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).
Graph plotting Horse Power.
| Identifier | WestWitteringFiles\K\November1923\ Scan13 | |
| Date | 27th November 1923 guessed | |
| HORSE POWER 10 20 30 40 50 Roa Mor | ||