In the course of time it was discovered that it was better to smear the grease on the _outside_ of the stick, or on the outside of whatever was to be burned; that is, that it was better to have the wick _inside_. Torches were then made of rope coated with resin or fat, or of sticks or splinters smeared with grease; here the stick resembled the wick of the candle as we know it to-day, and the coating of fat corresponded to the tallow or paraffin. Rude candles made of oiled rope or of sticks smeared with fat were invented in primitive times, and they continued to be used for thousands of years after men were civilized. In the dark ages--and they were dark in more senses than one--torch-makers began to wrap the central stick first with flax or hemp and then place around this a thick layer of fat. This torch gave a very good light, but about the time of Alfred the Great (900 A.D.) another step was taken: the central stick was left out altogether, and the thick layer of fat or wax was placed directly around the wick of twisted cotton. All that was left of the original torch--the stick of wood--was gone. The torch had developed into the _candle_ (Fig. 3). The candles of to-day are made of better material than those of the olden time, and they are much cheaper; yet in principle they do not differ from the candles of a thousand years ago. [Illustration: FIG. 3.--THE CANDLE.] [Illustration: FIG. 4.--A SHELL FILLED WITH OIL AND USED AS A LAMP.] I have given the development of the candle first because its forerunner, the torch, was first used for lighting. But it must not be forgotten that along with the torch there was used, almost from the beginning, another kind of lamp. Almost as soon as men discovered that the melted fat of animals would burn easily--and that was certainly very long ago--they invented in a rude form the _lamp_ from which the lamp of to-day has been evolved. The cavity of a shell (Fig. 4) or of a stone, or of the skull of an animal, was filled with melted fat or oil, and a wick of flax or other fibrous material was laid upon the edge of the vessel. The oil or grease passed up the wick by capillary action,[6] and when the end of the wick was lighted it continued to burn as long as there were both oil and wick. This was the earliest lamp. As man became more civilized, instead of a hollow stone or a skull, an earthen saucer or bowl was used. Around the edge of the bowl a gutter or spout was made for holding the wick. In the lamp of the ancient Greeks and Romans the reservoir which held the oil was closed, although in the center there was a hole through which the oil might be poured. Sometimes one of these lamps would have several spouts or nozzles. The more wicks a lamp had, of course, the more light it would give. There is in the museum at Cortona, in Italy, an ancient lamp which has sixteen nozzles. This interesting relic (Fig. 5) was used in a pagan temple in Etruria more than twenty-five hundred years ago.