Minute books of the Delta Squared V Club, a discussion group at University of Cambridge on mathematical physics, cover the period from the club's first meeting in 1900 until the 192nd meeting in 1937. In addition to resolutions and member lists, the minute books contain abstracts of some papers read at meetings. The two minute books of the Kapitza Club (named after Peter Kapitza, at the Cavendish Laboratory, Cambridge, 1921-1930 and director, Mond Laboratory, 1930-1934) cover from the 28th meeting in 1923 until the 678th meeting in 1958. Included is a list of speakers at the first 16 meetings (1922-1923), brief descriptions of topics discussed, and a small number of letters and clippings.