Many people who live in developed nations have forgotten what night really is — the other half of day – as if darkness was something to be banished with brilliant electric glare. And it might be hard to believe it was once common in the U.S. for farm families to work in their fields by moonlight. Even after electricity came into general use, small towns often turned off their street lamps when the moon was full.
The history of vehicle lighting systems dates at least as far back as ancient Egypt, when oil lamps lit the way for wagons and carts on moonless nights. It seems likely that improvements were made to increase light output and project a beam ahead of a vehicle by using a reflector positioned behind the flame. Indeed, many centuries later scientific studies would find that an open flame loses about 97% of its useful light from being unfocused; and even a flame with a reflector behind it loses about 83%. As time passed and more sophisticated lamps were devised, there were weatherproof lanterns for wagons and carriages in which a candle or an oil wick was enclosed in a housing with a reflector mounted behind the flame and a clear glass lens in front.
After people discovered how to make lenses that focused light beams, these lamps kept improving. In 1822, a French physicist named Augustin Fresnel devised a prismatic lens that captured and focused almost 80% of the useful light from a flame. In Europe, Fresnel lenses were quickly adopted for lighthouses, being able to project a beam 20 miles out to sea. Interestingly, it wasn’t until the 1850s that the U.S. began using these lenses, because the Lighthouse Commission thought them to be just a fad! Smaller versions of the Fresnel lens were used in navigation lights aboard ships, and also for carriage, wagon and stagecoach lighting.
