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 amperage over time with handwritten calculations and notes.
| Identifier | ExFiles\Box 54\1\ Scan238 | |
| Date | 15th February 1927 | |
| S2 15-2-27 155 S2 75 a.h. 101 Lbs. Average amperes = 6.24 Hours = 10.25 Ampere hours = 64.0 .634 1.80w After 13377 miles EVERETT EDGCUMBE & Co Ltd LONDON & HENDON | ||