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).
Photograph of a cluster of helical gears on a shaft.
| Identifier | ExFiles\Box 97\5\ scan0232 | |
| Date | 3rd July 1939 guessed | |
| 9045 | ||