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).
Performance graph of a Clayton Dewandre interior car heater, showing engine water and interior cabin temperature rise from a cold start.
| Identifier | ExFiles\Box 137\1\ scan0126 | |
| Date | 9th September 1932 guessed | |
| CLAYTON DEWANDRE INTERIOR CAR HEATER ON 20 Ex. (WARMING UP FROM COLD) ENGINE WATER TEMP. RISE. ENGINE SPEED CONSTANT AT 1000 R.P.M. RISE OF TEMP. IN INTERIOR OF CAR. TEMP. °C AIR TEMP TIME FROM START (MINS.) HEATER MOTOR RUNNING AT FULL SPEED HEATER MOTOR RUNNING AT HALF SPEED | ||