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).
Adopting the centre third lamp scheme for headlamp dimming on experimental cars.
| Identifier | ExFiles\Box 61a\2\ scan0079 | |
| Date | 3rd January 1920 | |
| X7860 COPY. EFC. from Hs{Lord Ernest Hives - Chair}/AJL. 3.1.20. .X.4477. HEADLAMPS ON EXPERIMENTAL CARS. X.7800 X.4520. The centre third lamp scheme has been adopted as being the best dimming scheme we know of; it has been selected after testing (1) Double filament bulbs in P.100 lamps. (2) Two separate bulbs in P.100 lamps. (3) Electrically and pneumatically operated dipping and swivelling reflectors. Several of our cars are fitted with one or the other of these condemned schemes and we wish to convert them all to the third lamp scheme. Sales have adopted the Butler lamp for the centre lamp, to be used in conjunction with a Court foot switch. Neither of these articles have, as yet, been tested on any of our experimental cars, and they both should therefore be used by us. Converting all our cars involves the following :- 12-G4. - No alteration. 14-G4. - Centre lamp and foot switch required. 17-G4. - " " " " " 18-EX. - No alteration. 19-EX. - Centre lamp required and head lamps (at present two bulb scheme) to be converted to standard single bulb P.100 20-EX. - Centre lamp required. Double filament bulbs in P.100 head lamps to be done away with and lamps altered to suit single pole filament bulbs. 22-EX. - No alteration. | ||