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).
List of recommended lamp bulbs for the 20/25 chassis.
| Identifier | ExFiles\Box 166\4\ img093 | |
| Date | 20th February 1931 | |
| 15.1.S1. 20.2.31 LIST OF LAMP BULBS RECOMMENDED FOR STANDARD ON 20/25 CHASSIS 1. Headlamp bulbs. 12/14 v.{VIENNA} 36 w. gasfilled, centre contact S.B.C. cap, BAS. 4 S. (Osram No. S.7012) 2. Central lamp bulb. 12/14 v.{VIENNA} 48 w. gasfilled, centre contact S.B.C. cap (Osram No. S.7014). 3. Side lamp bulbs. 12/14 v.{VIENNA} 4 w. vacuum, centre contact, S.B.C. cap (Osram No. S.7126). 3. Tail lamp bulb. As side lamp bulb. 4. Instrument lamp bulb. 16/18 v.{VIENNA} 3 w. (Osram No. S.7954) with S.B.C. centre contact cap as arranged with G.E.Co. by R.R. 5. Thermometer lamp bulb. 16/18 v.{VIENNA} 3 w. (Osram No. S.7954) with screw cap. 6. Inspection lamp bulb. 12/14 v.{VIENNA} 9 w. vacuum, double contact, S.B.C. cap, BAS.10.D. (Osram No. S.7172) 7. Body lamp bulb. 12/14 v.{VIENNA} 9 w. half opal, vacuum, double contact S.B.C. cap. or 8. 12/14 v.{VIENNA} 6 w. festoon, vacuum (Osram No. S.7282) EFC. | ||