Somerville, born in 1780, was the daughter of Admiral Sir William George Fairfax and Margaret Charters. Her education was haphazard and her mathematics largely self-taught. As an adult, she pursued her studies through her brief first marriage, widowhood and a second marriage to her cousin, naval surgeon Dr William Somerville. She combined her scientific career with being mother to six children and a stepson!
Best known as a mathematician, she invented commonly used variables for algebra. However, her scientific interests extended more broadly. In 1826 she presented a paper on solar magnetism to the Royal Society. (As a woman, she could not become a member so she was honoured instead by a bust in the Society's rooms.) The following year she published her first book, a translation of Laplace's Mécanique Celeste: she not only translated from French to English, but also popularised the work. In her own words, 'I translated Laplace's work from algebra into common language'. She went on to publish original works: On the Connexion of the Physical Sciences, Physical Geography and Molecular and Microscopic Science.
Somerville was respected by her fellow scientists, receiving honours including the Royal Geographical Society's Victoria Medal. She and Caroline Herschel were the first women members of the Royal Astronomical Society; she also received a Civil List pension of £200 per year. Her last book was published when she was 89; she continued to read algebra and solve problems until her death, aged 92.
Perhaps her most lasting memorial is Somerville College in Oxford, named for her. Or perhaps it's the word 'scientist' itself, coined by William Whewell in a review of her On the Connexion of the Physical Sciences.
Image: Mary Somerville, from Wikimedia Commons.