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 the Air Board regarding the accuracy of an optical indicator for aero engines.
| Identifier | ExFiles\Box 79\3\ scan0011 | |
| Date | 29th March 1917 | |
| Any further communication on this subject should be addressed to:- The Secretary, Air Board Office, Strand, W.C.. and the following number quoted. Telegraphic Address:- "AIRMINISTRY, LONDON." Telephone No.:- REGENT, 8000. X.2981 S.L. [STAMP: 30 MAR 1917] AIR BOARD, AIR BOARD OFFICE, STRAND, W.C. 29th March 1917. Dear Sirs, I have your letter of March 26th, addressed to me at Cambridge, about indicating Aero engines. I do not think that my optical indicator would give accurate diagrams at so high a speed at 1800 revs. per minute. Yours truly, B. Hopkinson Messrs. Rolls Royce, Ltd., Derby. | ||