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).
Chart recording from a Megger instrument showing the results of an electrical test.
| Identifier | ExFiles\Box 54\1\ Scan336 | |
| Date | 17th November 1926 | |
| S4 7 6 7 8 9 10 11 12 1 2 3 5 4 3 2 17-11-26 157 S4. 75 a.h. 100 lbs Average amperes = 6.07 Hours = 9.0 Ampere hours = 54.6 .546 1.80w REG'D TRADE MARK 'MEGGER' | ||