=

lime or iron, or by internal heat, and, after repeated operations of the same causes on the same locality, finally been raised above the waters as dry land. For example, according to Professor Phillips, "the Ganges which drains 300,000 square miles of plains, hills, and mountains, containing a great variety of rocky and earthy masses, delivers annually to the Bay of Bengal, 6,368,077,440 cubic feet of sediment, which is equal to I-IIIth of an inch in a year. The maximum thickness of the strata is supposed to be about 72,000 feet 864,000 inches, and dividing this by I-IIIth, we have the calculated antiquity of the base of the stratified rocks-95,904,000 years. But here two things are to be allowed for. The thickness of the old strata is taken at a maximum, and the new deposit is supposed to spread over a much larger space of sea bed than it really does, so that the period found is something too large. On the other hand, the Ganges carries much more sediment than some other great rivers nearly twenty times as much as the Rhine. It has the character of tropical or excessive effect, and on this account the period may be much too short."

Effects such as these are easily discernible, many alike in the materials employed, and many more implying great changes in the waters, in the materials suspended or in solution, requiring different oceans of different characters to have flowed over the same spot, all proving elevations and subsidences of the earth's crust, and affording evidence of the lapse of vast periods of time. The strata thus formed disclose the fact that numerous races of animals and plants must have occupied the earth, and passed away, from various causes, such as change of climate and fearful

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catastrophes, ere the recent races made their appearance, or were created. More than 30,000 species have already been discovered, none of them corresponding to those now living, with the exception of a few hundred species, principally shells, in the uppermost rocks. So that since life first made its appearance on the globe in organized being, it is supposed that ten or twelve entire races have passed away, and that its inhabitants have been changed as many times. Each of these groupes consisted of numbers so great, and occupied the world so long, as to leave immense quantities of their remains, as in the chalk deposits. Among the Pyrenees," says Lardner, "whole mountains consist of little else than the fossilized remains of minute shell-fish, and that of such materials the Pyramids of Egypt were formed." These Pyramids have existed four thousand years -the wonder of mankind-but how insignificant do they appear in comparison with those stupendous works, which, ages ere their foundations were laid, must have been forming in the hidden parts of this life-sustaining world! In calculating the period that must have elapsed since the world began, we must allow whatever is needful to account for the construction of each of these rocky leaves of our mundane book, and the perpendicular thickness of these in the aggregate, from the granite upwards, if it were possible to place them one upon another, would amount, according to Sir Roderick Murchison, to not less than fifteen miles, the larger portion of which are found filled with vegetable and animal remains. Reason cannot but revolt at the conclusion that a structure so enormous, and so composed, was formed within a period which commenced only six thousand years ago.

Who then can undertake to express in numbers the periods which make up the sum of the years of earth's history? The mind fails in the attempt, and becomes bewildered, like as when in astronomy, planet after planet leads us into the infinity of space. There was a point in time when the Almighty gave this world existence.

The Bible declares so much, but leaves the epoch unrevealed. The vast duration of the globe, like the vast expansion of the infinity of space, is in its contemplation an idea almost as sublime as eternity.

CHAPTER IV.

THE study of the leaves of the stone book affords information of no ordinary interest. Each leaf tells its own story somewhat independent of the others, but it requires the whole volume to be read through before one can rightly understand the wondrous tale. Imbedded in these leaves are the fossil remains, or organic remains, of animal and vegetable life, existing when the various leaves were impressed, and these are the illustrations which serve to make the subject of which we read more easily understood.

Beginning with the first leaves, or primary series of rocks, called also azoic or lifeless, from the fact that no remains of life have yet been discovered in them, we find the granite underlying all the others, now as a floor of undulating form, now as mountain ranges, or as veins forced up through the overlying strata, by the action of uncontrolable internal forces, yet everywhere exhibiting proofs of its original igneous state.

Once a molten liquid mass, as the surface, by radiation into space, gradually cooled down, the stratum became crystallized, forming one of the most beautiful rocks in structure, constituents, and colour. The process of refrigeration thus called into operation, the chemical affinities of the various gases, oxygen, hydrogen, nitrogen, and chlorine, the constituents in certain proportions of air and

water. Oxygen is so generally diffused that it has been estimated to amount to one half of the solid matter of the globe, in various forms;-it forms one fifth of the atmosphere, eight ninths of water, and a large proportion of almost every rock and metallic ore.

The needful condition having been reached in the cooling down of the globe, by the union of the component gases, the production of water took place, very probably in the form of steam at first, but gradually as ages rolled on, and refrigeration continued, being condensed into water, covering and enveloping the still heated mass. The combined action of the gradually lessening heat with that of water and other atmospheric influences upon the granite, chemically and mechanically disintegrated its particles. These taken up by the water and again deposited, formed, by sediment the gneiss and mica schist systems, thus covering the granite by its own waste, with a floor of loose sand and other materials, eventually, by heat and pressure, to be compacted into solid rock. Sir Roderick Murchison estimates these rocks to be of the enormous thickness of 26,000 feet. Immediately over them, and as it were a continuation of them, lies a stratum of sand, pebbles, and mud, deposited under less turbulent circumstances. These, as a whole, are the earliest watery deposits known. Their materials are but slightly altered from the parent bed, and they extend so largely over the world as to approach nearly to an universal formation, yet, from the circumstances that the waters in which they were deposited were then literally a boiling ocean, and in other respects unsuitable, they probably preceded the period of existence of life in any shape. It has, however, been supposed that the discovery of two