Enigma Code Breaker Turing Notebook on Sale at Bonhams New York

Alan Turing
Alan Turing became famous for building a machine that cracked the German military encrypted messaging system, Enigma, during World War II. Photographer: Spencer Platt/Getty Images

A notebook belonging to Alan Turing, the British mathematician responsible for breaking the German Enigma Code, goes on sale at Bonhams New York on Monday, with a value of at least $1 million, according to the auction house website.

The simple notebook, the only extensive Turing manuscript known to exist, contains 56 pages of his studies of logic kept during 1942-44, when he led a team of code breakers at Bletchley Park, U.K., according to Bonhams.

The story of Turing and the code breakers was made into the film “The Imitation Game.”

It forms part of Turing’s papers, which he left to fellow mathematician Robin Oliver Gandy a few months before committing suicide in 1954. When Gandy died in 1995, his executor sold it to the current owner, who is selling it at Bonhams.

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