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 from Edison Lamp Works discussing two-filament 'Woodlites' headlamps.
| Identifier | ExFiles\Box 61a\1\ scan0418 | |
| Date | 27th November 1928 | |
| COPY November 27th, 1928. Edison Lamp Works, Harrison, N.J. Mr. Maurice Olley, Rolls Royce of America, Inc., Springfield, Mass. Dear Mr. Olley: This will acknowledge receipt of your letter of November 19th with reference to the "Woodlites" and your letter of November 23rd regarding two-filament, 12-16 volt lamps. I should have answered these letters earlier, but was out of town all last week. A package of ten 21-21 lamps for 12-16 volt circuit has been forwarded to you today. As mentioned in a previous letter, the filaments in these lamps differ slightly from our standard filament, used in 6-8 volt lamps, but I am sure they will be satisfactory for experimental purposes and are in fact being used in two-filament headlamps mounted on motor coaches. We shall be glad to know the re-action of your Experimental Department in England to this type of depressible beam lighting. Regarding the "Woodlites" described in the pamphlet attached to your letter, I have not actually driven behind a pair of these lamps but I am familiar with their construction. They are somewhat similar to a type of lamp made by the Edmond and Jones Corp. a few years ago, which used an elliptical type of reflector and a very small lens. As you suggest, this type of lens is confined to a single filament light source and cannot to advantage employ two filaments to give a depressible beam. A fair statement would be that these "Woodlites" are probably equal to some of our single filament headlamps now available, but I do not feel that they are as satisfactory as our modern controllable beam headlamps. The trend is unmistakably toward the use of two-filament headlamps and I am sure that it will not swing over within the next few years to any such type of lamp as is described in this pamphlet. You of course understand that this is my own personal opinion, and probably from a company viewpoint, we should not discriminate or express too definite opinions regarding the merits or demerits of the particular device. However, from my contact with many people in the automotibe industry with whom I am serving on various committees of the Illuminating Engineering Society and Society of Automotibe Engineers, I feel that you are working along the right lines. -continued- | ||