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 concerning the return of two inaccurate 100 M.P.H. speedometers due to poor performance during testing.
| Identifier | ExFiles\Box 165\4\ img140 | |
| Date | 22th February 1932 | |
| X6129 c. Roy.{Sir Henry Royce} Hs{Lord Ernest Hives - Chair}/Wst.4/AD. February 22nd, 1932. Messrs. North & Sons, Ltd. Whippendell Rd. Watford. Dear Sirs, 100 M.P.H. Speedometer We are returning to you under separate cover the two 100 M.P.H. magnetic type speedometers which we have been testing. These instruments are too inaccurate for our purposes and their action has proved very erratic. The one which we have just received from you has shown itself to be 5.9% low at normal speeds, the zero position proved variable and at high speeds the needle sticks badly at 80 M.P.H. moving slow upwards to 100 M.P.H. when driven at a constant speed equivalent to *93.6 M.P.H. There appears to be undue friction in the movement. The other instrument has now proved faulty on a chassis and actually reads 10 M.P.H. when the car is moving at 18 M.P.H. (timed). The instrument is also correspondingly inaccurate in a lesser degree at higher speeds. We regret to say that we shall not be in a position to further test these speedometers until you can produce these approaching the accuracy and reliability obtained with our present standard. One instrument is being returned immediately and the other will be sent as soon as it can be released from the chassis. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||