Most Secret War

by R. V. Jones

  The atmosphere in the Laboratory was gradually changing, as to some extent I was myself. The Laboratory boy, Basil, even asked me what was happening—I seemed so much more serious than I had been two years before. The reason was simple enough—I was engrossed in the air defence problem. And despite the fact that Lindemann himself clearly felt the same way, I had to endure ragging from my contemporaries as a militarist for switching from pure research to air defence. They, along with most of our countrymen, seemed blind to what was happening in Germany; and yet the sight of a cinema newsreel of a Nazi rally should have been enough to open their eyes. These were the days when the Socialist-controlled London County Council suppressed the Cadet Corps in the London schools. While retrospectively we may sympathize with the anti-war feelings of those who knew the horrors of trench warfare in World War I, with all the doubts that these threw on the higher leadership, it should have been obvious that their actions were encouraging the very danger that they hoped to avoid.

  In 1936 and 1937 the predominant feeling in Oxford was still pacifist, as far as the University was concerned. But it was different among working men; I knew a number of them through the City of Oxford Rifle Club, which I had joined, and they warmly supported my suggestion that we should try to form an anti-aircraft battalion. I therefore wrote on 1st November 1937 to the First Anti-Aircraft Division at Hillingdon:

  I can offer to form a committee of representatives of municipal bodies and local firms, to consider the problem of raising, say, 1,000 men in Oxford, provided that the War Office would provide equipment and instruction. Presumably the way would be to establish a Territorial battalion here. Before we can start a recruiting campaign, we must be able to tell people what obligations they entail by joining, and we must also have some indication that the War Office will take the matter seriously. I believe that we can get the men—perhaps not a thousand (although Oxford has a population of 80,000), but at any rate enough to make it worth while. Despite the pacifist reputation of the university, the spirit in the town is good.…’

  The war broke out before anything was done. Another of my efforts may have been more fruitful. Shortly before I left Oxford in March 1938 the Germans annexed Austria, and the scales at last fell from the eyes of my contemporaries. They were now almost anxious to do something for defence, but there was no organization ready if their enthusiasm ever materialized to the point of action. I therefore wrote to D. R. Pye, the new Director of Scientific Research, at the Air Ministry on 18th March. After discussing some minor details of my work, I went on:

  The main purpose of this letter is to raise a far more important question: it seems very obvious, but since I have not heard it considered perhaps you will forgive me for mentioning it.

  The events of the past week have made the research people here realize that the position is more serious than they had thought. Yesterday one of them asked me what he should do in the event of war: he wanted to do something active, and pointed out there was nobody to tell him what to do. In the past, most scientists have tended to be conscientious objectors; following this spontaneous move, I investigated the feelings of other members of the laboratory, and found that out of eighteen people questioned, only two were now conscientious objectors. Most of the remainder wanted to do scientific military research, while one or two of the more pugnacious would prefer to take more vigorous measures.…

  The point is this: if war were to break out tomorrow the scientific directorates of the services would find themselves overwhelmed by volunteers, and much valuable time would be wasted in finding out what posts they were best suited for, and the necessary—and as far as I know unforeseen—expansion would have to be effected.

  I am suggesting therefore that the research workers in the universities should be asked what they want to do, and to state their lines of specialization, should they elect to join the scientific staffs during wartime. You would then know your prospective personnel, and could arrange your necessarily expanded programme accordingly. The men could then be informed where they were to be stationed, and laboratory accommodation arranged. They could start practically at the outbreak of war, and no time would be wasted.

  I received an interim reply from Pye saying that he would later reply more fully, but he never did. Fortunately, Tizard took the matter up; and by the outbreak of war many university physicists had been told where their services could best be applied.

  CHAPTER FOUR

  Inferior Red

  1936–1938

  THE SEQUENCE of events that led to my leaving Oxford in March 1938 had started in January 1936 with my work on infra-red detection of aircraft for the Tizard Committee. Within two months I had made some new detecting elements and had designed and built an electronic amplifier that caused a spot of light to broaden into a band whenever a faint source of heat came into the field of view of the detector, the breadth of the band increasing as the source grew stronger. Besides serious measurements, the equipment could do two ‘party tricks’: one was to scan a rack of tools, from which I had asked a visitor to withdraw one and then replace it, and I could then tell him which one it had been, because the few seconds’ contact with his hand had warmed it slightly. The other demonstration was to shine a torch at a black screen and then switch it off. The detector could then be made to scan the screen and discover where the spot of light from the torch had previously fallen, even up to a minute afterwards, because the light had been converted into heat, in an amount imperceptible to the senses, and this heat was now being re-radiated.

  The first visitor to see the demonstration was Watson-Watt, who came to talk to Lindemann on 24th February 1936. He was looking for recruits for the Air Ministry Research Establishment that he was setting up at Bawdsey Manor on the Deben Estuary just north of Felixstowe. Lindemann had recommended Gerald Touch, who was just finishing his doctorate, and who had been our reporter for the telephone-in-the-bucket-of-water incident. He was to be a significant influence in my career over the next few years, and a lifelong friend. Although he was not exactly like the research student of whom Edward Appleton said, ‘He was the kind of man for whom no experimental difficulty was too great to be thought of’, Gerald could usually see trouble ahead. Even when things were going well he would say, ‘That’s all very well, Reginald, but, you see, the trouble is…’ But he was an able experimenter of complete honesty, and Watson-Watt wisely accepted Lindemann’s recommendation.

