climate in which these extinct species may have lived, antecedently to the great inundation by which they were extirpated, is a distinct matter of inquiry, and on which the highest authorities are not agreed."

Cuvier is of the opinion, that many of the extinct fossil animals were of a different species from those now in existence, and therefore the inference may be drawn, that some species of the same genera might have been fitted for a cold, while others could live only in a warm climate.

Thus the fox is found, both in the coldest, and the hottest regions; and the Newfoundland dog is so protected by his coat, as to endure the cold of an arctic winter, while the naked African species would perish in a moderate climate.

On the other hand, it may be contended that the remains of many animals are found in strata in cold regions, which are not liable to any such variations, and which from their nature, or structure, are known to live only in hot climates; such are the crocodiles and some species of the tortoise.

But the want of vegetation in cold climates, is an insuperable objection to the hypothesis, that such animals as the elephant, rhinoceros and hippopotamus, could have been maintained during the winter season in Great Britain, let their natural clothing be supposed ever so warm. And besides, the bones of these animals, and especially those of the elephant, are nowhere found in such abundance, as in Siberia, one of the most inhospitable climates on the earth, and in which country, at the present day, there is hardly sufficient vegetation to maintain a few elephants, even during the few months of summer; and where that most hardy of all quadrupeds, the rein-deer, can with difficulty maintain itself through the rigors of an eight months' winter. At present, the elephant and rhinoceros, except through the tyranny of man, are never found out of a country perpetually verdant.

With respect to the supposition which has been offered, that these animals might have migrated with the seasons, and thus enjoyed the luxury of a constant vegetation, it is plain that the present geographical situation of England, would invalidate any such hypothesis, unless it can be shown that these animals found a warmer country by crossing the straits of Dover, a distance of more than twenty miles, by water. This, so far as regards the rhi

noceros, tiger and hyena, is clearly impossible, and it is well known that the hippopotamus not only lives exclusively in fresh water, but that its unwieldy bulk prevents it from taking long and rapid journeys.

Thus the fact which geology has brought to light, with respect to certain portions of the animal, as well as the vegetable kingdom, appear very clearly to concur in proving, that the climate of Europe was once, at least as ardent as the hottest parts of Africa are at this day; and that there was a time, when Siberia was clothed with a sufficiency of vegetation to support herds of elephants during the whole year.

Causes which have produced a change of climate. With respect to the cause, or causes which have effected so great a change in the temperature of the earth's surface, there are a great variety of opinions.

Burnet, as stated in the abstract we have given of his theory, accounted for this change by supposing that the earth's axis took a new and different position at the time of Noah's flood; but astronomy has shown the improbability of any such change in position.

Most writers who admit a deterioration of climate, suppose with Burnet, that the change was sudden, and that it took place about the period of the deluge. Some, however, and among them Mr. Lyell, believe it to have been gradual, occupying thousands of years, and to have been caused by the changes which have taken place in the relative positions of the sea and land. But in the first place, no such changes as this author supposes are proved to have happened with respect to the sea and land; nor second, had such changes been proved, is it at all probable, such local causes could have been adequate to effect a change so material and universal.

Other theorists, who maintain the deterioration to have been gradual, think that the most reasonable mode of accounting for it, is to suppose that the earth was created in the state of a fused mass, and that it has been cooling ever since.

Sir John F. W. Herschel has recently made some calculations and inquiries, with the view of ascertaining whether there existed any astronomical causes, which might account for the difference between the present and ancient heat of the earth's surface Geometers," he says,

"have demonstrated the absolute invariability of the mean distance of the earth from the sun; whence it would at first seem to follow, that the mean annual supply of light and heat derived from that luminary would be alike invariable; but a closer consideration of the subject will show, that this would not be a legitimate conclusion; but that on the contrary, the mean amount of solar radiation is dependent on the eccentricity of the earth's orbit, and therefore liable to variations.

Now the eccentricity of the earth's orbit," he continues, "is actually diminishing, and has been so for ages beyond the records of history. In consequence, the ellipsis is in a state of approach to a circle, and the annual average of solar heat radiated to the earth is actually on the decrease. But whether this diminution of radiated heat is sufficient to account for the refrigeration of climate, which geological facts appear to prove, is a question which has not been decided."

Allowing that the earth's orbit should become a perfect circle, we are at a loss to see how the mean annual radiation should thereby be diminished. It is the opinion of M. Arago, that the mean amount of solar radiation can never be materially affected by the irregularities of the earth's annual motion.

