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).
Requirements for a surface-type voltmeter for Mr. Brock.
| Identifier | ExFiles\Box 63\1\ scan0145 | |
| Date | 8th December 1923 | |
| X3035 To By/C. from EFC. EFC3/T8.12.23. RE VOLTMETER FOR MR. BROCK. What Mr. Brock requires is an instrument with one volt- (handwritten) full (struck through) scale only reading up to 30 volts. The instrument should be of the surface type. EFC. | ||