The most important thing in this method of kindling a fire is the rapidity with which the sticks are rubbed together. Some one of the savages more keen than the others conceived the idea that he could save labor and at the same time increase the rapidity with which the stick moved. He took his bow and twisted the cord once around a stick. Then he placed one end on a piece of wood, and by moving the bow back and forth twisted the stick with great rapidity. Soon the shavings which he had placed at the point of contact were ablaze. Little by little this drill was improved, and now among some of the American Indians it furnishes a comparatively easy way of kindling a fire. [Illustration: TINDER BOX, FLINT, AND MATCHES.] Most children have seen a spark caused by the shoe of a horse striking a stone in the road. Sometimes if one stone strikes another a spark is produced. All this was perceived even in the earliest times, and the best substances to be used became well known. The stone called flint was found to be the best for one of the two substances, and steel is usually preferred for the other. When steel and flint strike each other, if a spark falls upon some vegetable matter a fire is soon kindled. Perhaps the most common substance used to catch the spark was touchwood, a soft, decayed wood carefully broken into small fragments. After a time, in place of the touchwood, tinder was used, which was made by scorching old linen handkerchiefs. Later the tinder box was invented, in which a steel wheel was spun like a top upon a piece of flint set in tinder. After the discovery of gunpowder, flint and steel were used in guns. A hammer of flint struck an anvil of steel, and the spark produced fell into a pan of gunpowder, causing the flash which fired the gun. Before the American Revolution, and even into the present century, the process of kindling a fire was not a simple one. The most frequent means employed, as has been seen, was the borrowing of coals from a neighbor. Less often, recourse was had to the long and difficult process of rubbing a spark from two pieces of wood. Sometimes, among the well-to-do, the tinder box was used; but it was seldom satisfactory. For these reasons the fire was always most carefully watched; every precaution was taken to prevent it from going out. Seldom could the house be left by the whole family for any length of time, and all because of the lack of a match.