It would appear, therefore, that we cannot look to astronomy with much confidence, for a solution of the problem in question.

A recent and highly respectable author, Dr. Ure, of Glasgow, believes that the original heat of the earth was dissipated in consequence of the evaporation of the waters of the deluge.

The cooling influence of evaporation, under certain circumstances, is undoubtedly very great, and most probably in many instances, produces effects which are attributed to other causes. In India, ice is produced by the evaporation of water in the open air. It is said that under certain circumstances, by the spontaneous evaporation of one part of water from the surface of thirty-two parts, at the temperature of 62°, the remaining thirty-one parts will be rendered nearly ice cold, and by the evaporation of four parts more, the remaining twenty-seven will become

ice.

The effects of evaporation, together with the absence of a large heating surface, is strikingly illustrated in the tem

perate climate of St. Helena. This island, though less than eighteen degrees from the equator, and on a parallel with the burning plains of continental Africa, enjoys one of the most comfortable and salubrious climates on the earth. At Jamestown, the thermometer, in the warmest season, seldom rises above 80°. In the country, the climate is still more mild, the thermometer, in some seasons, never rising higher than 72°. At Jamestown, the average temperature during the year is from 66° to 78°, the heat at this place, being concentrated by the high rocks which rise above the town. At Plantation house, the average heat is only from 61° to 73°, and at Longwood, the last residence of Napoleon, from 56° to 68°.

The island of Sumatra, though directly under the equinox, presents a similar exemption from the excessive heats with which the interior of continents, situated on the same parallel, are oppressed. The heat, at this island, seldom rises higher than 85°, at any season; while at Bengal, which is situated in 22° north latitude, it is often above 100°.

It is at a distance from the sca, and where the surface is dry, that the greatest accumulation of heat takes place. Mungo Park relates that in some districts in Africa, the ground became so hot by the action of the sun, that even the negroes, though accustomed to that ardent climate, could not bear to touch it with their naked feet; and that he could not hold forth his hand against a current of air which entered the crevices of his hut, without feeling acute pain from its scorching effects.

Dr. Ure supposes that a portion of the ante-diluvian land is now covered by the ocean, and that the heating surface, or dry land on the earth, was twice as extensive before the deluge as it is now, and, consequently, as a whole, that its heating effects were doubled.

We cannot follow Dr. Ure through the detail of facts and arguments which he has brought forward on this subject; but after many additional statements to those we have given, he concludes, "that the facts and observations just detailed, seem adequate to prove that the events of the deluge involved such a change in the terraqueous constitution, as rendered the surface of the globe much colder and moister than it had previously been."-Geology, p. 491.

The great and sudden fall of temperature, which the

earth suffered at a former time, and which is supposed to have taken place about the period of the deluge, is indicated by the situation and number of fossil bones, belonging to species known to inhabit hot climates, found in northern latitudes.

66

The almost incredible number of bones of fossil elephants," says Dr. Ure, "found in northern Siberia, which betray no marks of having been rolled or transported from a distance, attest the existence on its plains of huge herbiverous animals at that distant epoch. These demonstrate that a vigorous vegetation clothed countries now covered with frost a great part of the year, where, even in summer, sterilizing cold and humidity perpetually reign, and where, at present, the reindeer can hardly pick up from beneath the snow its scanty mouthful of moss."

Not only the bones of elephants, but those of the rhinoceros, the mastodon, and hippopotamus, are found in Siberia. All these animals living on vegetables, and, from their sizes, requiring large quantities for their sustenance, it would seem impossible as we have before stated, that in the present state of the climate, there should have grown a sufficient quantity of nourishment for the support of these animals.

That these animals died where they had lived, and where their remains are now found, is proved by the circumstances that their skeletons are entire, and that their bones show no scratches, or other marks of transportation or friction That these bones have not lain for a long period in a hot climate, is proved by their state of preservation; many of the elephants' tusks being perfectly sound, and making the best of ivory, for which purpose vast numbers have been dug up and sold. The change of climate must therefore have taken place at the deaths of these animals, or soon after.

That these animals died suddenly, and remained in a cold climate after death, at least some of them, is proved by the circumstance, that the body of an elephant was found on the bank of the river Lena, in 1803. It was frozen in the ice, a large proportion of the flesh being still preserved, and serving as food for the white bears and dogs. Now, since there is no reason to believe that this animal could have lived in a cold climate, and as there is