The material includes notebooks, manuscript notes and drafts, drafts for lectures and papers (many unpublished or additional to those listed in the Bibliography compiled for the Royal Society Memoir of Thomson), photographs and slides of experimental results, and correspondence.
Of considerable interest are the drafts and text of Thomson's autobiography covering his career to 1966; this document, which he had written primarily for his family, is included at A.2 - A.14 and has, with permission, been drawn upon in compiling some of the catalogue entries. It is an important source of information for some of the `gaps' in the surviving manuscripts, particularly for such matters as Thomson's activities in the Second World War (other than the MAUD Committee), his many foreign visits and his public commitments. In his introduction to the autobiography, Thomson mentions his inability to write adequately of his wife Kathleen, and of his hope to compile a selection of her letters to him; bound copies of the autobiography, and of the letters, have been made available by Mr. D.P. Thomson and appear at A.14, A.14A respectively.
Thomson's scientific research on electron diffraction is well documented by notebooks, lectures and slides; his contribution to thermonuclear research, on which he was able to publish very little because of the demands of security, survives mainly in the form of manuscript notes and drafts (see Section E). Unfortunately, it is clear that much has been lost of the early correspondence on electron diffraction.
Thomson's service to the Royal Society, The Institute of Physics, the British Association and many other learned societies, is also very scantily documented.
Thomson's own distinguished contribution to scientific knowledge, together with his admiration for his father and early acquaintance with eminent men of science, made him always aware of the history of science and its practitioners. He wrote and lectured widely on these subjects, often for anniversary celebrations of various kinds, and also contributed many obituary tributes for individual scientists, many of them his personal friends. He frequently assembled information and recollections additional to those which appeared in the final publication, but which survive in the collection. Material relating to his historical and biographical writings on 'J.J.' can be found in the collection of papers of Sir Joseph Thomson.
In addition to an historical awareness, Thomson was also conscious of the impact of science on many aspects of life and thought. Section H groups together his lectures and writings on science-related topics of this kind; it includes inter alia material on his work for the Voluntary Euthanasia Society which occupied much of his interest in his later years.
