Dilly

by Batey, Mavis;

  Dilly’s tour de force did not appear in any British official history as he kept no records himself; at best F. H. Hinsley referred to it in a footnote as ‘short-lived’. But Rejewski took a different view of its significance. ‘We had the English to thank for yet another observation,’ he wrote in a reference to the weather messages’ important give-away of the Stecker setting. ‘Every day they changed the letters in the code in a way that betrayed the plug links. This was a cardinal error on the part of the Germans since in this way there was no need to even solve the code to find the plug links every day without difficulty.’

  Hut 6 Production had now taken over from Research with Gordon Welchman as its first head. The Cottage was shut down for security reasons and for a time Dilly was left like a fish out of water until new arrangements could be made. He made sure that the contact with PC Bruno continued and, according to Rejewski, flourished. ‘In the framework of the co-operation with the British,’ he said, ‘there was also regular liaison about the machine keys of the day. Whoever was the first in the possession of the keys for the given day would immediately notify their Allied counterparts. Thanks to this, during the whole Norwegian campaign there was, I believe, not one cryptogram that was not read by us or the British.’ To begin with there was the problem of how we could be in secret communication. Obviously we both needed the same cipher machine, but the French did not have one of their own and we could not have our Typex machine put at risk. However, we both had the Polish models of the German Enigma machine and that proved to be the answer. Bletchley and Bruno audaciously exchanged Enigma secrets on the Germans’ own machine, ending the messages ‘Heil Hitler!’

  Babbage, a key player in the new Hut 6, leaves us in no doubt of the vital role that Dilly Knox had played in what is referred to in the official histories as the ‘Pre-history of Enigma’:

  Knox had been the pioneer worker on Enigma in this country and his energy and enthusiasm had been an inspiration to all in the early months. When the Enigma had disclosed its secrets and Hut 6, under Welchman, was firmly on its feet, Knox and his Cottage party turned their attention to new problems.

  For Dilly this called for a Carrollian celebration, not a full-scale Alice pantomime with Birch, as in the final Room 40 days, but a throwaway imitation of Lewis Carroll’s poem Jabberwocky and its famous whimsical beginning.

  ’Twas brillig, and the slithy toves

  Did gyre and gimble in the wabe;

  All mimsy were the borogoves

  And the mome raths outgrabe.

  In the Knox version, Carroll’s ‘borogoves’ become the ‘wranglercoves’ newly recruited from Cambridge by Welchman for Hut 6, one of whom was my husband-to-be. The point at which ‘’twas brillig’ in the Knox version can be dated to February 1940, when Hut 6 was first up and running. The Ringstellung problem had been solved and they were profitably busy with Dilly’s cyclometer (abbreviated to ‘cyc’), and the Netz and Jeffreys sheets, but there is a warning in Dilly’s parody that the females and the Netz might be in trouble in the future or there might be a new seventh wheel introduced. Although he was in charge of ‘the Cottage crowd’, Dilly acknowledges his need of Welchman and his team of ‘registrators’. Babbage was shrieking with joy at his cillying but Foss sheets do not appear to be popular with the girls who had to deal with them. Dilly had shown everyone how to look for ‘confirmations’ and ‘contradictions’ in the Stecker knock-out. Alan Turing broke the blue traffic, whose discriminant had been identified by Welchman, on 29 January 1940, and Dilly’s ‘bombe-ish boy’ was all set to slay ‘the Jabberwock’ with his equivalent of Carroll’s ‘vorpal blade’. The Cottage had been shut down, leaving Dilly only a small haven in the plum store, no longer being used, where Turing could visit him away from the bustle of Hut 6.

  ’Twas HUTSIX, and the WRANGLERCOVES

  Did twist and twiddle at the CYC;

  All grimset were the JEFFREYBROWS

  And the BABBAGE outschreik.

  ‘Beware the SEVENTHWHEEL, my son!

  The pale FULLHOUSE, the NETZ that fail!

  Move not the UMKEHRWALZE, and shun

  The UNCONFIRMED FEMALE!’

  He took the COTTAGECROWD in HAND:

  Oft times the REGISTRATORS sought –

  Then midst his CILLIS, SLUGS and SNAKES,

  He sat awhile in thought.

