J D Bernal Read online

  Having completed the experimental work on graphite, Sage now set out to prepare charts that would be of practical use and enable crystallographers to establish directly coordinates in the reciprocal lattice for the diffractions appearing as spots on X-ray photographs. He wanted charts that worked for both flat plates and cylindrical films and this required a prodigious amount of calculation. In an important refinement of technique, he pointed out that even the very complicated patterns obtained from crystals with large unit cells could be resolved if instead of a complete rotation, they were subjected to a series of much smaller oscillations. At one point he asked Sir William Bragg if he could have £20 for the hire of an adding machine, but ‘as this was apparently beyond the capacity of the Institution, [he] had to do the whole thing by hand and eye using seven-figure logarithm tables’.23 The number crunching took him about two months – a degree of effort easy to overlook when reading the paper.24 The whole was an in-depth mathematical treatment of the methods he was using and also contained many practical tips to others on how to deal with crystals of different symmetry and complexity. He assured his readers that ‘these methods have all been tested in practice and it has been found that even for complex organic crystals, some of which give over 500 measurable planes, they are sufficient in themselves to do this. References would be given, but so far none of the work has had time to be published.’ The manuscript of Bernal’s paper was available to others at the RI for a year or so before it appeared in print, and it was extensively studied by Astbury and a research fellow from Canada, A.L. Patterson, in connection with their own experiments. During their reworking of the paper, Patterson and Astbury sometimes arrived at different answers from one another and from Bernal.25 Patterson made a list of minor corrections, which he gave to Sage, but the original version of the paper was the one that duly appeared, giving some sport to future researchers, who could correct Bernal’s mathematics in margin jottings.26

  With the publication of this landmark paper with its ‘Bernal charts’, Sage established himself as one of the leading exponents of the burgeoning subject of X-ray crystallography. While there were some frustrations working in the cramped, dingy, rooms of the Royal Institution, for someone steeped in the history of science like Bernal, it was also immensely satisfying to occupy the basement ‘still festooned with flasks full of Dewar’s rare gases’,27 where Faraday himself had worked. With his contemporaries, Bernal was establishing the fundamental techniques of X-ray crystallography, and young though they were, they all believed that their efforts would pave the way for important future discoveries. Bernal looked back on the RI as a place where one’s wits were sharpened, where all the scientists ‘shared in common a lively enthusiasm for the discovery of the new world of crystal structure which they were privileged to share. It was a very happy time: there was no real rivalry because that world was quite big enough for all their work. They were effectively and actually a band of research workers, dropping into each other’s rooms, discussing informally over lunch and ping-pong and formally at Bragg’s colloquia every week.’28 There was a youthful, irreverent atmosphere, where Sage felt he was accomplishing a lot of research just by wandering from room to room and chatting with his friends.

  The weekly colloquia were held in the study of Sir William’s flat at the top of the Royal Institution and, according to Bernal, tended to be dominated by Astbury, who ‘was always brimful of ideas but often these were rather difficult to understand. When he spoke, most people thought he was talking nonsense. I found out fairly early that when Astbury was talking, it might appear nonsense, but it always contained a valuable and new idea and I did my best at these meetings to interpret them and, what was much more difficult, to get Astbury’s agreement that I had interpreted him correctly.’29 Astbury was a buoyant, provocative figure, who referred to all his RI colleagues as Bill (regardless of their sex); he even gingered up the lunchtime table tennis matches by placing objects such as matchboxes at strategic points on the table.30 In addition to the in-house talent at the RI, a constant stream of distinguished scientists came to give lectures; there was also a library well-stocked with books and periodicals, thanks to more than a century of members’ annual subscriptions.

