993

Other problems.

You now have to prove that the shells cannot have originated if not in salt water, almost all being of that sort; and that the shells in Lombardy are at four levels, and thus it is everywhere, having been made at various times. And they all occur in valleys that open towards the seas.

Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.

Notebooks of Leonoardo da Vinci
XVI: Physical Geography.
. . .
973,
974
Whirlpools.
975
On the alterations in the channels of rivers.
976
The origin of the sand in rivers.
977,
978
The formation of mountains.
979,
980,
981,
982,
983
The authorities for the study of the structure of the earth.
984,
985
Doubts about the deluge.
986
That marine shells could not go up the mountains.
987
The marine shells were not produced away from the sea.
988
Further researches.
989,
990,
991
Other problems.
992,
993,
994
Constituents of the atmosphere.
995
On the motion of air.
996,
997,
998,
999
The globe an organism.
1000