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 testing of two cheaper A.T. speedometers and the decision to return them.
| Identifier | ExFiles\Box 165\2\ img135 | |
| Date | 13th November 1937 | |
| BY.{R.W. Bailey - Chief Engineer} BY/RD. 6051 Rm{William Robotham - Chief Engineer}/RC.{R. Childs}1/JH.13.11.37. re Cheaper A.T. Speedometers. The two cheaper A.T. speedometers handed to us by By/RD. have now been tested. These proved to be :- (1) A British Jaeger Magnetic speedometer. (2) A British Jaeger Chronometric speedomer. Preliminary tests were carried out, and criticisms of certain defects, and characteristics were made. These were embodied in a letter to the A.T. Co. From their reply HR.13/MS.4.11.37. it was decided that in view of the characteristics of this instrument, and the necessity for an extra part, (gearbox) the chronometric speedometer was unsuitable for the car. It was therefore decided to return the instrument. Although the magnetic instrument appeared promising it was decided on account of the noise it made and the tendency for the pointer to stick, to return it for overhaul before proceeding with the tests. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||