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).
Letter to A.T. Speedometer Co. Ltd. regarding the alteration of two speedometers.
| Identifier | ExFiles\Box 59\2\ Scan016 | |
| Date | 17th February 1930 | |
| X4308. Expl. Dept. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}2/WJ. Feb.17th.1930. The A.T. Speedometer Co. Ltd., 183, The Vale, Acton. LONDON. W.3. Dear Sirs, We are sending to you under separate cover A.T. Speedometers No. C.296 and C.278 for alteration. The revs/mile of this speedometer drive are 800 and we should like the miles recorder to be correct for these revs. We should like the M.P.H. reading to read 4% fast at 35°C. Owing to centrifugal action the effective radius of the tyre increases by this amount at high speeds. Neither of these instruments are temperature compensated. Will you please submit an estimate before you start this work. Yours faithfully, For Rolls-Royce Ltd. | ||