Thomson, Sir Charles Wyville
THOMSON, SIR CHARLES WYVILLE
(b. Bonsyde, Linlithgow, Scotland, 5 March 1830; d. Bonsyde, 10 March 1882)
natural history, oceanography.
Thomson was the son of Andrew Thomson, a surgeon in the East India Company. His earliest education was at Merchiston Castle School. When he was sixteen he matriculated at the University of Edinburgh to study medicine, a field that he was forced to give up after three years because of ill health. Moreover, his primary interest was natural history, especially zoology, botany, and geology. In 1853 he married Jane Ramage Dawson. Their only child, Frank Wyville, became a surgeon captain in the Third Bengal Cavalry.
Thomson held a number of academic positions. In 1851 he was a lecturer in botany at the University of Aberdeen; two years later, in 1853, he was appointed professor of natural history at Queen’s College, Cork. In 1854 he became professor of geology at Queen’s College, Belfast; and six years later, in 1860, he was named professor of zoology and botany at the same college. In 1868 Thomson accepted the professorship in botany at the Royal College of Science, Dublin, and in 1870 he assumed his last academic position, the regius professorship of natural history at the University of Edinburgh.
While at Belfast, Thomson began to establish himself as a talented marine biologist with his published studies of coelenterates, polyzoans and fossilized cirripeds, trilobites, and crinoids. He also became interested in determining whether life exists at great depths in the sea. Forbes suggested that below 300 fathoms there exists an azoic zone. In 1866, while visiting Michael Sars at Christiania (Oslo), Thomson had the opportunity to examine animals collected at depths below 300 fathoms. Thomson’s interest in this question led him to embark upon a series of crucial deep-sea dredging voyages that culminated in the classic Challenger expedition of 1872–1876.
In 1868 Thomson and William Benjamin Carpenter, who was at the time vice-president of the Royal Society, persuaded the Society to seek Admiralty support for a deep-sea dredging project in the North Atlantic. Support was granted, and in August of 1868 Thomson and Carpenter began their project on board the paddle steamer H.M.S. Lightning. Despite stormy weather they were able to undertake some dredging and to obtain sponges, rhizopods, echinoderms, crustaceans, mollusks, and foraminifers below the 300-fathom mark. Perhaps the most surprising result of this cruise was the discovery of diverse temperatures at similar depths in different regions. The discovery called into question the accepted theory of a relatively constant submarine temperature of 4° C. The success of the Lightning cruise led to additional Admiralty support, and in the summer of 1869 the survey ship H.M.S. Porcupine was placed at the disposal of the Royal Society. Thomson, Carpenter, and John Gwyn Jeffreys dredged and took serial temperatures off the west coast of Ireland and off the Shetlands. They also began to analyze the composition of seawater from various depths. After dredging in waters over a thousand fathoms below the surface, they obtained on 22 July 1869 samples of mud and marine animals from 2,435 fathoms down. The results of these two cruises clearly cast doubts upon the validity of the azoic theory.
All these findings contributed to a renewed interest in the science of the sea. In 1869 Thomson was made a fellow of the Royal Society for his work. He described the details and accomplishments of the two expeditions in his popular study The Depths of the Sea (1873). With the encouragement of Carpenter, the Royal Society again approached the Admiralty for support in extending the scope of the investigations from the North Atlantic to the oceans of the world.
The Admiralty agreed, and on 7 December 1872, H.M.S. Challenger, a steam-powered corvette of 2,300 tons, set forth from Sheerness. Thus began a three-and-a-half-year voyage of oceanographic exploration. Since Carpenter did not wish to command the expedition, Thomson was selected as head of the civilian scientists. Once at sea the staff of the Challenger began the arduous tasks of sounding, dredging, and taking serial temperatures and water samples. Their dredging confirmed that marine life exists at depths approaching three thousand fathoms. They also discovered nodules of almost pure manganese peroxide on the seafloor. As they dredged and sounded in deeper water, they discovered that a clay bottom is characteristic of great depths. The material of the ocean floor is the residue of a chemical process that removes the carbonate of lime from the calcareous skeletons of foraminifers, mollusks, and other species. In bottom deposits beyond four thousand fathoms in the Pacific Ocean, they discovered a seafloor with new characteristics–radiolarian ooze. John Murray, one of the staff naturalists, uncovered new data on the diurnal migration of plankton and the oceanic distribution of globigerina. The temperature readings at various depths in a number of areas contributed to the growing speculation as to the nature of oceanic circulation. This complex question was not resolved by the scientific staff of the Challenger, for there was no physicist aboard to analyze this problem. The Challenger expedition was weakest in its examination of the questions of physical oceanography. On 24 May 1876 the ship returned to her berth at Sheerness after a voyage of 68,890 nautical miles and after having made soundings at 362 stations.
Much of the work of the expedition still lay ahead, for the specimens and data collected had to be organized and distributed, and the scientific results published. Publication of this diverse information was an enormous task, one which ultimately cost the British Treasury over £100,000. Queen Victoria conferred a knighthood (1876) upon Thomson for his service to science. While Thomson established the format of the Challenger Reports, he did not live to see the completion of the publication of this multivolume work, which chronicled his epic years of oceanographic exploration.
I. oRIGINAL Works. Thomson’s scientific papers are listed in the Royal Society’s Catalogue of Scientific Papers, V, VIII, XI , and XIX . For the cruises of the Porcupine and Lightning, consult The Depths of the Sea (London, 1873). A popular account of the Challenger’s activities in the Atlantic may be found in The Voyage of the Challenger. The Atlantic. A Preliminary Account of the General Results of the Exploring Voyage of H.M.S, Challenger During the Year 1873 and the Early Part of the Year 1876, 2 vols. (London, 1877). The scientific results were published in Report on the Scientific Results of the Voyage of H.M.S. Challenger during the Years 1873–1876, 50 vols. (London, 1880–1895).
II. Secondary Literature. For a biographical sketch of Thomson by a former student and assistant, see William Herdman, “Sir C. Wyville Thomson and the ‘Challenger’ Expedition,” in Founders of Oceanography and Their Work (London, 1923). 37–67. See also Margaret Deacon, “The Magnificent Generalization” and “The Voyage of H.M.S. Challenger,” in Scientists and the Sea. 1650–1900 (London. 1971), 306–332, 333–365. For an examination of the problems of publishing the reports of the expedition, consult Harold L. Burstyn, “Science and Government in the Nineteenth Century: the Challenger Expedition and its Report,” in Bulletin de l’lnstitut océanographique, 2 , spec. no. 2 (1968), 603–611.
Phillip Drennon Thomas