On the 9th March 1953, Alan Turing made his last-ever visit to Sherborne School when he was invited to give a paper to the School’s science society, The Alchemists. The meeting was held at The Green, then run by housemaster L.S. May.
Laurence Seymour May (1914-1997), Senior science master at Sherborne School, had founded The Alchemists in March 1943 ‘to further an interest in science, by holding lectures, films and discussions on topics of general scientific interest and to arrange visits to factories and other industries.’ Members of the society were generally from the Science Sixth and three or four meetings were held each term.
Alan Turing’s prestigious election in 1951 to the Fellowship of the Royal Society (FRS) undoubtedly led to Mr May inviting him to address The Alchemists on 9th March 1953. At the meeting Alan Turing read a paper on the subject of the ‘Electronic Brain’, a report of which was later published in The Shirburnian (Lent term 1953):
THE ALCHEMISTS
The Society met for the first time this term on Monday, March 9th [1953], at the Green when a paper on the Electronic Brain was read by Mr Turing. Several members of the audience had foreseen the possibility that they might not understand a word of what was said, but they could not have been more mistaken. Mr Turing made a very clear analogy between a stupid clerk, with his mechanical calculating device paper to write his workings on and his instructions, and the Electronic Brain which combined all these in one. All that was necessary was to put the instructions into a tape machine and the mass of wires, valves, resistors, condensers and chokes did the rest, the answer appearing on another tape. The Brain was, however, liable to make mistakes and subtle checking devices were included to detect them. As yet it cannot do anything of its own accord, nor is it able to rectify its own mistakes. Slides were shown of the general layout of the machine and also of some previous ones made in the last century. The questions at the end of the meeting showed how much the Society had grasped the principles underlying the workings of the Electronic Brain.
Hon. Sec. Roger Secker-Walker (Harper 1948-53) [later Professor of Medicine at the University of Vermont in Burlington]
Although the actual text of Alan Turing’s talk is not recorded, it is probable that he read to the boys a version of a paper he had written in 1951 entitled ‘Digital Computers applied to Games’, which was later published in B.V. Bowden (ed.), Faster than Thought: A Symposium on Digital Computing Machines (London: Pitman & Sons, 1953).
The concept behind Faster than Thought arose from the 1951 Festival of Britain where Dr Bowden displayed at South Kensington a simple demonstration computer made by Ferranti Ltd. The computer was named NIMROD and played a game called Nim (similar to noughts and crosses). The visiting public were encouraged to try their luck against NIMROD and, according to Alan Turing’s biographer Andrew Hodges, Alan knew the rules by which NIMROD worked and managed to beat the computer which dutifully flashed up in lights ‘MACHINE LOSES’. Much to Alan’s delight the machine then demonstrated very human behaviour by going into a sulk and flashing up ‘MACHINES WINS’! In Faster than Thought Dr Bowden attempted to answer some of the many questions that had been asked at the demonstration by bringing together essays written by twenty-four well-known experts in their fields, including Alan Turing.
Dr Bowden wrote in the preface to Faster than Thought that ‘During the last year or two most people have heard of the remarkable devices often called “Electronic Brains”; every schoolboy knows that there are in existence some very complicated machines which are capable of astounding feats of arithmetic. This book contains descriptions of several of these monsters, an explanation of the way they work, and several essays describing how they can be used. We shall refer to them as “electronic digital computers,” a name which describes them more accurately and is less contentious than the one which popular usage has favoured.’
Alan Turing wrote ‘Digital Computers applied to Games’ in 1951 while working as Assistant Director of the Computing Machine Laboratory at the University of Manchester. In the paper he asks, ‘Could one make a machine to play chess?’ and goes on to suggest several possible meanings which might be given to the words:
- Could one make a machine which would obey the rules of chess, i.e. one which would play random legal moves, or which could tell one whether a given move is a legal one?
- Could one make a machine which would solve chess problems, e.g. tell one whether, in a given position, white has a forced mate in three?
- Could one make a machine which would play a reasonably good game of chess, i.e. which, confronted with an ordinary (that is, not particularly unusual) chess position, would after two or three minutes of calculation, indicate a passably good legal move?
- Could one make a machine to play chess, and to improve its play, game by game, profiting from its experience?
To these we may add two further questions, unconnected with chess, which are likely to be on the tip of the reader’s tongue.
- Could one make a machine which would answer questions put to it, in such a way that it would not be possible to distinguish its answers from those of a man?
- Could one make a machine which would have feelings as you and I do?
The problem to be considered here is 3), but to put this problem into perspective with the others I shall give the very briefest of answers to each of them.
To 1) and 2) I should say “This certainly can be done. If it has not been done already it is merely because there is something better to do”.
A typescript manuscript of ‘Digital Computers applied to Games’ was given to Sherborne School by Alan Turing’s mother and includes corrections made to the text by the Irish-born cryptanalyst and chess player Conel Hugh O’Donel Alexander (1909-1974) who during the Second World War had worked under Alan Turing at Bletchley Park as deputy head of Hut 8.
Rachel Hassall
Archivist, Sherborne School.
See also:
- Alan Turing’s typescript manuscript of ‘Digital Computers applied to Games’ (1951)
- B.V. Bowden (ed.), Faster than Thought (Internet Archive)
- Alan Turing at Sherborne School
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