Mangonel and Crossbow Ballistics; a Glass on a Spinning Hoop
The sling-cord mangonel throws faster, the bolt driven by the bow, and a glass that does not spill
Leonardo compares siege engines and the speed of their projectiles. He notes that a stone thrown by a mangonel whose arm ends in a sling-cord flies with much greater velocity than one thrown without, and that a crossbow bolt is both pushed by the cord and driven by the percussion of the released bow. On the left he records what we would call a centrifugal demonstration: a hoop spun around with a glass merely resting on it does not spill. The page is filled with pen diagrams of these devices, lettered n a - m f - g r.
On this page
Mangonel with a sling-cord arm
The mangonel is drawn with a flail for striking. Leonardo observes that a stone thrown by a mangonel whose arm ends in a cord used as a sling attains much greater velocity than one thrown without.
Crossbow and its bolt
A crossbow is sketched with its bolts. The bolt is both thrust by the cord and driven by the percussion made by the bow as it is held and released by the cord.
A glass that does not spill on a spinning hoop
On the left a circle is drawn with a glass upon it. Leonardo notes that a hoop turned round about, with a glass merely set on it, does not spill, a demonstration of what we call centrifugal force.