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 showing two bevel gears with polished surfaces after a lubricant test.
| Identifier | ExFiles\Box 114\1\ scan0098 | |
| Date | 11th January 1937 guessed | |
| Fig. 14 SHOWING POLISHED SURFACES AFTER TEST WITH SATISFACTORY LUBRICANT | ||