by R. V. Jones
The Air Defence Research Sub-Committee had recorded in its minutes of 2nd July, regarding infra-red: ‘Considerable progress has been made. Work should continue in view of the possible application of the results to other problems.’ I was not informed of this comment and its cryptic significance, but a month or two later Lindemann told me that Churchill had said that he understood from the Sub-Committee that they were going to shut down my infra-red work. I replied that infra-red certainly had its limitations of not being useful through cloud and of not giving an indication of range, but that radar, too, was vulnerable, especially to a ‘smoke screen’ of spurious radar reflections which only need be lengths of wire half a wavelength long. Lindemann told me that he would get Churchill to raise this point at the Sub-Committee. When I subsequently asked him what had happened he said that Tizard and Watson-Watt had rather ‘looked down their noses’ at the suggestion. My conversation with Lindemann about ‘smoke screen’ reflections was effectively the beginning of what came to be known in Britain as ‘Window’ and in America as ‘Chaff’ but for many years I had no evidence other than my own memory, which I could not expect others to accept. However, when Alfred Price was writing Instruments of Darkness he found a memorandum in Lindemann’s files, dated 8th March 1938, which ran:
Lest too much reliance be placed upon the R.D.F. methods, it is perhaps worth pointing out that certain difficulties may easily be encountered in actual use.
Though undoubtedly excellent for detecting single aircraft or squadrons thereof, flying together, it seems likely that great difficulties may be encountered when large numbers of aeroplanes attacking and defending are simultaneously in the air, each sending back its signals.
This difficulty may be very materially increased if the enemy chooses to blind the R.D.F. operator by strewing numbers of oscillators in the appropriate region. Such oscillators need consist merely of thin wires fifty to a hundred feet long which could easily be suspended in suitable positions from toy balloons or even, if only required for half-an-hour or so, from small parachutes. As far as the R.D.F. detector is concerned, each one would return an echo just like an aeroplane.
The first formal indication that I had that our work might close was when I was summoned to a meeting of the Tizard Committee on 21st October 1937, when the Committee at least seemed anxious that the work should be removed from Oxford. Tizard invited me to lunch on 8th November, to discuss the future in more detail, and I received dire warnings from Lindemann as to the artfulness to which I might be subjected. To my surprise, Tizard started in the most friendly manner by saying to me, ‘I don’t suppose that you can remember the last war!’ I replied that not only could I remember the war, and its air raids, but that I could remember my father leaving for France on 11th November 1914, and that I could recall incidents from 1913 when I could not have been more than eighteen months old. ‘In that case’, said Tizard, ‘you have the longest memory of any man I know—except myself. Do you know, I can distinctly remember having had a bottle!’
There could hardly be much guile in a man starting an acquaintance in such an informal manner, and we had a very cordial discussion. He referred to ‘this ridiculous quarrel between me and Lindemann’ and went on to tell me that Lindemann had been godfather to his sons. At the same time, he thought that it would be better if I would break with Lindemann, and come to Imperial College, of which he was Rector, and continue the infra-red work there. I was not anxious to leave Oxford for London, and so in that respect the discussion was fruitless.
On 3rd December I again visited Bawdsey, and this time was put under pressure by Watson-Watt regarding the relative merits of infrared and airborne radar. Gerald Touch actually worked in the Airborne Radar Group whose head was E. G. Bowen and which included an outstanding young electrical engineer, Robert Hanbury Brown. They had achieved a tremendous feat in getting airborne radar to work, and there was no question that it was going to be superior to infra-red. I had the impression, however, that Watson-Watt was not a good enough physicist to realize how slender a threat infra-red had always been to him, and something about his tactics aroused my resentment. Our discussion, which he had assured me was ‘off the record’, was reported back to the Air Ministry, and it seemed that somehow he wished to get me under his direct control. He seemed unwilling to face the fact that radar, too, had its weak points. This suspicion, which could be attributed to my highly personal viewpoint, was many years afterwards confirmed by A. P. Rowe, who succeeded Watson-Watt as Superintendent at Bawdsey. Writing to me in 1962 of the ‘Window’ episode, Rowe said, ‘When I took over from W-W at Bawdsey, I found that it was “not done” to suggest that the whole idea would not work.… What I want to emphasize is that from no one at no time did I hear a breath of anything like window.’
