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).
Dimensioned sketch of a cross-section for a component with a concave profile.
| Identifier | ExFiles\Box 104\1\ scan0064 | |
| Date | 7th February 1930 guessed | |
| 1.250" .50" PARALLEL .175 | ||