Leonardo da Vinci proposed an organ gun, a multi-barrel cannon intended to fire several shots in sequence.
The design arranged many small cannon barrels on a frame, giving the weapon an appearance similar to the pipes of a musical organ. Leonardo’s notes and drawings explored how the barrels could be loaded and aimed together. A broad volley could increase the rate of fire compared with a single muzzle-loading cannon.
The term “organ gun” is used for several historical multi-barrel weapons, not only Leonardo’s proposal. Leonardo’s version should therefore be understood as one design in a wider family of volley guns. It was not a modern machine gun: each barrel still required separate loading and ignition.
Renaissance armies experimented with multi-barrel artillery because reloading was slow and dangerous. Leonardo’s design addressed that problem mechanically, but there is no reliable evidence that his particular organ gun became an operational weapon.