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).
Explanation for why pull and speed curves are depicted as narrow bands.
| Identifier | ExFiles\Box 175\2\ img126 | |
| Date | 5th June 1941 guessed | |
| -4- The reason for shewing the pull and speed curves as narrow bands is that actually they would go up in a series of steps, one step for each layer of cable, and as the step from one layer to the next would be of indeterminate shape a band is shewn covering the extremes of the steps. | ||