Of objects of various thicknesses placed transversally in a uniform current of water and turned with equal inclination toward one of the banks, that one will dam up more water which, by its second obliquity, leans more against the oncoming flow of the waters.

The air that restores the void left by the water poured out of its vessel enters through the mouth of that vessel and passes to the surface of the water by the shortest route.

Of objects of equal thickness placed in water at equal obliquity and set transversally across the course of the river, and inclined toward the bank of that river at various obliquities, the one that is more oblique will dam up more water against that current.

Of slopes of equal thickness placed at equal obliquity in the water and inclining toward one of the banks with equal obliquity, that one will dam up more water which is more oblique to the line of the river's course.

That part of the object which rises above the common course of the water will be more occupied by the rebound of the water that strikes it, the one whose obliquity is more similar to the obliquity of the said course of the water.

Of that columnar object which rises out of the water's course, the greater part will be occupied whose obliquity is more similar to that of the water in which it stands.

Of the object that rises above the water, the greater part will be occupied by the rebound of the water that strikes it, the one whose obliquity is more similar to the obliquity of the aforesaid course of the water.