OF THE EARTH.
The great elevations of the peaks of the mountains above the sphere of the water may have resulted from this that: a very large portion of the earth which was filled with water that is to say the vast cavern inside the earth may have fallen in a vast part of its vault towards the centre of the earth, being pierced by means of the course of the springs which continually wear away the place where they pass.
Sinking in of countries like the Dead Sea in Syria, that is Sodom and Gomorrah.
It is of necessity that there should be more water than land, and the visible portion of the sea does not show this; so that there must be a great deal of water inside the earth, besides that which rises into the lower air and which flows through rivers and springs.
[Footnote: The small sketch below on the left, is placed in the original close to the text referring to the Dead Sea.]
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.