Correspondence between members of the Working Party formed by R. Woolley to consider the design study for a 150-inch telescope. The correspondents include Woolley; Redman; S.C.B. Gascoigne, Royal Greenwich Observatory; B.J. Bok, Director, Mount Stromlo Observatory; and A. Hunter, Royal Greenwich Observatory. Bok sends copies of his reports on visits to the Lick, Mount Palomar and Kitt Peak Observatories, and to Sir Howard Grubb, Parsons and Co. Ltd. There is also a copy of a letter from Redman to Hunter, 17 May 1964, in which he makes comments and suggestions on the Southern Hemisphere Telescope report and encloses a revised version of the proposed telescope design study.