Eddies at a river confluence; impressions in flowing water
The persistence of impressions in water and the right- and left-hand eddies of two joining rivers
The page pairs a statement that any impression made in water persists longer the swifter the current with two water studies: eddies (retrosi) passing beneath an obstacle and the right- and left-hand eddies formed where two rivers meet. Leonardo labels the exchanged eddies a and b and resolves to record how floating objects reveal the varied revolutions of the water. Pen sketches at upper center and lower right show the swirling coils of these eddies. Fainter writing and offset show-through appear lower on the sheet and are not part of the transcription.
On this page
Persistence of impressions in moving water
Leonardo states that every impression made in water is maintained over a long stretch, and all the more so the faster the water moves. This ties the retention of a surface disturbance to the speed of the current.
Right- and left-hand eddies at a river confluence
The right- and left-hand eddies (retrosi) are produced by the rubbing together of two rivers that join, with eddies exchanged at points a and b. He resolves to write down what revolutions floating objects make, since they take various shapes in the various revolutions of the water.
Eddies passing beneath an obstacle
A pen figure shows water and its eddies passing beneath an obstacle, the coiling current drawn at the upper center of the sheet.