  And as they over FOSSSHEETS groan,

  A REDHOTTIP (with wheels to name)

  Came TURING through the telephone

  And DILLIED as it came!

  4, 5 and 2! No more ado –

  The RINGSTELLUNG. Turn wheels about

  Still doubt appal, but STECKER fall

  Uncontradicted out.

  ‘And hast thou truly BROKE the BLUE?

  Come to the STORE, my BOMBE-ISH boy!

  Fetch JOSH, KITS, BOLS, AARD, CERA, WALTZ!’

  He LUFTGAUED in his joy.

  ’Twas HUTSIX, and the WRANGLERCOVES

  Did twist and twiddle at the CYC;

  All grimset were the JEFFREYBROWS

  And the BABBAGE outschreik.

  At the end of the real Alice’s Adventures in Wonderland, the first of Carroll’s two Alice books, Alice and the King of Hearts discussed the frustration of trying to make sense of all the lines of gibberish spouted by Carroll’s Knave of Hearts.

  ‘I don’t believe there is an atom of meaning in it,’ said Alice.

  ‘If there is no meaning in it,’ said the King, ‘that saves us a world of trouble, you know, as we needn’t try to find any … and, yet I don’t know … I seem to see some meaning in them after all.’

  EIGHT

  Dilly’s girls

  We’re breaking machines. Have you got a pencil?

  Admiral Sinclair’s concept of a country house with landscaped grounds for the secret work required was preserved even when expansion was urgently needed and the hut system put in place. The ground floor of the mansion with its stately rooms was kept intact for administrative and recreational purposes and, until a canteen was built, meals were also served there. The first small hut had been built in the early days near to the wireless tower and a discreet one which became Frank Birch’s naval Hut 4 was put up on the south side of the mansion in the former rose gardens. Hut 6, for decoding messages, and Hut 3, for processing the intelligence from the decoded messages, were built in readiness for the Enigma machine break. Many wartime hand ciphers, particularly those used in the Italian naval messages examined by ‘Nobby’ Clarke’s section, were already being broken and accommodation was needed for their staff. The bombe hut with blast-proof walls would be built in the old maze, leaving the tennis courts intact. Although the ha-ha was filled in as a danger to those crossing in the blackout from the huts to the mansion, the landscaped lake was protected and much appreciated for skating in the icy winter of 1939–40.

  Dilly’s cottage in the stable-yard, known as Cottage 3, was shut down after the first Enigma break; it was at the eastern end of a row of three cottages. Cottage 1 was internally separate but the lofts of Cottage 2 and 3 were joined and considered to be insecure as Cottage 2 was then inhabited by an estate worker, who, although having signed the Official Secrets Act, was unconnected with codebreaking. Although Dilly was intensely interested and involved in the activities of Hut 6, he bitterly resented not having his own accommodation, however small, and having to hand his work over to others before completion, which he said was ‘impossible for a scholar’. He was extremely allergic to what would now be called flow-charts. He was particularly incensed when Alan Turing was put ‘under Mr Birch’, which he thought to be ‘so absurd and unworkable’. To him Frank was best friend, good historian, but no cryptographer. Dilly refused to be pinned down, complaining that research was being downgraded in the rush for production. Another resignation letter, which Dilly knew could not be accepted, was dispatched.

  Alastair Denniston, who always did his best to humour him, recalled Dilly’s anger over the issue when answering a later outburst
protesting about the treatment of scholars.

  My dear Dilly,

  Thank you for your letter. I am glad that you are frank and open with me. I know we disagree fundamentally as to how this show should be run but I am convinced that my way is better than yours and likely to have wider and more effective results. If you do design a super Rolls-Royce that is no reason why you should yourself drive the thing up to the house, especially if you are not a very good driver … Do you want to be the inventor and the car-driver? You are Knox, a scholar with a European reputation, who knows more about the inside of a machine than anybody else. The exigencies of war need that latter gift of yours, though few people are aware of it. The exploitation of your results can be left to others so long as there are new fields for you to explore.

