970

On the way in which the sources of rivers are fed.

OF THE ORIGIN OF RIVERS.

The body of the earth, like the bodies of animals, is intersected with ramifications of waters which are all in connection and are constituted to give nutriment and life to the earth and to its creatures. These come from the depth of the sea and, after many revolutions, have to return to it by the rivers created by the bursting of these springs; and if you chose to say that the rains of the winter or the melting of the snows in summer were the cause of the birth of rivers, I could mention the rivers which originate in the torrid countries of Africa, where it never rains—and still less snows—because the intense heat always melts into air all the clouds which are borne thither by the winds. And if you chose to say that such rivers, as increase in July and August, come from the snows which melt in May and June from the sun’s approach to the snows on the mountains of Scythia [Footnote 9: Scythia means here, as in Ancient Geography, the whole of the Northern part of Asia as far as India.], and that such meltings come down into certain valleys and form lakes, into which they enter by springs and subterranean caves to issue forth again at the sources of the Nile, this is false; because Scythia is lower than the sources of the Nile, and, besides, Scythia is only 400 miles from the Black sea and the sources of the Nile are 3000 miles distant from the sea of Egypt into which its waters flow.

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

Notebooks of Leonoardo da Vinci
XVI: Physical Geography.
. . .
On the formation of Gulfs.
950,
951
On the encroachments of the sea on the land and vice versa.
952,
953,
954
The ebb and flow of the tide.
955,
956,
957,
958,
959,
960
Theory of the circulation of the waters.
961,
962
Observations in support of the hypothesis.
963,
964,
965,
966,
967,
968,
969
On the way in which the sources of rivers are fed.
970
The tide in estuaries.
971
confluence.
972,
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
. . .