Bridget Teresa McCrory
Helen Dick Megaw (1907 - 2002):
|Helen Dick Megaw|
Helen Dick Megaw was a highly distinguished figure in the area of mineralogy, and especially crystallography, as researcher, teacher and author. A leading academic journal in her field obituarised that she was "a well-known, highly respected and remarkable member of one of the most important scientific disciplines of the 20th century."
Helen Dick Megaw was born in Dublin (44 Northumberland Road) into a family of high achievers (known to some Ulster people rather begrudgingly as "over-achievers"): she was one of seven children of Robert Dick Megaw a lawyer (King's Counsel and judge of the Northern Ireland High court) and politician (MP for North Antrim); an uncle was Major-General Sir John Wallace Dick Megaw, a director of the Indian Medical Service. Of her siblings, one brother, Thomas M Megaw, was an engineer who worked on the construction of the Mersey and Dartford tunnels, Battersea power station and the Victoria line of the London Underground. Another brother, Sir John Megaw, followed their father into the legal profession and became a Lord Justice of Appeal. An oft-repeated story which might explain this achievement record relates that when taking a telephone call congratulating one of his daughters obtaining her degree, their father retorted that a second-class degree was no cause for pride in their family.
Helen was educated at Alexandra College, Dublin from 1926 until 1921, and Roedean School, England, from 1922-1925. Normally she would have proceeded to Girton College, then the women's college at Cambridge University, but apparently for financial reasons this was postponed and instead she matriculated at Queen's University, Belfast, though she remained there one year only; awarded a scholarship she indeed proceeded to Girton where she graduated BA in 1930. For the next four years she was a research student under J. D. Bernal, the outstanding British scientist (though Irish through his father and born in Nenagh, County Tipperary); Bernal was amongst other distinctions a pioneer in X-ray crystallography, and was a rather forceful personality, who encouraged Helen Dick Megaw to dedicate herself to this discipline; this was not especially difficult as she had already been developing an interest there, having read William Lawrence Bragg's X-rays and Crystal Structure, the research on which had led to his being elected a Nobel laureate in 1915 (Helen read the book while still at school).
Her research under Bernal brought her a PhD from Cambridge in 1934; one of her first scientific specialties, the structure of "heavy" and "normal" ice, would bring her the distinction of having an Antarctic island named after her. In 1934-1935 she was in Vienna on a Hertha Ayrton research scholarship, studying under Professor Hermann Francis Mark, the molecular scientist who occupied the chair in Chemistry at the university there. In 1935 there came an article in the Proceedings of the Royal Society", entitled "The Function of Hydrogen in Intermolecular Forces" published jointly with Bernal and describing their work on hydrogen bonding in metal hydroxides; the so-called Bernal-Megaw model" (to fix the position of hydrogen in trioctahedral layer hydroxides) derived from this influential article.
In 1935-1936 she was researching at the Clarendon Laboratory, Oxford, under Professor Francis Simon, the outstanding German-born low-temperature physicist (commemorated by a blue plaque on his former home in Oxford) This was followed by several years as a school teacher, first at Bedford High School, then at Bradford Girls' Grammar School. In 1943 she moved to Philips Lamps Ltd in Mitcham in 1943. It was there that she worked out the crystal structure of barium titanate, a significant industrial material: it is a ferroelectric ceramic material which is used to make capacitors found in items such as ultrasound machines; infrared cameras; microphones and other transducers. As a material it crystallizes in the so-called perovskite structure, and Megaw was the first to identify this; she became particularly renowned for her expertise in this area.
In 1945 Megaw moved to Birkbeck College, London, where she was able to work with Bernal again, and the following year she took up a post at the Cavendish Laboratory, Cambridge, which would be her last, and longest, appointment; concurrently she was a Fellow and Director of Studies in physical science of her old college, Girton. Moreover, the then Director of the Cavendish Laboratory was none other than WL Bragg, and perhaps the most significant - certainly now the best-known- crystallographers were also working in the Cavendish Laboratory at that time: Francis Crick and James Watson, carrying out their seminal work on the structure of DNA.
Megaw though had her own particular path to which to stick, mineralogy and inorganic crystals. For example, she provided her own crystal structure diagrams to the Council of Industrial Design, which were then used in the designs for textiles, window glass, ashtrays, and even a tea set used at the Festival of Britain in 1951. In 1957 she published her first book, Ferroelectricity in Crystals, a groundbreaking work which became within the discipline its "bible" according to a colleague.
Megaw's supervisor at Cavendish was WH Taylor, a leading (perhaps the leading) expert on feldspars, a group of minerals which are complicated in structure, but make up the larger part of the earth's crust and the surface of the moon. With Taylor's encouragement she continued his work, her major contribution being to in distinguishing between unit cell and lattice disorders. In 1973 came another book, Crystal Structures: a Working Approach, "a fine text that illustrated well her unique approach to describing the structure of crystals" according to AM Glazer, a crystallographer who studied with her.
Megaw was described by the same man this way:
"...a remarkable person: formidable in some ways, but also very kind and patient. She had a particularly interesting gift: a rare ability to be able to visualize in three dimensions, so that she could take a crystal structure and turn it around in her mind and then sketch it from any perspective. In the days before computer graphics, this was a very useful trick, especially for a crystallographer, who must somehow always be able to appreciate three-dimensional architecture."
Her academic and professional honours included honorary fellowships, the Roebling Medal of the Mineralogical Society of America and the first woman to be awarded this, and two honorary doctorates, from Cambridge University; and from Queen's University, Belfast. She retired in 1972 and divided her time between Cambridge, always keeping in touch with colleagues and scientific developments, and Ballycastle, County Antrim where she pursued one of her main non-professional passions, gardening. Other interests she had developed were photography (she had exhibited in the prestigious London Salon of Photography as early as 1943) and winter sports. Of being a woman in the world of science, she remarked that she had rarely if ever experienced any discrimination on this count, which she put down firstly to her parents, and also to Girton College, as those who advised and guided her having had a positive view of equal opportunities.
She died at home in Ballycastle. Among many tributes to her was from Professor Robert E Newnham of Pennsylvania State University: "Along with Kathleen Lonsdale and Dorothy Hodgkin, Helen Megaw is one of the grand old British school of women crystallographers who serve as role models for many of us - men and women alike."
|Born:||1 June 1907|
|Died:||26 February 2002|
Crystallography News (June 2002, obituary); Oxford Dictionary of National Biography; http://www.oxfordshireblueplaques.org.uk/; http://www.physics.utah.edu/
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