by Andrew Brown
A week later, Sage diagnosed himself as suffering from ‘sex repression’ after Dora Grey had spent the afternoon sitting in his lap. He began to think ‘there are more difficulties in our experiment than the first analysis showed’. After a night of tumultuous dreams, and not feeling as fit as he would have liked, Bernal walked to Dora Grey’s house with Hutt. Hutt had a more elaborate Freudian theory about their amorous connections: Grey’s ‘erotic energy first manifested towards him was inhibited and that the overflow went into the first suitable channel which happened to be the sympathetic and not unwilling Sage’.80 The arrangement was ended by Dora, a few days later, when she told Sage that she loved him ‘mainly from pity’ and because Hutt had suggested it. Bernal readily conceded that he had a great gift for self-pity and announced that he would exaggerate the love he had for Dora so that he could feel more miserable at having lost so much! In fact, his misery was short-lived because he soon found himself a new female companion, Eileen Sprague. She was a friend of Dora’s, also politically active and like her worked in Cambridge – at Miss Pate’s secretarial agency, where she had transcribed Keynes’ The Economic Consequences of the Peace in preparation for its publication. Bernal had first spotted Eileen at a CUSS meeting at Emmanuel at the end of his first year. Then he sat on the floor with a college friend, Lucas, and ‘looked at a girl in a yellow jumper and pale bobbed hair whom we both found very attractive. We learned afterwards that it was a certain Miss Sprague.’81
Bernal met Eileen Sprague on a casual basis at several other meetings, including one where they heard a talk on sex by ‘the stupendous Jonty Hanaghan’.82 Hanaghan was a self-proclaimed Freudian psychoanalyst, who was instrumental in setting up Hutt’s relationship with Dora Grey. Bernal decided that Eileen was also likely to be a free-spirited woman and invited her to tea in his rooms. Again she looked very pleasant but ‘her conversation for the most part is gush but it is affected so that does not matter’.83 Hutt was also there and they talked about religion. As usual, Bernal did most of the talking, but did discover that Eileen was agnostic. Agnosticism was, in fact, a Sprague family tradition – her grandfather, Thomas Bond Sprague, had been Senior Wrangler in the 1850s and was a fellow of St John’s College, Cambridge before leaving the academic life to become an actuary. He rejected the Bible as nothing more than a human creation and saw no evidence for divine providence in the world so that religion held no meaning for him.84 The afternoon conversation with Eileen finally pushed Bernal into action, and after Hall that evening, he went to see Father Marshall to announce his ‘gradual and inevitable descent from religion’.85 Bernal appreciated the priest’s ‘gentlemanly restraint and delicacy’; on leaving, ‘I wanted badly to go into the familiar chapel to pray to his God and mine, but I passed the door and stepped down the stairs… The God of my childhood is long departed from me.’
Bernal soon came to realize that Eileen Sprague was a formidable opponent in an argument, and also backed up her political beliefs with action. In a debate the following week, Bernal was arguing for moral relativism, denying the existence of an objective good. Eileen took him on in a spirited dispute, and he eventually backed down. Later that evening, the two of them wandered through the streets of Cambridge and she talked of ‘the hopeless monotony of most peoples’ lives’.86 There had been municipal elections in November 1920, and Eileen canvassed on behalf of the Labour Party. She ‘spoke of what she had seen in the Central Ward. Being a coward and an idler I have no arguments with people who dare and do things. I can only admire them and agree with them.’ They parted after four hours of talking with a handshake and Bernal felt he was ‘in love with Sprague but not enough to make me miserable’.87
Bernal and Eileen exchanged letters while he was in Ireland later that summer, but when he returned to Cambridge there was another suitor in her life. By taking her out on the river and walking in Grantchester meadows, Bernal soon ousted his rival. Their relationship was tempestuous though, with Eileen the dominant partner, now quite capable of making him miserable. She started to type his space lattice paper, but every few days, work seems to have been interrupted by a quarrel or by Eileen losing her temper. The Freudian seminars by Jonty Hanaghan continued, promoting the virtues of sex, but when Sage confessed that he was attracted to Sylvia Barnes, another mutual friend, Eileen threatened to leave him.
