Leonardo da Vinci’s many-barrelled gun design is commonly called an organ gun.
The organ gun arranged multiple small cannon barrels side by side on a frame. The resemblance to the pipes of a musical organ gave the weapon its name. Leonardo proposed a version with several rows of barrels, allowing one group to be fired while another was being loaded.
The design aimed to improve sustained fire, a major problem for early gunpowder weapons. A single barrel had to be reloaded after every shot, but grouped barrels could provide repeated volleys. The arrangement also allowed the frame to be aimed across a broad area.
Leonardo’s organ gun should not be confused with a modern machine gun. It still relied on separately loaded gun barrels and black powder, so it could not deliver continuous automatic fire. His drawing shows inventive battlefield planning, but surviving evidence does not establish that Leonardo’s particular design was manufactured and used successfully.