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 waveform analysis, likely from an oscillograph or similar instrument.
| Identifier | ExFiles\Box 138\2\ scan0165 | |
| Date | 18th October 1938 guessed | |
| ", | ||