Appleton, Sir Edward Victor
- J. A. Ratcliffe
- , revised by Roger Hutchins
Sir Edward Victor Appleton (1892–1965)
Appleton, Sir Edward Victor (1892–1965), physicist, was born in Maperton Road, Bradford, Yorkshire, on 6 September 1892, the eldest child of Peter Appleton, of Eccleshill, Bradford, a warehouse clerk on the staff of Charles Senior & Co., and his wife, Mary Wilcock.
Education and early career
In 1903 Appleton won a scholarship to Hanson School, Bradford, where he absorbed everything that his teachers put before him and showed a remarkable talent for grasping the significance of a subject as a whole. He obtained a first class in the London matriculation examination at the minimum allowable age of sixteen, and he passed the London intermediate examination the next year, again at the minimum age. Realizing the unusual ability of the young Vic (as his family always called him) his parents helped him to continue at school as long as possible.
Music in the home, and sport outside—especially cricket—were Appleton's main interests until the age of sixteen when he became interested in physics and mathematics, largely through the influence of his school physics master, J. A. Verity. By then the fame of the Cavendish Laboratory as a centre for modern physical research, under Sir J. J. Thomson, was even reaching the schools and he was firmly determined to go to Cambridge. In 1910 he was awarded the Isaac Holton scholarship tenable at Cambridge and in 1911 he was awarded an exhibition at St John's College, Cambridge, where he read for the natural sciences tripos. He gained first classes in part one in 1913 when he received the Wiltshire prize, and in part two (physics) in 1914, when he also received the Hutchinson research studentship in mineralogy and the Hicken prize in physics.
Appleton immediately began research with W. L. Bragg and helped in the unravelling of the structure of one or two metallic crystals. In 1914 he joined the 6th West Yorkshire battalion as a signals officer. His training with the Royal Engineers introduced him to the thermionic valve (then a new device which was little understood) and to problems of radio-wave propagation caused by interference. It was as a second lieutenant in the Royal Engineers that he married, on 23 May 1915, Jessie Longson-Range (1890/91–1964), a distant cousin, the daughter of the Baptist minister John Longson, sometime of Huddersfield, later of Canada; they had two daughters.
In 1919 Appleton returned to Cambridge as a fellow of St John's College and in 1920 he became an assistant demonstrator in physics at the Cavendish Laboratory. Rutherford supported his research with Balth van der Pol into the behaviour of thermionic valves, vacuum tubes, and radio atmospherics which originate in lightning and cause signal distortion. He worked on the theory of free electrons colliding with heavy particles, particularly in a magnetic field, and did laboratory experiments to determine the radio frequency properties of ionized gases.
In 1902 Oliver Heaviside and A. E. Kennelly had postulated a reflecting atmospheric layer of ionized gases to explain Marconi's 1901 transmission from Newfoundland to England. Appleton was aware of radio signals fading. In 1924 Miles A. F. Barnett helped Appleton's detailed experimental investigation, using the night-time availability of the new BBC transmitter at Bournemouth. A constantly varied frequency resulted in fading in and out over a distance of 70 miles. Altering the signal to achieve phase (coincidence of the ground wave and reflected sky wave) gave a direct estimate of the height of the ‘E’ or Heaviside layer at about 50 miles. This December 1924 result was confirmed by a polarization experiment which determined the angle of the reflected beam. Their crucial experiment was a breakthrough which demonstrated, for the first time, that radio waves were reflected when they fell steeply on the ionized part of the upper atmosphere (later called the ionosphere), and proved the existence of the Heaviside layer. Experimenting with long wavelengths, Appleton deduced that some variations were not usual double reflections off the E-layer, but direct reflection from an F-layer which he proved to be at 170 miles, now the Appleton layer. He then commenced a lifelong systematic investigation of the structure and electrical properties of the upper atmosphere. Between 1924 and 1929, to obtain critical radio frequencies to investigate the upper atmosphere, Appleton adopted the American method of using pulses over a selected range of frequencies. He had developed the Lorentz–Larmor electron theory, published in 1925, a magnetic-ionic theory, and the refractive index for propagation of radio waves along field lines. His 1937 Bakerian lecture showed how radio waves revealed conditions of atmospheric density and electron temperature and linked them to ionospheric magnetic variation controlled by the sun. These researches, the first distance measurements by radio, were of great technological significance for radio communication, and his experimental methods were used later by Robert Watson-Watt in the development of radar. For this long series of researches Appleton was awarded the Nobel prize in 1947.
