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).
Test data tables showing pull force vs. extension and plunger rise vs. temperature.
| Identifier | ExFiles\Box 39\4\ Scan315 | |
| Date | 4th May 1933 guessed | |
| -2- EXTENSION FROM INITIAL POSITION INS. | PULL LB. - 30°C. | PULL LB. - 40°C. | EXTENDING. | RELEASING. | EXTENDING. | RELEASING. .020 | 22 | 3 | 18 | 4 .040 | 25 | 4 | 22 | 7 .060 | 28 | 5 | 24 | 8 .080 | 29 | 10 | 25 | 8 .100 | 32 | 32 | 26 | 26 It was also found that at a given temperature the plunger extended to a definite position, the relation between temperature, and extension, being as recorded below :- TEMP. oC. | PLUNGER RISE INS. 50 | 0 52 | .025 55 | .150 60 | .350 70 | .525 80 | .625 90 | .700 100 | .800 Hs{Lord Ernest Hives - Chair}/W.Bell. | ||