Jim Wilkinson was older and more experienced than Mike Woodger, but he too found many days when it was better to keep out of the way of the now somewhat isolated ‘creative anarchy’ that was Alan Turing. ‘Likeable, almost lovable … but some days depressed’, he appeared; his mercurial temperament and his emotional attitude to his work showing clearly. It was at about this time that Alan got the long-promised promotion to Senior Principal Scientific Officer, and he took Jim Wilkinson and Leslie Fox from Goodwin’s department out to a celebration dinner in London. The train journey was spoilt by a sultry row over some mathematics, and then, as they arrived at Waterloo, the clouds cleared and he was buoyant again.
This particular argument arose because Alan had become involved in a problem of numerical analysis, the work done in Goodwin’s section. In 1943 the statistician H. Hotelling16 had analysed the procedure for solving simultaneous equations (or, roughly equivalently, for inverting a matrix) and his result made it appear that errors would grow very rapidly as successive equations were eliminated. If this were so it would undermine the practical usefulness of the ACE. Goodwin’s section, being directly concerned with the problem, had attacked it heuristically in 1946 by solving a set of eighteen equations that had come up in an aerodynamic calculation, and Alan had joined in (notably the least competent at the detailed work), on the desk machine exercise. To their surprise, they found the final errors to be remarkably small. Alan had undertaken a theoretical analysis of why this should be. It was a typical Turing problem, needing a fresh attack, and with a concrete application. He tackled it much as he had developed a theory of probability for use at Bletchley.
This work, of course, did not lie far in the past, and he set Mike Woodger some probability problems, including the one about the ‘barrels of gunpowder’. There was also professional contact arising out of wartime work. Jack Good and Newman had made a visit to the NPL – Newman, of course, being interested in setting up his Manchester computer project – and Jack had managed to disprove Alan’s assertion that no one could write an instruction table that was free from error at the first attempt. Jack Good had also written a short book17 on Probability and the Weighing of Evidence, effectively setting out the theory they had employed at Bletchley, though not its more advanced applications. The ‘sequential analysis’ method was, as it happened, soon published in America by the statistician A. Wald,18 who had developed it independently for the testing of industrial components. Alan, in contrast, published nothing that came of his Bletchley work, except in the less direct sense that almost everything he was doing was flowing from his wartime experience added to his pre-war theory of machines.
Rather than forming new ties of friendship at the NPL, he retained those of the war. Donald Michie, now an undergraduate at Oxford, was one of these friends, and a footnote on Alan’s October 1946 letter to Jack Good, with comments on the draft of his book, noted cryptically that ‘Donald has agreed to help and I have now got the necessary gadgets for the treasure.’ This was a reference to a proposed expedition to recover the silver bars. (David Champernowne had meanwhile realised a healthy profit in his ingots, which had remained safely in his bank.) There had been a previous attempt with Donald Michie, who was offered the choice of either a one-third share of the total proceeds or a payment of £5 per expedition. This was itself a nice example of the Turing theory of probability, which appealed to the odds that a perfectly rational person would be prepared to bet on an event. As a perfectly rational man, Donald Michie opted for the latter choice. The first real-life treasure hunt had been a failure, since when they went to the wood near Shenley where one bar was buried, Alan found that the landmarks had changed since 1940, and he could not locate the spot. The point of the ‘gadget’ was that it was a metal detector which Alan had designed and built himself. On the second trip, it functioned, though only to a depth of a few inches. It successfully located a great many pieces of metal under the surface of the wood, but not the silver bar. As for the second bar, he knew where that was, but they found that they were unable to apply the UNBURY routine when standing in the bed of the stream.
Such failures he would easily laugh off. This was not his only visit back to Buckinghamshire, for he spent a weekend, prob ably in December 1946, discussing D. Gabor’s new theory of communication19 with Don Bayley. This time he distinguished himself by fainting when he grazed himself shaving. He had told Don long before about this reaction to blood, but this was the first time Don had seen it happen. There had also been an occasion in October 1945, when he, Don Bayley, Robin Gandy and ‘Jumbo’ Lee met up to go to a lecture on wartime radio work at the Institute of Electrical Engineers. Afterwards they had gone to Bernard Walsh’s oyster restaurant and rather hoped to be fed on the house – in which they had been disappointed. Alan had cycled into London from Teddington and had parked his bicycle outside the Soho restaurant, from which it was duly stolen.
For him to cycle the fifteen miles was not entirely characteristic, since he would quite happily take in such distances on foot. His success in the Hanslope races had been followed up. On arrival at Teddington he had joined the local Walton Athletics Club, and had taken up running as a serious amateur. He was a long-distance runner, rather than a sprinter; it was his stamina that gave him the edge in races over three miles in length. During this period he would spend two or three hours every day on training, and would run for the club on Saturday afternoons. Thus in October 1946 he wrote to his mother:
My running was quite successful in August. I won the 1 mile and ½ mile at the NPL sports, also the 3 miles club championship and a 3-mile handicap at Motspur Park. That was the meeting* at which all the stars were trying to break records, but in fact were pulling muscles instead. Being a very humble athlete myself I was able to get away without pulling a muscle…. The track season is over now, but of course the cross country season will be beginning almost at once. I think that will suit me rather better, though the dark evenings will mean that my weekday runs will be in the dark.
