What weapon did Leonardo da Vinci design with a bow nearly 24 meters wide?

Leonardo da Vinci designed a giant crossbow with a bow nearly 24 meters wide.

Leonardo recorded the design around 1488–1489, probably while seeking military commissions from Ludovico Sforza in Milan. The enormous bow was intended to launch large stones or bombs, rather than ordinary arrows.

The design used a broad wooden frame and a winch mechanism to draw the bowstring. Leonardo’s notes emphasize intimidation and destructive power, although there is no reliable evidence that the giant crossbow was ever built or successfully tested.

It is often confused with a ballista, an ancient torsion-powered missile weapon. Leonardo’s design is more accurately described as a giant crossbow because it uses a flexing bow and a drawn string.