In the meantime, I continued to work at infra-red, and proposed a pulsed searchlight in which the range of an aircraft could be directly measured by optical pulses, and the glare of the light scattered back by the lower atmosphere could be eliminated. This subsequently was developed as ‘Lidar’ the optical analogue of radar. But on 28th January 1938 I received a letter from D. R. Pye saying, ‘I have decided that in view of the urgency of some of our other defence problems, the Air Ministry programme as a whole will best be served by employing yourself and Pickard elsewhere. I have suggested 31st March as a suitable date for the termination of the Air Ministry research work at the Clarendon.’
I was very annoyed, not so much at the justice of the decision, but of the way it had come about. The Tizard Committee had encouraged me to work on infra-red at the expense of my own career, and only two months before Tizard himself had been inviting me to continue the infra-red work at Imperial College. I had burnt my academic boats, for while my contemporaries had been continuing with their normal researches, I had been working to my utmost on developments which could not be published, on security grounds, even though we ourselves did not intend to use them. I had lost my chances of an academic appointment and was now a civil servant. At the same time, convinced that war was almost inevitable, I did not wish to leave the defence field, although I certainly wanted to get well away from Watson-Watt, Tizard and the rest, where I felt that I had been a pawn in a distinctly unpleasant game. I had almost made up my mind to join my father’s old regiment, the Grenadiers.
At that very time, my father lost the sight of one eye, and there was a danger that the other would go too, and I had to face the problem of his being unable to work and therefore of my helping him and my mother. I could not do this on a guardsman’s pay, and the most sensible thing would be to continue on some work that would maintain my relatively high salary, even if it meant working with Watson-Watt. I therefore saw Watson-Watt on 4th February, and told him frankly my personal position and also my dislike of his method of approach. On his side I must admit that I must have seemed an even more problematic ‘handful’ than will have so far appeared from this account. For, having decided that I was selling myself, I was determined to get the best price I could, not so much for myself as for the men who were already working at Bawdsey.
I had, of course, seen Bawdsey mainly through the eyes of Gerald Touch, who was not given to taking a rosy view of anything. Undoubtedly, they had had to start in the old manor house at Bawdsey in very uncomfortable circumstances, and the Air Ministry had done very little to provide reasonable amenities. I thought that by drawing attention to all my prospective discomforts, I might help to get the amenities improved; but it must have made me appear a very awkward personality to Watson-Watt and Rowe.
However, it was agreed that I should go to Bawdsey, and I received a formal letter from the Superintendent of Farnborough instructing me to report for duty at Bawdsey on 1st April. Pickard was not to go with me, but instead to Farnborough; and I saw our mechanic, W. S. Driver, into another job. As for my own preparations, I knew that Bawdsey had a lawn some three hundred yards long and so I thought that I would take up archery. I would, perhaps, acquire a rather exotic dog such as a
Saluki; and since there would be plenty of secluded time I would buy many of the books that I knew I ought to have read. Of all the books that I acquired, the one which I have valued most was Bartlett’s Quotations. Years afterwards I found that Churchill at Bangalore had done exactly the same thing: ‘It is a good thing for an uneducated man to read books of quotations. Bartlett’s Familiar Quotations is an admirable work, and I studied it intently. The quotations when engraved upon the memory give you good thoughts. They also make you anxious to read the authors and look for more.’
