The Power of Percussion: Hammers, Impact and Weight
Which hammer strikes harder, and how clay bodies deform under impact and load
This page treats the physics of percussion. Leonardo labels figures as 'agent' and 'patient' (disunited, neutral, united) and asks which of two hammers striking at equal descent gives the greater impact, and whether a hammer n striking a still m delivers more than when m advances to meet it halfway. In the long left column he states that percussion between bodies of equal material, weight and figure harms agent and patient alike: two falling clay balls flatten into equal 'crowns,' but a ball striking a large mass, or a larger body striking a smaller, deforms unequally and leaves a curved contact. He proposes experiments — pressing a heap of clay balls, then drying and examining which are spoiled, and stacking plates of clay under a central weight — to derive a general rule for how weight spreads and does harm. A column of small mechanical sketches runs down the right margin.
On this page
Which hammer strikes with the greater percussion
At equal descent, Leonardo asks which of two hammers gives the greater percussion. He also asks, the hammers being always of equal motion, whether hammer n striking a stationary m delivers more, or whether m advancing to meet it halfway does.
Agent and patient: how clay bodies deform on impact and under load
Percussion in bodies of equal material, weight and figure harms agent and patient alike: two clay balls flatten into equal crowns. But a ball on a great mass, or a larger body on a smaller, deforms unequally with a curved contact. He proposes pressing, drying and lifting a heap of equal clay balls, and stacking clay plates under a central weight, to find a general rule of how weight spreads and does harm.
Column of small mechanical sketches at the right margin
Down the right margin runs a column of small device sketches — striking and screw mechanisms, a hopper-like form and rods — accompanying the percussion figures labelled agent and patient. Further short captions beside these sketches are not included in the transcription.