Falling Water, a Balance Machine, Saws, and Prophecies
Water striking rock and waves on sand, a statics device, twin sawing machines, and a set of prophecies
Two mounted sheets (105b and 105a verso). The first is dominated by a large frame with a hanging counterweight and a geared axle, a study of balance, gravity and the resistance of the support (linked by the scholarly tags to Jordanus Nemorarius' statics). The second studies falling water: a cascade m n strikes a rock at b, rebounds to c and rises whirling at q, and further notes compare wind rippling sand to the making of water waves and describe how a wave strikes the bed. The same sheet carries a pair of two-saw cutting machines and, in an upside-down corner, a group of Leonardo's prophecies.
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Every figure created by motion is maintained by motion
An aphorism accompanying the mechanical and water studies: every figure created by motion is maintained by motion. It frames the sheet's balance frame with its counterweight and geared axle, tagged to the statics of the support and its resistance.
A cascade striking a rock and rebounding
The water m n descends to b and strikes beneath the rock b, rebounds to c and rises whirling at q; matter struck at equal angles rebounds beneath the same line q b. Terrestrial matter carried in the whirl does not rise higher than the line of the incident water, because it is struck by that motion together with the water that moves it.
Wind rippling sand compared with water waves
When the wind blows it smooths the sand and creates its waves; note how much more slowly the sand moves than the wind, and that the water does the same. He urges study of the differences between water and sand, and of how a wave thrusts toward the bed more where it is less oblique.
A machine of two saws (a b)
A drawing of a pair of saws lettered a b a b, the two saws. This will saw with two saws, that is, by four men; but the teeth will be set the opposite way.
A group of prophecies
In an upside-down corner, a set of Leonardo's prophecies: of a wretch flattered and robbed by his flatterers; of the striking of the sphere of the sun; of money and gold, of one who comes from the caverns to make all peoples toil; of the fear of poverty; and of counsel, whereby he who is most necessary is unrecognized and, once known, the more despised.