by Andrew Brown
After his initial homesickness, Desmond settled in well at Hodder and wrote to Aunt Mod (one of Sam’s sisters) on 11 November 1911: ‘I’m rather happy here. I go to Holy Communion every day and to confession every week.’22 He reported that he had come second in an oral exam in French, and sent love to all members of the family plus ‘kind regards to all the servants’. The religiosity of school life, under the gentle direction of Father Cassidy, found an eager receptacle in Desmond’s soul: ‘We played and learned and were good boys. Too good. I bought a missal, flagellated myself with nails, and had a knotted rope tied round my middle until I found, by the anger that was roused in me when I was bumped into, that it was rather an occasion of sin than a penance. I started the practice of cutting grottoes to Our Lady in the hillside, and a fraternity of Perpetual Adoration of the Sacred Heart.’23
The following September, Desmond transferred to Stonyhurst College, which he found to be as cold and imposing a place as it sounds. Despite coming top in every subject, Desmond hated it and left after just one term. He later wrote that at Stonyhurst, ‘I learned nothing but the joys of prison life. A regularity that even extended to defaecation. Dark corridors, wandering priests, terrible sermons on sins that must not be named lest they be practised. But against that there were forests of flaming candles, golden vestments, and the resonant chanting that tore out the soul for God.’24 Bessie was concerned that her eldest son’s piety was becoming so extreme that he would finish up in the priesthood, and whatever Sam’s opinion on the matter, the boys did not return to Stonyhurst following the Christmas holiday. As a temporary measure the boys returned to their previous school in Nenagh, which was not a satisfactory solution either. Desmond was already showing an increasing preoccupation with science; after Christmas, he bought himself a microscope with money he had saved. At the school in Nenagh, there was one textbook that had some extracts from Faraday’s lectures, but there was no formal science teaching. Bessie undertook a search for a public school that was strong in science and came up with Bedford School in the English Midlands. The Bernal brothers were accepted and began their careers there in January 1914.
From the first, Desmond seemed to adjust easily to life at Bedford and was soon showing a precocious, if uneven, talent for science. He wrote to his mother in October 1914 that he had started ‘la trigonometrie, c’est asssez facile’ but kept the letter short because ‘J’ai une violine [deep purple] migraine.’25 In early 1915, he was studying lines of force, the law of inverse squares, finding the moment of a magnet and using electroscopes. In the end-of-year examinations, he won a scholarship in physics for designing and executing an experiment to find the electrical resistance of a piece of wire. Surprisingly he found the mathematics exam very hard and managed only one problem out of eight. Apart from his studies, Desmond was an enthusiastic boxer, a disappointed cricketer and a good shot with a rifle.26
The brothers’ first year at Bedford was of course overshadowed by the outbreak of war in Europe. The first reference to the hostilities appeared in Desmond’s diary entry on 7 May 1915: ‘Lusitania torpedoed off Kinsale, 703 lives saved.’ Many of the senior boys were joining the army as soon as school was over for the year, and the next mention of them at school assemblies would be news of their deaths in France. The sinking of the Lusitania was a particularly shocking event and was taken to heart by Desmond, who remembered sailing off Kinsale in a transatlantic liner. More immediately, he had to sail on a ferry across the Irish Sea to go home for the school holidays. In the event, the most memorable part of his journey home was being met by his father at Nenagh station in a new motor car, then a rare mode of transport in County Tipperary. After a carefree summer, he returned to Bedford at the end of September, and was soon immersed in organized activities. He took up rowing in addition to other sports, and there was also daily military drill, which with each passing season must have taken on heavier significance. The school days were long, with lessons from nine in the morning until five-thirty in the afternoons, and there was also school on Saturday mornings. In the evenings Desmond often took the chair at meetings of the science society. Nocturnal guerilla warfare between the dormitories was incessant, with raids and counter raids; Desmond was a spirited participant in such ‘ragging’, as well as its leading chronicler.
