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).
Hand-drawn sketch showing a stepped profile with dimensional measurements.
| Identifier | Morton\M3.7\ img005 | |
| Date | 27th June 1919 guessed | |
| .010", .006", .004", .003", .002", E.H. | ||