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 AC-Sphinx regarding incorrect calibration and scale distortion on a sample speedometer, S-17281.
| Identifier | ExFiles\Box 165\2\ img038 | |
| Date | 4th March 1937 | |
| 6011 AC-SPHINX SPARKING PLUG Co. LTD. DIRECTORS: N.F. Stöckbridge, W.O.Kennington, C.J.Bartlett DUNSTABLE, BEDS.,ENGLAND. Telegrams: SPHINX,DUNSTABLE Telephone: DUNSTABLE 360. Our Ref. DBB/JB CAP 4th March, 1937. Messrs. Rolls Royce, Ltd., Derby. For the Attention of Mr. H.E. West Dear Sirs, With regard to the experimental sample speedometer S-17281, we very much regret to learn that the calibration of this instrument has been found by you to be incorrect. Unfortunately the writer has been absent from the works for some little time, and was unable to supervise personally the checking of the instrument before despatch, but it shall have his personal attention immediately it is received. Unfortunately on checking from the drawings since the instrument was sent to you, a further error has been noticed, and this is that while the scale of the dial is correct up to 80 m.p.h. the angular distance from 80-90 has been distorted, in order to give a more balanced appearance with the scale reading from 0-10, which owing to the design of the instrument has of necessity to be smaller than the remainder of the scale. Actually if accurate reading is required above 80 m.p.h. this scale will have to be remade, in spite of the fact that it will then look a little out of balance. We should be glad to hear from you whether the 80-90 reading is important, and if so we will take steps to make the necessary alteration. With regard to the enamel on the trip odometer, we are aware that this was not a good match with the remainder of the instrument, unfortunately this was the only colouring AC Air Cleaners - AC Clocks - AC Fuel Pumps - AC Oil Filters - AC Oil Gauges - AC Plugs - AC Speedometers - AC Windscreen Wipers. | ||