The record of the third day is a very important one, because it is the first point at which the Mosaic Record comes in contact with that other record which is written in the rocks. Up to this time we have only been able to compare the statements of Moses with conjectural views of the earliest condition of the earth, which, though they may be highly probable, are at best only conjectures. But from this point we have to deal with a number of ascertained facts—certain landmarks stand out which enable us to fix the correspondent parts of the two narratives, and guide us to the identification and interpretation of their minor details.

The first of these landmarks is the appearance of the dry land, or, in geological language, the commencement of the process of upheaval. At the close of the second day the earth was, in all probability, as we have seen, a globe internally molten, but having a solid crust which was uniformly covered with a layer of water, and surrounded by an atmosphere which, though it had parted with some of its ingredients, was still very much more complex, more dense, and more extensive than it is at present. The newly condensed waters would rest on the surface of the primeval rock, whatever that rock might be. The internal heat conducted through it would keep the waters in a state of intense ebullition, and at the same time their surface would be agitated by violent atmospheric currents as the heated air ascended, and was replaced by cooler air from the outer regions of the atmosphere. Under these circumstances the water would dissolve or wear down portions of the newly-formed rock on which it rested. At the same time the steam, which would be continually rising from the boiling ocean, would descend from the upper regions of the atmosphere in the form of rain, and bring with it in solution considerable quantities of those elements which still existed in the form of vapour, just as rain now brings down ammonia and carbonic acid which it has absorbed in its passage through the atmosphere. New combinations would thus be formed between the materials dissolved or abraded by the ocean and those brought down by the rain. When these combinations had reached a certain amount they would be deposited in the form of mud upon the bed of the ocean, and thus the earliest sedimentary rocks would be formed. As the temperature gradually decreased, the character of these combinations would probably be changed, and at the same time the atmosphere would be diminished in volume and density, and become more pure by the absorption of a large portion of its original constituents, which would have been incorporated into various minerals.

The earliest sedimentary rock with which we are acquainted at present is what is known as the Laurentian formation. [Footnote: The whole of the geological details in this section are taken from Sir C. Lyell's Geology for Students.] It occupies an area of 200,000 square miles north of the St. Lawrence; and is also traced into the United States and the western highlands of Scotland and some of the adjacent isles. It is divided into two sections—the Upper and Lower Laurentian. It is not certain that it is really the oldest rock; for as every sedimentary rock is formed of the debris of preceding rocks, it is very possible that all the exposed portions of some older rocks may have been decomposed and worn away; but it is the oldest yet known. The thickness of the lower portion is estimated at 20,000 feet, or nearly four miles, while the Upper Laurentian beds are 10,000 feet thick. At this point we meet with the first traces of that process of upheaval and subsidence which has ever since been going on in the earth. The Lower Laurentian rocks had been displaced from their original horizontal position before the Upper Laurentian were deposited upon them.

This process of upheaval of some parts of the earth, accompanied with subsidence in other parts, is one which cannot be accounted for by any natural laws with which we are acquainted. It is in all probability the result of a series of changes which are taking place in the interior of the earth, but of which we know nothing at all. It is in the commencement of this series of changes that we trace that direct interference of the Creator—which is indicated by the command, "Let the waters under the firmament be gathered together into one place, and let the dry land appear." We have not, however, any means of ascertaining how long a period elapsed before the process of upheaval reached the point at which the land would rise above the surface of the ocean.

The Lower Laurentian rocks are remarkable in another way. There is little doubt that traces of life, the earliest yet known, occur in them. They include a bed of limestone varying in thickness from 700 to 1500 feet. In all probability limestone, wherever it occurs, is an animal product, though in many cases all traces of its organization have been lost by exposure to heat. This particular bed appears to have been formed by a very lowly creature, which in organization was akin to the foraminifera, of which large quantities are now known to exist at the bottom of the Atlantic. It differed from them, however, in one respect—the individuals were connected together, as is the case now with many varieties of the coral animal. No notice of this first appearance of life is found in the Mosaic Record, nor, for reasons already given, was it possible that any mention of it should be made.

The rocks which come next to the Laurentian in the order of time are those known as the Cambrian. They are so called because they constitute a large portion of the mountains of North Wales, and it was there that their characteristics were first carefully studied by Professor Sedgwick. In one of the strata of this formation—the Harlech Grit—what are known as "ripple-marks" are found, proving that parts of these rocks at the time of their deposition formed a sea-beach, and that consequently at this time, at the latest, the dry land had emerged from the ocean. In these rocks there are also decided traces of Volcanic Action, which seem to indicate the existence of a Volcano similar to the recent "Graham's Island." At this point a considerable advance in animal life is found. The fossils comprise several corals, varieties of mollusca, and a class of crustaceans peculiar to the very early rocks—the trilobites.

On the Cambrian rocks rest the formations known as Silurian, from the fact that they were first thoroughly examined in South Wales (Siluria) by Sir E. Murchison. In these rocks many fresh varieties of invertebrate fossils are found, and the vertebrata make their first appearance, numerous remains of fishes having been discovered. The earliest specimen was found in the Lower Ludlow beds at Leintwardine, while the Upper Ludlow formation contains an extensive bed composed almost entirely of fish-bones. Immediately above this bed are found what seem to be traces of land-plants, in the shape of the spores of a cryptogamous plant.

The Silurian rocks are succeeded by rocks which present two distinct characters, but are probably contemporaneous, the Devonian and the old Red Sandstone. The former seem to have been deposited in the bed of the sea, while the latter is a fresh-water formation. In these decided remains of land plants are found, of which about 200 species have at present been discovered. The old Red Sandstone is also peculiarly rich in fossil fish. The first signs of coal appear in this series of rocks, but on a very small scale.

We now come to what are known as the Carboniferous rocks, of which the lower series is known as the mountain limestone, and above it come the "coal measures," containing numerous beds of coal, sometimes of great thickness. These beds have resulted entirely from the decomposition, under peculiar circumstances, of an enormous development of terrestrial vegetation. They seem to have originated in vast swamps, subject to occasional flooding, and to alternate movements of upheaval and subsidence. On these swamps there must have existed for ages a vegetation of whose luxuriance the richest tropical jungles of the present time can give us no idea. They tell the tale of a time when the temperature of the earth, was uniformly high (since coal fields are found in high northern latitudes), when the atmosphere was charged with moisture, and probably contained a large proportion of carbonic acid. In the coal measures we come upon the first traces of land animals. Several remains of reptiles have been found, as well as footprints left on the soft mud or sand of a riverbank or sea- beach. There seems to be no doubt that they were left by lung- breathing animals.

The carboniferous strata form the second of our landmarks. They seem to point to the fulfilment of the command that the earth, should bring forth vegetation. There is, however, one point which requires some notice. The Mosaic account, as we read it in our English Bibles, seems to be limited to phanerogamous plants— grass, the herb yielding seed, and the fruit-tree yielding fruit. Now, it is a well-known fact that the great mass of the vegetation, the remains of which constitute coal, consisted of cryptogamic plants, which do not produce seed, properly so called, but only spores; the distinction being that the spore contains the germ and nothing more, while in the seed the germ is provided with a store of nutriment to assist in the earlier stages of the development of the plant. What appears to be a farther discrepancy, the absence of any traces of the grasses, leads in reality to the solution of the difficulty.