Percussion of heavy bodies, a wheel system and aphorisms
Notes on rebounding heavy bodies, mechanical sketches, calculations and two witty sayings
A mixed working sheet combining mechanical sketches, calculations and jotted sayings. In a passage beside a drawing retraced by the later owner Pompeo Leoni, Leonardo reasons about the reflected percussion of heavy bodies, calling it at once the weakest and the strongest force in nature at equal movement, and describes when a rebounding body strikes hardest and when weakest. Small drawings include a building in perspective, a system of wheels and screw mechanisms, beside which he notes the reminder to soak a stone. In the corners he sets down two aphorisms about making images of God and about learning to die, while the sheet, turned on its side, carries columns of arithmetical calculation.
On this page
The reflected percussion of heavy bodies
Beside a drawing retraced by Leoni, Leonardo argues that the reflected (rebounding) percussion of heavy bodies is at once the weakest and the strongest found in nature at equal movement. The most powerful comes when, in rising, the body strikes a dense and resistant surface, so that its second natural motion rebounds and makes a second, maximal percussion. The weakest occurs when in a bounce it moves away from the centre of the world.
System of wheels and screw mechanisms
The sheet carries small mechanical sketches including a system of wheels, a screw or worm arrangement and framed devices, alongside a building drawn in perspective. Against the wheel system Leonardo writes a working reminder to put the stone in soak. The mechanisms sit among the physical notes on percussion.
Two aphorisms on images and on dying
In the lower right corner Leonardo jots: when he made the Lord God as a child they put him in prison, and if he makes him grown-up they will do worse. In the upper left he writes that when he thinks to learn to live, he shall instead learn to die. Both are personal, epigrammatic jottings set apart from the technical matter.
Columns of calculation with the sheet turned
Turned on its left side, the sheet carries stacked columns of figures set out for calculation, with multi-digit numbers arranged in rows and partial results bracketed. They read as working arithmetic rather than an account of money. The figures occupy a block separate from the mechanical and physical notes.