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).
Regulations for vehicle lamps, including beam deflection, anti-dazzle requirements, and bulb markings.
| Identifier | ExFiles\Box 167\1\ img019 | |
| Date | 30th April 1936 guessed | |
| 3 (b) on and after 3rd October, 1937, to every lamp the light of which is derived from an electric bulb carried on any vehicle, and on and after 4th October, 1936, to every such lamp carried on any vehicle registered for the first time under the Roads Act, 1920, on or after that date. (2) No lamp showing a light to the front shall be used on any vehicle unless such lamp is so constructed, fitted and maintained that the beam of light emitted therefrom— (i) is permanently deflected downwards to such an extent that it is at all times incapable of dazzling any person standing on the same horizontal plane as the vehicle at a greater distance than 25 feet from the lamp whose eye-level is not less than 3 feet 6 inches above that plane; or (ii) can be deflected downwards or both downwards and to the left at the will of the driver in such manner as to render it incapable of dazzling any such person in the circumstances aforesaid; or (iii) can be extinguished by the operation of a device which at the same time causes a beam of light to be emitted from the lamp which complies with sub-paragraph (i) of this paragraph; or (iv) can be extinguished by the operation of a device which at the same time either deflects the beam of light from another lamp downwards or both downwards and to the left in such manner as to render it incapable of dazzling any such person in the circumstances aforesaid, or brings into or leaves in operation a lamp or lamps (other than the obligatory front lamps) which complies or comply with sub-paragraph (i) of this paragraph. (3) This Regulation shall not apply to any lamp fitted with an electric bulb, if the power of the bulb does not exceed 7 watts and the lamp is fitted with frosted glass or other material which has the effect of diffusing the light. 10. The beam of light emitted from not more than two lamps showing a light to the front (other than the obligatory front lamps) fitted to any vehicle may be deflected to either side by the movement of, although not necessarily through the same angle as, the front wheels of the vehicle when turned for the purpose of steering the vehicle, provided that the centre of any such lamp is not more than 3 feet 3 inches from the ground. Side deflection. 11. On and after the 4th October, 1936, every bulb used in an electric lamp showing a light to the front fitted to any motor vehicle shall have the wattage thereof indelibly marked upon the glass or the metal cap thereof in a readily legible manner. Markings. | ||