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).
Blueprint of a thermostat-controlled radiator louvre system.
| Identifier | ExFiles\Box 77\4\ scan0260 | |
| Date | 1st August 1922 guessed | |
| STEAM FITTINGS Co LTD. WEST DRAYTON MIDDX. Thermostat FLOW TO RADIATOR. Controller Controller can be fixed in horizontal or vertical position LOUVRE FRAME 58° REGULATING CYLINDER. CLOSED OPEN DRG. No. T340 | ||