940

That the flow of rivers proves the slope of the land.

PROVES HOW THE EARTH IS NOT GLOBULAR AND NOT BEING GLOBULAR CANNOT HAVE A COMMON CENTRE.

We see the Nile come from Southern regions and traverse various provinces, running towards the North for a distance of 3000 miles and flow into the Mediterranean by the shores of Egypt; and if we will give to this a fall of ten braccia a mile, as is usually allowed to the course of rivers in general, we shall find that the Nile must have its mouth ten miles lower than its source. Again, we see the Rhine, the Rhone and the Danube starting from the German parts, almost the centre of Europe, and having a course one to the East, the other to the North, and the last to Southern seas. And if you consider all this you will see that the plains of Europe in their aggregate are much higher than the high peaks of the maritime mountains; think then how much their tops must be above the sea shores.

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

Notebooks of Leonoardo da Vinci
XVI: Physical Geography.
. . .
920,
921,
922,
923,
924,
925,
926,
927,
928
General introduction.
929
The arrangement of Book I.
930
Definitions.
931,
932
Of the surface of the water in relation to the globe.
933,
934,
935,
936
Of the proportion of the mass of water to that of the earth.
937,
938
The theory of Plato.
939
That the flow of rivers proves the slope of the land.
940
Theory of the elevation of water within the mountains.
941
The relative height of the surface of the sea to that of the land.
942,
943,
944,
945
Refutation of Pliny’s theory as to the saltness of the sea.
946,
947
The characteristics of sea water.
948,
949
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
. . .