Which Leonardo da Vinci weapon concept mounted several guns on a single rotating platform?

Leonardo da Vinci’s weapon concept with several guns on one rotating platform is known as the 33-barrel organ.

The 33-barrel organ was a multiple-barrel gun design attributed to Leonardo. It arranged 33 small cannons in three rows on a wheeled frame. The arrangement was intended to increase the speed of reloading: one row could fire while another was being prepared.

The name “organ” refers to the visual arrangement of the barrels, which resembles the pipes of a musical organ. It was not a musical instrument. The device belongs to the broader Renaissance development of volley weapons and multi-barrel artillery.

Leonardo’s design was not a modern machine gun. The barrels still required separate loading and firing, and the weapon’s practical battlefield performance would have depended on careful handling, ammunition, and recoil control.