Just as I was leaving for Bawdsey I received a telegram instructing me not to report to Bawdsey but instead to Air Ministry Headquarters in London. Watson-Watt had now been promoted from being Superintendent at Bawdsey to take charge of a new Directorate of Communications Development in the Air Ministry, and as such he would have control of infra-red work as well as of radar and communications generally. There was therefore no need for me to be posted to Bawdsey to be under his control, and in any event both he and Rowe were apprehensive about the disruptive influence I would represent. He had therefore arranged a meeting with the other two Services, and had persuaded them that infra-red should be continued, after all, on an inter-Service basis. The Admiralty Research Laboratory at Teddington was suggested as a suitable establishment, and I was to be posted there as the Air Ministry representative and placed directly under a Principal Scientific Officer in the Admiralty Service. I was thus to be removed as far as possible from any place where I could cause trouble and to be disciplined in the tradition of the Senior Service. Actually, the complete volte face by Watson-Watt took the Admiralty so much by surprise that they could not be ready for some months, and I was therefore attached to the new Directorate in Air Ministry to cool my heels.
In preparation for the move to Bawdsey my car was already loaded with my books and other possessions and so I drove instead to my parents’ home in Herne Hill and reported for duty at the Air Ministry the following morning. I can remember my feelings on leaving the Clarendon and Oxford for the last time. It would be easy to be sorry for myself. My prospects, which had appeared so bright in 1934, with Mount Wilson and South Africa in view, were now, less than four years later, completely shattered. Instead of a pleasant academic life I now faced a relatively dull one in a Government establishment, where I would be subservient to men who knew far less about infra-red than I did, and only my father’s situation had stopped me from breaking out of it. This was a rotten reward for three years of desperate work, from which I could not even recover the kudos of papers in scientific journals. I wanted never again to become involved with Lindemann, Tizard, or Watson-Watt.
CHAPTER FIVE
Exile
MY EXILE from active research in air defence did not start exactly as planned, for instead of being at the Admiralty Research Laboratory I was attached to Group Captain H. Leedham, the Assistant Director of Instrument Research and Development in Air Ministry Headquarters. A Regular officer of high principles, he was also a lay preacher; and I had already appreciated his friendly support in my arguments with Watson-Watt. Although office work was not really to my taste, the experience could be useful—and so it was to prove.
I found myself being given a widening range of jobs. Occasionally, I had something practical to do such as the acceptance trials of the first airborne television equipment for the R.A.F. Sometimes I would put up ideas myself. One that was to have later importance was a method by which a bomber could locate itself by receiving radio pulses sent out simultaneously by three ground stations. From the time interval between the pulses from any two of the stations being received by the bomber, it could tell that it was on a particular hyperbolic curve about the two stations as foci, and from the intersection of this hyperbola with another similarly determined from the interval between the pulses from one of the first two stations and the third one, the bomber could determine precisely where it was. The idea was turned down because the radio engineers said that the radio waves used would have to be short ones, and that these would not curve sufficiently round the earth to give a useful range. I found this surprising, but was not in a position to contradict them.
I was, incidentally, astonished by the complacency that existed regarding our ability to navigate at long range by night. The whole of our bombing policy depended on this assumption, but I was assured that by general instrument flying, coupled with navigation by the stars, Bomber Command was confident that it could find pinpoint targets in Germany at night, and that there was therefore no need for any such aids as I had proposed. I was not popular for asking why, if this were true, so many of our bombers on practice flights in Britain flew into hills.
The job that afforded me most interest was to examine the reports that occasionally came in from the Air Intelligence branches. These were usually very slight, but I tried to extract every possible item of information out of them, and I started to interact with Air Intelligence. Finally, a report came in that the Germans were undertaking some very high frequency radio developments on the Brocken, a well-known mountain in the Harz. Now I already knew something about the Brocken, because of the optical phenomenon known as the ‘Brocken Spectre’ or ‘Brocken Ghost’ which arises if you stand on the summit and the sun throws your shadow on a cloud below. If the conditions are right, you see your shadow with a saintly rainbow-coloured halo around its head. I decided that I would see if I could beat the official Intelligence Service in discovering more about whatever was happening on the Brocken, and so I wrote to Charles Frank explaining my interest in meteorological phenomena of the optical variety, and that I would be grateful for a first-hand account of the Brocken ghost. Before I heard from him, my time at the Air Ministry came to an end. I had in the meantime found so many jobs to do that five new Sections were set up to take them over; the Sections thus set up were to continue throughout the War.
