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).
Graph chart recording the amperage of a 'Peto & Radford' accumulator over time.
| Identifier | ExFiles\Box 38\5\ Scan059 | |
| Date | 1st July 1919 | |
| The New Peto & Radford Accumulator Co. Ltd. - ROLLS ROYCE SAMPLE - Amperes Hours Record of PDL9; on 6A Circuit; Date JULY 1919. | ||