  New fields there certainly were for Dilly to explore. He had been made chief assistant in January 1940, effectively giving him back the title of chief cryptographer that he had enjoyed in Room 40 but lost on the creation of GC&CS. The accommodation problem was settled in March as it was obvious Dilly could not be left as a cog in the hut system. Denniston and Edward Travis arranged for Dilly to return to a reorganised and enlarged stable-yard cottage which was made secure by joining Cottages 2 and 3. Dilly insisted that his new research unit should be entirely female and I was fortunate enough to be one of them. We became known even in high places in Whitehall as ‘Dilly’s girls’. A myth has arisen that he went round Bletchley Park picking the most attractive girls he spotted to work in the Cottage, whereas in fact we were selected solely from notes supplied by the formidable Miss Moore, who had interviewed us all at the Foreign Office. Dilly had made it clear that he did not want any debutantes whose daddies had got them into Bletchley through knowing someone in the Foreign Office, nor, he said, a ‘yard of Wrens’ among whom you couldn’t tell one from the other; he wanted to know our qualifications. He did now appreciate the mathematical input to cryptography and was pleased to be able to recruit Margaret Rock, a mathematician from Bedford College, London, who was older than most of the ‘girls’. She was a great asset to the Cottage and a great support for Dilly. I was initially sent to work for GC&CS at Broadway Buildings in January 1940, before Dilly’s new section was set up, and did not arrive until April.

  I am often asked what skills had to be shown at an interview for selecting codebreakers. We certainly weren’t given any crossword puzzles. I suppose Miss Moore was satisfied with my CV from University College, London (UCL), and my spell at Zurich University, as linguists were obviously needed. I had been booked into a German university but, when Hitler annexed Prague in March 1939, I was sent to the German-speaking University of Zurich instead, where I stayed for the summer and had to beat a hasty retreat when it was said the Siegfried line was being manned. Miss Moore seemed to approve of my reason for curtailing my university German studies. UCL was evacuating to Aberystwyth and I thought I ought to do something better for the war effort than reading German poetry in Wales, especially as the Nazi Propaganda Minister, Joseph Goebbels, had got his doctorate on German Romanticism, the very subject on which I was proposing to embark. I said I would train to be a nurse, but was told I should use my German and was sent to the Foreign Office. That was all right by Miss Moore, who clearly did not wish to prolong the conversation; the next interviewee was called in. Strangely enough it was in fact the romantic Dr Goebbels who had really got me into Bletchley Park. When Hitler’s troops occupied the Rhineland in 1936, he sent brochures over here offering bargain tickets, so that we could see for ourselves what a peaceful idyllic place Rhineland Germany was and that we had nothing to fear.

  My family only went on holidays to Bournemouth but I persuaded my parents that a Rhine holiday would be just the thing and that my recently acquired equivalent of O-level German would see us through any problems. I got my way and we bought cheap roving tickets for a brand new steamer trip along the scenic parts of the Rhine. We joined crowds of happy German workers with free tickets, all part of Goebbels’s ‘Strength through Joy’ campaign. They were to be indoctrinated in the myths and legends of German heroes as part of the Nazi philosophy of Aryan superiority, preparing them for the Third Reich, which was going to last a thousand years. Wagner’s blonde Rhine maidens were with us constantly and the band struck up as we passed Die Lorelei. I lapped it all up and when I got back decided to opt for German literature in the sixth form, where I managed to win a copy of The Romantic Movement in Germany by Leonard Willoughby, Dilly’s old Room 40 colleague, as a prize. My future was then decided but not in the way that I could have foreseen.

  My professor of German literature at University College turned out to be none other than Leonard Willoughby, who had appeared as ‘the Grumbling Willow’ in the pantomime Alice in ID25. It was he who had identified Schiller’s ‘himmlische Rosen’ crib for Dilly’s U-boat break, but of course I was unaware of that at the time. UCL was quite revolutionary in 1938, inspired by the dynamic Marxist professor J. B. S. Haldane. The Spanish Civil War was at its height and we starved for Republican Spain on a Tuesday, which was a bit confusing for me as I had just come from a convent school where we had prayed for General Franco at morning assemblies. However, I was soon into sewing red flags for the young men going off to join the International Brigade and waving farewell to them.

