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 to Messrs. Negretti & Zambra regarding a faulty Fahrenheit thermometer, including test results showing inaccuracies.
| Identifier | ExFiles\Box 40\1\ Scan055 | |
| Date | 10th October 1923 | |
| Y3695 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG. Messrs.Negretti & Zambra, 38, Holborn Viaduct, London, E.C.1. 10th. Oct. 1923. Dear Sirs, We are returning to you one of your Fahrenheit distance Thermometers which has been in use for some weeks but has unaccountably developed a very considerably errors. We should like you to correct this instrument for us and at the same time let us know the cause of its present inaccuracy. Do you consider the centigrade Thermometer we have just purchased from you is likely to behave in a similar manner? We have tested the Fahrenheit Thermometer and give below the results obtained :- Actual Temp. oF | Temp. Ind: by Thermometer. | Error. ---|---|--- 32 | Below 20 (min.fig. on instrument) | ----- 60.8 room temp. | 46 | -14.8 212 | 198.5 | -13.5 Yours faithfully, | ||