Leonardo da Vinci designed an organ gun with 33 separate barrels arranged in three rows.
The weapon was intended to fire multiple shots in succession or in a broad volley. Its name came from the visual and structural resemblance between its grouped barrels and the pipes of a musical organ. Leonardo’s design used a wheeled carriage so the weapon could be moved and aimed more easily than a large fixed gun.
The organ gun was part of Leonardo’s military engineering work, which included fortified defenses, artillery concepts, bridges, and other battlefield machines. It was not a modern machine gun: the barrels still required separate loading and did not provide fully automatic fire.
The number 33 is a key identifying detail. It distinguishes Leonardo’s organ-gun concept from his other artillery drawings and from later volley guns that used different barrel arrangements.