He was lengthening his distance, and working up to marathon running. If possible he would make official visits double as training runs. In particular, he would run the ten miles across west London to Dollis Hill in connection with the plodding development of the ACE delay lines. Every few months, he would run the rather longer distance of eighteen miles to Guildford, to put Mrs Turing’s social imperatives to some constructive use. It amazed everyone, but he did not care about that. It also, as Mrs Turing put it, gave him contact with men ‘in all walks of life’.
He even managed to combine running and chess. He saw something of David Champernowne from time to time, either at Oxford, where he now had a position, or at his parents’ house at Dorking. They would play ping-pong, and talk about probability theory, but they also devised a form of chess in which each player had to make his move while the other ran round the garden. Fast running would tend to prevent good thinking, so the problem was to choose the right balance. Alan was also interviewed by the Sunday Empire News on training hints. He might have remembered the discussion of ‘second wind’ in Natural Wonders, which explained how it depended upon ‘teaching’ the brain not to ‘raise such a row’ when it smelt a little carbon dioxide in the blood.
One of the difficulties of his position was that there was a good deal of carbon dioxide in the blood supplying the British brain. For all the talk of planning for the future, there was a terrible exhaustion after the war, and little eagerness to upset the apple-cart any further. In one way this became clear at once. At Hanslope, Don Bayley had continued to improve and test the Delilah. Later in 1945 he had taken it to Dollis Hill for evaluation where – hardly surprisingly – they failed to find any cryptographic weakness. In early 1946 he had taken it to the Cypher Policy Board, which was a coordinating organisation established in February 1944. He set it up in the basement of their London offices, and left it with one of their officers. They were more interested than the Post Office, and suggested to Gambier-Parry that his man might join
them to continue work. But Gambier-Parry turned this down, and this refusal closed the story. The Delilah’s two neat packages of equipment, providing speech security with no more than thirty valve-envelopes, were completely forgotten. As a contribution to British technology it had been a complete waste of time.*
*
But Delilah had been part of the preparations for the ACE, and this, Alan Turing’s logical Overlord, was what mattered. The plans were all ready, and only needed the signal to start. And they did at least gain a sort of second wind on 31 October 1946, when Mountbatten, as president of the Institution of Radio Engineers, gave a speech20 that conveyed – however inaccurately – the excitement of what had happened in the new technology of communication and control. It was as far beyond the old days of the Glorious as they had been ahead of the papyrus scroll:
The war not only taught us a great deal about techniques, but it proved the occasion for new departures in application, particularly in electronics, which had enormously augmented our present human senses. Apart from radar, which aided to a remarkable degree the sense of sight, we might in future be able, by pooling and transforming the potentialities of other forms of radiation, such as light, heat, sound, X-rays, gamma-rays and cosmic rays, to receive the counterpart of radar screen pictures from inside our bodies, or even from individual body cells. Or perhaps we might receive them from the interior of the earth, or from the stars and galaxies…. there was reason to believe that facilities for impressing information and knowledge on the human brain … may be extended by the direct application of electrical currents to the human body or brain….
The stage was now set for ‘the most Wellsian development of all’. It was considered possible to evolve an electronic brain, which would perform functions analogous to those at present undertaken by the semi-automatic portions of the human brain. It would be done by radio valves, activating each other in the way that brain cells do; one such machine was the electronic numeral [sic] integrator and computer (ENIAC), employing 18,000 valves …
Machines were now in use which could exercise a degree of memory, while some were being designed to employ those hitherto human prerogatives of choice and judgment. One of them could even be made to play a rather mediocre game of chess! …
Now that the memory machine and the electronic brain were upon us, it seemed that we were really facing a new revolution; not an industrial one, but a revolution of the mind, and the responsibilities facing the scientists to-day were formidable and serious. ‘Let us see to it,’ he concluded, ‘that we not only insist on being allowed to shoulder it; but that when we have established our right, we can also prove our fitness.’
In 1946 people still believed that the great war surplus of scientific and technical advance could be turned to good use, although Mountbatten’s comments on ‘responsibilities’ reflected the fact that few had any idea of how this was going to be achieved.
The ENIAC had been released from military secrecy months before, and Hartree had written about it in the scientific journal Nature,21 but it needed Mountbatten to make it ‘news’. He had taken his information from the NPL, and the inaccurate reference to chess-playing machines would suggest that he heard an excited Alan Turing talking about the future possibilities of the ACE. (There was, of course, no machine in existence that could play chess.) Darwin and Hartree were embarrassed not only by Mountbatten getting the wrong ends of the technical sticks, but also by his perfectly correct assertion that the ACE would exercise ‘hitherto human prerogatives of choice and judgment’. They did not like to criticse Mountbatten, but wrote22 to The Times complaining that its headline ELECTRONIC BRAIN had given a false impression.*
The official NPL press release,23 on 6 November, was very different in tone. It presented the building of the ACE as a somewhat distant possibility, rather than being just round the corner. Correctly it set the origin of the ACE in Alan’s ‘severely mathematical paper’ of 1936, and explained how electronic switching provided the speed to make such a machine practical. It explained the superiority of the ACE over the ENIAC, through its large memory store, and referred to the work already done on programming instruction tables. But the cost had now risen to a figure ‘in the region of £100,000 to £125,000’ and it was stated that ‘It will be two or three years before the completion of this machine can be hoped for, since its construction presents formidable problems, both mathematical and technical.’
