The polybolos was a repeating ballista invented by Dionysius of Alexandria used in antiquity, capable of firing multiple rounds without reloading like a modern machine gun. A Ballista The ballista (Latin, from Greek ballistēs, from ballein to throw, plural ballistae) is a powerful weapon resembling a giant crossbow, to eject heavy darts singly or in groups. ... Dionysius served as Patriarch of Alexandria (head of the church that became the Coptic Church and the Orthodox Church of Alexandria) between 248 and 264. ... A machine gun is a fully-automatic firearm that is capable of firing bullets in rapid succession. ...

It had a wooden magazine over the mensa (The cradle that holds the bolt prior to firing) capable of holding several dozen bolts. The mechanism is unique in that it is driven by a flat-link chain connected to a windlass, an invention often attributed to Leonardo da Vinci. When loading a new bolt, the windlass is rotated counter-clockwise with the trigger claw raised, this drives the mensa forward towards the bow string, where a metal lug pushes the trigger under the trigger claw, which is closed over the string. Once the string is locked into the trigger mechanism, the windlass is then rotated clockwise, drawing the mensa back, drawing the bow string with it. A round wooden pole in the bottom of the magazine is rotated down toward the mensa as it is drawn to the back of the polybolos, dropping a single bolt into the tray, ready to be fired. As the mensa is pulled further back, it meets another lug like the one that locked the string into position, this one pushes the trigger and automatically fires the polybolos, and the process is repeated. Hence, the repeating ballista, or polybolos. Leonardo da Vinci (Born April 15, 1452 in Vinci, Italy, and died in May 2, 1519 in Cloux, France) was an Italian Renaissance architect, musician, anatomist, inventor, engineer, sculptor, geometer, and painter. ... A Ballista The ballista (Latin, from Greek ballistēs, from ballein to throw, plural ballistae) is a powerful weapon resembling a giant crossbow, to eject heavy darts singly or in groups. ...