JEFFREYS, SIR HAROLD

born April 22, 1891, Fatfield, Durham, Eng. died March 18, 1989 British astronomer and geophysicist noted for his wide variety of scientific contributions. Jeffreys was educated at Armstrong College, Newcastle-upon-Tyne (D.Sc., 1917), and St. John's College, Cambridge (M.A., 1917), and was a fellow at St. John's from 1914. He served in the Meteorological Office (191722), lectured in mathematics at Cambridge (192332), was reader in geophysics at Cambridge (193246), and was the university's Plumian professor of astronomy (194558). He was knighted in 1953. In his work in astronomy, Jeffreys established that the four large outer planets (Jupiter, Saturn, Uranus, and Neptune) are very cold and devised early models of their planetary structure. His other astronomical work includes research into the origin of the solar system and the theory of the variation of latitude. In geophysics he investigated the thermal history of the Earth, was coauthor (1940) of the standard tables of travel times for earthquake waves, and was the first to hypothesize that the Earth's core is liquid. He explained the origin of monsoons and sea breezes and showed how cyclones are vital to the general circulation of the atmosphere. Jeffreys also worked on probability theory and on methods of general mathematical physics. Jeffreys' honours included the Gold Medal of the Royal Astronomical Society (1937) and the Royal Medal of the Royal Society of London (1948). Among his principal works are The Earth: Its Origin, History and Physical Constitution (1924, 6th ed. 1976), Scientific Inference (1931, 2nd ed. 1957), Earthquakes and Mountains (1935, 2nd ed. 1950), and Methods of Mathematical Physics, with Bertha S. Jeffreys (1946, 3rd ed. 1962). The Collected Papers of Sir Harold Jeffreys was published in six volumes from 1971 to 1977.