Codex Leicester
Leonardo's Water Studies — The World's Most Expensive Manuscript
As from the said pool of blood proceed the veins which spread their branches through the human body, in just the same manner the ocean fills the body of the earth with an infinite number of veins of water.
— Leonardo da Vinci, Codex Leicester
Overview
The Codex Leicester is a 36-folio manuscript that has changed hands dramatically in recent decades. In 1980, it was purchased at auction by Armand Hammer from the estate of Lord Leicester; in 1994, it was acquired by Bill Gates at the Hammer estate auction for $30.8 million — making it the most expensive manuscript ever sold.
The analysis of the movement of water is the central theme, together with studies of geology (fossils, the circulation of water, and natural disasters) and astronomy. Leonardo's observations on the nature of water remain among the most extensive and insightful pre-modern studies of fluid dynamics.
The Nature of Water
Leonardo's water studies in this codex are extraordinary in their breadth and precision. He writes about waves, currents, erosion, the flow of rivers, deluges, the movement of water through channels, and the relationship between water and the earth's geological structure. He drew an analogy between the circulation of water in the earth and the circulation of blood in the human body — centuries before William Harvey formally described blood circulation.
Key Topics
- The movement and nature of water — waves, currents, vortices
- Geology — fossils, rock strata, the age of the earth
- Astronomy — the nature of moonlight (earthshine)
- The water cycle and underground springs
- Deluges and natural disasters
- Canal engineering and hydraulics
Selected Passages — On Water
The wave is the recoil of the stroke, and it will be greater or less in proportion as the stroke itself is greater or less. A wave is never found alone, but is mingled with as many other waves as there are uneven places in the object where the said wave is produced. At one and the same time there will be moving over the greatest wave of a sea innumerable other waves proceeding in different directions.
If you throw a stone into a sea with various shores, all the waves which strike against these shores are thrown back toward where the stone has struck, and on meeting others advancing they never interrupt each other's course. Waves of equal volume, velocity and power, when they encounter each other in opposing motion, recoil at right angles, the one from the stroke of the other.
The deluges of rivers are created when the mouths of the valleys cannot afford egress to the waters that they receive from these valleys as rapidly as the valleys receive them. The progress of the water is swifter when it falls at a greater angle.