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).
Test result summary comparing EGO and EG2 brushes against the standard Z brushes.
| Identifier | ExFiles\Box 50\5\ Scan274 | |
| Date | 10th December 1923 | |
| Contd. -2- EFE3/T10.12.23. It will be seen from the results, that the EGO and EG2 brushes may be considered to be very nearly equally as good as the present standard Z brushes, and that either of these grades, perhaps preferably the EG2, judging from the present test, would be suitable as a second source of supply, should the supply of Z brushes fail at any time. EFC. {E. Fowler Clarke - Electrical Engineer} AB.96 att. | ||