From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Laboratory photomicrograph of a sample from Ransoms & Marles at 150 diameters magnification.
| Identifier | ExFiles\Box 114\2\ scan0059 | |
| Date | 13th April 1934 | |
| R.R. 403 (5H) (62316 13-4-34) J.H.,Ltd. ROLLS-ROYCE LTD. LABORATORY. PHOTOMICROGRAPH NO A1,012 MAGNIFICATION: 150 DIAMETERS. Ransoms & Marles. | ||