Friday, February 19, 2021

Hertha Ayrton, Mathematician, Physicst, Engineer and Inventor


Hertha Ayrton, linocut by Ele Willoughby
Hertha Ayrton, linocut, 9.25" x 12.5" by Ele Willoughby, 2021.

This is my linocut portrait of British engineer, mathematician, physicist & inventor Hertha Ayrton (1854-1923). She is remembered for her research on the electric arc lamp, on ripple marks in sand & water, and her inventions including of mathematical line dividers which allowed artists, architects & engineers to enlarge or diminish drawings. I’ve shown her with a diagram of the dividers from her 1st of 26 patents, one of her diagrams about the origin & growth of ripple marks & one of her diagrams of an electric arc lamp (a subject on which she literally wrote the textbook).⁠

Born Phoebe Sarah Marks in Portsea, Hampshire, she was the third of eight children of a Polish Jewish immigrant watchmaker father & seamstress mother. After her father’s death when she was 7 in 1851, the family was left penniless and her mother returned to work as a seamstress. Sarah, as she was then known, had to care for her younger siblings. When she was 9, her maternal aunt Marion Hartog, who ran a school in north-west London with her husband Alphonse Hartog, invited her to join their household and attend their school. Though a hardship to her family, her mother recognized her potential and supported the move to London and the opportunities for her daughter. Her cousins introduced her to math and science. In her family, she was known as a fiery and occassionally crude character. By 16, she was living independantly, employed as a governess.

Her friend Ottilie Blind nicknamed her Hertha after the poem by Algernon Swinburne. They coached each other to prepare for the Cambridge entrance exam. Blind introduced Hertha to her mentor feminist, suffragette and founder of Girton College (the first residential college for women in England), Barbara Bodichon, after who she would later name her daughter. Her extended family and the suffrage community helped her get a higher education; author George Eliot* (a friend whom she met through Bodichon) wrote in support her application to Girton College, at Cambridge. She did not win a scholarship and would not have been able to afford tuition but she was supported with loans and donations from the suffrage community. While there studying math, she founded the fire brigade, led the choral society, and with fellow student and mathematician Charlotte Scott, formed a mathematics club. She also developed her first patented invention, the line divider and developed and built a sphygmomanometer (for measuring a person's pulse) while still an undergraduate. She passed the famous Mathematical Tripos in 1880, but Cambridge wouldn’t grant women degrees. She was able to take and pass a University of London equivalency exam, and they granted her a BSc in 1881.⁠

She earned an income teaching embroidery and math. She ran a club for working girls and looked after her invalid sister. By 1884 she had her first patent for a line divider; she also sought a US patent for it in 1885. Lady Goldsmid and Barbara Bodichon provided the funding she needed to seek these patents. The invention was well-received and got good reviews in the scientific press. She presented a paper on her invention to the Physical Society in 1885 and the device was manufactured in six sizes by a scientific instrument maker. Supporters encouraged her to become an entreprenneur and inventor but she wanted to pursue a scientific career.

She began evening classes on electricity with Professor Will Ayrton, trailblazer in engineering education at Finsbury Technical College. She was one of 3 women among 121 students. He was a widower with a young daughter, and a supporter of women's education and fight for voting rights. They married in 1885 and began collaborating on physics experiments and she was able to work from the lab in their home. A year later, they had a daughter, Barbara Bidochon Ayrton. From 1888 she taught practical and domestic electricity to women. Between this, domestic chores and raising her young daughter she had little time for research.

When her mentor Bodichon died in 1891, she left Ayrton enough money to support her mother and hire a housekeeper. Will supported her research but was also careful to not always collaborate with her, so that her work would be recognized as independant from his. He once told a friend “you and I are able people, but Hertha is a genius.” She began her own studies of the electric arc, solving the pressing problem of why they would flicker and hiss. She showed this was a result of oxygen coming into contact with carbon rods used to create the arcs. She patented a number of improvements to arc lights and published 12 articles on her advances. She was the first woman to deliver a paper to the Institution of Electrical Engineers (IEE), which was more progressive than other institutions and always allowed women to attend meetings. She was also able to present three papers to the British Association for the Advancement of Science (BAAS, now the British Science Association) in 1895, 1896 and 1898. She was elected a member of the IEE, recognized a professional qualification, in 1899; she was the sole female full member of the institution until 1958. Her cousin Marcus Hartog used her 1900 lecture at the International Electrical Congress in Paris to argue that the British Association for the Advancement of Science shouls allow women on their committees. Denied the right to present her paper to the Royal Society due to her sex, renown engineer John Perry (and Will's former colleague) presented it on her behalf in 1901. After she published her textbook The Electric Arc, Perry proposed her as Fellow of the Royal Society but they rejected this (as she was married, and hence had no independant legal standing). But in 1904, she became the first woman to present her own paper ‘The Motion of Ripples in Sand and Wave’ to the Royal Society. By 1906 she was the first woman to win the Hughes Medal, for her work on ripples and the electric arc.⁠

In Paris in 1903 she met Marie Curie and they became close friends, both physicists who collaborated with their physicist husbands and dedicated to social causes, and concerned about the role of women in society. They visited whenever Ayrton was in France. Ayrton vocally defended Marie, when Pierre died and the British press identified him (rather than Marie) as the discovered of radium, writing ‘Errors are notoriously hard to kill, but an error that ascribes to a man what was actually the work of a woman has more lives than a cat.’ Then in 1911, Marie won the Nobel for chemistry but endured a scandal in when her affair with married physicist Paul Langevin. Ayrton defended her again, and Marie and her daughters took refuge with the Ayrtons in England for two months. She was deeply involved in the women’s suffrage movement, marched in many marches (and recruited her friend Marie Curie to the cause).⁠

After poisoned gas was used as a weapon during WWI, she put her expertise in fluid dynamics to work trying to develop a means of removing gas from the trenches. She also invented a fan and despite initial resistance from the War Office was able to demonstrate its effectiveness in protecting soldiers from poison gas and she herself organized production of her first manually operated fans in 1916. By 1917 she had developed a new, mechanically operated fan, more resistant to high winds, and she again fought War Office bureaucracy and organized the production of 104,000 sent to the Western Front.⁠ Her research on fans was later used to improve ventilation in mines and sewers. She continued to study vortices until she died. She left much of her estate to the IEE.

*Apparently, the character Mirah, in George Eliot's novel Daniel Deronda, is based on Hertha. You might recall that George Eliot was also friends with another mathematician I've portrayed, Sofia Kovalevski. The sentence "In short, woman was a problem which, since Mr. Brooke's mind felt blank before it, could hardly be less complicated than the revolutions of an irregular solid," from Eliot's Middlemarch, is undoubtedly due to her friendship with Kovalevski. I like to imagine George Eliot was quietly a math groupie. 


Elizabeth Bruton, The life and material culture of Hertha Marks Ayrton (1854–1923): suffragette, physicist, mathematician and inventor, Science Museum Group Journal, Autumn 2018, Issue 10 Article DOI:

Ayrton, Hertha. “The origin and growth of ripple-mark.Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character 84, no. 571 (1910): 285-310.

Kim Martini, The origin of ripples and other fantastic fluid experiments by Hertha Marks Ayrton, Deep Sea News, April 28, 2016.

Hertha Ayrton, Wikipedia, accessed February, 2021.

Joan Meiners, Meet Hertha Ayrton, the mathematician who cleared WW1 trenches of poisonous gas, Massive Sci, June 5, 2020.

Archives Biographies: Hertha Ayrton, The Institute of Engineering Technology, accessed February, 2021

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