During the Christmas vacation, Bernal told his family that he was planning to marry Eileen. There was outright opposition from Gigi and Cuddie, but his mother, recognizing that this was a futile tactic, made the enlightened suggestion that since ‘all these advanced girls believed in free love. Why can’t you do what you talk about, live together without marrying and make a success of it.’88 According to Sage, Hanaghan managed to weave a tangled web amongst his followers where ‘triangles have given place to the most complexly joined polygons and jealousy is by no means absent’.89 Sage and Eileen were the nexus for several of these relationships, involving Sylvia Barnes and Allen Hutt amongst others. After a week of mounting jealousy, Eileen came to Bernal’s room wearing a brown cloak and muffler. She challenged him to undress her and ‘perform the final rites’. Sage replied it would be like unveiling a statue and wished there was a brass band playing God Save the King, but gently slipped open the big buttons one after the other until ‘with a sharp turn of the wrist… all fell apart’.90
Despite the intensification of their affair, desultory intrigues continued on both sides. In March 1922, Bernal went with Sylvia to visit a friend, a bewitching blonde named Dorothy, in hospital. After a while, Sylvia left and Sage made overtures to Dorothy. Eileen apparently was very amused by this, and in turn flirted openly with his friends Lucas and Twam. When Sage visited Dorothy back at Newnham College, Eileen responded by going off with Hutt. After a few days, Sage was reconciled with Eileen, but could only think of Sylvia! Not the least surprising aspect of this tortuous story is that it appears in a letter to his mother, who was already suspicious of Eileen as ‘an experienced husband hunting woman’. The engagement was now a matter of public knowledge, and they decided to marry at the end of the academic year. Bernal wrote to his mother informing her of the plan, although he knew that she disapproved strongly, ‘partly for my sake, partly for the family’s, partly for your own’.91 If her objections that a wife would be a burden at the beginning of his career and that he was too young for the responsibility proved true, he would ‘find a way out, not so difficult in spite of abominable divorce laws’. He reminded her that his life was his work – science. To be successful he had certain minimum requirements: ‘food, clothing and to be left alone. If I am not happy, if I cannot do my best work without a mate, I must have one. For these ends I take what I can, not greedily, my wants are few, but what I take I feel is my right and I am not ashamed to have it gathered from the pennies of the poor by my own mother’s labour. What I give to the world is my own work’s worth, however poor it may be, I cannot give more.’ He feared that his mother saw only obstinacy, folly, and selfishness, where he felt determination, insight, purpose.
Reflecting on the eve of his twenty-first birthday, Bernal felt ambivalence towards his fast approaching marriage, about which he was ‘apathetic’. He was far more concerned about the Tripos Part I examinations, which started in two weeks and for which he felt unprepared, although he was desperate to get a first. Eileen was also harbouring doubts and shared them with Barbara Wootton,92 a young economics don at Girton and friend from CUSS. Sage felt ‘at the threshold of adulthood’ but thought his character remained childish and vacillating. While he felt no emotion about marriage, he believed that if he were in love at all, it was with Sylvia, although she would bore him in a week. Having experienced the excitement of sex with Eileen, he nurtured an ambition to have all that and more with many other women. Before the wedding, they pledged that each would still be free to take other partners,93 a vow which both upheld in the years to come. On midsummer’s morning, Lucas gave them a wedding breakfast in his rooms at Emmanuel,94 and follow
ing the civil ceremony, the happy couple spent the afternoon punting on the river with Hutt and Grey.95 Punting was always a favourite activity of Sage’s: he took ‘great pleasure in the swing of the pole as it springs dripping from hand to hand, the hard crunch of the gravel and then the straight steady push… while the others loll on their cushions and the water laps under the bows’.96
Bernal was awarded first-class honours in the Part I Natural Sciences Tripos. During his final year, as a married man, he had to live outside Emmanuel. He and Eileen found a flat to rent, where his youngest brother, Gofty, and friends like Hutt, Twam, Sylvia Barnes and Dickinson were frequent visitors. Eileen busied herself with decorating and furnishing the flat, but there was a general economic slump and little secretarial work available.97 Fortunately for Sage this meant that she was free to type new drafts of his mammoth derivation of the 230 space groups; their only income came from Bernal’s scholarship and his personal allowance from home. In January 1921, just as the post-war economic boom was cresting, Bernal noted in his diary that his income ‘from trusts and dividends was only 500 pounds’.98 This was about four times the income of a farm labourer.99 By 1923 agricultural prices had halved,100 and his mother, Bessie Bernal, worried about the dairy at Brookwatson closing down. Her eldest son, as usual, had no time for such worldly ‘trivialities’ and she was finally moved to write him a reproachful letter.101 After pointing out that some sons write to their mothers ‘unbidden’, Bessie castigated him: ‘If you prefer me never to mention our economic and labour difficulties here, I’ll do so. I have never interfered in your affairs. I supposed you took some interest in our efforts to keep things going here. It is our one preoccupation.’
