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 this remark, contains some notes on the construction of dams, harbours &c.]
953.
That the shores of the sea constantly acquire more soil towards the middle of the sea; that the rocks and promontories of the sea are constantly being ruined and worn away; that the Mediterranean seas will in time discover their bottom to the air, and all that will be left will be the channel of the greatest river that enters it; and this will run to the ocean and pour its waters into that with those of all the rivers that are its tributaries.
954.
How the river Po, in a short time might dry up the Adriatic sea in the same way as it has dried up a large part of Lombardy.
The ebb and flow of the tide (955-960).
955.