Includes obituaries and tributes, biographical notes by Jeffreys himself and transcriptions of interviews conducted by colleagues (see also Section H). There is career, honours and awards material spanning his whole life from birth certificate to his death including letters of condolence received by Lady Jeffreys. There is significant early material, for example, correspondence with St John's College tutors, 1909-1910, Jeffreys's notes of lectures by H.F. Baker, Ebenezer Cunningham and A.S. Eddington, 1911-1914, 'Letters from Johnians 1917', including M.H.A. Newman, records of Jeffreys's period with the Meteorological Office, 1917-1922, including copy of a reference from its director Sir Napier Shaw, and Jeffreys's memorandum on the constitution of the Senate at Cambridge, 1921, addressed to the Royal Commission on the Universities of Oxford and Cambridge. His appointment as Plumian Professor in 1946 and later honours, including 70th and 90th birthday celebrations, are documented. There is a little material relating to Jeffreys's father, 1886-1947, and a sequence of family and personal correspondence, 1917-1992, which reflects his continuing interest and connexions with the North East of England where he was born. Miscellaneous biographical items include a sketch book, possibly dating from Jeffreys's school days, a few letters relating to Jeffreys's early interests in photography and botany, including a letter from William Bateson, 1915, a collection of old railway tickets, Jeffreys's passports and a significant accumulation of travel literature.