What rotating firearm did Leonardo da Vinci design with multiple barrels arranged in a row?

Leonardo da Vinci designed a 33-barrel organ gun with multiple barrels arranged in three rows.

The weapon’s name comes from the resemblance between its parallel gun barrels and the pipes of a musical organ. Leonardo’s design placed small cannons on a broad frame so that one row could fire while another was being loaded or cooled. The frame could be tilted to aim the barrels, and wheels were included for movement.

This was not a machine gun in the modern sense. The barrels were separate, and the weapon still required manual loading and firing. Its proposed advantage was concentrated volley fire: many projectiles could be discharged in a short period, especially against tightly packed troops.

Leonardo’s version belongs to a wider family of organ guns developed in Europe. The design illustrates his interest in improving artillery through arrangement and timing rather than inventing a completely new type of projectile. As with many of his military drawings, there is no evidence that this exact machine entered regular service.