Somerville was the daughter of Vice-Admiral Sir William George Fairfax, scion of a distinguished family of Fairfaxes, and she was related to several prominent Scottish houses through her mother, the admiral's second wife,

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In 1804 she met her first husband, her distant cousin Lieutenant Samuel Greig, son of Admiral Samuel Greig, when he came to pay a visit. He was commissioner of the Russian navy and

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Somerville conducted experiments to explore the relationship between light and magnetism and she published her first paper, "The magnetic properties of the violet rays of the solar

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From 1833 onwards Somerville and her husband spent most of their time in Italy. Somerville maintained correspondence with a large number of leading scientists and remained engaged in

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From her first marriage she had a son, Woronzow Greig (1805–1865), named after Count Semyon Vorontsov, the Russian ambassador in London who had appointed Samuel Greig

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• 1826 "On the magnetizing power of the more refrangible solar rays"
• 1831 Mechanism of the Heavens
• 1832 "A Preliminary Dissertation on the Mechanisms of the Heavens"

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In the year following Somerville's death, her autobiographical Personal Recollections was published, consisting of reminiscences written during her old age. Over 10,000 pieces are in

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