BY THE WATERS IN THE ABOVE MENTIONED PLACE.
All the lakes and all the gulfs of the sea and all inland seas are due to rivers which distribute their waters into them, and from impediments in their downfall into the Mediterranean —which divides Africa from Europe and Europe from Asia by means of the Nile and the Don which pour their waters into it. It is asked what impediment is great enough to stop the course of the waters which do not reach the ocean.
On the encroachments of the sea on the land and vice versa (952-954).
952.
OF WAVES.
A wave of the sea always breaks in front of its base, and that portion of the crest will then be lowest which before was highest.
[Footnote: The page of FRANCESCO DI GIORGIO'S Trattato, on which Leonardo has written