Sage’s one preoccupation was to finish the space lattice paper, which he did at the end of February 1923. He had discussed the manuscript with Hutchinson, the mineralogist, and with H.F. Baker, a mathematics professor. The manuscript consists of eighty or so pages densely covered with mathematical formulae.102 In a short preface, even its author seemed to recognize the work’s inaccessibility since the theory ‘is given in extremely condensed form, and the absence of examples and diagrams may make it difficult to follow the geometric meaning of the various expressions… As the theoretical part has been written independently the absence of references will be understood.’103
The Cambridge Philosophical Society expressed some interest in publishing it, but decided that even a shortened sixty-page version was unprintable, on account of the expense involved in setting large numbers of tables containing unusual symbols. The work attests to Bernal’s mathematical powers as well as his extraordinary ability to think, in abstract, about three-dimensional patterns. Arthur Hutchinson, the Professor of Mineralogy, encouraged him to submit the paper for a prize at Emmanuel. The Herculean labours of Sage were rewarded with a half-share* of the Sudbury Hardyman prize and £30.104
3
Bohemian Crystallographer
While his two-year effort to develop a quantitative analysis of the 230 space groups cost Bernal the first-class honours degree he coveted, the resulting thesis, ‘On the analytic theory of point group systems’, launched his career as a scientist. Without a first-class degree in physics, there was little prospect of being taken on as a research student in the Cavendish Laboratory, and even if Sage had managed to take a first, it is difficult to see how he would have satisfied Sir Ernest Rutherford’s edict that no communist propaganda would be tolerated in the laboratory.1 Nor would Bernal’s interest in the physics of crystals and his idea to use discoveries in that field as the keys to unlock the secrets of chemical structure have met with any degree of comprehension or sympathy in Rutherford’s department, where the major goal was to advance understanding about the atomic nucleus. In Rutherford’s robust view, scientific work aiming to establish the relative positions of atoms in space rather than to dissect the miniscule aggregation of electric charge and mass at each atom’s core would probably have been regarded as a branch of geography rather than physics.
Fortunately for Bernal, there were other, lesser, Cambridge scientists who lacked Rutherford’s single-mindedness, but who were shrewd enough to recognize the young graduate’s outstanding ability. One was the ‘very gentlemanly don at Pemmer’, Arthur Hutchinson, who wrote to W.H. Bragg in London in June 1923, saying that in his opinion Bernal was a remarkable person:
He is a shy, diffident, retiring kind of creature, but something of a genius. He attended my course on Elementary Crystallography and I realized that he was interested and was taking things in quickly. I did not however realize (and he never let on) that he had got so keen that he spent the whole of his next vacation in developing a method of dealing with point systems in the hope it might be useful in X-ray work! When therefore, he suddenly appeared and deposited on my table a thick type-written MS, rather with the air of a dog bringing a poached rabbit to his master’s feet, I was quite amazed – of course I make no pretence of being able to appraise its merit or even its usefulness – still it seemed to me a remarkable effort for an undergraduate in his third year – and Professor H.F. Baker was much interested in it and I believe thinks well of it.2
Bragg replied that he had already heard about Bernal from Alexander Wood, the physics tutor at Emmanuel, who had sent him the space group dissertation. He was happy to take Bernal on as a research student, but had no funds available at that time to support him. Emmanuel College generously stepped into the breach by offering Bernal a research grant that would cover his first few months in London.
A man of equable temperament in his early sixties, Sir William Henry Bragg was about to take over as Director of the Royal Institution. Established in a grand Mayfair house in 1799, the Royal Institution (RI) from its inception had been concerned with harnessing science for the public good, both through research and education. Bragg was well qualified to oversee such efforts, since he was an experienced teacher and a natural communicator, in addition to being a Nobel Laureate. After graduating as one of the top mathematicians of his year at Cambridge, at the age of twenty-three years Bragg had taken the post as professor of mathematics and physics at the fledgling Adelaide University;3 from this flying start, strangely Bragg did not attempt any original research for nearly twenty years. His first published work in 1904 was a major contribution to the field of radioactivity and led to a regular exchange of ideas with Rutherford. Bragg’s initial research was concerned with the properties of alpha (α) particles, which he showed have a characteristic range in air that depends on their initial energy.4 He thought of the α-particles travelling through air in a straight line, like a bullet passing through a block of wood. Soon he convinced himself that the uncharged gamma radiation from radioactive sources also consisted of high-speed particles and not waves. He expressed this opinion confidently in a letter to Rutherford in December 1907: ‘I have got the decisive experimental proof that the gamma rays are not pulses, but corpuscular…’5 Other physicists, for example Charles Barkla in Liverpool, working with lower energy X-rays, found equally compelling evidence for wave properties of radiation, and a lively debate ensued.
Decisive evidence for the wave school came from Max Laue’s department at Munich University in June 1912, when it was demonstrated that X-rays could be diffracted by crystals. Bullets do not bend around objects – they cannot be diffracted – but waves can, providing that the object is comparable in size to the wavelength. Think of Bernal watching the waves bouncing off the hull of the ferry as he crossed the Irish Sea, and the subsequent interference patterns of the secondary wavelets in the ship’s wake, before the original wavefront would be restored. A lifeboat from the ferry would not have produced such a wave interference pattern because its size would have been so much smaller than the wavelength – the distance between successive crests. Similar constraints apply to the diffraction of light: the process depends on the wavelength of light* being comparable to the size of the diffracting object. Laue, after talking to his doctoral student, Paul Ewald, formed the idea that so
me kind of diffraction effect might be obtained from crystals, if they were subjected to incident radiations of wavelengths similar in magnitude to the inter-atomic distances in the crystal lattice. Ewald had explained to Laue that the atoms in crystals were thought to have internal regularity or periodicity of structure, and although the distances between neighbouring atoms were not known accurately, they were estimated to be perhaps 1/ 1,000th of the wavelength of visible light.6 Crystals could not serve to diffract light, but Laue thought that perhaps X-rays would have short enough wavelengths to be affected by their internal atomic framework.