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 from a speedometer company discussing test results for a Rev-Clock's temperature compensation.
| Identifier | ExFiles\Box 59\2\ Scan301 | |
| Date | 29th December 1933 | |
| 86051. The A.T. SPEEDOMETER Co., Ltd. A.T. (Logo) MAGNETIC SPEEDOMETERS & MOTOR CLOCKS. REVOLUTION INDICATORS FOR MOTOR CARS, MOTOR BOATS, AND ENGINES, MILEAGE RECORDERS, ETC. SOCIETY OF MOTOR MANUFACTURERS & TRADERS LTD (Logo) DIRECTORS. W. Henderson-Cleland. A.{Mr Adams} Gordon Smith. H.{Arthur M. Hanbury - Head Complaints} R.{Sir Henry Royce} Buckland. CHRONOS WORKS, NORTH CIRCULAR ROAD, LONDON. N.W.2. Telephone: GLADSTONE 1136 (4 Lines). Telegrams: Aytespeedo, Crickle, London. YOUR REF. Hs{Lord Ernest Hives - Chair}/Wst.5/MA. PLEASE QUOTE OUR REF. HRB/B. ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY. 29th December, 1933. Messrs. Rolls-Royce Ltd., Derby. WST For the attention of Mr. H.{Arthur M. Hanbury - Head Complaints} E.{Mr Elliott - Chief Engineer} West. Dear Sirs, We have now been able to carefully investigate the position with regard to your favour of the 18th inst., with which you sent us some figures regarding your tests re Temperature Compensation. This new Rev-Clock is compensated in exactly the same way as the new Speedometer, i.e. with Monel Shunt, and the exact figures obtained in our readings are as follows:- Degrees "C". Degrees "F". R.P.M. of Motor. Reading of Rev-Counter. 65 C. 149 F.{Mr Friese} 1000 4250 600 2650 minus 5 C. 23 F.{Mr Friese} 1000 4250 600 2600 20 C. 68 F.{Mr Friese} 1000 4150 600 2550 We would point out that these figures are arrived at during special tests made in the electrical apparatus at Cricklewood Works. A Stroboscope is used to get exact control of the revs, and, therefore, we are quite confident that the figures are reliable. | ||