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).
Demonstration and comparison of various fog lamps and their performance in dense fog.
| Identifier | ExFiles\Box 61a\2\ scan0401 | |
| Date | 16th November 1934 | |
| FOG LAMPS. During the dense fog on Tuesday last we carried out a demonstration of fog lamps using the Desmo "Safebeam," the Talbot antidazzle, the Currus, the Lucas FD{Frank Dodd - Bodies}37 and the Benjamin as fitted to 's car. There were present E.{Mr Elliott - Chief Engineer}, He., Rm.{William Robotham - Chief Engineer}, Hy.{Tom Haldenby - Plant Engineer}, Mx.{John H Maddocks - Chief Proving Officer}, & Est., and the unanimous opinion was that the Currus (which is a German made lamp) gave the best results the Benjamin being a close second. The Talbot was definitely inferior in fog and no better than an ordinary headlamp. Both the Lucas and the Desmo were spoilt by the fact that they had a centre beam of too much intensity causing glare. The Currus lamp which has a very original interior reflector construction gives a complete downward spread of diffused light immediately in front of the car with two slight beams which diverge from the lamp sufficient to illuminate the sides, of the road whilst the centre part of the lamp is coloured amber to reduce glare. In fog it is probably preferable to either have an intensely bright spot of light trained on the near side of the road immediately in front of the car without any spread of the beam or exactly the other extreme as with the Currus and the Benjamin which give a spread of light with no concentration of any intensity at any given point. Anything in between these two conditions causes annoyance and strain in very thick fog. We spoke to Messrs.Lucas regarding their fog lamp, pointing out to them the desirability of eliminating the bright spot from their lamp and they agreed that an improvement is necessary in this respect. Mr.Neill shewed me a thick ribbed glass which when placed over their lamp made an immense improvement and produced an effect similar to the Benjamin. They originally intended to market the Lucas FD{Frank Dodd - Bodies}37 lamp for the dual purpose of a pass light and fog lamp but this is now realized as impossible as the light suitable for a pass light under normal driving conditions is unsuitable for dense fog. Messrs.Lucas are therefore considering the possibility of supplying a clip on front glass when the lamp is used for fog driving. | ||