Are Headlights to See or Be Seen?

When our forebears traveled in horse drawn vehicles the horses could see where to go at night and coach lamps were there to show if another wagon was coming towards them. It was only with the greater speed of the ‘horseless carriage’ that seeing the road at night became a good idea.

The earliest lights were candle powered but still technically clever; as the candle burned down a coil spring pushed the remaining unburnt part upward. This kept the flame at the same point relative to a crude curved reflector at the back of the lamp. Candles burned quite quickly and were easily extinguished by wind or rain even though glass windows protected them.

The next development stage was the oil lamp, no brighter than candlelight but more reliable. The car industry then adopted a system that was used by miners underground. Water was slowly dripped on to pellets of calcium carbide, either in a container under the lamp or in a remote canister; acetylene gas was produced by this chemical reaction and when fed to a burner at the focal point of the reflector, produced a fairly bright light. The major problem was that the lights got very hot and the process created a lot of soot. After use, the owner had the problem of disposing of caustic lime, a very unpleasant and dangerous byproduct.

At this time, the turn of the 19th century, motive power for automobiles was steam, petrol or electricity; electric cars were able to use electric lights powered from their batteries and, following the development of small efficient dynamos, petrol cars could do the same. These early electric lights were not very bright and, except for their crude reflectors, did not have a focused beam of light. Also the filaments inside the bulbs were very fragile — but this was progress compared to candles!

In 1910 the Corning Glass Company of Corning, New York, introduced the first focusing lens, the ‘Conaphore’; the technology was based on that used in lighthouses. A stronger properly directed beam of light illuminated the road ahead more effectively and reduced glare for oncoming vehicles.

The next breakthrough was the ‘dipping light’, to stop the dazzling effect from motorists coming towards another car. At first this required the driver to stop the car and alter the angle of the lights by hand, but in 1917 Cadillac introduced a lever that moved the lamp’s beam downward. In 1924 the Osram Company introduced the ‘Bilux’ bulb, a twin filament bulb that gave a ‘high’ and a ‘low’ beam, the dipping headlight system that is still in use today. At first a foot switch operated the dipping action but this later changed to a lever on the steering column, or a switch on the steering wheel hub.

The American company Edmunds and Jones designed a spectacular bullet shaped aluminum headlight with a small round lens. They were principally an aftermarket light but were often fitted to Packard cars during the late 1920s, they later became very sought after by hot-rodders during the 1950s; a real old school period piece.


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