words, the strata of greater depth, were formed more early than such as lie upon them.

It is supposed to be well understood, or satisfactorily proved, that the work of creation began at the centre of the planet; if so, all, or nearly all, the subsequent formation is not more than could be accumulated by gravity and the motion of water, aided, immensely ded, by such apparently feeble creatures as shell-fish and corals; as it is now known that the component parts of the several strata mostly consist of sea-shells and coral, the products of animals who must have lived and died during the time the several strata were forming.

From very early times, these creatures have abounded at the bottom of the ocean, and they still continue to abound there; nay, they may be supposed to cover it; their naturally very great increase is calculated to have a vast effect, particularly, as on the extinction of life, their exuvia are placed in a situation which renders them nearly, or quite, imperishable.

The shells and the corals continually accumulate upon each other, and they have actually accumulated until they have formed strata of very great thickness; this could only have been done by the ordinary generation and death of the animals, and it is obvious that this operation is so slow as to require an immeasurably long time to form strata of very great thickness.

That strata, consisting in a very considerable degree of the shells of fish and corals mixed with sand and various sorts of earth, placed by the ocean where we find them, have accumulated to a thickness of two miles, is supposed to be incontrovertible; therefore our next inquiry should be, in how many years could this be done? This accumulation has been supposed to take place at the rate of about a foot in one hundred years. Two miles are 10,500 feet, and that number, multiplied by 100, produces 1,056,000 years, as the time in which these animals, aided by the waves of the ocean, may have accomplished that vast work.

Petrified Trees.

32. On the south bank of the river North Esk, a

short distance above the paper-mill at Penicuik, near Edinburgh, where the strata usually accompanying the coal formation of this country are exposed, a large portion of the trunk, and several roots, of a fossil tree, are visible. It rises several feet above the bed of the river, as far as the strata reaches, and the roots spread themselves in the rock.

It appears as if the tree had actually vegetated on the spot where we now see it. It is, where thickest, about four feet in diameter. The strata, in which the remains of the tree stand, are slate clay, and the tree itself is sand-stone. There is sand-stone below and immediately above the slate clay, and the roots do not appear to have penetrated the lower sandstone, to which they reach. Small portions of coal were observed where the bark existed, the form of which is distinct on the fossil.

33. Whilst sinking a pit, in 1818, at Mr. Fenton's colliery, near Wakefield, Yorkshire, the workmen, having dug to the depth of eighty-six yards, came to a bed of coal two feet six inches thick, beneath which they found a petrified tree, or rather plant, having no branches, standing upright, but rather inclining to the east. It was six inches diameter at the top; but, as they sunk down, it increased to twelve inches, and at the depth of fortytwo feet, seemed to branch out roots to another bed of coal six feet thick.

The body was a grey sand-stone, coated round with a black carbonized matter one-tenth of an inch, supposed to be its bark.

A species of siliceous fossil wood, was found by a serjeant of artillery, who accompanied Captain Sabine, near the top of a hill in Hare Island, on the west coast of Greenland, in latitude 70° 26'. It had been a part of the trunk of a pine tree, about four inches in diameter. The hill is in the interior of the island, about four miles from the shore, and is considerably more than 900 feet above the level of the sea.

34. The situation of the petrified trees found in Russia, which, separated from their stumps, are found sometimes as much as fourteen feet under ground, chiefly in marshes, proves that they were overturned

by violence, and prostrated in the spots where they formerly stood erect.

The bed of earth which covers them consists of sand and clay. Under dry sand, the wood is reduced to dust; but the form of the tree remains visible, if the dust be removed carefully. Under wet sand, the wood is found perfectly sound, with however a blackish colour. Only large oaks appear to have been torn up by the roots. The trees which are partly petrified, are found chiefly under a bed of potter's clay. The oaks which have not been petrified, on being exposed to the air, harden considerably. It is remarkable, that these trees are frequently found in grounds where none of the sort now grow. Professor Kunizyn imagines, that these trees were thus prostrated and covered with earth by the same violent motion of nature, which, in the north of Russia, separated enormous masses of granite from their foundations, and carried them to a considerable distance.

35. Mr. W. Chapman has communicated to the Royal Society, an hypothesis, that coal is derived from the prolonged compression of beds of peat.

