Chart recording of an electrical test with handwritten calculations for amperes and ampere-hours.
| Identifier | ExFiles\Box 38\5\ Scan180 | |
| Date | 9th December 1921 guessed | |
| Amperes per div = .285 Average amps = 10.03 Ampere hours = 50.8 TRADE MARK MEGGER REGd | ||
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).