Author: Leonardo Da Vinci
Language: Italian, Backwards
History: "The Hammer Codex," also known as the Codex Leicester, is a collection of scientific writings by Leonardo Da Vinci. Most of the writings are on the subject of water. Of the 30 surviving Leonardo notebooks, the Hammer Codex is one of the most famous. This codex brought record sales, at the Christie's auction house in 1994, a staggering 30,802,500 USD. Bill Gates was the winning bidder.