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 A.T. Speedometer Co. Ltd. regarding the test results of an instrument.
| Identifier | ExFiles\Box 50\4\ Scan213 | |
| Date | 21th August 1928 | |
| CONTRACTORS TO THE WAR OFFICE THE ROYAL AIR FORCE AND LEADING MANUFACTURERS. A.T. SPEEDOMETER CO. LTD. Trade Mark. DIRECTORS : F. {Mr Friese} T. FISHER, H. {Arthur M. Hanbury - Head Complaints} O. {Mr Oldham} BOOTH, S. D. {John DeLooze - Company Secretary} McKELLEN. Telephone : Fulham 1422. Telegrams : Aytespeedo-Hammer, London. PATENTEES & MAKERS OF MAGNETIC SPEEDOMETERS FOR MOTOR CARS AND MOTOR CYCLES. A.T. ELECTRIC SCREEN WIPERS AND PETROL LEVEL GAUGES. MOTOR CLOCKS, TACHOMETERS, MILEAGE RECORDERS. REVOLUTION COUNTERS AND INDICATORS FOR MOTOR CARS, MOTOR BOATS, ENGINES, ETC. ALL CLASSES OF SCIENTIFIC INSTRUMENTS. REPAIRS A SPECIALITY. 20, Avonmore Road, West Kensington, London, W.14. Your Ref. EFCI/T Our Ref. HOB/W. 21st August, 1928 Messrs. Rolls-Royce Limited, Nightingale Road, Derby. B.247 Dear Sirs, In furhter reference to your favour of the 12th June re instrument No.B.247, D.730, 15/52, we have made further very careful tests with this particular instrument and we beg to report that we find the percentage drop of reading from 18° C. to 30° C. lies well within the limits you allow us, viz:- 3%, and although we previously gave you a figure of 1.6% we think this must have been an error in typing and it should have been 2.6%, and this is the utmost error we have been able to find in the instrument on the retesting. In fact it seems to us to be even better than this. It is possible that you might find a very slight variation from instrument to instrument, but we still think that such error can be only a very small percentage and would not affect the figures we have already given you. We are now returning this instrument to you, which you will find does not exceed our statement as above. Yours faithfully, for A.T.SPEEDOMETER CO. LTD. H O Booth | ||