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).
Test chart recording electrical current over time with calculated results.
| Identifier | ExFiles\Box 58\3\ Scan201 | |
| Date | 18th March 1930 | |
| 18-3-30 2/7/8 P+RRRNII-5+B 75 a.h. 114 lbs. 8/1/18 For RR Time out in at time of fuel consumption Average amperes = 6.28 Hours = 10.5 Ampere hours = 66.0 .579 1.800 TRADE MARK EVERETT, EDGCUMBE, LONDON | ||