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).
Photographic record of three numbered test samples showing spray or deposit patterns.
| Identifier | ExFiles\Box 137\4\ scan0157 | |
| Date | 7th January 1931 guessed | |
| 2950 2500 2050 SS{S. Smith} 15 | ||