The rains are not continual during the wet season, but pour down in floods for several days together, or for several hours in a day.

"Peru is divided into two different climates by the Andes, for whilst it is summer in the mountainous parts, it is winter in the vales. Winter, on the mountains, begins in December, but this in the vales is the first summer month; and a journey of four hours conducts the traveller from one season to another.

"In general the confined regions on the west of the Andes are dry, whilst the wide countries on the east of that chain are deluged with torrents of rain, from the trade winds blowing over the Atlantic.

"Travellers, on the Andes, have sometimes enjoyed a delightful serenity in these elevated regions, at the same time that they have heard the horrid noise of tempests discharg ing themselves on the level country: they have seen lightnings issue from the clouds, and heard the thunders roll far beneath their feet.

"At Lima, rain is seldom or never seen, but a strong dew falls and waters the vallies. The country is much subject to earthquakes; the most dreadful seems to have been that of 1747, when the port of Callao was submerged, and out of 4,000 inhabitants only 200 escaped.

"In Brazil the wet season commonly begins in March or April, and is over in August; when the spring, or rather the summer, begins. The nights are very cold; and the nights in summer are colder than in winter.

In Jamaica the rain commonly begins in May. July is always very wet; and toward the end of that month, and the beginning of August, the weather is very close. In September and October hurricanes are frequent.

"In Nicaragua it rains six months, from the first of May to the first of November; in the other six months it is hot and dry.

"That part of the frigid zone which is inhabited, viz. Greenland, Lapland, &c. has only two seasons, winter and summer. Their night of winter, the sun never appearing above the horizon, is extremely severe. The most rapid rivers are sometimes frozen five or six feet deep or more; the largest lakes and bays are frozen to bear any weight, and rocks often burst by the intensity of the frost. brilliancy of the stars, the aurora borealis, and the full moon

The

which never sets, make some atonement for the absence of the sun. The long twilight also, which they enjoy before the sun rises and after he sets, considerably diminishes the time of their total darkness.

"The transition from winter's frost to summer's heat is very rapid in the frigid zone. The short summer is very warm, but foggy. The continual sunshine now enables the inhabitants to lay up a store of provisions for winter.

"The hottest part of the earth is in the middle and western parts of Africa. The trade winds, in passing over the extensive sandy deserts of this continent, become heated to an extreme degree before they arrive at the western coast.

"The climate, on the western continent, is much colder than it is in similar parallels on the eastern continent.

"Canada, in North America, which is nearly in the same parallel with France, has the winters almost as severe as at Petersburgh: the river St. Laurence, notwithstanding its breadth, is frequently frozen the whole of the winter, strong enough to bear even carriages upon it. Philadelphia and New York, nearly in the same parallel with Madrid, have often severe winters, but the heat of the summer is excessive.

"The cold, as I before observed, in the southern hemisphere is much greater than in the northern. The climate of Terra del Fuego is an instance of this: situated as far south as Newcastle is north of the equator; and, therefore, were the degrees of heat and cold proportionable to the latitude, we might expect the summers of Terra del Fuego as warm as those on the banks of the Tyne; yet Captain Cook, who was there at Midsummer, found the cold so excessive, that a party, botanizing on the hills, was in danger of perishing by cold.

"The mountains and vast fields of ice, around the south pole, extend to a much greater distance than those around the north pole. Navigators have penetrated to within 9 degrees of the north pole; yet Captain Cook could not get nearer the south pole than within 18 degrees.

"In great continents the weather is more settled than it is in islands: the summer's heat is greater, and the winter's cold is more intense.

"In islands the heat is tempered by clouds and vapours from the surrounding sea; but the weather is inconstant.

The cold of winter is also mitigated from the same cause, and the frost is generally of short duration. This is particularly the case with respect to Great Britain."

SECTION III.

OF SNOW AND THE POLAR ICE.

DR. WALKER." Pray, Edward, did you ever attentively examine a flake of snow? We are going to the land of snow and ice, and I wish you to understand, as well as view, the phenomena of nature, as far as human knowledge can account for them, but there are bounds the mind of man cannot pass. Dr. Grew, in speaking of the nature of snow, observes, that if a person will attentively view a thin, calm, and still flake of snow, he will find that many parts of it are of a regular figure; for the most part, as it were, so many little rowels or stars of six points: being as perfect and transparent ice, as any we see on a pool of water. On each of these six are set other collateral points, and those always at the same angles as are the main points themselves. Next, among these irregular figures, though many of them are large and fair, yet from these taking our first item, many others alike irregular, but much smaller may be discovered. Again, among these not only regular but entire parts of snow, looking still more warily, it will be perceived that there are divers others indeed irregular, yet chiefly the broken points, parcels, and fragments of the regular ones. Lastly, that besides the. broken parts, there are some others which seem to have lost their regularity, not so much by being broken, as by various winds, first gently thawed and then frozen into little irregular clumps again.