  Watson-Watt may well have discussed other matters with Lindemann on this visit; they had known one another since the Farnborough days of World War I, and it would be natural for them to discuss the whole air defence problem. Lindemann seemed to conclude that Watson-Watt needed more support than the Tizard Committee was giving him, for on 12th June 1936, he arranged to take Watson-Watt to meet Churchill. As could be expected, Lindemann had not been an easy member of the Tizard Committee, and had been pressing some of his own schemes, such as aerial mines supported on parachutes. His association with politicians was resented by other members of the Committee, and his introduction of Watson-Watt to Churchill behind the backs of the Committee was almost the last straw. Following what Watson-Watt told him, Churchill was critical of the Tizard Committee at the C.I.D. Sub-Committee meeting on 15th June. The Tizard Committee was due to write a progress report within a few weeks, and Lindemann insisted on writing a minority report, which went into the Official Records dated 20th July.

  Among the conclusions from which Lindemann dissented was one not to give aerial mines a highest priority. In the event he appears to have been wrong, for the mines were a failure when tried in 1940, but they were hardly less realistic than several of the schemes backed by the Committee, including one to floodlight the whole of southern England. As for the mines, they were not just a debating point as far as Lindemann was concerned, for when the work on mines had been held up because a ‘Queen Bee’ pilotless aircraft could not be made available by the Air Ministry, Lindemann offered to pilot the plane himself to see what happened when planes
ran into wires from which mines could be suspended, just as he had also done during World War I. As for radar, he agreed with the Committee that it should have the highest priority, but he made the sensible point that this would only be effective if a similar priority were given to develop the communications system by which the radar data would be transmitted to fighter controllers and by which instructions could be sent to our fighters. Such points might have been listened to in a less charged atmosphere, but by now the other members of the Tizard Committee were exasperated, partly because of Lindemann’s communicating his ideas to Churchill when their defects had already been pointed out at the Tizard Committee, and partly because he was now standing for Parliament, on the air defence issue. After the Tizard Committee meeting of 15th July, Blackett and Hill offered their resignations. Swinton, the Air Minister, refused to accept them, and instead dissolved the Committee in order to reform it again without Lindemann.

  Much has been made of the differences between Lindemann and the Committee. In retrospect, there was some right on both sides: far from holding up radar in favour of infra-red, as has sometimes been suggested, Lindemann earned Watson-Watt’s gratitude, and the latter afterwards wrote, ‘He gave to the radar team support, at the highest level, which was indispensable both psychologically and organizationally.’ Personally, if I had had to discuss with anyone on the Tizard Committee a problem requiring physical insight, I would have valued Lindemann’s judgement most. I can recall an incident from those days when an inventor had put up a proposal to the Committee of what is now called inertial navigation. It was dismissed by the Committee because the members said that it was well known that you could not establish the speed of an aircraft other than by measuring relative to the air in which the aircraft was moving and the wind would therefore always cause errors. This is true enough of a pitot tube but, as Lindemann pointed out to me, the proposal was perfectly sound if one used, as the inventor suggested, accelerometers. One could then integrate all the accelerations to which the aircraft had been subjected since it left the ground; this would give velocity, and a further integration would give position relative to the point of take-off.

  Tizard had more common sense than Lindemann, but to some extent he also had luck. Not only was radar presented to him, as it were, on a plate, but also he was dealing with a body of serving officers in Fighter Command who realized they would be in grave difficulty if the Germans attacked. They were therefore prepared in their predicament to look at any ideas coming from the scientists. True, Tizard had done as much as anybody, and perhaps more, to persuade the Royal Air Force to be receptive, but even he could not succeed if the officers concerned were complacent. Following the success of his original committee for surveying air defence, it was proposed that he should head a similar committee to look into problems of air offence. This second committee was set up towards the end of 1936, and some members were common to both committees. And yet, despite the brilliant example in defence, the work for offence was, as Tizard himself said, a failure. The basic explanation was that the officers concerned with bombing operations were complacent and convinced that they could hit their targets without scientific aids, and so they were not prepared to listen even to Tizard.

  Most of the Tizard Committee arguments were of course far above my head. While it was in turmoil in June 1936 I had been at Farn-borough trying out my infra-red equipment on the ground. It satisfactorily detected aircraft in flight—the speeds make odd reading now, a Westland Wapiti flying past at 70 m.p.h. With its small size the detector seemed worth taking a step further, at least to the stage of designing an airborne version. I was now in my second four months of work for the Tizard Committee. Churchill had commented at the C.I.D. Sub-Committee that he had understood that a man in Oxford had been paid £100 for four months work, and was shortly to receive another £100 for another four months, and he asked whether something more ought not to be done.

