- What is coal? How was it formed?
- In what parts of the world is coal found?
- The place of coal in the social life in industry.
- The future outlook of coal.
Coal is found in the earth, sometimes near the surface and sometimes yery deep down. Some of the best coal mines in England are hali a milę under the earth. After being taken half mile down the mine in a lift worked by machinery, the miners will have to walk about another mile along the passages to the place where they have to work.
Coal is formed of the trees, leaves and gasses of old forests. The mass of vegetation in those old jungles gradually formed a layer, and in the course of centuries became buried under masses of earth. At first soft, it gradually became pressed down till it was hard and black. But the heat and light it absorbed from the sun are still in the coal, and are given off when we burn it.
Coal is the finest fuel, giving a clear heat and burning for a long time. Most people in Europe still warm their houses by means of coal fires. What a blessing coal is to dwellers in cold countries! It is also used in industry, for without coal we could not smell the iron ore and produce iron and steel. Great industrial countries like Britain and America owe their prosperity to the fact that they have coal and iron mines close to each other.
It is hard and tiring work to dig. out the coal from the mines. It is also dangerous because a kind of explosive gas forms down in the mine. Then an explosion takes place and men are buried, often with great loss of life. Sometimes falls of coal cause accidents. In the best coal districts nowadays, the coal is cut and taken out by machinery.
Coal can be used as fuel directly, or can be turned into gas. It gives bye-product of coke, tar or pitch, and a kind of petroleum at the same time. Again coal can be used for the generation of electricity. China is full of rich coal-fields which should yield good supplies in the future. In India there are some districts where there is no coal, and that is why the poor people have to burn wood or the precious cowdung which should be used to manure the fields. But it is probable that there are good supplies of coal in India which have not yet been worked, just as good as the West Bengal mines.