Correspondence on miscellaneous matters, including correspondence with the National Institute of Oceanography; Sir Howard Grubb, Parsons and Co. Ltd, Newcastle-upon-Tyne; the Department of Geodesy and Geophysics, University of Cambridge; the Economic League; the Hydrographic Department of the Admiralty, concerning applications from the B.B.C. and the 'Yorkshire Post' to give publicity to the Isaac Newton Telescope mirror; Professor C. Fehrenbach of the Observatoire de Marseille; Dr T. Dunham, Jr., Imperial College of Science and Technology, London; the Institution of Professional Civil Servants, regarding the Isaac Newton Telescope lens and the desirability of a large telescope in the southern hemisphere; R.O. Redman of The Observatories, Cambridge; Professor G. van Biesbroeck of the Kitt Peak National Observatory, Arizona; the Science Research Council, concerning progress with the construction of the Isaac Newton Telescope; Hall and Ham River Ltd, regarding the supply of ready-mixed concrete, etc., for the construction of the Isaac Newton Telescope building; and the editor of 'Spectrum' at the Central Office of Information.