“Its tusks, which had a pronounced backward curve, measured four meters in length and weighed as much as four hundred and eighty pounds each. What must have been the strength of a colossus carrying between its lips a weight of nine hundred pounds as easily as a cat carries the hairs of its mustaches! “Man was already in existence at the time of the mammoth. Armed with sharp flint-stones and bone-pointed arrows, he made bold to attack the enormous animal whose weight made the earth tremble. He hunted it in the chase and feasted on its flesh. What a piece of game when the giant fell into the deep ditch masked by a light covering of boughs and foliage! The victim was then overwhelmed with masses of rock, after which there was an interminable banquet for the whole tribe. “Let us go no further, but merely say in conclusion that the animals of to-day are not the same as those of former ages. Long before the present species on land and in the sea, there gradually made their appearance other very different forms of animal life, which have now become extinct. Nowhere on the earth are there now living any creatures like those that have left their fossil remains for our inspection.” CHAPTER LX THE ORIGIN OF COAL “Coal is a fuel of inestimable value. By the heat which it develops in burning it gives movement to divers machines. It makes the locomotive move over the iron rails and the steamship traverse the ocean. With its aid metals are worked, fabrics woven, pottery is baked, glassware manufactured, newspapers and books are printed, tools are shaped, and all sorts of instruments necessary to our daily activities are produced. The arts and crafts have no more powerful auxiliary. If we had to substitute the heat of wood for that of coal, our forests would prove insufficient. “What, then, is the origin of this combustible, which feeds an immense industry and is the source of incalculable riches? Ordinarily a piece of coal has no great interest for the eye. It is black, lustrous, formless, friable, without any definite character to afford us instruction. One can learn more from the fragments of refuse rejected by the miner as too poor in carbon, fragments in which the predominating element is a kind of dark stone that splits in sheets. In these a surprise is lurking that will tell us the secret of coal.