Rebounding blows, crossbow arrows, and falling weights
Angles of the bounce; how coarse grains gather at the center of a sieve
This page multiplies questions on rebound, projectile force, and the fall of bodies. Leonardo asks how the angle of incidence governs a bounce, whether a single heavy arrow outranges several light ones of equal total weight, and how much faster a body falls over the second hundred braccia than the first. He records striking observations: dust on a struck board gathers into little heaps, and the coarse grains move to the center of a rotating sieve. A pair of sketches of a ball rebounding from a wall at different angles accompanies the text, which closes with the jouster who shifts his weight forward over the horse as he couches his lance.
On this page
The angle of a rebounding blow
Which blow is stronger that bounces straight back along the line of incidence against a resisting object? If the object rushes against the blow as fast as the blow against it, the blow is of doubled strength; and if the blow is great, the bounce is great.
Does one heavy arrow outrange four light ones?
If a crossbow shoots a four-ounce arrow 200 braccia, how far will it shoot four one-ounce arrows in a single shot? And of four arrows of 4, 3, 2, and 1 ounces shot together, which goes farthest, and by how much?
A ball thrown at a wall versus along it
The ball you throw straight at a wall returns and offends you little; the one thrown along the wall offends more the one who awaits its bounce. The blow is caused by motion, and is more powerful the swifter its cause.
Dust heaps and grains gathering in a sieve
Strike a flat board and the dust upon it draws together into little heaps. Move a sieve in a circle and the coarse parts of the grain gather to its center; dust stirred in a circle by the wind sends its coarser parts to the larger circle.
The jouster couching his lance
One who jousts, when he sets the lance in rest, shifts the center of his weight toward the front part of the horse. Metal struck at unequal angles flees beneath the blow and swells on the side of the obtuse angle.
