Alan Turing: The Enigma (52 page)

Peter Hilton was a racy raconteur, and his favourite Turing story concerned the Home Guard. The authorities quaintly insisted upon the Bletchley analysts doing soldierly work in their spare time. The heads of sections were exempt, but Alan conceived a passion for becoming proficient
with a rifle, which amazed Harry Golombek, who after two years in the army had no such enthusiasm. Alan enrolled in the infantry section of the Home Guard, and to do so
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had to complete a form, and one of the questions on this form was: ‘Do you understand that by enrolling in the Home Guard you place yourself liable to military law?’ Well, Turing, absolutely characteristically, said: ‘There can be no conceivable advantage in answering this question “Yes”’ and therefore he answered it ‘No’. And of course he was duly enrolled, because people only look to see that these things are signed at the bottom. And so … he went through the training, and became a first-class shot. Having become a first-class shot he had no further use for the Home Guard. So he ceased to attend parades. And then in particular we were approaching a time when the danger of a German invasion was receding and so Turing wanted to get on to other and better things. But of course the reports that he was missing on parade were constantly being relayed back to Headquarters and the officer commanding the Home Guard eventually summoned Turing to explain his repeated absence. It was a Colonel Fillingham, I remember him very well, because he became absolutely apopletic in situations of this kind.

This was perhaps the worst that he had had to deal with, because Turing went along and when asked why he had not been attending parades he explained it was because he was now an excellent shot and that was why he had joined. And Fillingham said, ‘But it is not up to you whether you attend parades or not. When you are called on parade, it is your duty as a soldier to attend.’ And Turing said, ‘But I am not a soldier.’ Fillingham: ‘What do you mean, you are not a soldier! You are under military law!’ And Turing: ‘You know, I rather thought this sort of situation could arise,’ and to Fillingham he said: ‘I don’t know I am under military law.’ And anyway, to cut a long story short, Turing said, ‘If you look at my form you will see that I protected myself against this situation.’ And so, of course, they got the form; they could not touch him; he had been improperly enrolled. So all they could do was to declare that he was not a member of the Home Guard. Of course that suited him perfectly. It was quite characteristic of him. And it was not being clever. It was just taking this form, taking it at its face value and deciding what was the optimal strategy if you had to complete a form of this kind. So much like the man all the way through.

This Looking Glass ploy of taking instructions literally was one that created a similar fuss when his identity card was found unsigned, on the grounds that he had been told not to write anything on it. It came to light when he was stopped and interrogated by two policemen as he took a country walk. His awkward appearance and habit of examining wild flowers in the hedgerows had excited the imagination of a spy-conscious citizen.
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But besides sharing in such victories over blimps and bureaucrats, there was the experience of free association with people who were among the best in British mathematics, in a sort of secret university, one in which tradition and form, together with rank, age, degrees and all such superficialities were ignored. All that mattered was the ability to think. And they had a mathematical Flash Gordon, a logical Superboy, to encourage them –
someone who refused to admit defeat, or any limitations on their capacities to succeed. To Peter Hilton, Alan was

… a very easily approachable man – though you always felt there was lots more you did not know anything about. There was always a sense of this immense power and of his ability to tackle every problem, and always from first principles. I mean, he not only … did a lot of theoretical work, but he actually designed machines to help in the solution of problems – and with all the electrical circuitry that would be involved, as well.

He did, for instance, design a special machine to help Harry Golombek with the analysis of the particular Enigma system employed by the German motor torpedo boats. There was another designed for use on the main naval Enigma problem; there was far more to it than the Bombe. The technology was not always new; thus the Banburismus process involved the use of paper sheets on which cipher-text messages were represented as punched holes. These had to be moved against each other and coincident holes laboriously counted before the sophisticated statistical methods could be used. There was a hint of irony in the way that Alan chose to call the process ROMSing – a reference to that progressive slogan, the Resources of Modern Science. But it also represented the essential truth about the Bletchley work, and Alan Turing was at the heart of it, never too proud to get his hands dirty with the ‘dull and elementary’:

In all these ways he always tackled the whole problem and never ran away from a calculation. If it was a question of wanting to know how something would in fact behave in practice, he would do all the numerical calculations as well.

We were all very much inspired by him, his interest in the work but the simultaneous interest in almost everything else… And he was a delightful person to work with. He had great patience with those who were not as gifted as himself. I remember he always gave me enormous encouragement when I did anything that was at all noteworthy. And we were very very fond of him.

Alan’s ‘great patience’ was not usually his most conspicuous characteristic, nor his approachability. But Peter Hilton was in fact the fastest thinker of the new Fish group, and drew out the most rewarding aspects of the ‘creative anarchy’ that was Alan Turing. It was pure joy to achieve something new, and show him, and have him grunt, gasp, brush back his hair, and exclaim, stabbing with his strange fingers, ‘I see! I see!’ But then it was down to earth again with the rules and regulations:

But there again, he began to be beset by the bureaucrats who wanted him to be in at a certain time and work till five o’clock and leave. His procedure – and that of many others of us, let me say, not only he, who were really fascinated by the work – would be maybe to come in at midday and work until midnight the next day. And then, the problem being essentially solved, go off and rest up and not come back for 24 hours perhaps … they were getting much more work out of Alan
Turing that way. But, as I say, the bureaucrats came along and wanted forms to be filled in and wanted us to clock in, and so on.

Once he ordered a barrel of beer for the office, but it was ‘disallowed’. Such questions were trivial, but behind them lay more serious confrontations with the old mentality, which little by little and nearly too late had been obliged to give way to intelligence. Alan’s role in this process, however annoying to authority, was not entirely unrewarded. One day in 1942 he, Gordon Welch-man and Hugh Alexander were suddenly summoned to the Foreign Office and awarded £200 each. Alan told Joan that they could not be given decorations, so had been given money instead. He probably found it more useful.

