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  • Writer's pictureDale DeBakcsy

From Quaker Crystallographer to World War Pacifist: The Journey of Kathleen Lonsdale

The list of Quaker women who made fundamental contributions to the science of crystallography while in prison is a short one.  In fact, it's a list of one, but that one person was such a foundational figure in her science that you hardly need any other.  Kathleen Lonsdale (1903-1971) was, for the better part of half a century, involved directly in either creating or promoting the techniques that paved the way for titans of crystallography like Rosalind Franklin and Dorothy Hodgkin to solve the geometric structure of some of the planet's most bafflingly complicated molecules.  

We know Hodgkin well because of the Nobel Prize she won, and Franklin well because of the Nobel Prize she didn't win, but of Lonsdale, whose work, example, and mentoring opened the way for them to succeed as they did, there is comparatively little written.  This is a shame as her life was rich in ways that extend far beyond the science that she did.  She was born Kathleen Yardley in Southern Ireland in 1903, 11 years to the day before the opening of World War I, to a poor postman father who eventually left the family, and a small, indomitable Scottish mother.  

Yardley was the youngest of ten children, and by the time she was ready for school there were enough elder siblings working that she didn't need to cut short her education to enter the work force, as her older brothers did.  After her mother moved the family to England in 1908 in the face of rising tensions in Ireland, Lonsdale attended elementary school from 1908 to 1914, and won a scholarship to attend the County High School for Girls from 1914 to 1919.  There were, however, no higher math classes at County High, or physics, or chemistry, and so, like Joan Freeman would do a decade later and a half a world away, Yardley and her mother looked further afield to complete her education, and she was ultimately allowed to take math and science courses at the County High School for Boys, and when examinations came around, she won awards in six different disciplines.  And so it came to pass that at the age of just sixteen, the local education board offered her extra money if she would stay in school and attempt admission to Cambridge University in a couple years' time.  

But Yardley was never one to wait.  In later life, she was known as effectively the only administrator in England with the ability to conclude scientific strategy meetings before their scheduled end time by virtue of her efficiency and her lack of sympathy with dawdling.  She decided, therefore, not to wait, and to enter Bedford College for Women directly, at age 16.  After just a year there, she switched her major from mathematics to physics in spite of general advice that she'd have more of a future in mathematics.  The old pen and paper of mathematical research, however, did not hold her interest in the same way that the alluring and complicated measuring devices of physics did, and she would make her career on her ability to develop and master new technologies while using her hefty mathematical skills to wring from them deep insights into the structures of nature.

After placing highly on her B.Sc. examination in 1922, Yardley caught the interest of examiner W.H. Bragg, who happened also to be a pioneering figure in a brand new technology that was compelling crystals to yield up their innermost structures: x-ray crystallography.  In 1912, Bragg and his son developed a way to use the patterns created when an x-ray beam is shone through a crystal to determine the structure of the atoms in that crystal (see the Archive piece on Hodgkin for a more detailed explanation of just how that works), and in 1915 father and son shared a Nobel Prize in recognition of the revolutionary implications of their methods.  The elder Bragg saw potential in Lonsdale, and offered her a grant of 180 pounds a year to come join his research team at University College London.

It was an almost miraculous windfall for Lonsdale, who found that not only could she make a career with her scientific and mathematical abilities, but she could make enough money to contribute to the general expenses of her family.  She worked closely with W.T. Astbury on the application of x-ray crystallography to new and tantalizingly tricky molecules and together they produced the 1924 paper 'Tabulated data for the examination of the 230 space-groups by homogeneous X-rays.'  This was a landmark paper, cited for decades to come for its detailed working out of the patterns associated with the 230 different symmetries that a three dimensional crystal can possess.  Yardley would go on to be a key player in the development of each new generation of crystallography charts, starting with the International Tables she developed formulae for in 1935, and continuing through new editions in 1951, 1959, and 1969.  

Beyond providing invaluable tools for other crystallographers to interpret their data by, however, Yardley was a first rank researcher into crystal structures, and when Bragg moved to the Royal Institution in 1923 he made sure to take his ace prodigy with him.  She began working with the structure of succinic acid in 1924, but didn't definitively break new ground until 1928 when she solved the structure of hexamethylbenzene and became thereby the first person to ever solve the structure of an aromatic compound (i.e. a molecule that possesses rings of carbon atoms in its structure).  She discovered that the benzene molecule at its core was planar (that all of the six carbon atoms in its ring lie flat in a single plane together), and her 1929 paper detailing her methods and measurements remains a classic in scientific writing.

