STUDIES ON THE MOTION OF WATER

Observe the motion of the surface original: "vello," literally "fleece" or "skin," used here to describe the top layer or film of the water. of the water, which behaves in the same way as hair, which has two motions: one depends on the weight of the hair-strand, the other on the direction of its curls. Thus, water has its swirling turnings original: "volte revertiginose," referring to vortical or eddying motion., of which one part depends on the impetus of the principal current, while the other depends on the incident and reflected motion.

note how

Note the motion of the surface of the water, which behaves in the same way as hair, which has two motions: one of which depends on the weight of the hair-strand, the other on the direction of its curls; thus the water has its swirling turnings, of which one part depends on the impetus of the principal current, the other depends on the incident and reflected motion. Leonardo is observing that water turbulence is governed by two forces: the gravity/momentum of the main flow and the reactive "bouncing" or swirling caused by obstacles or internal friction.

so great is the force of the water in its fall?

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