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The Codex Leicester is a collection of scientific writings by Leonardo da Vinci.

It is also briefly known as the Codex Hammer.

The codex is named after Thomas Coke, Earl of Leicester, who purchased it in 1717.

It provides an insight into the mind of the Renaissance artist, scientist and thinker, as well as an exceptional illustration of the link between art and science and the creativity of the scientific process.

The manuscript was last sold to Bill Gates at Christie's auction house in 1994 in New York for $30,802,500.

Manuscript is a mixture of Leonardo's observations and theories on astronomy and the properties of water, rocks, fossils, air, and celestial light.