Huggins, Margaret Lindsay (1848–1915), pioneer astrophysicist, was born 14 August 1848 at 62 Lower Gardiner Street, Dublin, first child of John Majoribanks Murray (1822–93), a Dublin solicitor who had been born in Scotland, and Helen Murray (née Lindsay) from Taree, Arbroath. A brother, Robert Murray (1851–1934), probably born in Inverness, later became a barrister, and as an old man was ‘Father of the Free State bar’. Margaret's paternal grandfather, Robert Murray, had brought his family to Ireland from Scotland in the mid 1820s; he became chief officer of the Provincial Bank. Margaret was educated at home, and apparently at a private school in Brighton, perhaps after the early death (1857) of her mother. With his second wife, John Murray had two sons and a daughter. Margaret's precocious interest in astronomy was fostered by her grandfather Murray, who taught her to recognise the constellations. As a teenager she read popular works by Dionysius Lardner (qv) and John Herschel, carried out observations with a small terrestrial telescope (which she may have made herself), and was interested in photography and apparently also in the developing science of spectroscopy. She seems to have met William Huggins (1824–1910), an amateur astromomer of her father's age, and of independent means, in London, possibly at musical evenings at the house of the Montefiore family. He pioneered stellar spectroscopy in his private observatory at Tulse Hill, south-west London. He achieved fame through his study of the spectra of nebulae, which led to his discovery in 1864 that planetary nebulae were composed of gases. In recognition of his achievements he received from the Royal Society the long-term loan of a set of new instruments designed and built for him by Howard Grubb (qv) in Dublin. Apparently Howard Grubb reintroduced Murray to Huggins, while he was in Dublin between 1870 and 1871, arranging the acquisition and transfer of this astronomical equipment. They married (8 September 1875) at the parish church in Monkstown.
Margaret Huggins worked along with Huggins in the observatory, and seems to have been largely responsible for the introduction of photography to assist their recording of data. The Hugginses pioneered photographic spectroscopy of celestial bodies, and Margaret Huggins was particularly adept at modifying apparatus for the work. They used the recently introduced gelatine photographic plates in association with a telescope and spectrograph to observe and identify a series of hydrogen lines (the ‘Balmer lines’) in the spectrum of the star Vega (α Lyrae); and, using the dry photographic plate process (1881), photographed the spectrum of Tebbutt's comet. In 1889 Margaret Huggins was listed as ‘co-author’ with her husband, rather than as his ‘assistant’, when they jointly published On the spectrum, visible and photographed, of the great nebula in Orion. This paper mentioned two mysterious lines in the nebula spectrum, which did not coincide with spectral lines produced by known terrestrial elements, suggesting that they emanated from an element unknown on earth, but the Hugginses did not put forward any hypothesis to explain the occurrence. In her influential writings on astrophysics Agnes Mary Clerke (qv), a close friend, discussed the supposed new element, backing the use of ‘nebulium’ as its name. It was not till 1927, after the development of the quantum atomic theory, that the American astronomer Ira S. Bowen realised that the ‘nebulium’ emission lines were actually produced by forbidden transitions in singly and doubly ionised oxygen, and singly ionised nitrogen atoms. The Hugginses investigated the spectra of the recently discovered Wolf-Rayet stars, without coming to firm conclusions, and in 1892 they studied the spectrum of the nova T Aurigae. In 1897 they published a Photographic atlas of representative stellar spectra; it was well received by the scientific community, and they were awarded the Royal Institution's Actonian Prize for an important scientific work, which according to the citation, was ‘illustrative of the beneficence of the Almighty’.
While William was president of the Royal Society (1900–05), the Davy prize was awarded to Pierre and Marie Curie. William and Margaret Huggins became interested in radioactivity and tried to develop ways of observing radioactive radiation spectroscopically. Their work on the spectra of certain radioactive substances between 1903 and 1905 constituted their last published research. Between 1889 and 1905 they published twelve research papers in the Proceedings of the Royal Society and two papers in the Astrophysical Journal. Margaret and William Huggins jointly edited and published the Collected scientific papers of Sir William Huggins (1909). Margaret Huggins also contributed obituaries of the astronomers William Lassell and Warren de la Rue to the Observatory magazine in 1880 and 1889. She was a competent artist and a keen musician, and published a monograph on the sixteenth-century violin maker Gio Paulo Maggini (1892). She contributed articles on the history of astrolabes and armillary spheres to the eleventh edition of the Encyclopaedia Britannica.
In 1890 she was one of the four women elected to the council of the recently established British Astronomical Society. Although barred (as a woman) from becoming a fellow of the Royal Astronomical Society, she was admitted as an honorary member in 1903. In 1897, Queen Victoria's diamond jubilee year, William Huggins was knighted; Margaret was mentioned in his citation, the only woman (other than Victoria) whose name appeared in the honours list. After William's death (12 May 1910) she worked on a biography of her husband. This was not completed but formed the basis of a memoir published in 1936 as A sketch of the life of Sir William Huggins. She was awarded a £100 annual pension from the Royal Society and in 1913 she moved to a flat in More's Garden, London. Throughout her life she had a keen interest in the education of women, and donated observing notebooks and scientific equipment to a women's college, Wellesley College, Mass., USA; Huggins was friendly with the founding director of its observatory.
She died after a long and difficult illness at her home in London on 24 March 1915, and was cremated at Golders Green. She had had no children. In March 1917 a memorial to the couple was unveiled in the crypt of St Paul's cathedral, London. The plaque, describing her as her husband's ‘fellow worker’, records her significance in their joint achievements in astrophysics. The concomitant status, not always accorded in her earlier years, was undoubtedly deserved.