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. regarding erratic speedometer readings caused by temperature changes.
| Identifier | ExFiles\Box 50\4\ Scan111 | |
| Date | 6th May 1927 | |
| X4306 Hs {Lord Ernest Hives - Chair} /Rn {Mr Robinson} 3/LG. Expl: Dept: 6th. May 1927. Messrs. The A.T.Speedometer Co., 45-45a Brook Green, London W.6. Dear Sirs, SPEEDOMETERS. We have recently been somewhat concerned owing to the erratic reading of your speedometers with changes of temperature in which they work. You will appreciate that even under normal British atmospheric conditions, the temperature of the dashboard varies from 15°C to 30°C under normal driving conditions. Tests we have carried out shew that within this range the reading of your speedometers vary some 12%. We should be obliged if you could let us know of any means of altering the characteristic of the instrument to obviate this fault, though from the principle on which it functions, we are unable to imagine any reasonable method of overcoming the trouble. Yours faithfully, FOR ROLLS-ROYCE, LIMITED. | ||