Nuclear physics in photographs : tracks of charged particles in photographic emulsions / by C.F. Powell and G.P.S. Occhialini. Powell, Cecil Frank. Occhialini, G. P. S., joint author. Nuclear physics. Radioactivity. Photography Scientific applications. Photography in nuclear physics. QC721 .P63 539.722 PON Errata slip inserted. Oxford : Clarendon Press, c1947. c1947. 1947 Text xii, 124 p. : eng