Hardback notebook, inscribed inside ‘Victor Appleton St John's College, Cambridge. Magnetism and Electricity', undated (probably before 1919 with some later additions). Both ends of the notebook are used. It contains notes and calculations, perhaps of undergraduate work (Appleton usually signed himself ‘E.V. Appleton' after 1919). Some notes on negative ions, ionisation, etc. may be of a later date.