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).
The accuracy of a speedometer at various speeds.
| Identifier | ExFiles\Box 126\2\ scan0029 | |
| Date | 2nd June 1931 guessed | |
| - 2 - Speedometer. The speedometer was found to be correct at 30.M.P.H. 2½% fast at 40.M.P.H., and 5½% fast at 50.M.P.H. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} | ||