Official correspondence with the General Post Office, Ministry of Works, Meteorological Office, Admiralty and others regarding solar physics, including letters concerning the Radar mirror for the Paris Observatory, including correspondence between the Allied Control Commission for Germany and H. Spencer Jones, 1947; correspondence regarding geomagnetic disturbances affecting General Post Office radio data and reports on sun spots and solar flares, 1947; and a report on the 'Solar Location diagram' and 'Co-ordinate Perspective Grille' submitted for examination by J. Swarbrick of the Codes of Practice Committee, Ministry of Works, 1945.