Appleton had been appointed in October 1924 to the Wheatstone chair of physics at King's College, London, and from there he set up an experimental field station near Peterborough where Barnett and others conducted researches under his direction. In 1932 the work was moved to a house in Hampstead. There were laboratories on the ground floor and a residence for Appleton and his family on the upper floors; since many of the experiments had to be made during the night this arrangement proved particularly convenient.
In 1936 Appleton returned to Cambridge to the Jacksonian chair of natural philosophy; this was attached to the Cavendish Laboratory under Lord Rutherford, and on Rutherford's unexpected death, in 1939, Appleton found himself acting, for a short time, as head of the laboratory.
When Bragg was appointed as the new director of the Cavendish, Appleton took the crucial step of leaving active scientific work to become secretary of the Department of Scientific and Industrial Research (DSIR). Almost his first task was to turn the attention of the department from peacetime to wartime activities. He firmly believed that work on fuel, roads, buildings, engineering, and the like, would continue to be necessary, and he emphasized that it was not in the national interest to drain off all the best of the department's staff to service laboratories. His teams were turned to work on the protection of stored foodstuffs from insect attack, on the design of civil defence protection of buildings, and on studies with models for bombing attacks on enemy objectives. He was closely concerned with the wartime development of radar.
As secretary of DSIR Appleton had control of the Tube Alloys project, Britain's organization of autumn 1941 for practical work on nuclear fission, initially directed by Sir Wallace Akers. Appleton was the link between the cabinet and Akers' teams. His demanding role was administration, securing and requisitioning rare materials and equipment, then arranging the relocation to Canada. His was an essential function in an untidy chain of interests until the whole project was handed to the Americans by the Quebec agreement (Clark, 120–28).
When the war was over, Appleton returned, in 1949, to academic work as principal and vice-chancellor of the University of Edinburgh, positions he held until his death. There he proved to be an inspiring and imaginative leader, diplomatic, and responsive to students. However, he faced much criticism of his handling of the university building programme, and he failed to mollify the opposition.
Up to 1939 Appleton was pre-eminently the leader in ionospheric research: in practically every point of importance his was the leading paper and it is fair to say that what was known about the ionosphere up to that time was almost entirely due to him, or to the research schools which he started and inspired. In 1950 he started the Journal of Atmospheric and Terrestrial Physics and remained its editor-in-chief for the rest of his life.
Appleton was an internationalist. Realizing that the observed behaviour of the ionosphere would depend on the position of the observer, Appleton played an important part in encouraging its study on a worldwide basis. He used the International Union of Scientific Radio for this purpose, and he was its president for eighteen years, from 1934 to 1952.
Appleton never lost his deep interest in the ionosphere. Until the end of his life the little notebooks that he carried around with him contained ideas and suggestions about it, interspersed with suggestions and stories for his speeches. When an ionosphere worker visited him in his office some new results would probably be produced from a drawer and, forgetting the worries of the principal of a great university, Appleton would discuss and argue again, just as he had once done with members of his research teams.
Appleton became a fellow of the Royal Society in 1927. He was appointed KCB in 1941 and GBE in 1946, and received decorations from France, the United States, Norway, and Iceland. He held honorary degrees from ten British and six foreign universities, and was honorary member or honorary fellow of several British and foreign scientific and engineering societies; he received medals from seven British and five foreign institutions. He published widely and in 1956 he gave the Reith lectures on the subject 'Science and the nation'.
Appleton's wife died in 1964 and on 24 March 1965 he married Helen Shannon Allison (b. 1919/20), the widowed daughter of John Gordon Lennie. She had been Appleton's secretary for thirteen years, and had helped him to keep a little time for his own researches during the pressure of his other work. He died suddenly at his Edinburgh home, Abden House, Marchhall Crescent, on 21 April 1965, of heart failure, just one month after his second marriage.
- Medical Research Council, London, corresp.
- U. Edin. L., corresp. and papers
- CAC Cam., corresp. with James Chadwick
- CAC Cam., corresp. with A. V. Hill
- IWM, corresp. with Sir Henry Tizard
- Nuffield Oxf., corresp. with Lord Cherwell
- Ransom HRC, letters to Sir Owen Richardson
- TNA: PRO, corresp. with Sir Henry Dale, CAB 127/224
- U. Edin. L., letters to John Ashworth Ratcliffe
- photograph, 1915, repro. in Clark, Sir Edward
- group portrait, photograph, 1925, repro. in Clark, Sir Edward, pl. 8
- W. Stoneman, photograph, 1930, NPG
- H. Coster, photograph, 1940–49, NPG [see illus.]
- W. O. Hutchison, oils, 1959, U. Edin.
- B. Hailstone, portrait, IWM
Wealth at Death
£127,280 10s. 5d.: confirmation, 24 Aug 1965, CCI