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).
Notes on diagram conventions for experimental test instruments and a keyless lock for switches and regulator adjustment.
| Identifier | WestWitteringFiles\F\January1921\ Scan31 | |
| Date | 21th January 1921 | |
| Contd. -4- EFC1/T21.1.21. (12) On our diagram the dotted connections represent the instruments addedfor experimental test. (13) It will be noticed that a lock is provided for the switches, but we have no key, neither have we a key for the regulator adjustment. EFC. | ||