Papers regarding the refurbishment of the Yapp 36-inch Reflecting Telescope and the 30-inch Reflecting Telescope. Much of the material relates to the Cassegrain Spectrograph and the Schmidt Camera. There is correspondence on the design and construction of these items between G.M. Sisson of Sir Howard Grubb, Parsons and Co. Ltd; E.H. Linfoot of Cambridge University; the National Physical Laboratory; and B.E.J. Pagel and Sir Richard Woolley of the Royal Greenwich Observatory. The papers also include a tender for the work submitted by Sir Howard Grubb, Parsons and Co. Ltd; memoranda, notes, diagrams and calculations by B.E.J. Pagel, H. Barker and Sir Richard Woolley; and drawings by Sir Howard Grubb, Parsons and Co. Ltd of the 11" x 20" Schmidt, the 12" x 20" Schmidt f9 and the 18" Schmidt f10.