Fireproof bastion, ship-capsizing mast, and a leaning-beam problem
How to defend and storm a bastion, a mast to overturn enemy ships, and the weight a propped rod gives to its supports
The sheet mixes military engineering with a statics exercise. Leonardo advises daubing a bastion with mud and grass so it will not burn, then describes storming a bastion that closes a pass by rushing in with portable, hay-filled pointed bastion-pieces that soak up artillery fire and mass together to cover the embrasures. Small marginal sketches show two ships in combat and a mast device built to capsize enemy vessels, while a triangular diagram (points S, t, m, a, n, f, c, d) poses a numerical problem: how a 4-braccia rod weighing 8 pounds distributes its load onto point m and the two supports c and d.
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Fireproofing and storming a bastion that seals a pass
So the bastion is not burned, it is daubed with mud and grass instead of cloth-clippings so the earth does not split. To storm a bastion built to close a pass, make portable bastion-pieces carried in by a rush of men, filled with hay and pointed in front so artillery does no harm; joined together they cover all the embrasures, and once the bridges drop the enemy can be fought at advantage.
Mast for capsizing enemy ships
A small sketch shows two ships in combat, meant for making a vessel capsize. A separate drawing of a ship's mast, worked by two men, is labelled as a mast for overturning the other ships.
Load a propped 8-pound rod gives to point m and supports c, d
A rod 4 braccia long weighing 8 pounds leans so its overhang equals half its length; the question is how much weight it gives to point m and to the two supports c and d. Halving the base m n S and cutting off the matching length at the top S t leaves one braccio (2 pounds) resting on c d and 6 pounds on m. By the distances of c and d from the perpendicular at n, c carries 16 ounces and d carries 8.