Bombard with a Flattened, Cheese-Shaped Stone Shot
Why a disc-shaped projectile cuts the air faster than a round ball
Leonardo proposes a bombard whose stone is flattened like a cheese, with a matching flattened bore, its tail deliberately off-centre so the shot spins in flight. He argues that at equal weight a flat disc outruns a round ball because the disc enters the air edge-on and meets less resistance. The page opens with two small sketches: a flattened disc seen face-on and the barrel of the bombard seen from the side with the disc lodged in its bore.
On this page
A flat, cheese-like stone in a matching flattened bore
Leonardo pictures a bombard whose stone is squashed flat like a cheese, with the gun's cavity shaped to fit it. He sets the centre of the tail off from the centre of the stone so that it will go spinning through the air, which he claims makes it very fast.
Disc versus round ball: air resistance and the cutting edge
Take a ball of 6 ounces and a disc of the same weight without angles at its edges, and you will see how much further one flies from its launcher than the other. A round shot strikes more air and finds more resistance, whereas the flattened one enters the air edge-on, pierces it sooner, and moves through it faster.