The most important and extensive collection of Alan Turing’s autograph material to come to auction, including over 40 pages of working notes and mathematics written by Turing have been sold at auction for nearly £400K
The collectionwith other papers from his key collaborator Donald Bayley, demonstrating their work on the portable voice-scrambler ‘Delilah’.
Turing learns the practicalities of electrical engineering from a young Donald Bayley and, in turn, Turing’s mathematical theorems and Bayley’s transcript of lectures given by Turing, demonstrate the maturity and extent of Turing’s knowledge of the mathematical side of circuit design which was so essential to the Delilah project and beyond.
The Delilah project was a joint project with the United States launched in 1943 with the aim of encrypting speech in transmission
The young Bayley, scarcely more than a university student, found himself working with an acknowledged mathematical genius on project ‘Delilah’ (so named by Turing’s lab-mate Robin Gandy after the infamous deceiver of men), the aim being to design a portable voice encryption system, ‘the first to be based on rigorous cryptographic principles’
Turing had already been working on Delilah at Hanslope Park, just five miles from Bletchley, for six months before Bayley joined him in March 1944.
The two men were to become close friends but as Bayley recalls, his first meeting with Turing was inauspicious: ‘…He was a bit slapdash; I was very well-organised… This chap had his shirt hanging out. There were resistors and capacitors, as fast as he’d soldered one on another would fall off. It was a spider’s nest of stuff – a complete mess. We made up a ‘breadboard’ sheet of plywood, you soldered between strips of metal, to make up the board. He hadn’t worked on it like that at all, soldered anyhow, and hoped they’d hold together. He was annoyed I mentioned his shirt hanging out. He took it for granted. He said I shouldn’t have mentioned it…
By the end of 1944, the equipment that sampled and enciphered the speech signal was finished.
Turing demonstrated the system to officials by encrypting and decrypting a taped speech by Winston Churchill. It was proved to work satisfactorily (‘…it did all that could be expected of it…’ Bayley later wrote to Jack Copeland), but the speech quality was poor. Germany fell in May 1945, not long after Delilah was finished and, too late to be of use in the war, it was not put into production.
