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).
Request for the minimum and maximum revolutions per minute for two nominal fan types for test verification.
| Identifier | ExFiles\Box 119\3\ scan0183 | |
| Date | 8th July 1931 guessed | |
| -2- In connection with these fans may I trouble you for the minimum and maximum revolutions per minute of your nominal two fan types which I require to check my own tests. With compliments, Yours faithfully, [Illegible signature] | ||