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).
Two photomicrographs showing the structure of a material's surface.
| Identifier | ExFiles\Box 120\1\ scan0326 | |
| Date | 20th June 1935 guessed | |
| Inner surface corresponding to the wearing surface. | ||