Anderson talks almost exclusively about his work during the thirties with particles of high energy involved in nuclear reactions. He covers in detail his discovery of the positive electron, his pair production work with gamma rays, his expedition to Pike’s Peak with Neddermeyer and their discovery of the mesotron. He mentions that it was in his speech accepting the Nobel Prize in 1936 that he first mentioned the possibility of negative and positive particles of intermediate mass. After noting the absence of any cosmic ray work during the war years, he mentions the postwar development of cosmic ray work into high energy physics.
