Performance comparison graph of DC Volts and Amperes versus RPM for various dynamos.
| Identifier | WestWitteringFiles\I\July1922\ Scan131 | |
| Date | 10th July 1922 guessed | |
| D.C. VOLTS R.P.M AMPERES VOLTS WATFORD EL06 USA Bosch Z R6 Ed {J. L. Edwards} 19 STD. WATFORD EO6.(C) | ||
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).