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 performance and testing of an A.T. Speedometer from a 40/50 car.
| Identifier | ExFiles\Box 50\4\ Scan265 | |
| Date | 7th December 1928 | |
| X4308 To Hs. {Lord Ernest Hives - Chair} From Hs {Lord Ernest Hives - Chair} /AJL. c. to EFC. {E. Fowler Clarke - Electrical Engineer} Hs {Lord Ernest Hives - Chair} /AJL1/LG7.12.28. A.T. SPEEDOMETER. The small diameter temperature compensated speedometer No. B.563 for a 40/50 car supplied by EFC. {E. Fowler Clarke - Electrical Engineer} on the 29th. of Aug. has been in use on 8-EX since that date. When fitted to the car in the first place it was checked on the road at 30 m.p.h. and found to read 3.3% fast. Suspecting that it was reading slow we have again tested it today at 10, 20 and 30 m.p.h. At speedometer reading of 10 m.p.h. the car speed is 15 m.p.h., at 20 m.p.h. speedometer reading it is 26 m.p.h. and at 30 m.p.h., 37 m.p.h. At 60 m.p.h. the speedometer does not appear to be very much wrong but we cannot check it at this speed. We are handing the instrument back to EFC. {E. Fowler Clarke - Electrical Engineer} in order that he may bench test it and compare its present performance with its original performance. During the period it has been in use the car has run only 5316 miles. | ||