The use of fat on the torch may have suggested the rush-light, which consisted simply of a rush-stem, or some tow, floating in a vessel of oil or liquid fat. The Indian chiragh is on just the same Principle. Both the torch and the rush-light were very imperfect, the one giving off thick clouds of smoke, and the other producing only a very dim light. A great improvement on the rush-light was the candle a wick of cotton enclosed in a pillar of hard and solidified fat; but the final development of the rush-light is the lamp, burning a mineral oil (such as kerosene) and often giving a hundred-candle- power light.
So far, the principle of all artificial light was the same they were all oil lights. But the discovery of the illuminating quality of coal-gas in the beginning of the 19th century, led to a new form of artificial light, namely, gas. And for the greater part of the 19th century, gas was the chief kind of artificial light used in towns. It gave a better light than lamps or candles, and was much more convenient; but it had its dangers, and was liable to foul the air of the rooms in which it was burning.
The queen of artificial lights is the electric and electronic light, which came into common use in the latter part of the last century. It has great advantages over every other kind. It gives a much more brilliant illumination; it is clean and gives off no smell; it does not consume the oxygen of the air; it is cool and produces scarcely any heat, and it is very convenient. No one who has had electric light in his house, ever wants to go back to gas, lamps or candles.