Leonardo da Vinci’s multiple-barrel cannon design showed 33 barrels.
The weapon is commonly described as a 33-barrel cannon or organ gun. Leonardo arranged the small barrels in three groups or rows, allowing one group to be fired while the others were being loaded or cooled. The arrangement aimed to provide a faster sequence of shots than a single cannon.
This concept addressed a serious problem with early artillery: reloading was slow, and repeated firing could overheat barrels. Multiple barrels offered a way to maintain pressure on an opponent, although the machine would still have been heavy and difficult to transport.
The design is sometimes incorrectly called a modern machine gun. It was not a self-loading firearm and had no automatic firing mechanism. Its significance lies in the attempt to combine several manually operated gun barrels into one organized artillery system.