Scope and Contents: Rochester period: Scientific correspondence on among other things investigation of cosmic radiation with photographic emulsions. India, Copenhagen and retirement periods: General correspondence, a little scientific correspondence and a few article manuscripts. Period 1948-54, political problems in the USA: Newspaper clippings, private correspondence. Private papers and private correspondence, regarding employments and awards.
Correspondents include: Hannes Alfvén, G. Bernardini, Homi J. Bhabha, Patrick Maynard Stuart Blackett, Bert Bolin, Jørgen Bøggild, Umberto Campagnolo, Edward U. Condon, Connie Dilworth (m. Occhialini), David Faiman, Enrico Fermi, Phyllis Freier, Gene Gardner, Werner Gentner, Gertrude Goldhaber, Kenneth Greisen, Lajos Janossy, Peter Kapitza, David Kaplan, Kodak Research Lab. (R.H. Hertz, John Spence), Devendra Lal, Ernest O. Lawrence, Louis Leprince-Ringuet, W.F. Libby, Ed Lofgren, Robert E. Marshak, M.G.K. Menon, Giuseppe Occhialini, Office of Naval Research (Urner Liddel); Frank Oppenheimer, Yash Pal, Cecil Frank Powell, C.V. Raman, G.D. Rochester, George T. Reynolds, Nathan Rosen, Bruno Rossi, J. Rotblat, Alfred Schild, Robert Serber, Amos de Shalit, Kurt Sitte, D.V. Skobeltzyn, Lyman Spitzer, Vatican State (M.S. Wallarta, G. Lemaitre), Sieg Woulthuysen, Hideki Yukawa.