Letters and cables regarding secondary mirror support systems, including copies of W.A. Goodsell's letters to J.B.S. Price, Sir Howard Grubb, Parsons and Co. Ltd, on the lack of progress and the specification for the performance of the secondary mirrors when supported in mercury girdles; and Redman's correspondence with S.C.B Gascoigne, including reference to primary mirror astigmatism, the performance specification of the secondary mirror support system, testing the mercury girdle and the acquisition of a new primary cell from Boller and Chivens for the Mount Stromlo 30-inch telescope