Family background; early interest in mathematics; physics at University of Manchester; Ernest Rutherford's influence; early research under Rutherford at Manchester; examination by Joseph J. Thomson for degree; recollections of associates at Manchester, including Niels Bohr; scholarship to Universitt̃ Berlin and work there with Hans Geiger; internment during World War I; scientific work at internment camp; return to Manchester; move with Rutherford to University of Cambridge; appointment as Assistant Director of Research at Cavendish Laboratory (ca. 1923); work with Rutherford on artificial disintegration; Rutherford's idea of the neutron; early experimental search for neutron; duties and experiences at the Cavendish Laboratory from 1919 to 1936; Rutherford's personality; Solvay conference of 1933; reasons for leaving Cambridge for University of Liverpool; initial plans, personnel and activities at Liverpool; cyclotron; award of Nobel Prize; encounter with Joliots, also in Stockholm for Prize in chemistry; influx of refugee theoreticians; work on the meson; changes effected by large machines; recollections of announcement of fission; World War II work; involvement with A-bomb project, Los Alamos Scientific Laboratory and General Leslie Groves; postwar considerations regarding international control of atomic energy; effect of Rutherford's death on Cavendish; return to Cambridge as Master of Gonville and Caius College; circumstances of resignation as Master; appraisal of personal satisfactions. Also prominently mentioned are: H. K. Anderson, John Anderson, Homi Bhabha, Patrick Maynard Stuart Blackett, Niels Henrik David Bohr, Paul Adrien Maurice Dirac, Albert Einstein, Charles D. Ellis, Walter M. Elsasser, Ralph Howard Fowler, Maurice Goldhaber, Otto Hahn, Walter Heitler, J. R. Holt, Ernest Orlando Lawrence, Douglas Lea, Lise Meitner, Stefan Meyer, Henry N. Moseley, Walther Nernst, Giuseppe Occhialini, Mark Oliphant, Maurice H. L. Pryce, Stanley Rolands, Heinrich Rubens, Joseph John Thomson, Merle Antony Tuve, Walke, H. C. Webster, Charles Thomson Rees Wilson; Department of Scientific and Industrial Research of Great Britain, Manchester Literary and Philosophical Society, Ministry of Aircraft Uranium Development Committee (Great Britain), Physikalische-Technische Reichsanstalt, Royal Society (Great Britain), University of Birmingham, University of Cambridge Cavendish Physical Society, and University of Liverpool.