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).
Article discussing the features, road-test performance, and pricing of the Desmo Safebeam Anti-Dazzle Road Lamp.
| Identifier | ExFiles\Box 61a\3\ scan0148 | |
| Date | 29th April 1932 | |
| Reprinted from “The Light Car and Cyclecar,” April 29, 1932. Handwritten note: Fog Lamps. SAFE DRIVING By NIGHT With Special Reference to the need for Correct Focus and to a Lamp which provides a Diffused Anti-Dazzle Beam By Dr. A.{Mr Adams} H.{Arthur M. Hanbury - Head Complaints} Stuart, B.Sc., Ph.D., etc. shown that my laboratory findings are borne out in practice. The lamp was mounted on the near-side front dumb-iron of a car at a height of 24 ins. from the ground. The focusing and setting of the lamp were carried out on a straight and level tree-lined road, the beam being set slightly to the near side, whilst the top of the main portion was approximately horizontal. In this position it was found that dazzle ceased at about 180 ft. in front of the car when the lamp was viewed from normal eye level, say, 5 ft. The driver of a low-built car sitting well down in the driving seat might find that the dazzle effect continued for a little longer, whilst conversely, a driver seated high up, such as in a lorry or ‘bus, would experience practically no dazzle effect, even when at a considerable distance from the car, by reason of his line of vision being well above the beam. This was shown to be the case during the road tests. The illuminating power of the lamp is considerable, the full width of a normal main road being adequately lighted, thus making it very easy to negotiate corners, especially those turning to the left. The light is of a diffused nature, and is projected far enough ahead to allow of a safe cruising speed of 40 m.p.h. It should be stressed that the beam is not of the definitely flat-topped type, a diffused portion of it being projected upwards with sufficient power clearly to illuminate the lower branches of the trees lining the roadside. During the time that I was testing the lamp I found that approaching drivers tended always to dip or dim their headlamps upon entering the anti-dazzle zone of the Safebeam lamp. The “flicker” enthusiasts, after demonstrating violently whilst still far off, eventually left their lamps in the dipped position when they realized that my lamp was really of an anti-dazzle feature. Image caption 1: This sketch depicts the special B.T.H. looped filament bulb described in the text. It provides a powerful forward illumination. Image caption 2: The Safebeam lamp with the ribbed glass cut away to show the formation of the superimposed conical reflector. The boss at the rear of the lamp carries the external focusing device. The Desmo Safebeam Anti-Dazzle Road Lamp PRICES: MODEL, DIAMETER OF LAMP FRONT, EACH. Senior . . . . 7 3/4 in. . . . . All Black . . . . 60/- Senior . . . . 7 3/4 in. . . . . All Chromium . . . 70/- Junior . . . . 6 in. . . . . All Black . . . . 50/- Junior . . . . 6 in. . . . . All Chromium . . . 57/6 The above prices include Bracket, Cable and Switch. Special Bracket supplied for Austin Seven. IMPORTANT.—When ordering, it is essential to specify the Bracket, the Voltage, and whether for double or single pole wiring system. There are three standard types of bracket: “T” TIE BAR, “D” DUMBIRON, “L” LAMP STANDARD. We can also supply another Bracket “F” for attachment to the rigid fixing which supports the Bumper, where these are fitted. Special Brackets can be made up to suit requirements, but in such cases an extra charge would be made. DESMO LIMITED, Stafford Street, BIRMINGHAM Temple Press Ltd., 5-15, Rosebery Avenue, E.C.1. | ||