Blueprint chart showing multiple straight lines plotted on a grid.
| Identifier | ExFiles\Box 181\M7\ img064 | |
| Date | 28th May 1928 guessed | |
| 64 | ||
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).