Dr. W.B. Lewis, to whom I had reported directly before we left for the USA, was now Chief Superintendent of TRE. He telephoned me one day in the summer of 1946 and asked, “Would you like to spend a couple of years in Cambridge?” I responded, “Yes, why?” It transpired that an old friend of his, F.P. Bowden (no relation to the B.V. Bowden of IFF days), had asked him for help in updating the experimental techniques in his laboratory, by providing someone who was familiar with the wartime advances in electronics. F.P. (Philip) Bowden’s “Research Laboratory on the Physics and Chemistry of Rubbing Solids” (PCRS) had recently returned from Australia, where it had been sent early in the war, out of the way of German bombs, because its research on friction and lubrication had military implications. It had been housed by CSIRO Melbourne, but was now once more attached to the Physical Chemistry department of Cambridge University. Not surprisingly, most of the graduate students in the Laboratory were, at that time, Australians.
Lewis offered me the opportunity to go join the PCRS Lab on loan from TRE; that is to say on full salary with no strings attached. I went up to Cambridge to meet F.P. Bowden and see the labs. I liked the atmosphere and saw plenty of opportunities to do just what this new Bowden wanted. So, after discussing the move with my wife, Nesta, I agreed to go, on condition that, in addition to being a consultant to the Labs, I could register on the side as a ‘research student’ so that I could submit a thesis for the Cambridge Ph.D. degree I had missed because of the war. Bowden and Lewis agreed, so we moved from 7, Southlea in Malvern to 17, Kimberley Road in Cambridge in the fall of 1946. We occupied the upper floor of the house. The lower floor occupant, Valerie Bell, became a friend of our family. She was single then, but we were still in touch with her more than half a century later when her husband – a well-known and distinguished advertising executive died in the year 2005.
Both F.P. Bowden and W.B. Lewis were Fellows of Gonville and Caius College , Cambridge so they sponsored me for membership. Belonging to a college was an essential preliminary to getting a Cambridge degree. I was soon granted MA Status on the basis of my Manchester degree (another essential preliminary) and my wartime work. It is interesting to note that I would not have been eligible to register for a degree in Cambridge at that time if I had not previously matriculated in Latin. However, I had done so in my School Certificate Examination in 1933, following six years of Latin at Clitheroe Royal Grammar School.
1. Commonly referred to as Caius College.
The pronunciation of ‘Caius’, if not the behaviour of its Fellows, is most entertainingly illustrated by a Limerick from “Alma Mater”, by Benstead and Norfield (Frederick Muller, 1944):
A festive old fellow of Caius
Once took a young maid on his knaius
But as soon as he tried
To embrace her she cried
You mustn’t do that, if you plaius.
The PCRS Laboratory was wholly engaged on research on what happens at the interface between two metals when they slide over each other; in other words, the fundamental processes that determine friction and wear. F.P. Bowden and David Tabor had devised experimental equipment, made measurements and developed theories of the mechanism of sliding friction, with and without lubrication. All their experiments were made on a large apparatus which applied loads of at least several hundred grams between the surfaces during sliding. It was this fact that led me to do my own research at very much lighter loads.
There were about ten research students working on various aspects of the problem, including one on the frictional detonation of explosives. This student, Owen Gurton, built a heavy concrete ‘box’ in the middle of one room, in which he caused small amounts of explosive to detonate and used a rugged high-speed camera as one way of observing the results. His room was round the corner from the main lab and he would appear every now and again with a pear-shaped push button in his hand shouting “FIRING”. There would follow anything varying from silence to an explosion that rocked the laboratory. The uncertainty of the outcome of each “FIRING” stimulated a good deal of friendly banter, particularly on the part of the Australians. My young technician, Bob Horne, who was a gifted cartoonist among his many other talents, appeared one day with a superb cartoon showing a recognizable Owen Gurton peering around the corner saying “FIRING” while, in the background, chunks of concrete mixed with symbolic camera parts (lenses, bellows, etc) flew through the air.
Nesta and I became close friends with several of the graduate students from Australia and we often entertained them at our flat. They were great characters and we have maintained contact with most of them to this day. I was to have the opportunity to visit some of them in Australia in 1973.
