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 Cambridge Instrument Company regarding a delayed order and the specifications for thermo-couples.
| Identifier | ExFiles\Box 175\4\ img031 | |
| Date | 27th May 1926 | |
| X3875 TELEGRAMS: INSTRUMENT, CAMBRIDGE. CODES: A.B.C. (5TH AND 6TH EDITIONS); WESTERN UNION: BENTLEY'S. TELEPHONE: CAMBRIDGE NO. 615. CAMBRIDGE INSTRUMENT COMPANY, LIMITED, HEAD OFFICE AND SHOWROOMS: 45, GROSVENOR PLACE, LONDON, S.W.1. WORKS: LONDON AND CAMBRIDGE REGD. TRADE MARK. MANUFACTURERS OF MECHANICAL & ELECTRICAL INSTRUMENTS OF PRECISION. YOUR REF..... Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG. CAMBRIDGE, ENGLAND. IN REPLY PLEASE QUOTE.... CCM/MV. 27th May, 1926. Messrs Rolls-Royce, Ltd, Derby. Dear Sirs, We regret that the reply to your letter of the 22nd May has been delayed by the Whitsuntide Holidays. We are proceeding with the special thermometer with electrical contact, and hope to send this to you in a day or two. We regret the matter was delayed owing to your official order being sent to our London Office, where the matter was not recognised, and by the oversight of a clerk the order was not sent on here. With regard to thermo-couples for measuring bearing temperatures, we are afraid your particular requirements at the moment are difficult to meet. A single couple with a temperature difference of 200° would only give about .008 volts. To obtain a full scale on the Weston Millivoltmeter that you mention it would be necessary, therefore, to have about nine couples in series supposing the couple resistance itself could be ignored. As it would be necessary to use very fine couples this resistance would be considerable and, therefore, in actual practice a still larger number of couples | ||