The Nile's source and the great rivers of Asia
Mountains, river courses and a reckoning of water descending 3000 miles
A mirror-written geographical page in which Leonardo argues that the highest mountains are those upon which, snowing, the origin of the Nile falls from the clouds, then catalogues the great mountains and rivers of Asia. He traces the Oxus running from the mountains between Bactria and India, the Indus with its many tributaries reaching the Indian sea by seven mouths, and the Ganges running south and southeast. Down the left side runs a column of arithmetic computing the time for water to descend three thousand miles at a mile per hour. A faint linear mechanical drawing crosses the top of the sheet, not covered by the transcription.
On this page
The highest mountains and the origin of the Nile
Leonardo concludes, in several reworked phrasings, that those mountains are of greatest height above which, snowing, the origin of the Nile falls from the clouds. The passage ties the height of mountains to the point at which snow feeds the river's source.
The Oxus and the Indus and their tributaries
From the joined mountains of Caucasus, Comedorum and Paropamisus, born between Bactria and India, the Oxus runs 500 miles north and as many west into the Hyrcanian sea, joined by many great rivers. Opposite, the Indus runs 600 miles south, gathers its tributaries, turns 800 miles west, elbows against the Arbeti mountains and reaches the Indian sea by seven branches.
The course of the Ganges
From the aspect of the same mountain rises the great Ganges, which runs 500 miles south and 1000 southeast, accompanied by the rivers Sarabus, Diamuna, Esoas, Escilo and Dranunda. It pours into the Indian sea by many mouths.
Water descending 3000 miles at a mile an hour
A note reckons the water that will descend three thousand miles descending one mile per hour, opening a hypothetical of what would happen if it moved with fury. Beside it a column of arithmetical workings resolves into hours, and into 155 months and 7 days.