Alan Turing’s unpublished Second World War papers relating to the ‘Delilah’ project. Stopped from export under the Waverley criteria by the Reviewing Committee on the Export of Works of Art.
Patricia McGuire, Archivist, writes: Though he only lived to 41, World War II cryptanalyst and mathematician Alan Turing made groundbreaking contributions to the early development of artificial intelligence, computer science and what is now known as epigenetics.
King’s College, where Turing was an undergraduate and then a Fellow, holds the largest known collection of material written by him and a considerable amount of material closely related to him. The Delilah Project papers were the most important and extensive collection of Turing’s autograph material to come to auction and we are delighted to be able to add them to our Turing collection.
Towards the end of the Second World War Turing pivoted from designing better decryption devices, to building a portable voice encoder for short-distance transmission. The United States had developed a transatlantic voice encoding protocol, but the size required for lossless transmission over long distance required a device that filled a room. Turing devised a system that, though it would work only over short distances, such as by telephone or short-wave radio, it was only the size of a typewriter. He moved a few miles up the road from Bletchley Park to a new facility established in 1938 (in anticipation of a possible war with Germany) where government communications engineering was to take place; it is now His Majesty’s Government Communications Centre at Hanslope Park and still supplying British intelligence with specialised hardware and software. Turing was given space to develop his ideas for a voice encoder and it became known as the Delilah Project.
Unfortunately Turing’s electric circuit-board skills were not as advanced as his mathematical understanding. Enter Donald Bayley, a recently graduated University of Birmingham electrical engineer. Together they built a working model of Turing’s design which successfully scrambled a recording of Churchill’s voice and then played it back, ‘noisy’ but comprehensible. The war ended soon after and only the one prototype was made.
During the development work Turing and Bayley kept a logbook of their experimental results. Bayley also kept notes at lectures Turing gave to interested Hanslope Park engineers about the mathematics behind the project, along with loose pages of diagrams, calculations, explanations, and other electronic and mathematical theorems and problems. The papers were kept in the Bayley family from his death in 2020 until the auction sale in November 2023. They will be added to the existing Turing collection, scanned and added to our Turing Digital Archive.
The collection comprises two bound notebooks and six separate gatherings of loose paper sheets. It comprises the papers of Alan Turing (1912-54) and Donald Bayley (1921-2020).
King’s College is delighted to have been chosen to be the custodian of these documents for the nation. We are enormously grateful for FNL’s own grant and for securing the wonderfully generous donation from XTX Markets. We are also grateful to the National Heritage Memorial Fund and other private donors for their support.
