Formative years; family history; schooled in Ottawa and Toronto. University of Toronto and University of Western Ontario for undergraduate studies. Returns to Toronto for graduate studies; comments on courses and teachers. Thesis adviser Richard D. Brauer; Ph.D., 1939. Employment as a mathematician. Comments on the effects of the Depression. Instructor in math at University of Mannitoba, 1938-1939; comments on student and faculty body. Wartime research; Canadian war projects. Teaches navigation to naval volunteer group; Brown Summer School, 1941. Joins the Montreal Lab in Applied Math (Hans von Halban), 1943; European emigres that made Leslie Groves uneasy (George Placzek); Canadian-American relations, security. Moves to Los Alamos Scientific Laboratory (LASL), May 1945. Experimentalists at LASL. Neutronics calculation at LASL. Comparison of earlier methods and the more sophisticated calculation by Mark, Sydney Goldstein, and Bengt E. Carlson. Education in physics. Postwar plans. Comparisons of the atmosphere in LASL and Toronto/Winnipeg. Plans to stay in LASL; reorganization at LASL. Discussions on the control of atomic energy. Baruch presentation. Thermonuclear research; the Super Conference; relationship with Edward Teller; decision to proceed with Super (Teller). The Greenhouse test series, 1951. Staffing at LASL; Teller's reconstruction of events. Pacific tests. LASL and Livermore Laboratory, reorganization of thermonuclear research. Military security at LASL. Teller's relations with J. Robert Oppenheimer and Hans Bethe; Teller as seen by others.