On 2nd July I went to Teddington, and parked my car in the grounds of the National Physical Laboratory. I knew that the Admiralty Research Laboratory adjoined it, but was not certain of the way. A mild-looking man passed me and I enquired if he could tell me the way. He said that he was going there himself, and so we walked chatting pleasantly on a fine summer morning. He told me where I would find Dr. E. G. Hill, who was to be head of the Infra-Red Group, and so I made my way to Hill’s office. Hill said that he had instructions to take me to the Superintendent, who wanted to see me before I started work. So we went together to the Superintendent’s office, and he turned out to be the very man of whom I had asked the way. He then surprised me by more or less reading the riot act to me, and saying that he understood that I had hitherto worked in a university laboratory, and that I would find things different in a Government establishment, and that in particular I would be under direct orders from my superior officer, Dr. Hill. It struck me that he was overdoing things a bit, and I could very easily have exploded. However, his attitude did not altogether accord with what I would have expected of the very pleasant man who had guided me to the Laboratory, and I guessed that something must have happened. If indeed I lost my temper, this would confirm the suspicions that he obviously had. I therefore took the dressing-down as meekly as I possibly could, and he finally ran out of steam. Hill and I then departed, and as we were walking back, Hill said, ‘I’m sorry about that. Someone has been talking about you—do you know a man called Watson-Watt?’
I intended to lie as low as possible, but within the hour an opportunity occurred that I could not resist. The next step in the disciplinary process was to overawe me with the Official Secrets Act. I was shown the Laboratory copy of the Act and asked to sign a certificate to the effect that I had read the Official Secrets Act (1911) and understood it. I could not resist adding a postscript to my signature: ‘The 1920 Act is also worth reading.’ Actually, having been interested in official secrets I had some time before purchased from the Stationery Office copies of both Acts to see how they applied to my work and to anyone who might try to reveal it. It was almost incredible th
at the security authorities in the Admiralty had not been aware of the later Act, and I awaited results. The certificate was duly taken back to the Laboratory office and a little later a despatch rider was sent up to the Admiralty to check whether there really was an Act in 1920. The upshot of the affair occurred on the following afternoon when the Superintendent, whose name I now knew to be Chaffer, sent for me and said that now that I had been with them for two days they had seen quite enough to realize that what they had heard about me was entirely unjustified, and that he wished to apologize for what he had said at our first interview, and that he hoped I would have a happy time at A.R.L. Chaffer was a gentleman, and this was true generally of his staff. They made me very welcome, and I much enjoyed my time with them.
Curiously, before he became a civil servant Chaffer had been a mathematics schoolteacher, and among his pupils had been E. A. Milne, one of our professors at Oxford. An interesting brush thereby occurred between Milne and an officer at A. R. L., Colonel Kerrison, who had been seconded to the Laboratory for the development of predictors for A.A. gunfire. Kerrison was a very able mathematician, but Chaffer thought that some of his mathematics ought to be checked, and had sent the calculations to Milne. The latter replied saying that Kerrison was wrong, and that this was only to be expected from someone who knew no more mathematics than a colonel in the army. The story was that Kerrison had thereupon written to Milne saying, ‘Dear Milne, With reference to what you were saying about colonels, you may recall that in 1941 you gained the second scholarship at Trinity, Cambridge. The first scholar did not take up his scholarship but went to fight for his country. He was, Yours sincerely, A. V. Kerrison.’ I once asked Kerrison whether the story was true: he told me that he had not sent the letter but the facts were correct.
