On local motion and percussion; a diagram of rayed lozenges
The bombard gains power along its bore, the crossbow loses it at every degree
The lower text treats local motion: percussion is defined as the terminus of motion, or the 'bending' of motion, and Leonardo asks when a moving body is proportioned to the power of its mover. He distinguishes simple from composite motion and two kinds of mover, one gaining velocity and one losing it, citing the bombard, which gains power along its bore, against the crossbow, which loses power at every degree of motion. The upper two-thirds of the sheet is filled by a large figure: rows of red-washed lozenges from whose apices dense straight lines radiate up to a band of small circles and down to a chain of round nodes.
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Percussion as the terminus of motion
The right column defines percussion as the terminus of local motion, or the impediment to observing it. Leonardo proposes to call percussion the terminus, that is, the 'bending' of motion.
Bombard gains power, crossbow loses it
Asking when a moving body is proportioned to its mover, he distinguishes movers that increase velocity from those that decrease it, and simple from composite motion. The bombard gains power at every degree of its bore, whereas the crossbow loses power at every degree of motion.
Lattice of red lozenges with radiating lines
The upper two-thirds of the sheet is filled by rows of red-washed lozenges. From the apex of each, dense straight lines radiate upward to a band of small circles and downward to a chain of round nodes.
Bundles of straight rays between the rows
The straight lines fan out and cross between the top band and the lozenges in tight, ray-like bundles converging on single points. The figure reads as a study of lines projected from many sources onto common foci.