This extraordinary drawing of a very destructive weapon of war demonstrates Leonardo's artistic and technical abilities. It was a presentation piece drawn for a potential patron in the hope of attracting ongoing financial support. In the drawing, Leonardo detailed the parabolic path the shells followed after they were fired and how they exploded as they hit the ground.
The heavy cannons were mounted on strong wooden platforms. The angle of fire could be regulated by a wheel moved by a worm screw that was in turn moved by a jack (another invention of Leonardo).