Da Vinci notebook sells for over $5M

https://www.history.com/this-day-in-history/da-vinci-notebook-sells-for-over-5-million?cmpid=email-hist-tdih-2022- [login to see] 2&om_rid=
On December 12, 1980, American oil tycoon Armand Hammer pays $5,126,000 at auction for a notebook containing writings by the legendary artist Leonardo da Vinci.

The manuscript, written around 1508, was one of some 30 similar books da Vinci produced during his lifetime on a variety of subjects. It contained 72 loose pages featuring some 300 notes and detailed drawings, all relating to the common theme of water and how it moved. Experts have said that da Vinci drew on it to paint the background of his masterwork, the Mona Lisa. The text, written in brown ink and chalk, read from right to left, an example of da Vinci’s favored mirror-writing technique. The painter Giuseppi Ghezzi discovered the notebook in 1690 in a chest of papers belonging to Guglielmo della Porto, a 16th-century Milanese sculptor who had studied Leonardo’s work. In 1717, Thomas Coke, the first earl of Leicester, bought the manuscript and installed it among his impressive collection of art at his family estate in England.