With the recent release of the film The Imitation Game, he's now becoming known to a whole new generation. It's only fitting, therefore, that a rare collection of his scientific notes is about to head to auction.

The handwritten notes are contained within 56 pages of a notebook, which has never been seen by the public. Judging by its content, it dates from 1942, at which time Turing was working on cracking the Enigma code at Bletchley Park north of London.

The book was part of a collection of papers that he left in his will to mathematician Robin Gandy, who was one of his close friends. Gandy proceeded to donate most of those papers to the Archive Center at King's College, Cambridge in 1977. He held onto the notebook, however, and used the blank pages in the middle to keep what is described as an "intensely personal" dream journal.

No doubt due to that personal content, the book remained amongst Gandy's possessions until his death in 1995 – hopefully he'd be OK with people reading it now.

The notebook is due to be auctioned at Bonhams Fine Books & Manuscripts in New York on April 13th and is expected to fetch at least seven figures, a portion of which will go to charity. According to Bonhams, "it is almost certainly the only extensive autograph manuscript by Turing in existence."