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.

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