Back at Brookwatson, the new year of 1916 opened uneventfully, as Desmond helped with the milking and planted rows of fruit trees with his father. He took long walks through the countryside, and there were novel outings in the car. Each day he would find several hours to read and to study local flora and fauna with his microscope or to carry out a chemistry experiment in his makeshift laboratory. Nor was the routine very different during the Easter break, but on 26th April Desmond noted in his diary: ‘There is very little news of the Sinn Fein.’27 The inhabitants of Brookwatson, like the rest of Ireland, had been astonished by the news that a small ragged army of revolutionary Irish Volunteers and Sinn Feiners had staged an armed rebellion in Dublin on Easter Monday, and that they now controlled the city centre. From the time of Gladstone’s second premiership thirty years earlier, the Irish Nationalists had been engaged in a series of ungainly independence minuets on the dance floor at Westminster, with successive Liberal governments.28 The dance never seemed to reach a conclusion, either because the Conservatives in the House of Lords stopped the music with a veto, or the Protestants of Ulster threatened a fight outside the ballroom at the prospect of being forced to partner their Catholic countrymen. After two elections in 1910 when Asquith could sustain power only with the acquiescence of the Irish Nationalist MPs, the Liberals removed the veto power of the House of Lords in the Parliament Act of 1911. The minuet could at last be concluded and so the Home Rule Bill passed into law in 1914.
In Ulster, crowds of increasing size and bellicosity protested against the new law, and a disciplined, well-armed Ulster Volunteer Force took shape, unnerving Prime Minister Asquith. He realized that he could not quell their anger nor make them accept ‘Rome Rule’, as they called it. After bowing politely to his former Irish Nationalist partners, Asquith was forced to explore amendments that might appease the Ulstermen and their determined leader, Sir Edward Carson. The most likely solution seemed to be to exclude the six counties of Ulster from the Home Rule agreement and let them form a self-governing, northern province.29 No such compromise was agreed by the two Irish sides, who were becoming increasingly antagonistic. Only the outbreak of the much larger conflict in Europe had the effect of ‘pouring oil on the stormy Irish waters’, in Asquith’s words, and instead of fighting each other, Irishmen from both camps volunteered to fight the Germans.30
The Home Rule Bill was suspended for at least a year or until the end of the war (whichever was longer), causing one Nationalist leader to describe it ‘as a cheque continually post-dated’.31 Other Nationalists were already disaffected by the attempts at constitutional change that had ground on for so many years without tangible result. To them the notion of proving the Irish worthiness of nationhood by fighting side by side with the British troops in France was anathema, and indeed they inclined towards the basic viewpoint that my enemy’s enemy is my friend. Thus it was, with the promise of arms from Germany, that the revolutionary Irish Volunteers and Sinn Fein planned the Easter rebellion in 1916. A proclamation of national independence was read from the steps of the General Post Office, their headquarters. While the British authorities had found themselves taken completely unawares by the uprising, within days they were able to bring in heavy reinforcements to throw a cordon around the city and bombard the city centre, reducing major buildings to smoking rubble.32 By 30th April, news reached Brookwatson farm that most of the Sinn Feiners had surrendered. There seemed to be little further discussion there about the rebellion or about the executions of fifteen rebel leaders that followed over the next ten days. During that period of inflamed passions and continued violence, Sam took his two sons to Dublin on the way back to Bedford. Desmond recorded that ‘we had lunch and looked at t
he ruin of Sackville Street’*.33 They needed to get passes from the Town Hall in order to board the ferry at Kingstown; at the port they encountered a fierce military officer with a revolver and had their luggage searched.
