Why Boiling Upwellings Are Intermittent
Faster surface water and slower bottom water contend in balance
A short fragment on water beating against its banks and levees gives way to a study headed 'Water vortex.' Leonardo asks why the boilings are not continuous although the falls that feed them are continuous, and answers that the water running above is faster than that below; when the lower water plunges into a hollow it rises with nearly equal impetus, sometimes overcoming the upper flow and sometimes overcome by it, so the two remain in balance. Small labelled sketches in the right margin (further untranscribed annotations) accompany the notes.
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Why the boilings are not continuous
Although the falls are continuous, the boilings are not, because the descending upper water is faster than the water running below. When the lower water plunges into a hollow it rises with almost the same impetus toward the surface, at times passing the upper flow and at times being overcome by it, so the two stay in balance.
The current beating against its banks
A continuing fragment refers to the water that beats against its banks and levees, tying the vortex discussion to the flow's confinement by its channel.
Small labelled sketches in the right margin
The right margin bears four small ink sketches, each set beside a short caption, arranged in horizontal registers. These captions are not transcribed in the bundle and are noted here only as present.