Sir William Henry Mahoney Christie was a British astronomer. He was the eighth English Astronomer Royal, a position he held from 1881 until 1910.
Background
Christie was born on October 1, 1845, in Woolwich, London, the son of Samuel Hunter Christie, a professor of mathematics at the Royal Military Academy and secretary to the Royal Society (1837-1854). The famous London firm of auctioneers was founded by Christie’s grandfather.
Education
Christie was educated at King’s College, London, and Trinity College, Cambridge, where he was the fourth wrangler in 1868. He was elected a fellow of his college in 1869, but a year later he left Cambridge to become a chief assistant at the Royal Observatory at Greenwich. There he was engaged primarily in positional astronomy, and one of his early minor achievements was to improve Airy’s transit circle in several respects.
Having been Chief Assistant at the Royal Observatory at Greenwich from 1870 to 1881, he was appointed to replace George Airy as Astronomer Royal in 1881 and remained in office until 1910. Despite Airy’s influence over him, Christie was anxious that Greenwich should undertake physical as well as positional observations, and with the help of E. W. Maunder he undertook daily sunspot observations (correlating them in due course with terrestrial magnetic observations) and also made many attempts, although not highly successful ones, to measure the radial velocities of stars. He made and reported many planetary observations, as, for example, that of the Mercury halo during the transit of 6 May 1878, and made many eclipse expeditions, often bringing back very fine photographic records.
Nevertheless, Christie made no remarkable advances outside the realm of “fundamental” astronomy. Work on this subject, which had been the prime justification for the foundation of the observatory, necessarily continued as before, after Christie was made astronomer royal in 1881, but it is to his credit, and that of the Admiralty, that the scope of observations during this period went far beyond utilitarian needs.
Christie equipped the observatory with many new instruments, notably a twenty-eight-inch visual refracting telescope (completed 1894), and a twenty-six-inch photographic refractor with a twelve-and-three-fourth-inch guiding telescope. This had a nine-inch photoheliograph on the same mounting (the gift of the surgeon Sir Henry Thompson in 1894) and enabled Greenwich to participate in the international photographic survey. He added several new buildings to the existing range and moved the magnetic pavilion to an isolated building in Greenwich Park. With the twenty-eight-inch refractor, Christie initiated a large program for the micrometric observation of double stars.
Christie was elected a fellow of the Royal Society in 1881 and was president of the Royal Astronomical Society from 1890 to 1892. In 1910 he retired to Downe, in Kent. Christie himself died and was buried at sea near Gibraltar in 1922.
Achievements
Membership
Royal Society of London
,
United Kingdom
June, 1881
Royal Astronomical Society
,
United Kingdom
1888 - 1890
Connections
Christie married Mary Violette in 1881, daughter of Sir Alfred Hickman. She died in 1888, after only seven years of marriage, and one son survived Christie.