Once back at Bedford, Desmond’s thoughts were dominated by the demands and pressures of school. His physics course that summer term included optics, a subject whose mathematical intricacy and simple beauty instantly appealed to him. He was already a keen historian of science and would have been familiar with Newton’s famous demonstration of the spectrum of light in 1665. Desmond understood that the dispersion of sunlight as it passes through a glass prism is due to the fact that the constituent colours are refracted (bent) to different degrees depending on their wavelengths. The index of refraction is higher for shorter wavelengths so that blue light is bent more than red. Nearly two hundred years after Newton, Kirchhoff and Bunsen had discovered that if certain elements were heated in a flame they produced spectra that were not continuous, but consisted of bright lines interspersed by lengths of darkness.34 These line spectra are unique for each element so that the wavelengths of the lines act as a fingerprint for that substance, enabling its presence to be detected as a trace component of any compound. In May 1916, Bernal used the spectroscope in the dark room at school and saw the spectra for potassium, sodium, calcium, sulphur and barium. At the end of the week, he managed to come second in the chemistry exam but only fifth in physics. In addition to formal laboratory experiments, Bernal and his friends from the science society were active astronomers and were allowed to borrow telescopes from Mr Tearle, his housemaster, who christened Bernal his ‘Astronomer Royal’. The housemaster would argue with his favourite student ‘for hours on scientific and political subjects’ and lend him interesting books. However much he enjoyed the burgeoning intellects of his charges, Mr Tearle also bore the unenviable responsibility of needing to keep order in the dormitory. Bernal, despite his special relationship with Mr Tearle, was not above the juvenile fray and towards the end of the summer term received ‘four with a gym shoe’ from two prefects for ragging. This punishment was not resented by Bernal in any way, and he took the view that Mr Tearle was ‘on the whole a kind and obliging man, though the house thinks he is the opposite’.35
The Great War consumed lives at an unprecedented and rising rate throughout 1916. More Irishmen were killed on 1st July, the first day of the Battle of the Somme, than on any other day in history. The New Year of 1917 brought only bleak prospects and very cold weather. In early February war rations were introduced at Bedford School: ‘one slice of bread at breakfast, half at dinner, two at tea and one for supper.’36 The only compensation for the cold was skating on the river – Desmond fell through the ice on 1st February, just after announcing to his friends, ‘It’s perfectly safe’! His diary, a week later, nonchalantly informs us that a total of seven were drowned; the following day a biplane, flying low, crashed into some trees behind the school. The machine caught fire and ‘burned brightly’: the boys, much to their disappointment, were not let out of school to watch. While in Ireland for Christmas, he and Kevin had bought some ‘dog’ bombs, small explosive devices, which they threw around with irresponsible abandon. They brought some back to school and the chemistry master even analysed one in a lab class, showing that it contained potassium chlorate and antimony sulphide. When one exploded during prep, they were made to hand over their remaining stock, and Mr Tearle gave ‘the whole house a frightful jaw’ without singling out the Bernal brothers for special punishment.
Desmond’s passion for science intensified as his knowledge increased. He later said his reading was indiscriminate – by going to the school library every Sunday after Mass, he managed to devour the whole collection of books, without ever bothering to note any author’s name. He continued to study the heavens at every available opportunity, and while at home on 8th January 1917, he got up early to see his first eclipse of the moon, (noting the moon was ‘a light reddish brown’). The following week at Bedford, he observed ‘two large sunspots on the lower left limb of the sun’. One night in March, Mrs Tearle made him come into the dormitory to sleep, causing him to miss the opportunity to see Saturn. He continued to be fascinated by spectroscopy and on the last day of the Easter term ‘saw the Fraunhofer lines for the first time though I had to lie on the floor to do so’. Fraunhofer lines are thin dark lines that interrupt the continuous solar spectrum. These lines had been invisible to Newton, not only because of his poor eyesight, but because the quality of glass in his prism was not uniform enough to produce sharply defined spectra. A young Bavarian optician, Joseph von Fraunhofer, first observed the numerous lines in 1814 and accurately measured their constant wavelengths. The Fraunhofer lines are again examples of atomic line spectra, but unlike the bright lines Bernal saw a year before, the dark Fraunhofer lines result from discrete energy absorption, for example by sodium atoms, as light passes through the cool vapours surrounding the sun.