The deepest peat-bogs are from thirty to forty feet; and he finds, by calculation, that, if this mass was compressed, it would be about equal to the strata of coal at Newcastle. He also traces the analogy between the timber or trees found in peat-bogs, and on the sea-shores of Northumberland, and the grit-stone found in the Canton mine at Newcastle. This stone, specimens of which have been sent to the British Museum, has the perfect form and appearance of trees; and even its apparent fibres are such as to leave no doubt of the kind of wood which had preceded the present sand or grit. The combustion which assisted the change of peat into coal, he considers as having been effected by means of the pyrites. Account of the Mammoth, or fossil Elephant, found in the Ice at the Mouth of the River Lena, in Siberia.

36. Mammoths' and elephants' bones and tusks are found throughout Russia, and more particularly in Eastern Siberia and the Arctic marshes. The tusks are found in great quantities, and are collected for the sake of profit, being sold to the turners in the place of the living ivory of Africa, and the warmer parts of Asia, to which it is not at all infe

rior. Towards the end of the month of August, when the fishing season in the Lena is over, the Tungusians generally go to the peninsula of Tamut, where they employ themselves in hunting, and where the fresh fish of the sea offer them a wholesome and agreeable food.

One day, their chief, Schumachof, perceived among the blocks of ice a shapeless mass, not at all resembling the large pieces of floating wood, which are commonly found there. The following year (1800) he found the carcase of a walrus (trikchechus rosmarus.) He perceived, at the same time, that the mass he had before seen was more disengaged from the blocks of ice, and had two projecting parts, but was still unable to make out its nature. Towards the end of the following summer (1801,) the entire side of the animal, and one of his tusks, were quite free from the ice. But the summer of 1802, which was less warm, and more windy than common, caused the mammoth to remain buried in the ice, which had scarcely melted at all. At length, towards the end of the fifth year (1803,) the ardent wishes of Schumachof were happily accomplished; for the part of the ice between the earth and mammoth having melted more rapidly than the rest, the plane of its support became inclined, and this enor mous mass fell, by its own weight, on a bank of sand.

In the month of March, 1804, Schumachof came to his mammoth; and, having cut off his horns (the tusks) he exchanged them with the merchant Bultunof for goods of the value of fifty rubles.

Two years afterwards, a Mr. Adams, traversing these distant and desert regions, found the mammoth still in the same place, but altogether mutilated. Wild beasts, such as white bears, wolves, wolverines, and foxes also fed upon it; and the traces of their footsteps were seen around. The skele ton, almost entirely cleared of its flesh, remained whole, with the exception of one fore-leg. The spine from the head to the oscoccygio, one scapula, the pelvis, and the other three extremities, were still held together by the ligaments, and by parts of the skin. The head was covered with a dry skin; one of the ears, well preserved, was furnished with a tuft of hairs.

All these parts have necessarily been injured in transporting them a distance of 7,330 miles; yet the eyes have been preserved, and the pupil of the left eye can still be distinguished. The point of the lower lip had been gnawed, and the upper one, having been destroyed, the teeth could be per

ceived. The brain was still in the cranium, but appeared dried up.

According to the assertion of the Tungusian chief, the animal was so fat and well fed, that its belly hung down below the joints of the knees. This mammoth was a male, with a long mane on the neck, but without tail or proboscis. The skin is of a dark grey colour covered with a reddish wool, and black hairs. The dampness of the spot where the animal had lain so long, had, in some degree, destroyed the hair. The entire carcase was ten feet high, and seventeen long, from the point of the nose to the end of the tail, without including the tusks, which together weighed 360 pounds. The head alone, without the tusks, weighed 414 pounds. The place where he found the mammoth, is about sixty paces distant from the shore, and nearly 100 paces from the escarpment of the ice from which it had fallen. This escarpment occupies exactly the middle between the two points of the peninsula, and is two miles long. The skeleton is now in the Museum of the Academy of Petersburg, and the skin still remains attached to the head and the feet.

The preservation of the flesh of the mammoth, through a long series of ages, is not to be wondered at, when we recollect the constant cold and frost of the climate in which it was found. It is a common practice to preserve meat and berries through the winter by, freezing them, and to send fish, and all other provisions, annually at that period, from the most remote of the northern provinces, to St. Petersburg, and other parts of the empire.

37. In 1817, Dr. Mitchell assisted in disinterring the remains of a mammoth, at Chester, fifty-four miles from the city of New York, about a year ago. Since that time, the remains of another individual of this species have been found in a marsh, only thirty-two miles north. He also discovered another in the town of Goshen, Orange County, within sixty miles of New York, in a meadow belonging to a Mr. Yelverton. The soil is a black vegetable mould, of an inflammable nature. It abounds with pineknots and trunks, and was, about thirty years ago, covered with a grove of white pine-trees. The length of the tooth was six inches, the breadth