Codex Leicester
The Codex Leicester (also briefly known as the Codex Hammer) is a collection of scientific writings by Leonardo da Vinci. The codex is named after Thomas Coke, Earl of Leicester, who purchased it in 1717. The codex provides an insight into the inquiring mind of the definitive 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. When the manuscript was last sold—to Bill Gates at Christie's auction house on 11 November 1994 in New York for ()—it was the most expensive manuscript ever sold. Manuscript The leather-bound notebook comprises 36 sheets, 29 × 22 cm. The manuscript is not a single linear script but a mixture of Leonardo's observations and theories on astronomy and the properties of water, rocks, fossils, air, and celestial light. The topics addressed include: An explanation of why fossils of sea creatures can be found on mountains. Hundreds of years before plate tectonics became accepted scientific theory, Leonardo believed that mountains had previously formed sea beds, which were gradually lifted until they formed mountains. The movement of water. This is the main topic of the Codex Leicester. Among other things, Leonardo wrote about the flow of water in rivers and how it is affected by different obstacles put in its way. He made recommendations about bridge construction and erosion from his observations. The luminosity of the Moon. Leonardo speculated that the Moon's surface is covered by water, reflecting the Sun's light. In this model, waves on the water's surface cause the light to be reflected in many directions, explaining why the Moon is not as bright as the Sun. Leonardo explained that the pale glow on the dark portion of the crescent Moon is caused by sunlight reflected from the Earth. Thus, he described the phenomenon of planetshine one hundred years before the German astronomer Johannes Kepler proved it. The codex consists of 18 sheets of paper, each folded in half and written on both sides, forming the complete 72-page document. At one time the sheets were bound together, but they are now displayed separately. It was handwritten in Italian by Leonardo, using his characteristic mirror writing, and supported by copious drawings and diagrams. History Historical owners Guglielmo della Porta, Michelangelo's student (?) Giuseppe Ghezzi (until 1719) Thomas Coke, 1st Earl of Leicester (1719–1759) Leicester estate (1759–1980) Codex Hammer The codex was purchased at auction from the Leicester estate in 1980 by the wealthy industrialist and art collector Armand Hammer, for $5.1 million ($ in ); he later renamed the notebook the Codex Hammer. Hammer commissioned Leonardo da Vinci scholar Carlo Pedretti to compile the loose pages of the codex back into its original form. Over the next seven years, Pedretti translated each page to English, completing the project in 1987. Bill Gates The codex was sold to Bill Gates by Christie's auction house on 11 November 1994 in New York for . Until 2021, the codex remained the most