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).
Blueprint for a testing outfit featuring a graduated dial.
| Identifier | ExFiles\Box 175\4\ img132 | |
| Date | 1st May 1931 guessed | |
| beo Dial Divided into, Deg. and 20th of a Deg., 20, 0, Key., TESTING OUTFIT, MESSRS. ROLLS-ROYCE LTD, C.I.Cº L.T.D | ||