One thing Leonardo da Vinci may have understood better than any of his contemporaries was the psychological effects of weapons in warfare. Da Vinci knew that the fear weapons could instill in enemies was just as important (if not more so) than the damage they could actually inflict.
This was one of the main ideas behind many of da Vinci’s war inventions – among them, his giant crossbow. Designed for pure intimidation, da Vinci’s crossbow was to measure 42 braccia (or 27 yards) across. The device would have six wheels (three on each side) for mobility, and the bow itself would be made of thin wood for flexibility.