  Kristallnacht soon followed in November and we marched on the German embassy, bearing our mascot Phineas, but it had little effect on the fate of the Jews. The German department encouraged students to befriend the influx of refugees and try and find jobs for them. I went through all the situations-vacant columns with my pair and finally found an advertisement for a couple needed in a country house in Kent and took them down to settle them in. Unfortunately, Hitler had found the Jewish exodus a perfect opportunity to infiltrate fifth columnists and it was my bad luck to have been given two of them. Perhaps I should have been suspicious that they were so keen on Kent as they were subsequently caught photographing military installations along the coast and gave my name as sponsor when they were arrested. This was at the time that my application to the Foreign Office was being processed, but it took me some time to find out that the reason for the delay, from the interview in November 1939 until being summoned to Broadway Buildings in January 1940, was that MI5 had been investigating my blameless past with the local Croydon police.

  Broadway Buildings, opposite St James’s Park Underground station, where the German spy match seller was watching us, housed ‘C’, the chief of SIS, which those of us working for GC&CS on the floor beneath called ‘the other side’ in hushed tones. Being put onto commercial codes seems pretty trivial compared with what was going on upstairs but in fact it was considered very important in the phoney war. I now know that we were supplying industrial intelligence for the Ministry of Economic Warfare (MEW), whose mission was ‘comparable to the operations of the three Services in that its object is the defeat of the enemy and complementary to them in that its function is to deprive the enemy of the material means of resistance’. My section’s task was to blacklist firms in neutral countries supplying Germany with the essential goods they needed through scrutinising the codebooks they used to order them.

  Commercial telegraphic codes sent in Morse were internationally available on the market and easily mastered; there was no super-encipherment as with secret codes. The codebooks were look-up tables for code and decode and the code-groups could represent a whole sentence. When the Government Code and Cypher School was set up it firmly implied in its title that codes and ciphers were two different things but nowadays the term ‘codebreaking’ is commonly used for both. Scherbius was quite clear that he had not invented a codebreaking machine but a ‘ciphering and deciphering’ machine, whereby one letter was encrypted into another mechanically. The important thing for the MEW was that we should identify the neutral country that was providing the illegal commodity. One miscreant from a place called St Goch, which could not be found in the gazetteer, had foxed them, and the problem was given casually to m
e.

  After a time, I realised that the issue might be being confused by the capital letter and that perhaps it was not necessary to chase a saint around the world. There is much of Wonderland in cryptography and it often pays to be like Alice and ask disconcertingly innocent questions. I simply asked how they knew when there was a capital letter in Morse code and they had to confess they didn’t as there was no provision for them. I then tried changing the capital letter and looking for an abbreviation and, when I got to StgoCh, I thought it might be Santiago, Chile; it worked and the culprit was tracked down. This seemed to impress somebody and, aged not quite nineteen, I was given a railway ticket to Bletchley and told which train to get and that I would be met there. At least I knew where I was going and could tell my family, but I met up with a new recruit, Joyce Mitchell, who had merely been told to be at Euston at a certain time, where she would be met and given a ticket, but when she left home she did not know whether her destination was Watford or Scotland. Having arrived at Bletchley and reported to Commander Denniston, I was taken across to the Cottage by his secretary, Barbara Abernethy, and introduced to Dilly Knox.

  When Penelope Fitzgerald came to see me, when writing her book The Knox Brothers, she asked me if I could remember my actual first meeting with her uncle. I described the cottage room where he was sitting by the window in wreaths of smoke and, taking his pipe out of his mouth, he looked up and said: ‘We’re breaking machines. Have you got a pencil?’ I knew nothing about the existence of the Enigma machine, only having seen commercial book codes at Broadway, as he knew, so that did not get me very far. He then handed me a bunch of gobbledegook messages made worse by his purple inky scrawls over them and said: ‘Here, have a go.’ My code-groups had been neat and tidy and although not comprehensible were at least pronounceable or even in clear. ‘But I am afraid it’s all Greek to me,’ I said in despair, at which he burst into delighted laughter and said: ‘I wish it were.’ I felt very embarrassed when I discovered that he was a distinguished Greek scholar.