Primary Collection: 21 notebooks consisting of mathematical equations and calculations; 4 boxes of miscellaneous pamphlets and publications mainly relating to telegraphy, many annotated; 5 boxes of papers, mostly loose notes, some drafts of papers, some correspondence; miscellaneous items, including presentation of Swedish medal, 1924; 5 bundles of notes by Heaviside on the backs of old letters; 55 envelopes of letters to Heavisde from various correspondents.
Material found at Paignton, 1957: preliminary drafts of articles for 'Electromagnetic Theory', with annotated proofs; miscellaneous correspondence and papers including calculations, Christmas card etc.
