The notes are in pencil, blue and red ink or biro, and include short narratives, diagrams, calculations, bibliographical indications, etc. The notebooks are all headed 'J.J. Thomson' but are not dated.
D/13: Notes on J.J. Thomson's papers (some in detail) and those of others, or on history of Cavendish Laboratory. Includes plan for 'Chapter IV'.
D/14: Similar material. Both ends of book used. Includes notes for 'Unplaced possible additions' (on pumps - used as Appendix in book).
D/15: Similar material. Both ends of book used. P.3 is headed 'J.J.T. continued'. Pps. 1 & 2, headed 'Leckhampton', contain a draft proposal for Leckhampton House, the postgraduate campus of Corpus Christi College, Cambridge, officially established in 1961 during the Mastership of G.P. Thomson.