  During the 1920s, Sage and Eileen lived, appropriately, in London’s two most Bohemian quarters – Soho and Bloomsbury. Their credentials and Cambridge connections gained them ready access to left-wing intellectual circles.31 They would often go to the 1917 Club in Gerrard Street, where they could rub shoulders with other young admirers of the Russian Revolution. They were fringe members of the Bloomsbury group of artists and writers, and shared the same creative spark. The Bernals seemed intent on proving that the sex life of a scientist could be as variegated and piquant as that of any painter or novelist. An inkling of the open nature of the Bernal’s marriage surfaced when they had another couple, Peter and Aimee, to stay in their Soho flat. Lying in bed with Eileen, Sage wanted to kiss Aimee good night, but his courage failed him. He thought of his countryman, Oscar Wilde, who could resist everything except temptation. Eventually Eileen egged him on and he ventured into the adjoining room where Aimee kissed him with an OPEN AND WET mouth [Sage’s ecstatic capitals], and ‘wonder of wonders, her tongue peeped out’. Peter then reciprocated with Eileen, before Sage and Eileen enjoyed ‘a perfect fuck’.32 On leaving the next morning, Aimee promised Sage future favours.

  A few days before Aimee and Peter’s visit, Sage had been ‘indiscreet’ with another woman, identified only as Pearl, and had spent the night with her ‘on the Canterbury road’.33 In the spring of 1925, Sage reflected that while at Cambridge just three years earlier, he had been finding out about life and sharing common experiences, he was now moving beyond the conventions of society. Such is the mark of a Bohemian, but to live by their own lights, Sage and Eileen were finding there were penalties to be paid: ‘Today Eileen has her lover and I have my loves and we live together but it is difficult… I cannot be jealous of E. or indifferent to her… Is it all worthwhile? What is gained by exchanging the secure bliss of conjugal fidelity for this feverish, dangerous life, a life that may… wreck all our happiness.’ Later that year, on a visit to Cambridge where they saw old friends who seemed to have lost their former lustre (Dickinson was ‘cowed’, Sylvia ‘insipid’ and Dorothy, the bewitching blonde, ‘miserable’), Sage took the ‘cowardly’ step of writing his diary after Eileen had fallen asleep. He reflected that they were ‘too close in marriage’ and as a result of knowing each other so well, were adept at hurting each other when the occasion arose and suffered the consequences. He also wrote he was in love with Pearl, ‘the devil is in the woman’, who combined charm, intellect, beauty and inaccessibility.34

  For Sage, the opportunity to be a social rebel and to explore the boundaries of personal behaviour was as irresistible as the chance to be at the leading edge of science. At times he appeared distracted in both arenas, seeking new excitements, but he thought of himself as a serious pioneer, who could help those following on ‘to avoid the snares’ in their private or scientific lives. In fact his hectic schedule, both in and out of the laboratory, was not given to imitation. He was able to concentrate for long hours on abstruse scientific problems and then seek sexual adventure in the evenings. January 1926 was a particularly full month. The night of the 8th found him in bed with the inaccessible Pearl, his hand on her ‘unexpectedly lovely breast’, while Magda’s warm body curved round his naked back – ‘with infinite pains we all turned round in the narrow bed… then by magic we all slept.’35 The next week he had lunch with Molly at her club and then she came home to dinner. Over the ensuing fortnight, there were separate assignations with Magda, Pearl, and Naomi. Not surprisingly he sometimes got into trouble by making too many appointments; quite remarkably, he still found time to finish the paper on single-crystal rotation techniques. By the end of the month, even Eileen had had enough of his energetic philanderings, and they discussed separation; Sage was miserable for the next day until they ma
de up. No sooner was harmony restored than he embarked on an affair with a married woman, named Ivy, who lived in Hampstead. Ivy’s young daughter, who became immensely fond of the entertaining Sage, had her first introduction to him when her mother opened the bedroom door one morning, and she saw the enormous head of a man fast asleep. Ivy said to her, ‘This is my new lover and he’s the most fascinating, brilliant man I’ve ever met.’36

  At the time of these shenanigans, Eileen was six-months pregnant, but probably not with Sage’s child. As her confinement approached at the end of April, Sage was moved to write: ‘And now she lies in child bed fighting out life… This is her great moment because with the child she justifies all the difficult year behind and our struggle for freedom… For the child don’t imagine anything, he seems incidental now, I doubt any less than if he were mine. Love may things go well with you.’37 Eileen was admitted to a nursing home on 29th April and Sage spent an anxious night. A son arrived the next day and Sage was there to see the first bath. During Eileen’s pregnancy, her mother-in-law, Bessie Bernal, had often sent new-laid eggs and other farm produce from Ireland; in return, Bessie felt that Desmond had been ignoring her. ‘I think’, she wrote, ‘I am not unreasonable in asking you to devote ten minutes per week in writing to Brookwatson; the letters you write could not take much longer than that.’38 She had no idea of her son’s unconventional domestic life and wrote anxious for information ‘about how Eileen and the boy are, what he is to be called and many other interesting facts that you must supply’.39 She was also concerned that the General Strike would stop all mail and although she hoped the strike would be short-lived, did not know where Desmond’s ‘sympathies lie, so will say no more’.40

