun. It relied on separate artillery barrels and historical gunpowder loading methods. Leonardo’s drawings show an engineering proposal rather than evidence of a successfully deployed battlefield weapon.