George Campbell, age 10, of Willingboro, N.J., for his question:
WHEN WERE OIL AND GAS LAMPS INVENTED?
Lamps, which provide man with light, rank as one of his most important inventions. We don't know who invented the first oil lamp since they date back to prehistoric man. But the first commercially important gas lamp was developed in Scotland in 1792.
A Scottish engineer named William Murdock was the man who came up with the gas lamp. He lit his entire home with gas lamps that burned coal gas.
By the early 1800s, gas lamps had come into use as street lamps in London and other cities. Gas lamps served as important sources of light until the late 1800s, when electric lamps started to replace them.
Early gas lamps had one chief problem: the open gas flame. The flame often flickered and produced uneven light.
Some gas lamps had glass chimneys, like that of the Argand lamp, which helped to control the flickering. In the late 1800s, a device called mantle solved the problem.
The Argand oil lamp, by the way, was invented in the 1780s by a Swiss chemist named Aime Argan. It was one of the best improvements to the oil lamp in hundreds of years. Argand's lamp had a wick bent into the shape of a hollow cylinder. Such a wick allowed air to reach the center of the lamp. As a result, the Argand lamp produced a brighter light than other lamps did.
Later, one of Argand's assistants made another improvement after discovering that a flame burns better inside a glass tube. His discovery led to the invention of the lamp chimney, a clear glass tube that surrounded the flame.
The mantle that solved many of the gas lamp's problems was,a loosely woven cloth bag soaked with a chemical substance. The cloth quickly burns away in the lamp and the chemical glows steadily as the gas burns around it.
Most modern gas lamps, including liquid fuel lamps used by campers, have mantles.
The first lamps were fat lamps made from sea shells or hollowed out stones. Prehistoric man used pieces of grasslike plants called rushes as wicks and burned animal fat as fuel in his lamps.
The ancient Egyptians also made stone lamps. But the Egyptian lamps burned oil and had cotton wicks. The ancient Greeks and Romans made lamps from bronze or pottery.
Early Greek lamps looked like saucers and burned olive oil or the oil of other plants. The wick simply floated on the oil. Later Greek lamps had a groove at the edge of the saucer to hold the wick.
The earliest candles were made by coating a wick with wax and pitch, but later candle makers used tallow, a waxy substance obtained from animal fat.
An early lamp was called the rushlight. It was made by dipping dried rushes into melted animal fat. It burned like a candle.