Skip to Main Content
Skip Nav Destination

The Royal Society’s first woman physicist

25 January 2018

Crystallographer Kathleen Lonsdale overcame early-career obstacles to become one of the first two women elected to the Royal Society of London.

Lonsdale lecturing
Kathleen Lonsdale (standing, third from left) lectures to a class. Credit: AIP Emilio Segrè Visual Archives, Fankuchen Collection

For nearly three centuries, the storied Royal Society of London, home to some of history’s most celebrated researchers, was a male-only space. That was by design. From the society’s founding in 1660 through the early 20th century, it seemed obvious to the fellows that admitting the allegedly less intellectual sex would hinder the society’s goal of pursuing and advancing natural knowledge.

It was not until May 1945 that the Royal Society opened its doors to female scientists by electing two women, one in the biological sciences and one in the physical sciences. The physical scientist was Irish crystallographer Kathleen Lonsdale (1903–71), who is best known for her work on the structure of the benzene molecule. To break the Royal Society’s glass ceiling, Lonsdale had to not only perform extraordinary research but overcome the lack of opportunities in science for women—particularly married women.

Early life and career

The youngest of 10 children, Kathleen Yardley was born in 1903 in Newbridge, Ireland. When she was five years old, her mother moved all the children to a small town in Essex, England, to escape both political unrest in Ireland and her increasingly unstable husband. In Essex, Yardley quickly distinguished herself as an excellent student with a talent for mathematics and science. At age 16 she won a scholarship to Bedford College for Women, a school in the University of London system. In 1922, the year she graduated, she earned the highest score of any University of London student on the Honors Physics BSc exam.

Yardley’s exceptional performance caught the eye of one of the examiners: William H. Bragg, the Nobel Prize–winning physicist who had helped establish the field of crystallography. Yardley joined Bragg’s laboratory at University College London (UCL) after her graduation, then followed her mentor to a new position at the Royal Institution in 1923. Under Bragg’s supervision, Lonsdale learned both the demanding mathematics and careful experimental technique required to become a crystallographer.

In 1927 Yardley married a chemist, Thomas Lonsdale, whom she had met during her short time at UCL. Although Thomas had a high opinion of his wife’s ability and enthusiastically supported her career, many members of the scientific community believed that married women would inevitably leave the laboratory to have children.

That attitude soon had a direct impact on Lonsdale’s career. Shortly after her wedding, Lonsdale applied for an 1851 Exhibition Fellowship, awarded by the British crown to “young scientists or engineers of exceptional promise.” Several of Bragg’s protégés had won this award, and Bragg assured Lonsdale that her application would be successful. It was not. In turning her down, the commissioners of the scholarship told Lonsdale that they “would be breaking the spirit of the regulations in awarding an exhibition to a married woman.” A married woman, it seemed, was by definition not a scientist of exceptional promise.

The 1945 election

Fortunately Lonsdale’s alma mater, Bedford College, stepped in with a research grant, which Lonsdale took to the University of Leeds. There she performed the work for which she would become best known: her crystallographic study of the benzene ring in hexamethylbenzene (C6(CH3)6). At the time, there was fierce debate among organic chemists and crystallographers over whether the benzene ring was planar or had a zigzag structure like cyclohexane. Benzene itself was difficult to crystallize, but Lonsdale was able to develop hexamethylbenzene crystals that she could subject to crystallographic analysis. She published her preliminary results in a 1928 issue of Nature and her full report in 1929 in the Proceedings of the Royal Society of London. Her careful work convincingly demonstrated that the benzene ring was planar, which settled the debate.

Kathleen Lonsdale
Credit: National Portrait Gallery, London, CC BY-NC-ND 3.0

Lonsdale followed that success with a major life change. In 1929 she gave birth to the first of three children, and she spent the early 1930s working at home on a series of short-term research grants while caring for her babies and toddlers. Because of her mathematical ability, Lonsdale was able to find projects that did not require laboratory space, only paper and pencil. Most significantly, she finished calculating the structure of hexachlorobenzene (C6Cl6)—further affirming her conviction that the benzene ring had to be planar—and developed a useful and popular set of crystallographic reference tables, building on work she had done in the 1920s with her former Royal Institution colleague W. T. Astbury.

By 1932 Lonsdale had returned to the Royal Institution as a research assistant operating on year-to-year grants. Though she did not have a permanent scientific post, she continued to build her reputation as a skilled and insightful crystallographer. That reputation would serve her well when, in 1943, the leadership of the Royal Society began a campaign to nominate the first female fellows. As Royal Society president Henry Dale supervised a vote on whether to change the society’s constitution in order to permit the election of women, other fellows quickly singled out Lonsdale and biologist Marjory Stephenson as the strongest potential candidates. An overwhelming majority of fellows approved the change to the society’s constitution, and Lonsdale and Stephenson were added to the list of nominees for 1945.

One of the members of the selection committee that oversaw the election of new fellows was Lonsdale’s old friend Astbury. He was a vocal supporter of her candidacy, both in private conversations and in his personal correspondence, and he sent her regular updates on the proceedings. “I did my damnedest for you at the meeting of the Roy. Soc. Selection Committees the other week,” he wrote to her on 1 March 1945 in a note marked “Confidential!” “I managed to get you on the ‘short list’ that is submitted to Council from which to make the final selection.” When the list of 15 new fellows was announced in May 1945, both Stephenson and Lonsdale were among them.

Kathleen Lonsdale, FRS

Lonsdale’s election brought new attention to her scientific work, and in 1946 she finally obtained a permanent position. When her old Leeds colleague Christopher Ingold moved to UCL in 1946, he hired her as a reader in crystallography. In 1949 Lonsdale and Ingold persuaded UCL to create a department of crystallography, the first such department in Britain. Lonsdale was promoted to full professor and became the department’s chair. She would spend the rest of her career at UCL, mentoring new generations of young crystallographers and continuing her own scientific work. In 1957 she won the Royal Society’s prestigious Davy Medal, given to a scientist who has made a significant discovery in chemistry. She also became known as an outspoken pacifist, driven by her Quaker faith.

Despite her impressive accomplishments, Lonsdale fell into something close to obscurity following her death in 1971—overshadowed, perhaps, by two other crystallographers, Dorothy Hodgkin and Rosalind Franklin. However, lately Lonsdale has been more widely remembered for her groundbreaking crystallographic work and for building a successful scientific career despite a myriad of obstacles facing women of her generation.

One of the most striking things about Lonsdale’s biography is how familiar many of the challenges she faced will be to scientists today. Like many postdoctoral researchers in 2018, Lonsdale had to string together a series of temporary posts before finding a permanent job. Many parents, particularly women, also have to juggle maintaining an active scientific career with caring for young children. And the 1945 change to the Royal Society’s constitution hardly ushered in an era of gender parity. In the past 73 years, there have been 35 female fellows elected in the physical sciences, and there are just 111 women in total among the 1600 living fellows. Lonsdale’s story demonstrates how far science has come in making space for women—but it also highlights how many of the obstacles she faced remain with us.

Close Modal

or Create an Account

Close Modal
Close Modal