In September 1942 the British position was a little less hopeless, but only inasmuch as there had been no serious loss since that of Tobruk. Rommel’s eastward advance on Egypt had been checked by Auchinleck in July and by Montgomery in August, the latter being particularly helped by deciphered signals. The desert war was more like a naval war than a conventional front, and was particularly dependent upon information. It desperately required the effective integration of the three services, who had been obliged to swallow a bitter pill indeed by allowing Bletchley information and interpretation to be transmitted over the heads of the London chiefs directly to an intelligence centre in Cairo. But a more centralised system was forced upon them by the cornucopia of north Buckinghamshire. By May 1942 they were breaking every Enigma key system of the African theatre. In August this was joined by a new Hut 8 success, the breaking of the system used by Mediterranean surface ships. Rommel was now losing one quarter of his supplies through British attacks which were almost totally dependent on detailed Enigma information – sometimes enabling them to pick out the more important cargoes for destruction. News of this triumph was passed back to the analysts in Hut 8 to encourage them in their work.

But the Mediterranean was, ultimately, an Anglo-German diversion. In the world struggle there had been a major setback for Japan at the battle of Midway, where the US Navy proved it could put its own Intelligence to devastating effect. But in Europe there was no such hint of a reverse. The Axis attack on Russia had reached Stalingrad, and the Dieppe raid had ended lingering fantasies of an easy victory in the west. More frightening than either of these developments, however, for Churchill and for everyone else, was the state of the fragile Atlantic bridge. Without it Britain was nothing.

Although the first American troops had arrived in Britain early in 1942, it was the stream of war materials, tanks and aircraft in particular, that alone could make the reconquest of western Europe conceivable. That stream had to face the Atlantic U-boat fleet, which by October amounted to 196 in number. Since 1940 the numbers had trebled, and the sinkings had trebled too. Until mid-1942, American reluctance to provide coastal convoys had diverted U-boats to easy pickings off the eastern seaboard, but in August
counter-measures had remedied this gap in defence. Accordingly, the U-boats had turned back to the Atlantic convoys, exploiting the area in mid-ocean where air cover was not supplied, and were now accounting for over half the merchant fleet required to supply Britain within a year. The revived American shipyards were turning out new vessels at top speed, only to have each sunk after three or so ocean voyages. But now the United States had its own pressing demands in the Pacific. The total Allied stock of shipping was actually declining, while the number of U-boats was increasing: there would be 212 at the end of 1942, with another 181 on trial.

Fast approaching was the crisis of the western war. 1943 might see either Britain stocked up as the forward base of an impregnable American industry, or might see it slowly sink. Though more diffuse a crisis than that of the air war of September 1940, it likewise stood to see a make-or-break resolution. Ten years earlier, Alan had conceived a model of action: ‘We have a will which is able to determine the actions of the atoms probably in a small portion of the brain… The rest of the body acts so as to amplify this.’ Now he was one of the clustered nerve-cells, and around him a colossal system which had translated his ideas into concrete form: a British brain, an electric brain of relays clicking through the contradictions, perhaps the most complex logical system ever devised. Meanwhile the two years of the reprieve had rendered the rest of the body more prepared and coordinated to use its intelligence. In the Middle East it was amplifying the dim Morse signals into the sinking of Rommel’s army. But the Atlantic was different; here Eisenhower and Marshall might be cut off on a far greater scale than Rommel unless the brain could awaken into life again.

But those two years had seen another momentous change. The ten-fold increase in rotor positions had forced Poland to turn to the technically superior West. And now the twenty-six-fold increase had brought the United States into the electromagnetic relay race. Its Admiral King, who had been more obstinate than the British Admiralty, resisted the setting up of a tracking room until mid-1942. But the US Navy’s cryptanalysts had been quick off the mark to see what was needed. Their department had been using modern machinery since 1935, and when the black-out came in February 1942 they were not content to stand and wait until the British caught up: they could do it themselves. This did not accord at all with the British view, which held that the Americans should concentrate on the Japanese ciphers, and not duplicate the work done at Bletchley. But the US Navy was particularly insistent. Already in June, its relations with GC and CS were ‘strained’ by complaints at the delay they experienced in obtaining a promised Bombe, and then
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in September the Navy Department announced that it had developed a more advanced machine of its own, would have built 360 copies of it by the end of the year, and intended to attack the U-boat Enigma settings forthwith.

These were figures to send Bletchley minds reeling. The whole of GC and CS Enigma work depended upon managing with just thirty Bombes in summer 1942, although another twenty were on the way. The Americans were proposing a take-over bid for the Atlantic work, by the brute-force expedient of building twenty-six times as many Bombes as the British had available, and using them in parallel.

But in October a second
deputation from GC and CS to Washington negotiated another compromise. GC and CS ‘acceded to US desires to attack the German naval and submarine problems’ and agreed to supply the Navy Department with the intercepts and with technical assistance. In return the Navy Department … undertook to construct only 100 Bombes, accepted that GC and CS should be responsible for co-ordinating the work done by the American machines with that done by the British, and agreed to the complete and immediate exchange of the cryptanalytic results.

There was only one person who knew everything about the methods and the machines, and who was free from day to day responsibility. The responsibility for the detailed coordination thus promised now fell to the Prof. Sorting out the tensions between American bluster and British arrogance was not at all the kind of work he enjoyed, but the Anglo-American liaison had to be made concrete. There was a war on. Accredited as an official with the British Joint Staff Mission in Washington, he was issued with a visa
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on 19 October. He told Joan, The first thing I shall do is to buy a Hershey bar.’