A Program of Questions on Water and Waterwheels
Eddies, surface impressions, the ounce of water, and matching a fall to a wheel
A dense list of research questions in mirror script, with only a faint red-chalk sketch of a waterfall noted in the right margin. Leonardo asks why eddies are hollowed at the centre of their revolution, why impressions on the water's surface persist as they are carried along, and why such impressions pass through one another without changing their first figure. He then sets out the 'rule of the ounce of water' and three reciprocal problems relating a wheel's resistance to the thickness, length, obliquity, and lowness of the waterfall that drives it.
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Questions on eddies and surface impressions
Why are eddies hollowed in the middle of their revolution? Why do impressions on the water's surface persist while carried by the current, and why do the motions of these impressions penetrate one another without changing their first figure? A 'rule of the ounce of water' is also proposed, fixing width, depth, and velocity for a given space and time.
Relating a wheel's resistance to its waterfall
Three reciprocal problems: given a wheel's resistance and the obliquity and lowness of the fall, find the required thickness of water; given thickness, length, and obliquity, find the wheel's matching power; and given the resistance, obliquity, and thickness, find the length of the fall.