Leonardo da Vinci’s multi-barreled weapon intended to fire many small cannonballs in sequence was an organ gun.
Leonardo’s organ-gun design arranged multiple small cannon barrels side by side on a frame. The arrangement resembled the pipes of a musical organ, which explains the weapon’s name. The barrels could be loaded together and fired in succession or in a coordinated volley, producing a broad field of shot against approaching troops.
The design addressed a problem in early gunpowder warfare: single-shot cannons were slow to reload, while a group of barrels could provide repeated fire before the enemy reached the position. Leonardo also considered ways to elevate and transport the weapon.
The organ gun is not the same as Leonardo’s steam-powered cannon concept, often called the Architonnerre. It is also distinct from the armored vehicle. These designs belonged to a wider collection of military proposals, and it is uncertain how many were ever built or tested.