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).
Microscopic views showing the surface and edge of a spring.
| Identifier | ExFiles\Box 151\2\ scan0346 | |
| Date | 2nd July 1937 guessed | |
| SPRING SURFACE, EDGE | ||