Leonardo da Vinci sketched an organ gun, a multi-barrel weapon with 33 small cannons arranged in three rows.
The design appears in Leonardo’s notebooks and was intended to fire many projectiles in a broad volley. Its nickname comes from the visual resemblance between the parallel barrels and the pipes of a musical organ. The arrangement could have allowed one row to fire while the others were being reloaded.
Leonardo’s drawing is a proposal rather than proof that he built or successfully tested the weapon. Renaissance armies experimented with different forms of volley artillery, but practical problems included weight, recoil, aiming, transport, and slow reloading.
The weapon is sometimes called a machine gun in popular accounts. That label is modern and can mislead readers: Leonardo’s design used separate gun barrels and did not have the continuous automatic mechanism associated with modern machine guns.