What firearm concept did Leonardo da Vinci sketch with three parallel barrels?

Leonardo da Vinci sketched a triple-barrel cannon with three parallel gun barrels.

The design belongs to a group of military-engineering studies in which Leonardo sought to improve the speed and effectiveness of artillery. Multiple barrels could allow one set of weapons to fire several shots before the crew had to reload every barrel. The arrangement also helped present a broad line of fire, although it did not solve the major limitations of early gunpowder weapons.

Leonardo’s drawing is often connected with the organ gun, a type of volley gun whose many barrels were arranged in rows. “Triple-barrel cannon” is a precise description of the particular concept, while “organ gun” refers more broadly to multi-barrel firearms.

The sketch was a design study, not evidence that Leonardo invented the modern machine gun. Early artillery remained slow, inaccurate, and difficult to operate. His military notebooks contain many proposals, but only some were ever built or tested.