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).
Comparison of present and proposed anti-dazzle headlamp systems and their test results.
| Identifier | ExFiles\Box 167\1\ img312 | |
| Date | 10th January 1939 | |
| BY.5/B.10.1.39. ANTI-DAZZLE. Present System :- England - Dip and Switch, i.e. Offside extinguished. Nearside dipped. Continent - Double filament bulbs. Yellow glass - France and Germany. Proposed System :- England - Headlamps and Passlamp, i.e., Extinguish headlamps and switch on pass lamp. Pass lamp also has a dipper in it for fog or mist. Winter 1937 - 8. Tests to find best lighting to enable speed to be maintained, and to see cyclists, etc. DERBY. Pass lamp system satisfactory. Pass lamp system unsatisfactory. Dim filaments of double filament bulbs - unsatisfactory. Dim filaments of double filament bulbs - satisfactory. Cx.{Major Len W. Cox - Advertising Manager} LONDON. Dim filaments of double filament bulbs with pass lamp - satisfactory. Main filament of double filament bulbs just passable. ------------ | ||