"From hence the true notion and external nature of snow seems to appear, viz. that not only some few parts of snow, but originally the whole body of it, or of a snowy cloud, is an infinite mass of icicles regularly figured; that is, a cloud of vapours being gathered into drops, the said drops forthwith descend; in which descent, meeting with a soft freezing wind, or at least passing through a colder region of

air, each drop is instantly transformed into an icicle, shooting itself forth into several points on every side from its centre; but still continuing their descent, and meeting with some sprinkling and intermixed gales of warmer air, or by their continual motion wafting to and fro, touching each other, some are a little thawed, blunted, and frosted, others broken, but the greater part clinging in parcels together, which we call flakes of snow.

"You now know what snow is, and though it appears so soft, yet it is truly hard, because it is, in fact, really and truly ice. On the first touch of the finger, the extreme points thaw; else would these small but sharp particles pierce our fingers. As for the whiteness of snow, it is, thus easily ac counted for ;- -snow consists of many parts, all transparent singly, but, being mixed together, they appear white, as the parts of froth, glass, ice, and other transparent bodies.

The appearance of a mass of ice led to the following dialogue on its formation "The expansion of water, during its conversion into ice, is shewn by the circumstance of ice swimming upon water; and if water in a deep vessel be examined, at the time ice is forming, it will be found a little warmer at the bottom than at the top; and these circumstances are of great importance in the economy of nature. Water congeals only on the surface where it is liable to be acted upon by the sun, and by warm currents of air, which tend to restore it to a fluid state again; and when water approaches near the point of freezing, it begins to descend, so that no ice can be formed till the whole of the water has been cooled to the point where it preserves the greatest density; and in the deep parts of the sea and lakes, and even in some of the northern latitudes, the duration of the long winter is insufficient to cool the water to the degree at which ice forms."

EDWARD." At what degree does water freeze, Sir?" Dr. Walker." At a temperature below 32 of Fahrenheit it becomes solid, or ice, and when heated to the degree of 212 it boils. The stupendous masses of ice, known by the names of Ice Islands, Floating. Mountains, or Icebergs, common to Davis's Straits, and sometimes met with near Green, land, from their height, various forms, and the depth of water in which they ground, are calculated to strike the beholder with wonder: yet the fields of ice, more peculiar to Greenland, are not less astonishing. Their deficiency in elevation is sufficiently compensated by their amazing extent

of surface. Some of them have been observed near a hundred miles in length, and more than half that breadth; each consisting of a single sheet of ice, having its surface raised in general, four or six feet above the level of the waters, ‘and its base depressed to the depth of nearly twenty feet beneath." "When the sea freezes, the greatest part of the salt it contains is deposited, and the frozen spongy mass probably contains no salt, but what is natural to the sea-water filling its pores." The Captain of the ship here observed that," the ice frozen from sea-water is not so solid and transparent as that procured from snow or rain-water, and that sailors distinguish it into two kinds, accordingly as it seems to have been formed from one or the other.

"When salt-water ice floats in the sea at a freezing temperature, the proportion above, to that below the surface, is as 1 to 4 nearly; and in fresh water, at the freezing point, as 10 to 69, or 1 to 7 nearly. Hence, its specific gravity appears to be about 0.873. Of this description is all young ice, as it is called, which forms a considerable proportion of packed and drift ice; in general it occurs in flat pieces commonly covered with snow of various dimensions, but seldom exceeding fifty yards in diameter.

"Fresh-water ice is distinguished by its black appearance when floating in the sea, and its beautiful green hue and transparency when removed into the air. Fresh water ice is fragile, but hard; the edges of a fractured part are frequently so keen as to inflict a wound like glass.

"The most dense kind of ice, which is perfectly transparent, is about one-tenth specifically lighter than sea-water at a freezing temperature. Plunged into pure water, of temperature 32°, the proportion floating above to that below the surface, is as 1 to 15, and placed in boiling fresh water, it barely floats. Its specific gravity is about 0.937. Fields, bergs, and other large masses chiefly consist of fresh-water ice. Brash-ice, likewise affords pieces of it, the surfaces of which are always found crowded with conchoidal excavations when taken out of the sea. Some naturalists have been at considerable pains to endeavour to explain the phenomena of the progressive formation of the ice in high latitudes, and the derivation of the supply, which is annually furnished, for replacing the great quantities that are dissolved and dissipated by the power of the waves, and the warmth of the climate into which it drifts. It has frequently been urged that