AYRTON, HERTHA (née Marks; 1854–1923), British physicist of Jewish parentage. She married Professor W.E. Ayrton, whom she greatly assisted in his research, especially on the electric arc. She later established the laws that govern the behavior of the electric arc. She presented many papers on this and other subjects before the Royal Society of London and other scientific bodies. During World War I, she invented an anti-gas fan which was distributed to thousands of British troops. Ayrton explained the formation of sand ripples on the seashore and, at the time of her death, was investigating the transmission of coal gas. She was the first woman to become a member of the Institution of Electrical Engineers and in 1902 was nominated for election as a Fellow of the Royal Society. However, the election of a woman to the society was impossible at the time. She played a militant role in the campaign for woman's suffrage. Hertha Ayrton had two daughters, one of whom was the wife of Israel Zangwill and the other, BARBARA AYRTON GOULD (d. 1950), was a Labour member of Parliament and chairman of the Labour Party (1939–40), and a forceful supporter of the Zionist cause in the House of Commons. Her son was the painter and sculptor, MICHAEL AYRTON (1921–1975).