Letter from H L Penfold to Archibald Vivian Hill, Ministry of Fuel & Power, Directorate of Opencast Coal Production, 19 Cavendish Crescent North, the Park, Nottingham, Encloses copy of his Universal System of Weights and Measures [MDA/A/20/1] for opinion of Royal Society before being sent to Social and Economic Council of the United Nations. Has also sent this document to the National Physical Laboratory; British Standards Institution' British Association; Edward Appleton; Charles Inglis; British Council; Federation of British Industries, and many other bodies. 6 March 1946