Earth beneath water, rebound at equal angles, and the four elements
192v–189r: rare and dense elements and their natural motions
On folio 192v a memorandum 'Look in Florence for the Ramondina' is followed by the principle that a falling body rebounds between equal angles, and by an account of how earth lies beneath water and, where more mingled with it, grows lighter and more water-like. Marginal notes accompany lettered and numbered figures: one directs that water be let fall around the circle a b, another that the body of greater resistance descends more slowly. Folio 189r sets out a schematic treatise on the elements — rare (fire, air, water) and dense (earth) — their continuous and discontinuous quantities, and their natural motions of elevation and declination.
On this page
Memorandum: the Ramondina in Florence
A brief personal reminder to himself, 'Look in Florence for the Ramondina,' opens the folio before the natural-philosophical notes. It is the kind of practical jotting Leonardo interleaves with his physics.
Earth beneath the water
Earth lies under water as a heavier body, and the water does not press upon it; the part of the earth more mingled with water partakes more of it, grows lighter and more like water, and so lighter than earth mixed with less water. Adjacent to this a note directs that water be let fall around the circle a b.
Rebound and rate of descent
A falling thing that strikes between equal angles rebounds between equal angles, and the body with the greater resistance descends with the slower motion. The remarks pair reflection at impact with the retarding effect of resistance.
The elements: rare and dense, their quantities and motions
The elements have two qualities, rare (fire, air, water) and dense (earth); two quantities, continuous and discontinuous; and two natural motions, elevation and declination. Fire never shows gravity in earth as air and water do; no part of an element weighs within its own element; and the descent of water through air, or air rising through water, is never straight.