Leonardo da Vinci's organ-like multi-barrel weapon design arranged 33 barrels in a single weapon.
The concept is often called an organ gun because its parallel barrels resemble the pipes of a musical organ. Leonardo proposed arranging many small cannons in rows so that they could fire in sequence or in a coordinated volley. The design appears among his military-engineering studies from the late fifteenth century.
The goal was to increase the rate and concentration of fire compared with a single muzzle-loading cannon. A rotating or repositionable frame could allow one row to fire while another was prepared, although the exact operating method depends on how the drawing is interpreted.
Leonardo did not create a modern machine gun. The weapon still relied on gunpowder, individual barrels, and Renaissance loading techniques. The 33-barrel figure belongs specifically to this organ-gun design, not to every multi-barrel weapon associated with Leonardo.