A second edition, the title-page of which is shown left, was published in 1670 and it is the name that appears just above the large vignette that is key to the significance of that later, revised edition.
Pierre Fermat had owned a copy of the 1621 editio princeps. In it he wrote notes questioning Bachet’s statements and forming his own theorems to solve the mathematical problems which Diophantus had posed.
Fermat died in 1665 without any intention of having them published, but his son included his father’s annotations and commentary in this second printing. They form a first contribution to the theory of numbers and a step towards the invention of the differential calculus.
Most famous of the 48 observations made by Fermat is the first statement of his celebrated ‘Last Theorem’, which was not proven until 1995, when Andrew Wiles, a professor of mathematics at Princeton, completed a 130pp proof. Fermat had claimed he knew the proof but lacked the space in the margin to show it.
At a record £19,000, a copy in bowed and repaired but contemporary vellum binding was the most expensive of the books that made up the second portion of scientific books from the library of Giancarlo Beltrame, offered by Christie’s on November 30.
More on that sale in the next issue.
