Leonardo da Vinci sketched an organ gun with 33 small cannons arranged in three rows.
The weapon appears in Leonardo’s military-engineering designs and is often compared with a pipe organ because its barrels were arranged in parallel lines. The intended arrangement allowed one row to fire while another was being loaded or repositioned. In theory, this could produce repeated volleys and make the weapon more useful against massed troops than a single cannon.
The organ gun was not a machine gun in the modern sense. It fired separate projectiles from multiple gun barrels and required substantial manual handling. Leonardo’s proposal belongs to a broader period of experimentation with rapid-fire artillery, including weapons with many barrels mounted on a frame. The number 33 refers to the commonly identified barrel layout in this design, not to a universal count for every multi-barrel weapon associated with Leonardo.