It took the genius of Danish physicist, Niels Bohr, to realize that these line spectra were the key to understanding the way electrons surrounding the atomic nucleus were constrained to travel in stationary or fixed orbits. This key insight formed the basis of his quantum model of the atom in 1913.37 Bohr’s audacious idea was that when an electron moves from one stationary state to another in an atom, a quantum of energy will be absorbed or emitted corresponding to a light photon of fixed frequency. He presented his theory at the British Association meeting in 1913 and there was a full report in The Times so that although Bernal does not refer to Bohr directly, it is quite possible that he knew of it; spectroscopy carried the extra excitement of being at the leading edge of physics. Two days after arriving home for the Easter holiday, Bernal had ‘rigged up a spectroscope which worked moderately well’.38
Aside from spectroscopy, Desmond sampled a cornucopia of scientific and pastoral activities that Easter. He took more pleasure in the great paper-chases over the countryside, when a pair of human hares set off in advance, leaving a meagre trail of paper for the pursuers to follow. On a splendid outing that April, Desmond waded through a fast flowing river with water up to his waist and then stumbled into a field where he was confronted by a disgruntled bull. Two days after assembling the spectroscope, Desmond turned his hand to chemistry experiments and ‘went down to the weir and got some plastic clay and bog iron ore. I made little crucibles with the clay and heated chalk and sulphur in them and made a sulphide that gave off hydrogen sulphide with water. I got ferric oxide out of the ore.’39 In the evenings, he would work with his microscope and now started to be fascinated by the study of diatoms. These are single-celled algae that are extremely abundant in freshwater and marine ecosystems. Besides forming the basis of many food chains, diatoms contain chlorophyll so that they undertake photosynthesis, producing much atmospheric oxygen. Their appeal to the microscopist lies in their silica exoskeleton: a two-part shell that fits together like a shoe-box to enclose each organism. The silica gives the diatom a glassy appearance, and the skeletons come in a wonderful variety of geometrical shapes, both symmetrical and slightly asymmetrical, with intricately grooved and perforated surfaces. Desmond collected his first samples from a drain on the farm and started a catalogue of drawings. He was delighted to find that a farmer in the neighbourhood, Mr Launcelot Bayly, was a fellow enthusiast. Desmond rode his bicycle over to visit Bayly’s laboratory: ‘he showed me several beautiful diatoms and then some minerals under the polariscope. The colours were simply gorgeous.’40
The Easter holiday lasted two days longer than scheduled for the Bernal boys because all the Irish ports were closed temporarily owing to U-boat activity. When they did sail from Kingstown on 4th May, there was a flat sea and a beautiful full moon so they spent the entire night on deck. The crossing was put to good use by Desmond: ‘I had an excellent opportunity of studying wave formation in the wake of the ship.’41 No doubt he was thinking about diffraction (the process by which waves bend around an object) and interference (where s
econdary wavelets bouncing off the ship either overlap in phase with their respective troughs and crests superimposed to give a heightened pattern due to constructive interference, or where the overlapping wavelets cancel each other out as the crest of one is superimposed on the trough of another in destructive interference). Fortunately, there was no destructive interference from German U-boats.
Desmond celebrated his sixteenth birthday at Bedford and was given the news that the school thought he should take a Cambridge scholarship examination in mathematics with a view to a degree in Natural Sciences. He remained in the thick of school activities for the remainder of the year. A typical day involved science experiments, boxing followed by an outing on the river, military drill, and then perhaps some star gazing after prep. The astronomical highlight was seeing ‘the moon, some double stars and Jupiter and four of his moons. I could make out the bands on Jupiter quite well.’42 At the beginning of 1916, conscription had been introduced in England, Wales and Scotland, but not in Ireland. This meant that older boys at Bedford did not stay to complete their senior year, passing from the Officer Training Corps to leadership of men in the trenches, with little or no intervening preparation. On 12th December, Desmond wrote that his ‘oldest pal’ Mayne had been killed. While almost every British family was mourning the loss of a friend or relative by this stage in the war, the civilian population as a whole remained virtually immune to direct attacks. The notion of the homeland as safe territory was starting to erode just a little since the Germans had started to mount sporadic, daylight air raids on London with Gotha bombers.43 Desmond was caught in one of these during his homeward journey for Christmas. On 18th December, he spent three hours in the Euston underground station listening to the noise of anti-aircraft fire and exploding bombs.
