Turing’s Secret Notebook Is Up for Auction

The notebooks offer a glimpse into the mind of a codebreaker

Bombe Machine
Turing's journal was kept while he helped build the Bombe Machine, a device used to encrypt Nazi codes. ALESSIA PIERDOMENICO/Reuters/Corbis

Alan Turing is known for being as enigmatic as the code he helped crack. But now some of the British codebreaker's own secrets could come out— a private notebook he kept in the 1940s is being sold at auction. Abby Ohlheiser reports for the Washington Post that an upcoming auction at Bonham’s could fetch millions for notebook—which sheds light on Turing’s inner life during the time in which he managed to break the Nazis’ vexing Enigma Code.

It turns out that the notebook’s history is just as mysterious as Turing’s. When Robin Gandy, a mathematician and friend of Turing’s who inherited his papers, came across the notebook, he took his own notes in the book, recording his dreams and ruminating on the meaning of his friend’s life and work.

“The book then became something else — simultaneously a priceless look into the mind of Turing’s work during a critical period of his career, and a deeply personal journal containing Gandy’s waking reflections on his own dreams,” says Ohlheiser, who notes that though Gandy donated the remainder of Turing’s work to King’s College, he held on to the journal.

Bonham’s is calling the notebook “almost certainly the only extensive autograph manuscript by Turing in existence” and estimates it will sell for at least seven figures. The auction, which will take place in April, will continue a long tradition of high-profile sales of the works of esteemed figures in science, math, and physics. In 2013, Christie’s sold a letter in which DNA discoverer Francis Crick explains the double helix to his young son for a cool $6 million.

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