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).
Photograph of a piece of British Thomson-Houston test equipment, labelled as Figure 3.
| Identifier | ExFiles\Box 138\2\ scan0069 | |
| Date | 15th January 1937 guessed | |
| Fig 3, BRITISH THOMSON-HOUSTON CO. LTD., RUGBY, C.801096, START, STOP, SPEED, PULL, INCH, M/M, 0, 1, 25 | ||