Leonardo da Vinci designed an organ gun with 33 small-caliber gun barrels. The barrels were arranged in three rows of eleven, giving the weapon the appearance of a musical organ. The design aimed to increase the rate of fire compared with a single muzzle-loading cannon.
The weapon was not a machine gun in the modern sense. Each barrel still required loading and ignition, but a prepared volley could fire many shots in rapid succession. The carriage also allowed the rows to be elevated, helping the operator aim the weapon.
Leonardo’s organ gun belongs to his broader group of military-engineering studies. His notebooks contain designs for artillery, fortifications, bridges, and other battlefield equipment. The surviving drawings demonstrate the concept, but there is no reliable evidence that Leonardo’s exact 33-barrel version was successfully used in combat.