Water against an obstacle and the rise of falling water
Mid-depth wrinkles, surface percussion, and why water a n c falls more steeply than b d
Four notes continue Leonardo's study of moving water. In moderately fast water the mid-depth layer shows only minute wrinkles, and the surface water differs in nature because it receives the percussion of both incident and reflected flow, which fall on it like a heavy body and penetrate below. Two further notes treat falling water that rises again into a half-column wave, and ask why the water along a n c falls more directly than that along b d. The right margin shows water bursting against a rounded obstacle and, below, a cascade falling into a pool.
On this page
Minute wrinkles in mid-flowing water
In water of middling velocity, the mid-depth water shows only minute wrinkles rather than true waves.
Surface water struck like a heavy body
The water lying between the mid-surface and the bed differs in nature from the surface water, because the surface receives the percussion of both incident and reflected flow. Being at the boundary with air, these fall upon the water below and, like a heavy thing, penetrate into it.
Falling water rises into a half-column
Falling water first descends, then rises again, lifting its wavy half-column higher than the opposing semicolumnar wave, which makes the fall more oblique.
Why water a n c falls straighter than b d
With the fall labelled a, b n and c d, Leonardo asks why the water a n c falls along a more direct line than the water b d.