  My own position was that the Balliol post ran out at the end of September, and had my astronomical career been continuing I should have gone to Mount Wilson for the next two years. I applied for a Commonwealth Fellowship with Mount Wilson in mind, but I was worried that war might break out within the following two years, and if this happened I wanted to be in England rather than America. I told the Commonwealth Committee that there was a chance that even if I were offered a Fellowship I would feel that I had to give air defence the first priority, if the Air Ministry decided that it wanted me to continue the work after September 1936. This in fact happened, and I was appointed as a Scientific Officer and a full-time member of the Air Ministry staff from 5th October 1936, and accredited to the Royal Aircraft Establishment at Farnborough even though I was still to work in Oxford. My salary was £500 per annum which, low though it may seem now, was higher than that of any other scientist of my age in Government service.

  In the meantime three of my friends had left Oxford. The first was Carl Bosch; the second was Gerald Touch, who left to join Watson-Watt at Bawdsey on 8th August. The third was F. C. Frank, my exact contemporary, in the Chemistry School. I had first seen Charles Frank when we tried for Scholarships in December 1928, his cherubic and intellectual countenance prominent among those at the top of the Balliol Hall steps, anxious to get at the examination papers as quickly as possible. In our first year I had seen him coming away from Blackwell’s clutching a great textbook of chemistry with an air of anticipatory delight, and also on the river as cox of one of the Lincoln torpids. We hardly met until we were postgraduates, when he shared lodgings with one of my friends, and we discovered that we had much in common. Although he was a theorist, he clearly appreciated experimental dexterity, and although I was an experimenter I found that he could expound theory in terms that I could understand. We grew closer together with each year and so, when on 13th July 1936 he left to work with Peter Debye in Berlin for two years, I could tell him my thoughts about the prospects of war, and ask him to watch for anything that might affect our ideas about defence.

  The next stage of the infra-red work was to make a detector capable of operating in an aircraft. On 16th October I attended a meeting of the Tizard Committee for the first time, and outlined what I saw of the possibilities, including a device for converting infra-red into visible radiation so that one could form in effect a thermal picture of a scene in which the warmer regions would show up as brighter. The Committee appeared reconciled to the fact that despite their differences with Linde-mann I should continue to work in his Laboratory. He was in the middle of his Election campaign for Parliament, and on 30th October Winston Churchill came to Oxford to speak in his support. On the following morning Lindemann brought him to the Clarendon, and showed him my work. This was the first sight that I had of Churchill, and I remember well the impression that he created on all of us. He looked so tired and florid that our general verdict was ‘Poor old Winston—he can’t last much longer!’

  During the winter I constructed a new infra-red detector for mounting in an aircraft, the main difficulty being to render it sufficiently immune from the vibration to which all aircraft of that period were susceptible; besides simple detection, it was capable of giving an indication of whether the target was to the right or left, and up or down. I was at this time joined by George Pickard, who had just completed his doctorate in low temperature physics and who, like me, now became a member of the Air Ministry staff. We took the detector to Farnborough in April 1937, and on 27th April I flew with the equipment, and managed to detect another aircraft in flight. As far as I know, this was the first occasion on which one aircraft was detected from another in flight by infra-red means.

  Over the next few months we made good progress. I showed that even if the engines of an aircraft were screened it could still be detected because of the heating of its wings and fuselage caused by the compression of the air in front of it (aerodynamic heating) and I also started to grow large crystals of materials that would transmit infra-red radiation. When it seemed that, if we developed the detector to
the operational stage, it would have to be mounted in single seater fighters (for these were what the Air Staff intended to use at night) there would obviously be a difficult stage where the pilot of the trial aircraft would need to know a good deal about infra-red. I thought that the simplest method of dealing with this stage would be for me to learn to fly fighters, and I therefore suggested to D. R. Pye that I join the Oxford University Air Squadron with this in mind. It came to nothing because the Commanding Officer found that he was up against a regulation that allowed him to take only undergraduates as cadets; and although I was still only 24 I was a doctor with two years’ seniority. The Air Staff were not worried—I was told that they had plenty of men who could fly aeroplanes.

  In June 1937 I paid my first visit to Bawdsey at Gerald Touch’s invitation and with Watson-Watt’s approval. I had already guessed what they were doing, since the radar equipment on the liner Normandie had been described in the press. The technique of detecting aircraft by echoes arising from reflected radio waves was obviously much more powerful than the infra-red method that I had been asked to pursue, although there might be a possible gap at short range which infra-red would serve to cover. At the same time, radar had some disadvantages. One was that with its relatively long wavelength of 1.5 metres it would be difficult to obtain accurate indications of the direction of the target, and these would certainly be needed for a satisfactory interception. Another weakness occurred to me when Gerald Touch said that the method was so sensitive that it could detect a wire hanging from a balloon at forty miles. All one might therefore need to do to render the system useless would be to attach wires to balloons or parachutes at intervals of half a mile or a mile, and the whole radar screen would be so full of echoes that it would be impossible to see the extra echo arising from an aircraft.