Hertha Ayrton, Library of Congress Prints and Photographs (glass negative,
digital id. ggbain 36552 //hdl.loc.gov/loc.pnp/ggbain.36552).

Trained as a mathematician, Hertha Ayrton (1850-1923) devoted her career to investigating electrical phenomena and the behavior of gases while seeking ways to transform her experimental results into inventions of immediate practical use.

Ayrton was born on April 28, 1854 as Phoebe Sarah Marks in Portsea, into a Polish Jewish family. Her father was a watchmaker and jeweler. After his death in 1863 propelled the family into poverty, she was sent to her aunt's home in London, where she eventually found work as a governess. During these years she changed her first name to Hertha at the urging of a friend.

While living in London Ayrton met Barbara Bodichon, leader of the Langham Place group of feminist activists and co-founder of Girton College, the first women's college at Cambridge. Bodichon's support of Ayrton's education extended to securing a loan for her to attend Girton, where Ayrton read mathematics from 1877-1881. In 1880 she sat for the Mathematics Tripos, a notoriously difficult multi-day exam. Her Third Class placement did not satisfy her. Of her performance she wrote to Bodichon: "I am so sorry. I am afraid you will be very disappointed" (qtd. in Ogilvie, p. 119).

With the same restless energy that marked her mature career, Ayrton filled her Girton years with far more than just mathematics. She was active in the choral society, and she founded both the Girton College Mathematical Club and the Girton Fire Brigade, an organization of trained student fire-fighters. Her talent for invention manifested itself as well: she invented the sphygmometer, a device for recording the pulse, and the line divider, a drafting device she patented in 1884. It was also at Girton that she met George Eliot, for whom she seems to have provided the model for Mirah, the heroine of Daniel Deronda.

In 1885 she married William E. Ayrton, a professor of applied physics who taught at several schools in London. After his papers were destroyed in a fire, Ayrton helped to recover the lost work by replicating his experiments with the electric arc, an arrangement of two carbon electrodes that incandesced when electrical current passed between them. In the course of this research she independently discovered relationships between elements of the experimental assembly (e.g., pressure, arc length, voltage) and established laws governing the behavior of the arc. Her results contravened the commonplace assumption that the hissing and sparking of arc lamps were due to evaporation rather than oxidation of the carbon electrodes. This insight was of great immediate practical value, for if arc lamps — then used for street lighting — could be designed to keep the mechanism from direct contact with the air, their performance and safety could be vastly improved. In 1895 Ayrton published these findings in a series of articles for The Electrician.

In 1899, she presented a paper, "The Hissing of the Arc," to the Institution of Electrical Engineers; it was the first paper read by a woman to that organization, and she was awarded a prize for the work. The following year, she gave another paper on the same topic, "L'Intensité lumineuse de l'arc à courants continus," to the International Electrical Congress in Paris. In 1901, her paper "The Mechanism of the Electric Arc" was read by John Perry, an engineer, to the Royal Society. Her work on the electrical arc also found practical application in the development of anti-aircraft searchlights used by the Admiralty. In 1902 she published a book, The Electric Arc, which became the standard work on the topic.

Her husband's worsening health prompted a move from smoggy London to more salubrious Margate. The change of scene inspired a notable shift in Ayrton's scientific interests. Proposing that ripples she observed on the sandy beach at Margate were caused by vortices in the water passing over it, Ayrton began to consider whether a similar process might govern the behavior of gases. During World War I, she invented the Ayrton Fan, also known as "the Ayrton Flapper," a hand-held fan used by thousands of soldiers to disperse poison gas according to the principles of vortex action that Ayrton supposed to be operative in water as well. She spent her later years engaged in developing ideas related to the dispersal of gases in tight spaces like mines and sewers. She also contributed a series of problems and solutions to the "Mathematical Questions" section of The Educational Times, a prominent English serial that disseminated mathematical concepts and results to an audience of educators, students, and interested lay readers (Manzo, n.p.).

In 1899, She became the first woman to become a member of the Institution of Electrical Engineers and chaired the Physical Science section of the International Congress of Women. In 1902 Perry put Ayrton forward for election as a Fellow of the Royal Society. Although his proposal was co-signed by no fewer than eight colleagues, her candidacy was rejected on a technicality: because married women had no legal status due to coverture, they were ineligible for membership in organizations like the Royal Society. The vacuousness of this rebuff seems to have been evident to at least some portion of the Royal Society, for the Society awarded her the Hughes Medal just four years later, in recognition of the high quality of her experimental work.

Ayrton's scientific work cannot be separated from her activism in the service of women's rights. In 1906, Ayrton joined the Women's Social and Political Union, a suffragette organization, and participated in marches and demonstrations. She linked her political work with her professional experiences, understanding that her personal struggle to garner recognition for her work emerged from a social formation of inequality within which women were assumed incapable of work worthy of recognition in the first place. In 1909, when Ayrton's close friend Marie Curie was in danger of losing to her husband her priority in the discovery of radium, Ayrton penned a fiery letter of support to the Westminster Gazette, in which she famously asserted that "an error that ascribes to a man what was actually the work of a woman has more lives than a cat" (qtd. in Bruton, n.p.).


Bruton, Elisabeth. "The life and material culture of Hertha Marks Ayrton (1854– 1923): suffragette, physicist, mathematician and inventor." Science Museum Group Journal. October, 2018.

Gregersen, Erik. "Hertha Marks Ayrton". Encyclopedia Britannica, 22 Aug. 2020.

Manzo, Robert M. "The Educational Times Database: Women Contributors." Convergence. March, 2021.

Mason, Joan. “Hertha Ayrton (1854-1923) and the Admission of Women to the Royal Society of London.” Notes and Records of the Royal Society of London, 45.2, 1991, pp. 201–220.

Ogilvie, Marilyn Bailey. "Marital Collaboration." In Uneasy careers and intimate lives. Women in science 1789-1979. Eds. Pnina G. Abir-Am and Dorinda Outram. New Brunswick and London: Rutgers University Press, 1987. 115-123.

Created 5 April 2021