Ring-back notebook, with a few loose pages inserted. The material consists of typescript and manuscript notes, mainly on radar, reflection coefficient and similar topics, including notes on the literature, summaries of wartime research reports and committee meetings, notes of discussions, visits to laboratories and research stations, ideas for research, etc. It mainly runs from 1941-1943, but also includes a few references from 1939, and press-cuttings on 'Radar and the weather', dated 1946.