Jeofry Courtney-Pratt was one of the graduate students from the antipodes. Like F.P. Bowden, he was born in Tasmania. He was experienced, brilliantly inventive and inordinately proud of his English ancestry and the fine Courtney name – not to mention the hyphen. Jeof arrived in Cambridge before we did and he also was recommended to join Gonville and Caius College. When he arrived at the College, he was summoned to the Master’s presence. The story goes that he knocked at the door and the Master called out “Come in Mr. Pratt and take a chair.” Jeof, stiffly, said “The name is Courtney hyphen Pratt.” “Take two chairs,” was the Master’s withering reply.
Jeof was a bit eccentric, even on his own admission. He professed always to be cold in England and he often mooched about the Laboratory in a long black overcoat. Not that we saw much of him by day, because, at that time, he preferred to work from about 4 pm to 4 am ostensibly to be free from distractions but actually because he hated mornings. Nothing would deter Jeof once he got an idea. The less conventional the approach, the better. When he wanted a rigid, long optical bench for some experiment, he scrounged from somewhere a steel I-beam which I will swear was 20’ long and 3’ in height. It weighed tons and was far too big to bring into the laboratory by conventional means. So he knocked a large hole in the wall and had it brought in that way. Our cartoonist, Bob Horne did not miss the opportunity. A cartoon appeared on the notice board showing the lab containing nothing but a huge I-beam, with a tiny figure in a long black overcoat looking up at it with evident satisfaction.
Bob Horne himself was quite a phenomenon. Soon after I arrived in Cambridge I advertised for a technician; we had about 40 replies. I interviewed a truly nondescript lot, some of whose paper qualifications were adequate, but who didn’t appeal to me for one reason or another. The last one to be interviewed was a 21-year-old, straight out of the RAF with practically no relevant education or experience that I remember. I liked him. He was self-deprecating but obviously bright and willing to work. I took him on and he was quick to catch on to the job. Moreover he was popular with both the scientists and the other technical staff. When I was working on the electron microscopes over in the Cavendish by courtesy of the celebrated electron microscopist Dr. Cosslet, Bob asked if he could come with me and learn something about these instruments. Before I left PCRS, Cosslet advertised for an electron microscope technician. He was looking for a senior man with a lot of experience. He couldn’t find one. Every time I saw him I suggested he try Bob Horne for the job. Finally he did. The move turned out to be a great success for both of them. Apparently, after a year or two, Bob became interested in the microbiological research being done using the microscopes by members of the Biology Department. He began to do some research himself and, to cut a long story short, he was awarded an honorary MA by Trinity College and later elected to a Fellowship – a unique series of events for a self-taught technician. When I last saw him, several years ago, he was the Director of a large Government Agricultural Research Laboratory.
One of the cheeriest and most agreeable young graduate students in the PCRS lab. at that time was Peter Gray, a chemist, also a Member of Caius College. We heard from him forty years later, in 1989, on his appointment as Master of the College. He is a worthy member of a long line of distinguished Masters which included the famous physicist, Sir James Chadwick, who was Master during my last year there. Chadwick always seemed to me to be uncomfortable with the job. There are strict, unwritten rules of behaviour at High Table in College and Chadwick seemed to have little interest in them. If the Master did not appear in the Senior Common Room for the assembly for Dinner, the President of the College Council would preside. Chadwick had the habit of appearing at the table half-way through the meal, urging everyone not to be disturbed. He would pull up a chair beside me (the only other physicist present) and talk physics (apparently his only interest) for the rest of the meal. You have to have known the Cambridge Colleges at that time to appreciate the magnitude of that breach of College etiquette. However, it is hard not to forgive a Nobel prize-winner.
Caius Court, Gonville and Caius College: Ackerman print.c. 1815
The Gate of Honour is on the right and the Senate House in the background.