  Sage’s sympathies of course were completely with the strikers, and he was as exultant in making street speeches against the evils of capitalism as any undergraduate taking a turn as a stand-in bus driver or docker. On 6th May, towards the end of the first week of the General Strike, he walked eight miles through the City of London to Leather Lane in the East End to give a speech, and noted with satisfaction that there was a complete stoppage everywhere. The Government printed a newssheet, the British Gazette, under the direction of Winston Churchill, to make the case for the authority of Parliament and to offer the prospect of negotiation about the crisis in the coal mines that had pushed the Trades Union Congress (TUC) to call the General Strike in the first place.41 The Prime Minister, Stanley Baldwin, made a conciliatory BBC broadcast on 8th May, and forty-eight hours later, Bernal felt that the tide was turning against the strikers. He wrote in his diary: ‘A gloomy day. Government propaganda telling. I go to work and do not speak.’42 On 12th May, the TUC drew back from the precipice and decided that it could no longer support a continuation of the strike, since there seemed to be willingness on both sides to negotiate a ‘fair deal’ for the miners.43 Sage found consolation the week after it ended, when Vera, a friend of Eileen’s, invited him ‘to distract her from the strike’.44

  Occasionally Bernal would escape from the multifarious demands of his London life by visiting Cambridge for a day or two. In January 1926, he had dinner there with Nathan and Susan Isaacs. Their other guest was J.B.S. Haldane, the geneticist, with whom Sage argued about the philosophy of science.45 Susan, a woman her early forties, had made a reputation as a psychologist before being recruited to run Malting House – a progressive school which aimed to educate the young children of Cambridge dons in an environment that would encourage curiosity and self-reliance. The school was conceived by Geoffrey Pyke, a flamboyant and disorganized eccentric, who financed the enterprise by nerveless speculation in the London commodities market. Bernal was introduced to him a few weeks later at a Bloomsbury gathering, where Pyke stood out amongst the self-conscious crowd. Geoffrey Pyke was very tall and gaunt; he talked with the conviction of a man entirely reliant on his own ideas. Sage for once was the beguiled party, and was fascinated by Pyke’s incongruous appearance. In particular, he could not understand why Pyke was wearing a pair of highly coloured spats – the insignia of a city slicker – at a radical soirée. When he chided Pyke about them, Pyke explained that they were very sensible items, and reaching down to his ankle, said: ‘You see, they can be worn for weeks – and they obviate socks which I’d have to change much more often!’46 Shortly after this first encounter, Sage and Eileen invited Pyke to dinner, and he stayed the night. Somewhat to Sage’s discomfiture, Pyke and Eileen spent hours discussing his affair with Ivy.47

  Both Sage and Eileen had joined the Communist Party of Great Britain (CPGB) soon after moving to London, but were still entitled to membership of the Holborn Labour Party, which was a particularly active, left-wing constituency.48 Just as the General Strike polarized the country at large and left a legacy of bitterness that endured much longer than the strike itself, the Holborn Labour Party was riven by factional disputes. In the summer of 1926, it appeared to Bernal that the Left-Wing Group within the branch might dissolve, but it survived and he subsequently emerged as its leader. The position did not bring him much joy, and in November he complained that ‘The Labour Party saddle me with many unpleasant jobs.’49 The coal miners had remained on strike through the summer, desperately surviving on ‘home-grown lettuce and mutton stolen from the hills’,50 but eventually gave up. Many pits closed, throwing hundreds of thousands out of work, and those who did return were forced to accept lower wages – the original grievance that had sparked the strike. The Communist Party in the 1920s provided no specific role for intellectuals in its ranks,51 and Sage found himself instead at the Holborn Labour Party offices ‘addressing letters for the belated Miners’ Appeal’.52 In February 1927, Sage carried the Holborn banner during a march to Trafalgar Square,53 but even his patience and conciliatory nature could not hold the Left-Wing Group together; he soon resigned the leadership, one senses, with little regret.

