The American geographer and geologist William Morris Davis (1850-1934) formulated a concept of the cycle of erosion, but his theories of landscape evolution are now sharply contested.
Of Quaker stock, William M. Davis was born in Philadelphia, Pa., on Feb. 12, 1850. He graduated from Harvard in 1869. From 1870 to 1873 he was a meteorological assistant at the Córdoba observatory in Argentina. In 1878 he returned to Harvard to teach geology and geography. Warned by senior colleagues that it would be difficult to gain promotion without publication, Davis soon became known for his contributions to journals. In all he wrote some 500 papers, chiefly on physical geography but also on the teaching of geography in schools and universities. These included 42 papers on meteorology and a textbook, Elementary Meteorology (1894).
In 1890 Davis became professor of physical geography at Harvard, and 9 years later he was appointed professor of geology. He retired from Harvard in 1912.
In 1889, in the first volume of the National Geographic Magazine, Davis published a notable paper on the rivers and valleys of Pennsylvania, followed in 1890 by a study of the rivers of northern New Jersey. For 10 years he published papers in this journal, which was then austerely academic; his work also appeared in numerous American and European journals. Steadily he developed his theory of the cycle of erosion under humid, arid, glacial, and other conditions. It provided a wonderful framework for teaching and research, profitably used by his disciples, notably the geologist Douglas W. Johnson. Block diagrams and sketches of unique clarity helped readers to visualize landscapes in three dimensions. For a time Davis's ideas on the evolution of landscapes were the basis of most geomorphological teaching. But there were always dissenting voices that called attention to the large assumptions on which some of the Davisian views were based, and at present some geomorphologists regard his views as interesting period pieces.
Davis was always anxious to bring geographers together, and through his enterprise the Association of American Geographers was founded in 1904. In 1911 he ran a 9-week "geographical pilgrimage" from Wales to Italy. He also organized the 8-week transcontinental expedition of the American Geographical Society in 1912 for European and American geographers. He was an enthusiastic fieldworker, and several of his papers were based on his careful fieldwork in Europe.
Davis was professor of physiographic geology at the California Institute of Technology from 1930 to 1934. He died in Pasadena on Feb. 5, 1934.
Davis's Geographical Essays, edited by Douglas Wilson Johnson (1909), gives his most important papers. His work is discussed in Preston E. James and Clarence F. Jones, eds., American Geography: Inventory and Prospect (1954).