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 temperature in degrees Celsius against pull and push force in pounds for Smith Calorstats with 'H' filling.
| Identifier | ExFiles\Box 39\4\ Scan223 | |
| Date | 12th January 1931 | |
| SMITH CALORSTATS "H" FILLING SIX OFF:- RECEIVED FROM BY/S.S. 12-1-31 TEMP °C 100 80 60 40 20 PULL - LB. 60 40 20 PUSH - LB. 20 40 60 80 | ||