Childhood on Missouri farm, early education and interest in science. Enters University of Missouri, 1907; B.A., 1910, M.A. 1911; influence of Oliver Kellogg, Eli Haines, Frederick Seares. To Princeton University, 1911-1914; first doctoral student of Henry Norris Russell; close relationship with Russell, impressions of him as teacher, co-worker, and friend; works on orbits of eclipsing binaries and Cepheid variable star theory; Russell's experiments with darkening at the limb; Shapley's research methods, requirements for doctorate in astronomy, 1910; Robert W. Wood, R. S. Dugan, O. W. Richardson, and Annie J. Cannon. Ph.D. on theory of eclipsing binaries, 1913; also works on the velocity of ants in relation to environmental temperature. To Mt. Wilson Observatory (Frederick Seares, Milton Humason, Ferdinand Ellerman, Hale, Walter S. Adams); continues work on globular clusters, eclipsing binaries, pulsation theory; 60-inch and 100-inch telescopes; the personalities and work of Jacobus C. Kapetyn and Adriaan van Maanen; Shapley-Curtis debate on the scale of the universe, 1920. Director of Harvard Observatory, 1921-1951; detailed discussion of reorganization of observatory from research to teaching institution (Harvard University); work on Magellanic Clouds (Henrietta Leavitt, Cannon), early 1920s; classification for the Henry Draper Catalog; fund-raising activities; move of Harvard Southern Station from Peru to South Africa; social and intellectual life of the Observatory. Discussion of Shapley's cultural and philanthropic activities (rescue of European scholars, rebuilding of European observatories and libraries, formation of UNESCO). Discussion of his political activities; the Condon Affair; conflicts with the Rankin and McCarthy committees. Active participation in scientific and scholarly organizations: President of American Academy of Arts and Sciences, 1939-1944; founding of journals, Daedalus and American Scientist; Sigma Xi society; President of American Association for the Advancement of Science; Worcester Foundation for Experimental Biology (Hudson Hoagland, Gregory Pincus); National Science Fund and National Science Foundation. Reflects on changes in state of astronomy through the years, international relations, funding, and his own career. Also prominently mentioned are: American Astronomical Society, Arequipa Observatory (Peru), Carthage Academy, Institute for the Study of Religion and the Age of Science, radio astronomy, Rockefeller Foundation, and Tonantzintla Observatory.