Gonville and Caius is not the oldest College in Cambridge, but it celebrated its 600th Anniversary in 1947 with a magnificent banquet. The name “Sexcentenary Celebrations” aroused a good deal of ribald comment from the undergraduates, who assembled in the College Hall which was set with priceless College silver for the occasion. I complemented the Master on the magnificent silver. He remarked “It’s a pity we can’t bring it out more often; we haven’t had it out of the cupboard since the last time.” “The last time?”, I asked. “Why, the last centenary, of course”, he said. It is indeed a fact that the Cambridge Colleges are very wealthy and have many treasures which rarely see the light of day. The remark was characteristic of the dedication of a good Master to the continuity of the institution, not the individual, so that he practically feels that he was present at the last centenary.
One of the pleasures of Cambridge (and there are many) was punting on the Granta (Cam) along the ‘backs’ (of the Colleges). We took advantage of it and spent many lazy afternoons on the river. A favourite trick was to attract the attention of a punter away from his task, just as he was approaching one of the diving boards. With luck he would be left hooked over the diving board while the punt and his girl friend went on down the river. Another was to stand on one of the bridges and grab the punt pole just as the punter raised it for the last push before the bridge. If he was stubborn and held on, he could then be gently lowered into the river on the end of the pole.
I spent the first two years in Cambridge advising the research students and staff in the PCRS Laboratory on their experimental techniques. By the summer of 1948, I decided I had better start some research of my own if I wanted to get a Ph.D., as I was committed to returning to TRE in the spring of 1949. Of course metallic surface phenomena in friction and lubrication were not really my specialty. But in the course of the two years I had privately deplored the fact that the whole laboratory had, up to that time, confined its experimental work to sliding metals over each other at loads of over 100 grams, with the consequent catastrophic damage. According to Bowden and Tabor’s theory, the metals only made contact over a very small fraction of the total apparent area of contact, because, on a microscopic scale all surfaces are rough and if you put one rough surface on another they only touch at the tips of the asperities. Bowden and Tabor argued that the pressure at these tips was so great that the metal flowed plastically until the integrated real area of contact was just sufficient to support the applied load without further movement. But no-one had proved it by experiment because the damage to the surfaces was so great as to defy quantitative interpretation.
Even at loads as low as 100 grams, the damage looked rather like a furrow in a ploughed field. I decided I would like to take observations at loads which were light enough that, on a well-polished surface, a slider would ride on a single asperity. On the other hand, such measurements would mean little unless I could compare them directly with the mass of measurements that had already been made at loads between 100 grams and several kilograms by Bowden, Tabor and their students. I estimated this would mean making measurements at loads over a range approaching a million to one, i.e. from 1 milligram to 1 kilogram. To do this on a single apparatus without changing the geometry of the system was a challenge. I solved it by using a series of cylindrical rods to hold the slider . The vertical deflection applied the load and the horizontal deflection (electronically determined) measured the friction. The apparatus looked rather like a very slow phonograph turntable. The machinery was built by our machinist, Roy Moss, with great precision.
2. The deflection of a cylinder under a given force is proportional to the fourth power of the diameter.
The results were spectacular. At loads below a few grams, Amonton’s Law, which postulates that the frictional force is proportional to the applied load, broke down. On certain materials the frictional force at lighter loads was much less than expected from previous theories. It turned out that, on materials like copper, the microscopically thin oxide layer formed by exposure to the atmosphere protected the surface at very light loads and the slider found itself ‘skating on thin ice’, with very low friction. At loads above a few grams the ‘ice’ (which was a microscopic film of copper oxide, formed on exposure of the clean metal to the atmosphere), was penetrated and the metals fused together and tore apart during sliding to produce the catastrophic damage that had always been seen before.
The apparatus for measuring sliding friction over a wide range of loads
I used electron microscopy to examine the surfaces after sliding and was able to confirm the Bowden-Tabor theory of plastic flow for the first time by actual measurement.
The electron microscope images of the surface damage were obtained by making thin-film replicas of the area – a technique that was only invented in the 1940s. I used two accepted techniques. One was to oxidize the surface to a depth of about 800 Angstrom Units and then strip off the oxide. The other was to use a thin film of polyvinyl formal (formvar) deposited on the surface to form a removable replica. As a result of this work I received an invitation to present a paper to an electron microscope conference in Paris in 1947. It was my first visit to Paris on which I felt the stirring of an affection for that City that has grown with the years.