The 1920s were not just a period of scientific accomplishment, but also a time of immense personal growth for Yardley.  In 1927 she married Thomas Jackson Lonsdale, who had also been a researcher at University College.  She pondered whether she ought to give up her scientific career in order to concentrate on her roles as wife and eventual mother, but Thomas insisted that she continue with her science, stating that he did not marry her in order to gain a free housekeeper.  Kathleen did have to relocate to be where Thomas's job was, but she continued her mathematical analyses and computations, which did not require access to expensive lab equipment.  

The couple attended different religious services together, looking for something that would at last fit their idea of the world and answer some of the doubts that scientific research had given rise to in their minds.  They eventually settled on the Society of Friends, or Quakers, as best representing their pacifist and egalitarian ideals.  The Quakers had a long history of devotion to gender equality, and as long-time readers of this column will recall, America's first professional astronomer was a Quaker woman, Maria Mitchell.  The Society's work ethic, focus on strong personal morals, and impassioned stance on the futility of war all resonated with Kathleen, even as, scientifically, she could never entirely resolve what she knew about the world with what scripture dictated.  

With the birth of children in 1929, 1931, and 1934, Lonsdale's life became several orders of magnitude more complicated still, but of course she found a way to make it work, performing calculations while nursing and in 1931 rejoining Bragg in London after he offered to find a stipend to pay a maid to replace her at home.  He offered 200 pounds for the purpose.  She ran some calculations and determined that it would cost 277 pounds to replace the value of her domestic labor, and he in turn increased the offer to 300 in an example of respecting the value of unpaid work that most companies and governments have still not figured out.  

After her return to London, her research expanded to multiple emerging fronts of structural analysis.  She took an interest in the impact of thermal considerations on crystallography, or in how differences of temperature caused differences in atomic motion that manifested themselves in changes to the x-ray patterns of a crystal.  She promoted the use of magnetic anisotropy (the tendency of molecules to be more easily magnetized along some axes than others) in determining structural data, and was an early champion of using divergent x-ray beams to reveal more clearly crystal structures, and used that method to great effect in the analysis of different diamond types.  

In 1939, World War II broke out, and though as a mother Lonsdale was exempt from war duties that she would have had to decline as a conscientious objector, she did have to register for civil defense duties, which she accordingly did not do.  The authorities did not notice until 1943, whereupon they charged her two pounds for failing to register, a fine which she did not pay, and so she was sent to Holloway jail for a period of one month.  While there, she continued her mathematical analyses of anomalous reflections in x-ray patterns which she sent back to the Royal Institution and through long conversations with inmates and guards deepened her knowledge of the prison system and its shortcomings.  Upon her release she would become a major spokesman for prison reform, investigating and commenting upon jail systems the world over.  

Her time in prison had given her perspective, and yet another life's goal to accomplish with her seemingly bottomless reserves of energy, and her colleagues, far from condemning her anti-war stance, wrote her comforting and supportive letters while in jail, and showed their esteem more materially in 1945 when she and Marjory Stephenson became the first women ever elected as Fellows of the Royal Society.  It was a historic moment, but Lonsdale took it in characteristic stride, continuing her research using newly developed Geiger counter spectrometry methods in 1947 while increasing her leadership roles on the international stage with high-profile travels to the Soviet Union in 1951, China in 1955, and Czechoslovakia in 1969 in the name of international scientific cooperation, nuclear disarmament, prison reform, and peace.  

Thomas retired upon turning sixty, and devoted himself during Kathleen's 

remaining years to supporting her in her many roles and occupations.  He helped with her voluminous correspondence, and when she got home at 8:30 pm from a long day of work he would pack her off to bed and bring her dinner and tea there.  In December 1970 she was diagnosed with cancer, and with only one return to her home to celebrate Thomas's 70th birthday, she was kept in the hospital until her death on April 1, 1971.  

Lonsdaleite, a rare form of diamond only found in meteors, is named in her honor.


Pretty much everything you see about Lonsdale can be traced back to the Royal Society memoir of her life published in the 21st volume of the Biographical Memoirs of Fellows of the Royal Society (1975), written by none other than Dorothy Hodgkin herself.  It's not the easiest volume to find, but it also contains a piece on Emmeline Jean Hanson, so for the WIS book collector, it's a good one to get. 


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