Whirlpools and How River Water Strikes Different Beds
Why water striking water makes circular eddies instead of leaping straight
The page pairs a spiralling ink drawing of a whirlpool at its center with two linked notes. The first asks what difference water makes when it strikes a shore, a bank, or another body of water, and how a river behaves debouching over different beds — stone, earth, tufa, clay, gravel, mud, dead water, or a crosswise current. A second note headed 'Of the eddies' asks why the percussion of water within water produces circular motions and eddies rather than leaping straight.
On this page
Water striking shores, banks, and varied beds
Leonardo distinguishes the effects of water striking a shore, a bank, or another water, and of passing through dead water or a crosswise current. He further asks what difference arises when a river debouches over stone, earth, tufa, clay, gravel, mud, dead water, or a crossing current, whether obliquely, head-on, or along the same line but slower, faster, flatter, or more oblique.
Why percussion of water makes circular eddies
Under the heading 'Of the eddies,' the note asks why the percussion of water within water makes lines of circular motions and eddies, and does not leap straight as other struck water does.
Spiral drawing of a whirlpool
At the center of the page a single pen study renders a whirlpool as a tight spiral of curved strokes converging on a dark core, with trailing filaments spreading outward. It illustrates the circular eddy motion discussed in the text.