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 plotting electrical test results over time with calculated values.
| Identifier | ExFiles\Box 48\3\ Scan340 | |
| Date | 30th November 1923 | |
| Jars. 30-11-23 Average amperes = 6.44. Amperes per div = 192D Ampere hours = 29.5 Ohms in circuit = 1.75 | ||