Things carried by water, channel bends and bed erosion
Floating bodies in air and water, pipes that draw or push, and where currents wear the bed
This page gathers observations on moving water. An object carried by a current follows the air when most of its bulk rides above the surface and the water when most is submerged; Leonardo resolves to make a whole book on where a channel's bend runs fastest, at bottom, middle or top. A faint sketch of floating objects is lettered c a b e f d, and further notes compare a pipe that draws water up, which is less worn, with one that pushes it, and observe that the swifter and more constricted the flow, the more it wears away the bed.
On this page
What follows the air and what follows the water
Of things carried by a current, that which has more of its bulk in the air obeys the motion of the air more than that of the water; and conversely, that which has more of its bulk in the water obeys the current of the water more than that of the air.
Speed in the bends of a channel (c a b e f d)
Leonardo notes to observe, in the bends of channels, whether the water runs faster below, in the middle or above, and resolves to make a book of it. The accompanying sketch of floating objects carries the letters c a b e f d.
A pipe that draws water up versus one that pushes it
The pipe from which water is drawn upward suffers less damage than the pipe from which water is pushed, because in the first the mover stands above and in the second the mover stands below.
Faster, narrower flow wears the bed more
Where the water is faster it consumes the bed it rubs against more; where the water is more constricted it becomes faster, and by its passage wears the bed still more.