Research Questions on the Bombard and Its Powder
A list of problems on cannon form, breech and barrel, and the impetus of ignited powder
This page is a list of research questions on artillery, written in Leonardo's mirror-hand with no diagram. He asks how a bombard would behave if its barrel were bent, if the breech joined the barrel at various angles, if several breeches fed one barrel, or several barrels one breech, and what difference the shape of the bore (long, short, round, square) makes with the same charge of powder. The final questions turn to the physics of the charge: where ignited powder makes the greatest impetus, how to measure how much powder fills a square braccio, and how compressed air behaves like the barber's rose-water vessel.
On this page
How barrel, breech and bore shape change the bombard
Leonardo lists variations to test: a bombard whose barrel is bent, a breech joined to the barrel at differing angles, several breeches set into one barrel, and several barrels issuing from one breech. He also asks what difference results, with the same weight of powder, from a bore that is long, short, round, or square.
The impetus of ignited powder and compressed air
He asks where ignited powder makes the greater impetus inside the bombard, and how to measure what amount of powder fills a square braccio. He closes with an analogy: if air compresses upon itself, as the barber's rose-water vessel shows, and doubles in density, the fire is reduced to a quarter by the force of a place where it cannot expand.