What machine did Leonardo da Vinci sketch with 33 gun barrels?

Leonardo da Vinci sketched an organ gun with 33 gun barrels.

The organ gun was a multi-barrel firearm arranged in three rows of eleven barrels. Leonardo included the concept in his military-engineering studies during the late 15th century. The name comes from the resemblance between the parallel barrels and the pipes of a musical organ.

Its purpose was to fire a broad volley of small cannonballs or other projectiles. Compared with a single cannon, multiple barrels could increase the number of shots delivered in a short period, although reloading and aiming remained major practical problems.

The design was not a machine gun in the modern sense. It did not use automatic loading, cartridges, or continuous fire. Leonardo’s drawing belongs to the long history of volley guns, in which several barrels are fired together or in sequence. Similar multi-barrel weapons were later developed by other engineers and armies.