Coal is a metal, which is composed of the remains of trees and plants, after it is changed by pressure, heat and moisture into the shape in which we find it. It is found in many countries of the world, notably in Great Britain, Germany, Russia, France, China, India and Canada.
Coal is found in layers beneath the earth’s surface at depths varying from one hundred to about two thousand feet. It is obtained by mining, that is, by digging it out of the earth. Deep holes are dug in “the coal-fields in order to get coal. These holes are called mines.
The colour of coal is bright black. It looks like smooth, shiny black stone, although it is far less harder than stone, it can be broken into pieces even with a hammer.
Coal is mainly used as fuel. It is used with equal importance in household and industrial premises for cooking food, heating houses, melting metals, propelling locomotives and various other purposes.
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When a piece of coal is heated, it gives out a gas which burns on the top of the fire. This gas can be collected and sent through long pipes to give light and heat at long distances. This gas in found to burn in the streets, shops and houses in towns.