Leonardo da Vinci sketched an organ gun with multiple parallel barrels.
The weapon arranged many small guns in a row or fan-shaped formation so that several projectiles could be fired in a volley. Its nickname comes from the visual resemblance between the grouped barrels and the pipes of a musical organ. Leonardo's drawings belong to his broader work on military engineering during the Renaissance.
An organ gun was not the same as a modern machine gun. It required loading and preparation between volleys, and the technology of the period limited reliability and rate of fire. The design aimed to increase the amount of shot delivered at once, making it potentially useful against tightly packed troops. Leonardo did not invent firearms, but he explored ways to organize them more effectively.