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 comparing 'Plain', 'Slotted', and 'Wellworthy' samples at 500x magnification.
| Identifier | ExFiles\Box 148\3\ scan0144 | |
| Date | 1st October 1935 | |
| R.R. 403 (10m) (92117-1-10-35) J.H., Ltd. ROLLS-ROYCE LTD. X1256 LABORATORY. WP PHOTOMICROGRAPH No. A1466/7. MAGNIFICATION: 500 DIAMETERS. PLAIN. SLOTTED. WELLWORTHY. | ||