The Da Vinci Notebooks
On the encroachments of the sea on the land and vice versa (952-954).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.
191:502 : The page of FRANCESCO DI GIORGIO'S Trattato, on which Leonardo has written this remark, contains some notes on the construction of dams, harbours &c