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 with calculated values for amperes, hours, and ampere-hours.
| Identifier | ExFiles\Box 49\5\ Scan359 | |
| Date | 2nd January 1924 | |
| X 4288. 2-1-24 oxide cf 82 55 Average amperes = 10.51 hours = 5.83 Ampere hours = 61.3 REGD. TRADE MARK REGD. X4288 1.17w. | ||