Gravity, force, percussion; water poured between two pipes
Motion as parent and child of the powers; the discharge of pipes governed by water height
A philosophical note at the top argues that gravity, force and percussion are at once the mothers, daughters and sisters of one another and of motion, since none of these powers can exist or be shown without motion. Below, a pen diagram of two connected pipes m and n accompanies the claim that a wider pipe m pours the same quantity of water as the narrower n when the water in n stands twice as high. The text generalises that, for pipes of equal width, the water discharged in equal time is proportional to the height of water standing above each.
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Gravity, force and percussion as kin of motion
Gravity, force and percussion are said to be reciprocally mother and daughters of one another, and all together sisters, because they are generated by motion. They are likewise both begetters and daughters of that same motion, since without them motion cannot be created among us, and without motion these powers cannot be demonstrated.
Discharge of a wide and a narrow pipe (m, n)
The pipe m, being twice as wide as the pipe n, will for the moment pour an equal quantity of water to n, because in n the water stands twice as high as in m. Among pipes of equal width, the quantities poured out in equal time hold the same proportion to one another as the heights of the waters resting above them.