Volume, lightness, and the force of percussion in falling weights
Two squares meeting at a vertex illustrate percussion and yielding springs
Two propositions on weight and impact open the folio: a weight that grows larger in volume is shown to be lighter, and a weight that strikes with a part farther from the central line of its gravity delivers a smaller percussion as it descends. A diagram of a larger and a smaller square, one lower corner of the larger touching an upper corner of the smaller, accompanies a note that percussion is softened when the blow meets something yielding, such as a spring or a person landing on the tips of his toes.
On this page
Greater volume means a lighter weight; off-centre blows strike less
A weight that becomes larger in volume proves lighter, and a weight that strikes with a part farther from the central line of its gravity gives a smaller percussion in descent. The two rules pair the effect of bulk with the effect of where the blow lands relative to the centre of gravity.
Percussion softened by a yielding part, like a spring
Impact is lessened when it falls into a part that yields, as when jumping onto a spring, or when the striking body itself has a yielding part, like a spring, or like someone jumping onto the tips of his feet. The larger and smaller squares shown in contact stand for the striking and struck bodies.