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 Joseph Lucas Ltd. discussing headlamp bulb technology and test results.
| Identifier | ExFiles\Box 61a\1\ scan0241 | |
| Date | 25th August 1926 | |
| WF45 JOSEPH LUCAS LTD., To Messrs. Rolls-Royce Ltd., D E R B Y. PAGE DATE 2 25th August, 26. light on the normal filament with no perceptible interference but on changing over to the half obscured filament you get a sharp line cut off above the horizontal which in our opinion gives a much better result than the dipping headlight, and obviously avoids much mechanism. When using this bulb we would suggest that you make your tests in a C.A.V. or very early pattern Lucas Headlamp as this will provide the necessary rotational adjustment of the bulb holder to get the cut off in a true horizontal plane. We shall be very pleased to hear the result of your tests and can let you have any further bulbs you may require for this purpose. The actual lamp which your American friends refer to is possibly the "TILTRAY" which was fitted by the Buick for some time, although we understand that they have recently given up using this type. If it would be of interest to you, we could get one of these for your inspection and test, although we have not got one available at the moment, otherwise we should have sent it on. Perhaps you will be good enough to advise us on this point. With reference to the latter part of your letter referring to the call for a more powerful headlamp, we have this matter under very active consideration, and hope to be in a position to submit something for your criticism at a very early date. We have ourselves, tried the Steven Grebel and also the Zeiss, but have found these very disappointing especially in view of their impressive appearance and high cost. These remarks being, in our opinion, particularly applicable to the latter lamp. As our new model is still in the designs stage, it would be very useful to have | ||