Shadowed E.M. replica image of a minute 3 micron wide scratch on polished
(Magnification about 10,000). Shown for the first time in Paris, 1947.
Towards the end of my research, I registered my discoveries in a brief note to the journal “Research” . As a result, to my great surprise and delight, I received a telegram from the Royal Society inviting me to present these results at a full meeting of the Society in London. It was a daunting prospect. After the presentation Bowden’s principal rival, Professor Finch of London University rose and asked me who I thought I was to break Amonton’s Law after all these years (It was propounded in 1699) and dismissed my work as “a lot of nonsense”. Fortunately, before I could speak, E.N. da C. Andrade, who happened to be a boyhood hero of mine because of his books, rose, supported my theories, and essentially told Finch not to be an old fuddy-duddy. So the meeting ended in a congratulatory mood.
My research work for the Ph.D. only started in the fall of 1948 and I was recalled to TRE in the Spring of 1949, so I rushed to write a full paper to be published in the Proceedings of the Royal Society , preceded by the note to the journal “Research”. I worked night and day taking photographs, processing electron micrographs and drawing figures. Bertie Dean, the wonderfully helpful Lab Steward of the PCRS Lab worked with me to process prints from some hundreds of negatives for the thesis, while my wife Nesta typed and edited it. I had to leave suddenly to visit TRE before the thesis was completed and Nesta labelled and inserted all the illustrations, completed the editing and had to deliver it without my ever seeing the final version. I guess she earned the Ph and I the D.
3. Metallic Friction and Surface Damage at Light Loads; “Research” (2) 1949.
4. Friction and Deformation of Solids at Light Loads, Proc. Roy. Soc., A 201, 109.
I only saw F.P. Bowden once after I left the PCRS Lab. It was about 20 years later, a year or so before his death. He flattered me by saying that the work of the Lab over that 20 years had mainly been stimulated by the breakthrough made during my six months of ‘nodding in’. He added, graciously, that it was a pity I had felt a commitment to return to TRE. His book  contains many references to my research.
That was a busy time. I had been working for about a year in ‘spare’ time on the book Superregenerative Receivers (loc cit.), based on the wartime work and the post-war collaboration with George Macfarlane, while developing the theory. J.A. Ratcliffe, now back from TRE in the Cavendish Laboratory, asked me to write it as one of a series of books he was editing for the Cambridge University Press. The deadline for this also arrived in the Spring of 1949 and I remember well that Nesta was typing both manuscripts at about the same time. It was published in 1949 and is still, I believe, the definitive text on the subject. I had a request for a copy from someone in the United States as recently as the Spring of 1989, 40 years after publication. I sent him my last spare copy. He never wrote to thank me. I had another request from Harold Wheeler, the celebrated pioneer of radio and television, whom I knew during my wartime stay in the USA. Harold, now in his 90s, was writing the second volume of his autobiography. The first volume  was published in 1980; the second  in 1993.
5. The Friction and Lubrication of Solids, by F.P. Bowden and D. Tabor; Oxford at the Clarendon Press, 1950.
6. The Early Days of Wheeler and the Hazeltine Corporation – Profiles in Radio and Electronics, by Harold Alden Wheeler; copyright Hazeltine Corporation; Hamilton Reproductions Inc., Poughkeepsie, NY.
7. Hazeltine Corporation in World War II, by Harold Alden Wheeler; Pathfinder Publishing of California, Ventura, 1993.
That was the end of our Cambridge interlude and we returned to TRE and 7, Southlea in Malvern. Our daughter and first child, Valerie was born on August 11th, 1949 – A very productive year!
Nesta with Valerie a few days old.
I was now Head of the Physical Electronics Division in the Physics Department under Dr. R.A. Smith. My colleagues were Dr. G.G. Macfarlane (Theoretical Physics) and Dr. F.E. Jones (Experimental Physics). George Macfarlane went on to become Deputy Director of the National Physical Laboratory and then returned to TRE as undoubtedly its best post-war Chief Superintendent. He became Chief Scientist of the UK Department of Defence later. He later received a knighthood. Frank Jones moved at about the same time (early ’50s) to the Royal Aircraft Establishment (RAE) as Deputy Director and then entered industry. He was the Managing Director of Mullards (UK Philips) for many years. He died in 1984.