Now that this stirring if remote prospect had at last been entrusted to the British public, the Daily Telegraph showed itself the most eager to spread the good tidings, which it imbued with a suitably patriotic flavour. The headline BRITAIN TO MAKE A RADIO BRAIN/‘Ace’ Superior to US Model/BIGGER MEMORY STORE appeared on 7 November, followed up next day with an account by its own reporter, who had interviewed Hartree, Womersley, and Alan at the NPL:
‘ACE’ WILL SPEED JET FLYING
… Revolutionary developments in aerodynamics, which will enable jet-planes to fly at speeds vastly in excess of that of sound, are expected to follow the British invention of ‘Ace’, which has been commonly labelled the electronic ‘brain’.
… Professor Hartree said: ‘The implications of the machine are so vast that we cannot conceive how they will affect our civilisation. Here you have something which is making one field of human activity 1,000 times faster.
In the field of transport, the equivalent of Ace would be the ability to travel from London to Cambridge … in five seconds as a regular thing. It is almost unimaginable.
… Dr Turing, who conceived the idea of Ace, said that he foresaw the time, possibly in 30 years, when it would be as easy to ask the machine a question as to ask a man.
Dr Hartree, however, thought that the machine would always require a great deal of thought on the part of the operator. He deprecated, he said, any notion that Ace could ever be a complete substitute for the human brain, adding:
‘The fashion which has sprung up in the last 20 years to decry human reason is a path which leads straight to Nazism.’
The Germans, like the computer, had only been obeying orders, but this allusion did not deter Alan when next day a reporter from the local newspaper came to investigate the ‘New NPL Wonder’. He only lengthened the time-span of his prophecy. They published the interview24 of the ‘34-year-old mathematics expert’ under the headline ELECTRIC BRAIN TO BE MADE AT TEDDINGTON:
Dr Turing, speaking about the ‘memory’ of the new brain … said it would be able to retain for a week or more about as much as an actor has to learn in an average play. Asked about Lord Louis Mountbatten’s statement that it would be able to play an average game of chess, Dr Turing said that was looking far into the future…. The point was then put to him that chess and similar activities required judgment as well as memory, and Dr Turing agreed that that was a matter for the philosopher rather than the scientist. ‘But,’ he added, ‘that is a question we may be able to settle experimentally in about 100 years time.’
This was the most exciting if embarrassing thing to happen at the NPL for a long while, and Darwin was sufficiently encouraged to make a radio broadcast25, in which he outlined the ‘idealised machine’ of Computable Numbers, and explained that ‘Turing, who is now on our staff, is showing us how to make his idea come true.’ But as the newsreel music faded away, the awkward fact remained that it was now nearly a year since Alan had shown in detail how to ‘make his idea come true’, and Darwin still did not know how the NPL was to give effect to his proposals.
On 22 October, when Hartree enquired about progress on the ACE, Darwin had to confess that ‘Post Office assistance had not been as great as was expected.’ On the TRE side, there had been more technical progress, since F. C. Williams had begun in about June to investigate the behaviour of spots on cathode ray tubes with a view to creating a storage system. During the war he had seen attempts at the Massachusetts Institute of Technology radar research laboratory to employ ordinary cathode ray tubes for echo cancellation, attempts which failed beca
use of the transience of the spots, which faded in a second or so. But during the autumn of 1946, he had the idea, independently of Alan’s proposal in the ACE report, of refreshing the spots periodically to overcome this problem.26 He had also seen a way to do it. On the other hand, from an administrative point of view there had been a setback to NPL’s plans, since Williams had accepted the chair of electrical engineering at Manchester University – an appointment which he believed he owed to Blackett. Darwin explained to the Executive Committee that
He had also hoped that considerable assistance could be obtained from Dr F. C. Williams of TRE, but that he now understood that Dr Williams had accepted a University appointment. He said that he would explore the possibility of Dr Williams working on this project at his University – perhaps with the help of NPL or TRE staff …
The possibility, thin as it was, was indeed duly explored. On 22 November 1946, Williams, together with two other top TRE men, R. A. Smith and A. Uttley, made a visit to the NPL ‘to discuss with Mr Womersley and Dr Turing in what way help could be given to the ACE project.’ The official minutes27 were a masterpiece of discretion, Darwin being furious that Williams had been seduced into the Manchester orbit. Speaking alone with Smith, he banged on the negotiating table:
The Director emphasised the extreme importance which he attached to the development of ACE, and put it as having the highest priority in his opinion of any work that was being done for DSIR at TRE. He was most anxious that some effort should be set aside for work done on this project.
Alan Turing: The Enigma: The Book That Inspired the Film The Imitation Game Page 55
