from University of London in 1936 while at the Royal Institution. In addition to discovering the structure of benzene and hexachlorobenzene, Lonsdale worked on the synthesis of diamonds. She was a pioneer in the use of X-rays to study crystals. Lonsdale was one of the first two women elected a Fellow of the Royal Society (FRS) in 1945 (the other was the biochemist Marjory Stephenson). In 1949 Lonsdale was appointed professor of chemistry and head of the Department of Crystallography at University College London. She was the first tenured woman professor at that college, a position she held until 1968 when she was named professor emeritus. As a keen table tennis player, Lonsdale made use of ping pong balls to demonstrate the molecular structure to her students. One such model—of the silicate group —is in the Science Museum collection During her later career, she became interested in stones and minerals produced in the human body e.g. kidney stones or gall stones. Some of her crystallographic models are in the collection of the Science Museum in London. Selected publications Simplified Structure Factor and Electron Density Formulae for the 230 Space Groups of Mathematical Crystallography, G. Bell & Sons, London, 1936. "Divergent Beam X-ray Photography of Crystals," Philosophical Transactions of the Royal Society 240A: 219 (1947). Crystals and X-Rays, G. Bell & Sons, London, 1948. “Human Stones”, Science Vol. 159, Issue 3820, pp. 1199-1207, 15 Mar 1968 Quakers visit Russia, Edited by Kathleen Lonsdale : an account of a visit to the Soviet Union in July 1951 by seven British Quakers, 145 pages. Published by the East-West Relations Group of the Friends Peace Committee. Other authors: Margaret Ann Backhouse, B Leslie Metcalfe, Gerald Bailey, Paul S Cadbury, Mildred Creak, Frank Edmead. Removing the Causes of War, 1953. Is peace possible? (1957) Forth in Thy Name: The Life and Work of Godfrey Mowatt (1959) Personal life After beginning her research career, in 1927 Yardley married Thomas Jackson Lonsdale. They had three children – Jane, Nancy, and Stephen. Stephen became a medical doctor and worked for several years in Nyasaland (now Malawi). Pacifism Though she had been brought up in the Baptist denomination as a child, Kathleen Lonsdale became a Quaker in 1935, simultaneously with her husband. Already committed pacifists, both were attracted to Quakerism for this reason. She was a Sponsor of the Peace Pledge Union. She served a month in Holloway prison