What military device did Leonardo da Vinci design to fire many shots from rows of barrels?

Leonardo da Vinci designed a multi-barrel cannon arranged in rows to fire many shots.

The weapon is commonly described as a “33-barrel organ,” because its barrels were arranged in three rows of eleven. The idea was to fire a volley and then use the time while one row cooled to prepare another. A wheeled frame would allow the device to be moved across a battlefield.

Leonardo’s design addressed a major problem with early artillery: slow reloading. Multiple barrels could increase the rate of fire, while the arrangement also distributed the weight. However, the machine would have been difficult to transport and coordinate, and there is no evidence that Leonardo’s exact design was built or used in battle.

It is not the same invention as his armored fighting vehicle. The multi-barrel weapon was a separate artillery concept, while the fighting vehicle used armor and internal propulsion mechanisms.