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 sheet recording the temperature of air at the rear of the fan in relation to water temperature at speeds of 25 and 45 mph.
| Identifier | ExFiles\Box 38\2\ Scan201 | |
| Date | 15th October 1923 | |
| X3456 (copied. - 15.10.23. 30.11.23.) TEMPERATURE OF AIR AT REAR OF FAN IN RELATION TO WATER TEMPERATURE. Speed 25 m.p.h. Centigrade Scale. X3456 X3438 Atmosphere. 10°C | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 10 Top water. 100°C | 95 | 90 | 85 | 80 | 75 | 70 | 65 | 60 | 55 | 51 Bottom wtr. 89°C | 84 | 79 | 74.5 | 70 | 66 | 60 | 56 | 52.5 | --- | --- Rear of Fan. 53.25°C | 49 | 44.5 | 41 | 36.75 | 33.5 | 30.5 | 27.5 | 26.5 | 24 | 22.5 Speed 45 m.p.h. Centigrade Scale. 17.10.23. Atmosphere. 12.5°C | 12.5 | 12.5 | 12.5 | 13 | 13 | 13 | 13 | 13 | 14.5 | 14.5 Top water. 100°C | 95 | 90 | 85 | 80 | 75 | 70 | 65 | 60 | 55 | 50 Bottom wtr. 80°C | 84 | 79 | 75 | 70 | 65 | 60 | 55 | 50.5 | --- | --- Rear of Fan. 56.5°C | 49.5 | 44 | 39.75 | 36.5 | 33.5 | 31 | 29.5 | 27.5 | 25.5 | 23.75 | ||