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).
Extract about sending a 12-volt battery and an adjustment key to Mr. Royce.
| Identifier | ExFiles\Box 38\3\ Scan016 | |
| Date | 14th May 1918 | |
| EFC2/T14.5.18. -3- Contd. to re-adjust them at any time with this key if necessary. We will also send Mr. Royce another 12 volt battery. EFC (Photostats - see X.3231). | ||