Leonardo da Vinci’s organ gun design placed 33 small cannons in a single weapon.
The concept arranged the barrels in three rows of eleven. The weapon was intended to fire repeatedly as different rows were raised into position, allowing one group to discharge while another was reloaded. This arrangement addressed the slow reloading problem of many early firearms.
The design is often called a triple-barreled cannon or a volley gun, but “33-barrel organ gun” is the clearest description of the surviving concept. It was not a modern machine gun: the barrels were separate, and firing depended on manual operation and period gunpowder technology.
Leonardo developed many military ideas during his career, including fortified structures and armored vehicles. As with several of his inventions, the organ gun is known primarily from drawings rather than evidence of battlefield deployment. Its significance is the attempt to improve firepower and firing speed through mechanical organization.