A Cistern with Equal Inlet and Outlet Vents
When inflow exceeds outflow until the pool level rises and the two balance
This mirror-written red-chalk page, headed by a small red diagram of a water structure at the upper right, examines a cistern (bottino) through which water enters and leaves. Leonardo supposes the outlet vents equal to the inlet vents but the inlet's fall longer than the outlet's. In that case the inflow exceeds the outflow until the water of the pool has risen, after which the entering and leaving flows become equal.
On this page
Equal vents but unequal falls of inlet and outlet
If a cistern's outlet vents equal its inlet vents, and the fall feeding the inlet is longer than the fall of the outlet, then more water enters than leaves. This continues until the water of the pool rises, and thereafter the two flows become equal.