The Superintendent of the Physics Department, Dr. R.A. Smith went on eventually to become Rector of the Herriot-Watt University in Edinburgh, where we were able to visit him on one or two occasions in later years when our daughter Valerie was at the University of Edinburgh on a Commonwealth Scholarship. He was a modest man whose wartime contributions to science were underestimated. Incidentally, he inherited our hi-fi equipment and a pile of classical LPs when we emigrated to Canada in 1951, including a heavy oak floor cabinet I had crafted myself.
Life in Malvern in the late 1940s was very pleasant. There was the occasional concert at the Winter Gardens. I remember Sir Adrian Boult conducting an Elgar concert there. Elgar, of course was closely associated with Malvern. Also the Winter Gardens was the home of the Shaw Festival. While we were there G.B. Shaw wrote a new play “Brewster’s Billions” for the Festival and it was presented starring the platinum blonde star, Frances Day. One of our next door neighbours, Bernard Hodlin, who was the executive assistant to the Chief Superintendent of TRE was an amateur potter. For the occasion of the Shaw play, he sculpted a miniature porcelain figure of Frances Day in the costume of the Shaw role and presented it to her at the theatre. He also decorated, inscribed and glazed a christening mug for our daughter Valerie in 1949. She was christened in the Priory Church in Great Malvern. We had no premonition that she would die so tragically in Edinburgh in 1985.
In 1950, it was decided to hold an historical pageant in the grounds of the Winter Garden. There would be hordes of costumed performers, some of them galloping in on horseback. For some reason I still don’t understand, I was persuaded to select the recorded music to accompany the pageant story. I remember choosing the rising horn passage from the single-movement Sibelius 7th symphony to accompany a triumphal entrance, but have no longer any recollection of the story or the rest of the music. I was an unlikely candidate for the job because I have never studied music. I guess my only qualifications were a love for classical music and a decent collection of records. After the war, we had picked up cheaply a number of the original vinyl LPs, known as V-discs, made for the US Armed Forces, as well as having a good collection of 78s.
Nevertheless, the two years after our return from Cambridge were something of an anticlimax. I was now a Principal Scientific Officer – one of the youngest in the civil service – and life had been pretty eventful. Now it became more routine and I think we became a little restless. The post-war head of TRE, Dr. W.B. Lewis, who had arranged my interlude in Cambridge, had emigrated to Canada to create the Atomic Energy of Canada Research Laboratories. He persistently nagged us, either by letter or in person, to join him in Chalk River, Ontario. This must have started in 1949, because I can picture him in our apartment, on a visit from Canada, trying to be polite to the proud mother with a week-old baby; he had no idea what to say to either mothers or babies. Nevertheless he was a very kind, sincere man who had more influence on our future than anyone, except perhaps Blackett.
One day, in 1951, we received a letter from Lewis which called attention to a vacancy in the Eaton Electronics Laboratory of the Physics Department of McGill University at the level of Associate Professor. I was busy and we didn’t seem to get around to discussing it for a day or two. One evening Nesta and I were sitting on the couch, waiting for a taxi to arrive when I said, “We haven’t replied to Lewis; what do you think we should do?” “What do you think,” she asked. “I don’t know,” I said, “its really up to you.” “Alright then, let’s go,” she said. Then the taxi arrived. That is the only discussion I remember ever having on the subject.
Looking back almost 50 years, it is impossible to outguess that decision. We have no way of knowing how our life in England would have developed. The new Chief Superintendent of TRE, Mr. Richards, was astounded when I broke the news to him that we were leaving and angrily said that we were fools to emigrate to that “ill-developed country where scientific research is in its infancy”. There was some truth in his remarks and, for all we know his advice might have been good. However, in the event, we never did try to question the decision at any time during our later lives. I suppose we were always too busy going forward and turning perceived shortcomings of our environment into opportunities to look back. In the event, it was to be eight years before we even returned for a visit.