FULL HEADLIGHT POWER

Press, Volume LXXIV, Issue 22306, 21 January 1938, Page 8

FULL HEADLIGHT POWER

REAL NECESSITY IN DRIVING EFFICIENCY LOST BY CARELESSNESS VALUE OF CONSTANT MAINTENANCE "One would think that the motorist driving along a highway at night with 50,000 candlepower of light guiding him through the darkness would be immediately conscious if 15,000 candles were suddenly snuffed out, or 10,000 or even 5000 of them. But, somehow, he does not seem to be; perhaps because the reduction of light is less sudden on the average than the snuffing-out would imply," writes William Ullman in the "New York Times." "The fact remains that in the case of the average car of recent years there are 50,000 candles of light at the disposal of the motorist, if the headlamp equipment is kept in good condition. That is a great deal of light, but the 'if involved is very large. "The motorist buying a new car gets 50,000 candlepower of light for little or nothing. But he cannot keep it on the same basis, and if he thinks otherwise he is cheating himself. And cheating himself dangerously, for 50,000 candlepower is what he needs all the time for safe driving under the variety of conditions of current motor-car operation. -' "Headlights have been increased in their ability to endure the rigours of service as well as in power, but they still require periodic maintenance attention. "That this is the case should be obvious from even a fragmentary knowledge of the units of which they are composed. Essentially, the lamp is an arrangement of wiring, bulb, reflector, and lens. There was a time when all of these items were subject to disorders, but the work of engineers in recent years has eliminated most of those affecting wiring. Bulbs Should be Checked "Bulbs, whether they be of the twofilament or three-filament type, not only will burn out but will diminish in power output. This bears more or less constant watching on the part of the car owner. The bulb is the basis of headlight power. That it can be made to give a total of 50,000 candlepower, in astonishing contrast to its essential 32 candles of power, is due tj the magnifying capacity of the reflector, of course, but the reflector must have the full power of the light lo magnify or there will be no such force of light available. The situation calls for the periodic checking of bulb strength instead of the usual practice of waiting until the bulb has burned cut completely. Most motorists wait for that to happen, and then many of them are not aware of' it until their attention is called to it. "Simplest of all forms of correct headlight maintenance is that of keeping the lenses clean. Although few motorists seem aware of the fact—for all its obviousness—it is possible that the volume of light available may be reduced 10 to 15 per cent, by a dirty lens. Moreover, it is likely that this amount of dirt on the glass will result in beam distortion which cannot provide the stream of light that can be followed with safety in high-speed night driving. "The startling amount of light v/hich can be obtained from a bulb of 32 candlepower is due entirely to the reflector's work in magnifying the original volume. "The cleansing method remains much the same as in the past if the motorist wants to do the job at home. A small supply of jeweller's rouge, moistened with a few drops of alcohol and rubbed lightly on the surface of the reflector will restore its original brighiness if it has not become scratched or chipped. If it has, new reflectors or wholly new lamp units are dictated. "Correct maintenance of headlights has become a matter of tremendous importance in Ihis period of highspeed night driving. That this is the case is implied in the desire of motor-car engineers for the legal right to produce headlights of 75,000 candlepower. That enormous volume of light, ihey are convinced, is not too much under current conditions. But, in sharp contrast with the technician's hopes for more light—and more safety —the motorist goes on being extremely wasteful and apparently indifferent."