COAL by Frederick Griggs

Pacific Press Publishing Company · Oakland, California · Feb 5, 1902

COAL

By Frederick Griggs

In my previous article on the growth of stones, I omitted to speak of one mineral, as I wished to speak of it more at length. That mineral is coal. I sit by my pleasant coal fire. It is a blustering New England winter evening. The north wind whirls around the corner of the house, but within all is warmth. It is dark without, but light within. The flames shoot up the chimney, and the smoke, after curling about in a fantastic manner, follows them. Whence come all this light and warmth?—From the dark prison under the ground. Yes, and even further than that—from the sun itself; for all this light is but sunlight after it has been bound in prison for hundreds of years, a prison deep under the earth. This coal, as I built my fire, was black and dirty, but once it was far different, beautiful tropical vegetation. From the coal scuttle at the side of the hearth, to the gorgeously verdant vegetation of the forest of mammoth trees, is certainly a long step. But yet just such a step as this has to be taken in going back to the origin of my warm fire.

I have before spoken of the effects of the flood upon the crust of the earth as we now find it. It is almost entirely due to the flood and its action that the great coal beds of our present time exist. “At this time immense forests were buried. These have since been changed to coal, forming the extensive coal beds that now exist, and also yielding large quantities of oil. The coal and oil frequently ignite and burn beneath the surface of the earth. Thus the rocks are heated, limestone is burned, and iron-ore is melted. The action of the water upon the lime adds fury to the intense heat. As the fire and water come in contact with the ledges of rock and ore, there are loud explosions, and volcanic eruptions follow. These often fail of giving sufficient vent to the heated elements, and the earth itself is convulsed, the ground opens, and villages, cities, and burning mountains are swallowed up.”

Prior to the time of the flood, the climate was not changeable as now, but was of a warm tropical nature, and, together with the rich, fertile soil, produced a very prolific vegetation. Some faint idea of the immense growth of plants and trees can be gathered from a statement of one writer upon this point. When speaking of our supply of coal, he says, “Were our present forests [in England] uprooted and overthrown, to be covered by the sedimentary deposits such as those which cover our coal seams, the amount of coal which would be thereby formed for use in some future age, would amount to a thickness of perhaps two or three inches at most, and yet in one coal field alone, that of Westphalia, the 117 most important seams, if placed one above the other in immediate succession, would amount to no less than 294 feet of coal.”

I have spoken of the light and warmth which come from the coal, as the sunshine of ages ago. The grand old forests which lived before the deluge, were bathed in a flood of sunlight. It was the action of this sunlight on lofty tree and tiny flower that made possible my warm fire this cold winter’s evening. There are some kinds of animals in the sea, which, all their lives, are attached to rocks. The currents of water bring them their food. Just so do the currents of air bring to the tree its food. One of the constituent elements of air is carbon. While it is a very slight quantity, yet it is a very constant one. The under side of leaves is provided with little mouths. These mouths eat up the carbon food which the air so kindly gives them. But after a thing is eaten, to be of any benefit to the eater it must be digested. Here is where the sun does its beneficent work, for its light and heat are the powers which do the digesting and assimilating of this carbon food. The food, thus digested, goes to build up the body of the plant, be it large or small. “As a man eateth, so is he;” and so is a tree. The tree has eaten the carbon, and there are large quantities of it in its body. Carbon is easily burned, partly because it has used so much sunlight in being turned from its gaseous form in the air to the form in which we find it in the tree. But the body of the tree is not alone all that makes coal. Indeed, it may be but a small proportion. Any one who has ever visited a tropical forest has been impressed with the great growth of leaves. Many tropical plants which have small bodies have very large leaves. Now all these leaves have gone to make our coal.

We find the process of coal-making going on to-day on the surface of the earth. This coal-making process occurs largely in peat bogs. They are found in all parts of the world, but nowhere in more abundance than in Ireland, where it is said there are some three million acres covered by them. Peat bogs, as their name indicates, are found in low, marshy places. One of these bogs in Ireland is between two and three miles wide and fifty in length. The peat varies from thirteen to as much as forty-seven feet in depth. These bogs are continually forming; for at their surface grow every year peat moss, rushes, horse-tails, and reeds of all description. This growth thrives upon the decaying ruins of not only last year’s growth, but all its ancestors. This vegetable formation undergoes certain chemical changes which make the peat, when cut and dried, valuable fuel. But the bogs do not consist of peat alone; for the trunks of trees are often found mingled with the decaying reeds and mosses. These tree trunks take on a decidedly coaly appearance. From the Bog of Allen, in Ireland, pieces of oak, known as bog oak, are often taken. No coal is blacker than are these, and they are so hard that they are used in the manufacture of ornamental objects. In a peat bog in Maine, a substance very similar to cannel-coal has been found. If all these peat bogs could be covered by great quantities of earth, as were the forests by the action of the flood, and thus subjected to great pressure and heat, coal would certainly be the result.

There are several varieties of coal. They are commonly divided into hard and soft, but this is not a very definite division. The graphite or plumbago of our lead pencils is very closely related to coal, being a purer form of carbon. We can take the common coal, and, by sufficiently heating and subjecting it to pressure, convert it into a substance similar to plumbago.

Next to graphite, anthracite coal is the hardest and most difficult of all coal substances to burn. The softer coals are called bituminous coals. They take this name from the nature of the chemicals which they contain. There are several kinds of these. They give a much brighter flame, and burn far more readily than does the anthracite coal, but do not have the same amount of heat per ton that it has.

Coal has been known for ages. The Chinese early knew of it, and used it for baking their porcelain. So far as is known, it was first used to any extent in England, and this was only about one hundred and fifty or two hundred years ago, tho of course it had been known and used to a very limited extent long before this. Bituminous coal was first mined in Virginia in 1750, and around Pittsburg, Pa., about 1760. In 1762 anthracite coal was discovered near Wilkesbarre, Pa., but it came into use very slowly because it was so hard to burn. It took the colonists a long while to learn not to poke the fire when it was of anthracite coal. As an evidence of the rapid increase of the use of coal, it may be cited that from the Lehigh Valley in 1820 but 365 tons were sent to market, while in 1892, from this same region, 6,500,000 tons were shipped.

But I have already made this article too long, and yet I have said nothing of the many interesting things which might be said concerning the mining and handling of coal; nor of the useful products of coal, such as gas, tar, oil, and many chemicals. You should certainly read further concerning this wonderful mineral. In every library are books or magazines containing many interesting facts about coal. It has undoubtedly been the greatest single factor in bringing about the progress and enlightenment of this time. By it the printing press, the steamship, and the railway train are driven,—all that the whole earth may be lighted with the glory of the Coming King.

FREDERICK GRIGGS.

South Lancaster, Mass.