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 discussing vehicle instrumentation and carburetter settings required for high-altitude driving.
| Identifier | ExFiles\Box 114\4\ scan0022 | |
| Date | 30th January 1937 guessed | |
| 2. 12/2 The two other instruments which are necessary are a Hughes motor compass (50s. less 20 per cent.) obtainable from S.Smith & Sons (M.A.) Ltd. or direct from Henry Hughes & Son Ltd., 59, Fenchurch Street, E.C. 3 and a motor Aneroid, calibrated up to 9,000 ft. - I think Smiths can supply this. A Tapley gradient meter would also enable us to make interesting observations in the mountainous country in Kenya. Our road goes up to 9,000 ft. - as high as the Stelvio Pass in Italy. Will you therefore obtain and fit these instruments? Turning to another matter, the carburetter setting should be on the weak side, or capable of being weakened below normal, preferably without having to stop and change jets. Once we leave Algiers we shall be driving all the time at 1,300 to 2,000 ft. above sea level. On the Col des Caravanes and Atlas mountains we reach 4,500 ft. and in Kenya even greater altitudes. Only ordinary petrol, with a rather poor octane value, is generally obtainable. Economy on a run of this sort obviously matters much more than power. Yours faithfully, AHSymons * Useful in case we appear to be boiling. | ||