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).
Performance and acceleration comparison graph for the B III and Wraith systems.
| Identifier | ExFiles\Box 122\4\ scan0206 | |
| Date | 31th October 1938 guessed | |
| SECONDS FT/SEC² B III SYSTEM WRAITH SYSTEM ACCELERATION (FT/SEC²) PERFORMANCE (SECS TO ACHIEVE A GIVEN ROAD SPEED) WRAITH SYSTEM B III SYSTEM M.P.H. | ||