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 results for a 'J' Filling Thermostat, detailing its opening and closing temperatures.
| Identifier | ExFiles\Box 39\4\ Scan233 | |
| Date | 11th February 1931 | |
| X3499. 11.2.31 Copy for Files. "J" FILLING THERMOSTAT. 22-EX. X. 34991 X. 7250. Starts to open @ 77.3°C. Fully open @ 81°C. Starts to Close @ 79°C. Fully closed @ 74°C. 3 readings taken for - STARTS TO OPEN as follows - 76°C. 79°C. 77°C. Average 77.3°C. G.H. Whyman. | ||