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).
Performance comparison graph of electrical components, plotting Amperes and Volts against RPM.
| Identifier | ExFiles\Box 49\5\ Scan182 | |
| Date | 2nd August 1939 guessed | |
| S.C. AMPERES D.C. VOLTS. R P M AMPERES VOLTS WATFORD EL06 USA/Bosch ZR6 Ed {J. L. Edwards} 19 STD WATFORD E.O.6.(c) | ||