CHAPTER PAGE I. IN THE BEGINNING 1 II. THE COMPOSITION OF COAL 6 III. WHEN COAL WAS FORMED 14 IV. HOW THE COAL BEDS LIE 22 V. THE DISCOVERY OF COAL 35 VI. THE INTRODUCTION OF COAL INTO USE 51 VII. THE WAY INTO THE MINES 75 VIII. A PLAN OF A COAL MINE 94 IX. THE MINER AT WORK 112 X. WHEN THE MINE ROOF FALLS 127 XI. AIR AND WATER IN THE MINES 147 XII. THE DANGEROUS GASES 159 XIII. THE ANTHRACITE COAL BREAKER 176 XIV. IN THE BITUMINOUS COAL MINES 192 XV. THE BOY WORKERS AT THE MINES 204 XVI. MINERS AND THEIR WAGES 222 COAL AND THE COAL MINES. CHAPTER I. IN THE BEGINNING. Every one knows that mineral coal is dug out from the crust of the earth. But the question frequently is asked concerning it, How and under what conditions was it formed? In order to answer this inquiry it is necessary to have recourse to the science of geology. A brief review of the geological history of the earth’s crust will be of prime importance, and it will not be inappropriate to go back to the origin of the earth itself. But no man can begin at the beginning; that is too far back in the eternal mists; only the Infinite Mind can reach to it. There is a point, however, to which speculation can journey, and from which it has brought back brilliant theories to account for the existence of the planet on which we live. The most philosophic of these theories, as it certainly is the most popular, is the one known as the Nebular Hypothesis, propounded by Laplace, the great French astronomer, in 1796. This theory accords so well with the laws of physics, and with the human knowledge of the age, that most of the great astronomers have adopted it as the best that has been given to us, and the world of science may be said to have accepted it as final. Let us suppose, then, in accordance with this theory, that our earth was, at one time, a ball of liquid fire, revolving on its axis, and moving, in its orbit, around the parent sun with the motion imparted to it in the beginning. As cooling and condensation went on, a crust was formed on its surface, and water was formed on the crust. The waters, however, were no sooner spread out than they were tossed by the motion of the atmosphere into waves, and these waves, by constant friction against the rock crust of the earth, wore it down into pebbles, sand, and mud. The silt thus made being washed up on to the primitive rock and left there by the receding waters became again as hard and firm as before. Occasionally a subsidence, due to the contraction of the earth’s body, would take place and the sea would again sweep over the entire surface, depositing another layer of silt on the one already