Contains report on Current-Temperature Calibration of an Optical Pyrometer of the Disappearing-Filament Type, dated June 1937, with four supporting monochrome photographs, Nos. 24367/68, N11654/55. Additional 68 unidentified monochrome photographs and negatives of telescopes. Eight monochrome photographs identified with a negative number, 2033/2, 4926-1, 4926/2, 6233/3, 7097, 7097/1, 8756/2. Four monochrome photographs from A.C. Curtis numbered 1 - 4 with handwritten details on the reverse sides.