Early education, Real-gymnasium; Universität Berlin, 1930; early interest in physics; courses, books studied, method of noting original ideas; University of Cambridge, 1933; first formal paper on nuclear physics; reaction in Berlin to discovery of neutron, colloquium of Lise Meitner; beta decay and the neutrino hypothesis; working habits at Cavendish Laboratory; collaboration with James Chadwick; photodisintegration of the deuteron; work with slow neutrons; circumstances of move to U.S., 1938; consequences of death of Ernest Rutherford on research at Cavendish Laboratory; use of proportiona