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).
Letter to Joseph Lucas Ltd. providing feedback on the trial of special P.100 bi-focal headlamps.
| Identifier | ExFiles\Box 61a\2\ scan0425 | |
| Date | 8th December 1934 | |
| rl6 Hs{Lord Ernest Hives - Chair}/Wst.1/MA. 8th December, 1934. Messrs.Joseph Lucas Ltd., Great King Street, Birmingham, 19. For the attention of Mr.R.N.Neill. Dear Sir, We have now had an opportunity of trying out on a chassis the two special P.100 headlamps with bi-focal bulbs. We agree with you that a little more spread is required to the main beam for the majority of driving conditions. On a perfectly clean night the beam is satisfactory but if there is the slightest trace of mist the extreme intensity of the beam gives uncomfortable glare and a little spread would possibly alleviate this. Is it possible for you to supply us with a couple of glasses giving a little more spread for experimental trial? Regarding the question of bi-focal lamps we find that with these lamps and also with double dipping lamps it is difficult to get 100% acknowledgement from other drivers unless they actually see you dip the lights. This is probably due to the fact that in England dip and switch to the left is so universally used, on the Continent there is no difficulty at all as drivers expect to see two lamps burning even in the dipped position. Of course one can always switch on the main beam which with these headlamps must give the oncoming driver a terrifying start and show him you were really dipped. I do not think there is too much contrast between the two beams as when one is about to dip one naturally expects less brilliance and are prepared for it. | ||