Leonardo da Vinci’s organ-gun design placed 33 small cannons in three rows.
The weapon was a multi-barrel gun arranged like the pipes of a musical organ. Leonardo proposed three rows of 11 guns, creating 33 barrels in total. A frame allowed one row to fire while another was being loaded, at least in principle. The design aimed to combine a broad volley with faster reloading than a conventional cannon battery.
Leonardo included the weapon among his military studies in the late fifteenth century. The surviving drawings show the arrangement and operating concept, but there is no reliable evidence that Leonardo’s particular 33-barrel machine was built and used in battle.
The name “organ gun” refers to the visual arrangement of parallel barrels, not to a musical function. The weapon is also sometimes confused with later volley guns and modern multiple-barrel firearms. Leonardo’s version was a proposed artillery system powered by gunpowder, not an automatic weapon.