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).
Data log on graph paper recording test measurements and calculations.
| Identifier | ExFiles\Box 168b\3\ img138 | |
| Date | 20th October 1927 | |
| 521 Average Temperances - 6.57 Hours - 8.75 Amperes - .557 180w 20-10-27 X75368 P.A.R.BD.{Mr Berend} H.II-1.2 183r/f 75 a/h 107 lbs 183 S 2 | ||