Fluid Dynamics

Contributions Publications Honors

Hertha (Sarah) Marks Ayrton 1854-1923

Jobs/Positions Education Additional Information

Some Important Contributions: Her work on the electric arc was precursor to the field of plasma physics. She discovered the connection between pressure in the arc and current length, and the composition and shape of the electrodes. -- Professor Walter Gekelman. "In her research on the electric arc she had carried all before her, and produced the standard book on the subject." -- A. P. Trotter, President of The Institution of Electrical Engineers, ... - ... Analyzed the fluid dynamics of waves on the sea shore; the causes and process of formation of ripples in the sand. "The movements of waves and eddies of perfect fluids .. have been a favourite theme for mathematicians. .. Lord Rayleigh and Prof. George Darwin had made such calculations... Mrs. Ayrton began with pure experimental observation. .. After her husband' death she turned the large drawing room of her house into a laboratory and equipped it with glass tanks. .. I do not know if Mrs. Ayrton found that her practical observations conflicted with their [ Lord Rayleigh and Prof Darwin] results. They were offered to The Royal Society and criticisms were raised. .. Her paper wa rejected by a referee; but Lord Rayleigh ..championed her cause, her paper was accepted, and the Hughes gold medal was awarded to her for this and her work on the electric arc." -- ibid. Her understanding of fluid dynamics enabled invention of a fan to create eddies of air that could be used to repel gas attacks. It was called the Ayrton fan. "It must be remembered that when poison gas was first used in war [WWI], chlorine, a heavy gas, was blown across by the wind. The Aryton fan was quite capable of rolling it back in the open and, unexpectedly, even by Mrs. Ayrton, of clearing dugouts into which gas had fallen." -- ibid. Some Important Publications "The Light Emitted by the Continuous Current Arc," Electrician 45: 921 (1900). The Electric Arc. New York: D. Van Nostrand Co., 1902. "The Origin and Growth of Ripple Marks," Proceedings of the Royal Society of London A84: 285 (1910). "On a New Method of Driving off Poisonous Gases," Proceedings of the Royal Society of London A96: 249 (1919-20). Honors First woman to be elected member of The Institution of Electrical Engineers (London) 1899 Hughes Medal, Royal Society (London) 1906 Hertha Ayrton Research Fellowship established in Girton College, Cambridge. Education 1876-81 Girton College, Cambridge University Completed the Cambridge Tripos in 1881. 1884-85 Finsbury Technical College References consulted [1 N20], [8 MBO], [33A LSG], [n1923ha], [n1923tm] Additional Information Ayrton's father died when she was seven leaving his family in debt. As a young woman she supported herself and helped support her family by tutoring and embroidery. While she was in her teens Sarah Marks adopted the name Hertha, after the Teutonic earth goddess eulogized by Swinburne. Married William Edward Ayrton, professor of physics and noted electrical engineer, in 1885. He is known to have been very supportive of women' education and legal rights. They had a daughter Barbara. First woman to read a paper ("The Hissing of the Electric Arc," 1899) to the Institute of Electrical Engineers. The Institute elected her their first female member. She was awarded £10 prize for that paper. First woman to read a paper ("The Origin and Growth of Ripple Marks," 1904) to the Royal Society (London). Three years earlier, Ayrton's paper, "The Mechanism of the Electric Arc," had to be read to the Society by a man (John Perry). [8 MBO] Ayrton began to study sand ripples in 1901 after her husband had become ill and required long stays at the seashore. [15B PGA] For further reading about Ayrton's scientific work see reminiscences of A. P. Trotter. Ayrton actively participated in demonstrations for women's suffrage. Founding member, in 1920, of the National Union of Scientific Workers. [1 N20] In 1912, provided refuge for Marie Curie from the turmoil and tragedy of her husband' untimely death, and wrote in her defense that "An error that ascribes to a man what was actually the work of a woman ha more lives than a cat." For further reading see, for example, the interesting biographical article by Marjorie Malley [33A LSG] Field Editors: Professor Walter Gekelman/ Nina Byers <gekelman@physics.ucla.edu> /<nbyers@physics.ucla.edu>