Kathleen Lonsdale
Irish crystallographer (1903-1971)
Dame Kathleen Lonsdale DBE FRS (née Yardley; 28 January 1903 – 1 April 1971) was a British pacifist, prison reformer and crystallographer. She got her degree from University College London in 1924, and was awarded a doctorate in 1934. She used X-ray diffraction to work out the structure of lots of chemicals, and used X-rays to study crystals.
Lonsdale was the first woman to be made a professor at University College London (1949), one of the first women to be made a Fellow of the Royal Society (1945), and was made a dame in 1956.