Helen Megaw


Helen Dick Megaw was an Irish crystallographer who was a pioneer in X-ray crystallography. She made measurements of the cell dimensions of ice and established the Perovskite crystal structure.

Education and career

Megaw was born in Dublin and educated there and at Rodean. While still at school, Megaw read Bragg's X-rays and Crystal Structure. She spent a year Queen's University, Belfast before moving to Girton College, Cambridge to study Natural Sciences in 1926. She graduated in 1930 and was a research student in crystallography under J. D. Bernal. Megaw's first speciality was the structure of ice, and she was awarded her PhD in 1934, and Girton awarded her a Hertha Ayrton research scholarship which she used to study in Vienna in 1934-1935 under Hermann Francis Mark. In 1935 Megaw co-published with Bernal an influential method for fixing the position of hydrogen atoms known as the Bernal-Megaw model. She spent the year 1935-1936 in Oxford with Francis Simon and then spent several years as a schoolteacher before becoming an industrial crystallogropher with Philips Lamps in London in 1943. It was through work at Philips on barium titanate that Megaw first worked on the perovskite crystal structure, on which she established herself as an acknowledged expert. In 1945 Megaw returned to working with Bernal, now at Birkbeck College in London, for a year before taking a post at the Cavendish Laboratory in Cambridge. She became a Fellow and Director of Studies at Girton. Megaw retired in 1972 and divided her time between Cambridge and Ballycastle, County Antrim, where she died in 2002.
Her first book, Ferroelectricity in Crystals, was published in 1957. It was followed by a second book, Crystal Structures: a Working Approach, in 1973.
Following a conversation with Mark Hartland Thomas in 1949, Megaw was appointed scientific consultant for the Festival Pattern Group of the Festival of Britain, 1951. She became the prime scientific mover in the group which put crystallographic images in the hands of industrial designers for them to use in products which were displayed at the Festival and in some cases beyond.

Legacy and honors

In recognition of her work in determining the structures of ice crystals, Megaw Island in the Southern Ocean is named for her. Megawite, a perovskite-group mineral, is also named after her.
In 1989, Megaw became the first woman to receive the Roebling Medal of the Mineralogical Society of America. She had honorary doctorates from the Universities of Cambridge and Queen's University Belfast.