What Leonardo da Vinci invention was a 33-barrel weapon arranged on a single platform?

Leonardo da Vinci’s 33-barrel organ was a multi-barrel weapon arranged on a single platform.

Leonardo designed the weapon in the late fifteenth century as a way to fire many small guns in a coordinated sequence. The barrels were mounted in three rows of eleven, giving the design its commonly used name. The arrangement was intended to increase the rate of fire compared with repeatedly loading one barrel.

The device was not a musical organ. Its name comes from the organ-like grouping of barrels, and the design belongs to Leonardo’s military-engineering studies. Like many of his weapons, it survives as drawings and descriptions rather than as a clearly documented battlefield machine built by Leonardo himself.

The 33-barrel organ is also called a volley gun or organ gun. It should not be confused with the later Gatling gun, which used a rotating group of barrels and a different loading mechanism. Leonardo’s design instead emphasized multiple fixed barrels fired in volleys.