Carl David Anderson (1905-1991). Early education and interest in electricity. Robert Millikan's and Oppenheimers' influence on A's undergraduate education at the California Institute of Technology. Research with Loughride on photoelectric effect of x rays; Ph.D. thesis. Postdoctoral work on cosmic rays. Discovery of the positron and its publication. Confirmation of Cockcroft-Walton work on fission at Kellogg laboratory; financing of equipment. Accusations of Communism during the 1930's. Awarding of the Nobel prize. Work as chairman of the physics division and undergraduate education at Caltech. Cosmic ray work that led to the discovery of the meson. Charles Lauritsen's war work on the proximity fuse (1940). Early assessments fo Enrico Fermi's A-bomb group at Chicago. Acquaintance with Ernset Lawerence and development of the first cyclotron. Seth Neddermyer's A-bob work. Development of rockets for the Navy with Bowen during the war. Relationship between Caltech and the Jet Propulsion Laboratory postwar. Relations among mathematics, physics, and astronomy at Caltech. President Kennedy's dinner for Nobel laureates (1962).