Falling water and rising bodies on a moving incline
A research programme on scoured beds, with a mechanics proof and a spinning-bucket test.
A page of Notebook F given mainly to the science of falling water, with one point of mechanics. The opening note lays out a research programme for studying the concavities that falling water scours in beds of uniform and of varied material, the impediments to its descent and to its reflected motion, and how it redistributes sediment across a pool. A central diagram argues that a moving body struck by a moving inclined surface is carried higher than its own impetus would have taken it. A marginal sketch proposes testing spinning water in an iron-lined bucket.
On this page
Programme for studying how falling water scours a bed
Leonardo sets out an order of study: first the simple concavities made by simple falls of water on a uniform bottom, then on varied material, then the impediments in the descent, in the place struck, and in the reflected motion. He then wants to describe where the water takes its course along the lips of the pool, what materials are raised or left on the bottom, and what speed or slowness it has at different heights and widths from surface to bed.
A moving incline drives a body higher than its own impetus
When a moving body carried by impetus rises against an oblique surface, and that oblique surface moves against it with its own impetus without descending, the body rises higher than it ever would of itself. If the line a b were the rise of body b, ending its impetus at height r, then when the obliquity S c meets it with impetus along line c n S t, the body that was to stop at r instead rises to the line n c.
A bucket experiment for spinning water
A marginal instruction directs the reader to make this trial in a bucket fitted with an iron plate, and to have a small bucket made for it. The adjoining sketch shows a basin of water set spinning.