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 re-calibration of a special Bentley speedometer, including a table of nominal versus actual readings.
| Identifier | ExFiles\Box 165\2\ img101 | |
| Date | 10th July 1937 | |
| 6011 AC-SPHINX SPARKING PLUG Co. LTD. DIRECTORS: N. F.{Mr Friese} Stockbridge, W. O.{Mr Oldham} Kennington, C. J.{Mr Johnson W.M.} Bartlett. Telegrams: SPHINX. DUNSTABLE DUNSTABLE, BEDS., ENGLAND. Telephone: DUNSTABLE 360. Our Ref: DBB/DJG Your Ref: 10th July, 1937. CAP Messrs. Rolls Royce Ltd., DERBY. For the Attention of Mr. H.{Arthur M. Hanbury - Head Complaints} F.{Mr Friese} West. Dear Sirs, With regard to the special Bentley speedometer which the writer brought back for re-calibration, we are sorry that owing possibly to a misunderstanding we were unable to finalise this matter until the receipt of your Speedometer Specification which only came last week. An attempt has been made to calibrate this instrument within your limits without changing the actual printing of the dial. As our speedometer gives a practically straight line calibration it is of course essential that where various percentages fast or slow are required at different points in the scale the scale itself should be suitably distorted to allow this being done. Following are the figures to which this instrument is now reading :- Nominal Actual Reading. 10 M.P.H. 10.2 30 M.P.H. Accurate 60 M.P.H. 62.6 90 M.P.H. 93. AC Air Cleaners - AC Clocks - AC Fuel Pumps - AC Oil Filters - AC Oil Gauges - AC Plugs - AC Speedometers - AC Windscreen Wipers. | ||