In the United States there are about 120,000 square miles underlaid by
known workable coal-beds, besides what yet remains to be discovered;
while on the cliffs of Nova Scotia the coal-seams can be seen one over
the other for many hundred feet, and showing how the coal was originally
formed. With this immense stock of fuel in the cellars of the earth, it
seems evident that we need not trouble our minds or be anxious as to the
duration of our coal supply. Besides, the conversion of vegetable matter
into coal seems to be going on even now. In the United States there are
peat-bogs of considerable extent, in which a substance exactly
resembling cannel coal has been found; and in some of the Irish
peat-beds, as also in the North of Scotland, a similar substance has
been discovered, of a very inflammable nature, resembling coal.

Yes! what could have produced this singular-looking, black, inflammable
rock? How many times was this question asked before Science could return
an answer? This she can now do with confidence. Coal was once growing
vegetable matter. On the surface of the shale, immediately above the
coal, you will find innumerable impressions of leaves and branches, as
perfect as artist ever drew. But how could this vegetable matter ever
accumulate in such masses as to make beds of coal of such vast extent,
some not less than 30 feet thick? It would take 10 or 12 feet of green
vegetable matter to make 1 foot of solid coal. Let us transport
ourselves to the carboniferous times, and see the condition of the
earth, and this may assist us to answer the question. Stand on this
rocky eminence and behold that sea of verdure, whose gigantic waves roll
in the greenest of billows to the verge of the horizon--that is a
carboniferous forest. Mark that steamy cloud floating over it, an
indication of the great evaporation constantly proceeding. The scent of
the morning air is like that of a greenhouse; and well it may be, for
the land of the globe is a mighty hothouse--the crust of the earth is