  After solving the structure of graphite, Bernal was preoccupied with general improvements in the practice and theory of crystallography and attempted little more experimental work at the Royal Institution. He was stimulated by a talk given by A.J. Bradley, a young research student from Lawrence Bragg’s department in Manchester. Bradley was establishing himself as the most brilliant crystallographer in the field of metals, especially alloys, and he had just employed the powder method, with unrivalled virtuosity, to establish the structure of brass (Cu5Zn8). Emboldened by his previous success with graphite, Sage decided that the single crystal method would be superior to the powder technique and set out to study bronze, an alloy of copper and tin. He succeeded in taking the first cylindrical diffraction photograph in February 1926, and the following month began to measure the spacings between the atoms of copper and tin in a crystal of bronze. He needed to ascertain the density of the crystal, which was less than half a millimetre in size, and decided to use a very delicate flotation technique:

  I sat all day in the cellar next to where Faraday worked. All around were great globes, which held the first of the rare gases, on the table a trough of water and in the middle my beaker of heavy yellow liquid. I had six floats of aluminium wire and six small counter weights and then I had my crystal, very precious crystal, which I hung in a small cage, a cage the size of a breadcrumb. One by one I had put the floats in with their counter weights, and then gradually, with the most delicate touch, I cut with a razor a mere shaving off the ends of the fine wires so that in the liquid they hung steadily suspended neither rising nor falling. Each time I cut I weighed them again on a fine balance made of quartz fibre. A thousandth of a milligramme more or less, that is what I must know. All were out, and weighed and balanced, and last of all the crystal in its cage was in the liquid and floated. I took the aluminium wire and shaved and shaved at it until the whole stood irresolutely in the liquid, moving still upwards. So imperceptibly upward, that I seemed at the end of my task. I waited, then cut again, and now it sank. I lifted the wire and the cage from the liquid, carefully, delicately and then without knowing, my hand shook, it had di
sappeared, gone. The crystal had gone. Crystal that I had worked on for months. Crystal about which I knew everything, but that one final weighing, and now it was gone, and all those months of work with it. ‘Stupid’, I thought, and as I gathered patiently all the dust of that room, looking through it grain for grain, for my crystal, ‘If you had thought more, this could not have happened.’ It was stupid to arrange things so that any weakness or wavering may lose everything.54

  Sage did recover from this setback, and a year or so later published a letter in Nature55 in which he announced that the structures of bronze were much more complex than metallurgists had previously believed. The single crystal of δ-bronze, the type he first studied at the Royal Institution, he demonstrated was closely related to γ-brass and had a cubic structure. The δ-bronze crystal had a very large unit cell probably containing 328 atoms of copper and 88 of tin: instead of the currently used formula of Cu4Sn, Bernal suggested that the simplest formula could be Cu41Sn11. Displaying generosity and also a fluidity of purpose that would be repeated many times in his career as a scientist, Bernal chose not to carry his investigations further and instead gave his δ-bronze data to Bradley (who had published the structure of γ-brass in 1926), and the beautiful needle crystals of ∈-bronze to Linus Pauling, when he visited England from the US in 1930.56

  For the year or so that Bernal remained at the RI, he concentrated on designing an accurate and serviceable crystal rotation X-ray camera that could be used in any laboratory. The result was the universal X-ray photogonio-meter, a solid and versatile instrument, which could take single-crystal rotation and oscillation photographs as well as Laue and powder photographs. It would be the mainstay of many crystallography laboratories for years; details of its construction, as well as notes for its use under various conditions with different types of crystals, were contained in a series of four papers that appeared over the next four years. Bernal approached the Cambridge firm of W.G. Pye and Company to manufacture the photogoniometer; by the spring of 1928, they were able to offer the ‘spectrogoniometer’ for the basic cost of £50, plus £26 12s for extras such as the goniometer head and powder attachment.57