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).
Chart showing the heat output of an S2 car heater at varying fan speeds and regulator positions.
| Identifier | ExFiles\Box 137\1\ scan0231 | |
| Date | 22th December 1936 guessed | |
| CX{Major Len W. Cox - Advertising Manager} / 95. (L.452/CZ) CHART SHOWING HEAT OUTPUT ON S2. CAR HEATER AT VARYING FAN SPEED & REGULATOR POSITION. B.T.US/HR./100°F TEMP. DIFF. FAN SPEED. R.P.M. FULL ON (12 VOLTS) A B C D OFF ON Θ 500 1000 1500 2000 4000 6000 | ||