C. Wyville Thomson, Scottish naturalist and oceanographer, studied medicine at the University of Edinburgh for three years but had to give up his studies as a result of ill health. His main interests were in zoology, botany and geology and in 1851 he began an academic career as lecturer in botany at the University of Aberdeen. Subsequently he moved to Ireland, where he became professor of natural history at Queen's College, Cork (1853); professor of mineralogy and geology at Queen's College, Belfast (1854); and professor of botany at the Royal College of Science, Dublin (1860); before returning to Scotland as professor of natural history at the University of Edinburgh in 1870.
Thomson was a talented marine biologist and particularly interested in the distribution of life and conditions in the deep oceans. His early papers, written during the eighteen-fifties, dealt mainly with the zoophytes (plant-like marine animals such as sponges, corals and sea anemones). Later he published on a wide variety of both modern and fossil marine invertebrates. With support from the Admirality he and Dr W.B. Carpenter carried out important dredging expeditions to the north of Scotland as far as the Faroe Islands. From a depth of more than 200 meters they recovered sponges, rhizopods, echinoderms, molluscs, crustaceans and foraminifers, thus demonstrating the abundance of life at these depths. Against expectations they also found that the temperature of the ocean at a constant depth varies from place to place. The next year he and others extended this research to the ocean west of Ireland and off the Shetlands, finding living organisms to a depth of more than 2000 meters. He wrote up the results in the form of a popular book, The depths of the sea. An account of the general results of the dredging cruises of HMSS 'Porcupine' and 'Lightning' during the summers of 1868, 1869 and 1870... (London, 1873). By this time he had also published some 30 papers, including several on echinoderms, a group that includes starfish and sea urchins.
The success of his research led to the organisation, again with support from the Admiralty, of the Challenger expedition and his appointment as chief of the expedition's civilian scientific staff of six persons, including H.N. Mosely*. The purpose of the venture was an oceanographic and biological study of the Atlantic, Pacific and Antarctic oceans. Sailing from Portsmouth on 21 December 1872 the expedition visited the West Indies, Madeira, the Cape Verde Islands, Brazil and Tristan da Cunha, before anchoring in Simon's Bay from 28 October to 17 December 1873. From there they visited the Prince Edward Islands (which now belong to South Africa) and sailed into Antarctic waters, becoming the first steam vessel to cross the Antarctic circle on 16 February 1874. The expedition was also the first to photograph Antarctic icebergs and the southern islands. Thomson communicated "Preliminary notes on the nature of the sea-bottom procured by the soundings of HMS Challenger during her cruise in the southern sea in the early part of the year 1874" to the Royal Society of London for publications in its Proceedings (1874-1875).
After returning to England in May 1876 Thomson was knighted and appointed director of a commission to arrange the expedition's collections and publish its results. After his death in 1882 the work was continued under the direction of J. Murray. The resulting publication, edited by Thomson and Murray, was entitled Report on the scientific results of the voyage of HMS Challenger during the years 1873-1876... and was published in 50 volumes during 1880-1895. It included a narrative of the voyage, an atlas, and volumes on physics and chemistry, deep-sea deposits, botany, and zoology. The expedition took soundings at 362 stations, found living organisms to depths of over 5000 meters, and discovered nodules of almost pure manganese peroxide on the ocean floor. On his own Thomson published a shorter work, The Atlantic: An account of the general results of the exploring expedition of HMS 'Challenger' (London, 1876, 2 vols; re-published as The voyage of the 'Challenger'... in 1877) as well as a number of papers on his observations.
Thomson was awarded several honorary doctoral degrees and was a Fellow of the Royal Society of Edinburgh (1855), the Royal Society of London (1869), the Linnean Society, the Geological Society of London, and the Zoological Society of London.