What she actually did
In the 1890s the entire developed world was lit by carbon arc lamps, and every one of them hissed, flickered and spat. Ayrton established that the cause was oxygen reaching the carbon rods and eroding a crater in them, and she worked out the quantitative relationship between arc length, current, voltage and pressure now known as the Ayrton equation. Her 1902 book The Electric Arc became the standard text. She later turned to fluid dynamics, explaining how sand ripples form on a beach, and used the same vortex physics to design a hand fan that cleared poison gas out of First World War trenches.
Why you have never heard of her
Ayrton's exclusion is unusually well documented because it was written down as policy. In 1902 the electrical engineer John Perry proposed her as a Fellow of the Royal Society; the Council rejected the nomination on the legal reasoning that a married woman had no independent standing and was therefore ineligible. She could win the Society's medal but not join it. The War Office initially dismissed her anti-gas fan, relenting only after public pressure in the press; 104,000 Ayrton Fans were eventually issued to the Western Front, and the invention is still usually filed as a curiosity rather than engineering.
Her life
Born Phoebe Sarah Marks to a Jewish watchmaker who had fled Tsarist pogroms, she was sent at nine to live with relatives who ran a school in London. She took the name Hertha as a teenager, from a Swinburne poem about an earth goddess. She read mathematics at Girton College, Cambridge, where she also founded the fire brigade, led the choral society and built a sphygmomanometer.
Cambridge would not grant women degrees, so she took an external BSc from the University of London in 1881. Her first patent, at twenty-nine, was a line-divider — a draughtsman's instrument for dividing a line into equal parts — and it sold. She then enrolled in evening classes in electricity at Finsbury Technical College, taught by Professor William Ayrton. She married him in 1885.
She began her own investigation of the electric arc after a legacy from her friend Barbara Bodichon freed up her time. In 1899 she became the first woman ever to read her own paper to the Institution of Electrical Engineers — "The Hissing of the Electric Arc" — and was promptly elected its first female member. The next woman admitted to the IEE joined in 1958, fifty-nine years later.
She was a militant suffragette, marched with the Women's Social and Political Union, and nursed hunger-striking women released under the Cat and Mouse Act in her own home, including Emmeline Pankhurst. She gave seven papers to the Royal Society between 1901 and 1926 — the last one read after her death.
“An error that ascribes to a man what was actually the work of a woman has more lives than a cat.”— Hertha Ayrton
Things worth knowing
- Her medal beat her membership by a centuryShe won the Hughes Medal in 1906. The Royal Society did not elect its first woman Fellow until 1945, twenty-two years after Ayrton died.
- 104,000 Ayrton FansHer trench fan — waterproof canvas on a cane frame with a hickory handle — was tested in a friend's back garden in Kensington and ended up issued across the Western Front.
- Only the second woman to win the Hughes MedalIn the prize's first 106 years, only two women received it: Ayrton in 1906 and planetary scientist Michele Dougherty in 2008.
- She invented the line-divider at 29Her first patent was a drafting instrument used by architects and engineers — she filed British and international patents on it with money advanced by two women friends.
Timeline
Takes an external BSc from the University of London; Cambridge will not award her a degree.
Patents the line-divider, the first of twenty-six patents in her lifetime.
First woman to read her own paper before the Institution of Electrical Engineers, and its first female member.
Barred from presenting to the Royal Society; John Perry reads "The Mechanism of the Electric Arc" in her place.
Publishes The Electric Arc. Her Royal Society fellowship nomination is rejected because she is married.
Becomes the first woman to read a paper before the Royal Society, on the origin of ripple marks.
Awarded the Hughes Medal for her work on the electric arc and on sand ripples.
Tests the Ayrton Fan; the War Office eventually issues 104,000 of them.
What it means now
In 2010 a panel of female Fellows of the Royal Society and historians of science named Ayrton one of the ten most influential British women in the history of science. Her quote about errors having more lives than a cat is quietly the thesis statement of this entire project — and she wrote it about her own field, while it was happening to her.
