Photograph of an engine piston, showing its crown, ring grooves, and wrist pin boss.
| Identifier | ExFiles\Box 111\2\ scan0246 | |
| Date | 2nd October 1934 guessed | |
| 1044 | ||
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).