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).
Test results for an A.T. Speedometer after a 10,000-mile run, showing readings at various temperatures.
Identifier | ExFiles\Box 59\2\ Scan041 | |
Date | 25th June 1930 | |
X4308. 25.6.30. X.4308. A.T. SPEEDOMETER No. C.561. 740. 48.6 EX 10,000 MILE TEST CHASSIS 14-GIV. This instrument has again been tested subsequent to the 10,000 mile run on 14-GIV. Driven at 600 r.p.m. it has now been found to give the following readings in miles per hour at the temperatures quoted :- | Temperature (°C) | Miles per hour indicated at 600 R.P.M. exactly. | |------------------|-------------------------------------------------------| | 20.0 | 51.2 | | 22.0 | 51.1 | | 24.0 | 51.0 | | 26.0 | 50.9 | | 28.0 | 50.8 | | 30.0 | 50.7 | | 32.0 | 50.5 | | 35.0 | 50.5 | It will be seen that these figures are slightly in excess of the figures previously obtained and given on sheet dated 28.2.30. It cannot be said therefore that the instrument has suffered loss of reading due to loss of magnetism. The increase of reading may be due to a decrease in the main spring control. EFC. | ||