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than for their height. If they reach a great elevation, it is by a gradual rise, and in a succession of terraces. Perhaps we should not deviate far from the truth if we were to venture the assertion, that the whole body of the African mountains forms one great plateau, presenting toward each coast a succession of terraces. This nucleus of the African continent seems to contain few long and high ranges in the interior, so that if the sea were to rise to a height above its present level sufficient to cover all the low lands which line its shores, Africa would perhaps appear almost a level island in the midst of the ocean.

"None of the known chains of Africa are adverse to this view of its surface. Atlas, which lines nearly the whole of the north coast, is a series of five or six small chains, rising one behind another, and including many table lands. The littoral chain of the red sea, or the Troglodytic chain, resembles Atlas in its calcareous steeps, so imposing to the eye of the traveller, yet really of very moderate height.— The Lupata chain, or the spine of the world, which seems to reach from cape Guardafui to the Cape of Good Hope, in a direction not well known, contains the plateaus of Adel and Mocaranga; it terminates in the south in high and barren plains, called the Kanos, and in steep mountains with flat summits, one of which has received the significant name of the Table Mountain. This chain then seems to resemble the former two. The rivers of Guinea descend in a series of cataracts, not in long and deep valleys. It is the usual character of calcareous mountains to be formed into terraces, and such seems to be the nature of the Kong mountains.

"In the interior of Africa, some of the vast plains which occupy the greater part of its extent, covered with sand and gravel, with a mixture of sea shells and encrusted with crystallizations, look like the basins of evaporated seas. Such is the famous desert of Zahara, where the sands moving like the waves of the sea are said to have swallowed up entire tribes. Many

During the whole of my route I had reason to suspect that the accounts in books of travels, which have generated such terrific notions of the moving sands of Africa, are greatly exag

of the slender rivulets never unite to form permanent currents, but disappear with the rainy season, to which they owe their origin. Africa contains an infinite number of those torrents and rivers which never reach

the sea. Some of them have a long course and rival the greatest rivers in the world. Such is the Niger or Joliba, unless it has an outlet, as yet unknown, in the Gulf of Guinea.

"No where do the empire of fertility and that of barrenness come into closer contact than in Africa. Some of its lands owe their fertility to high wooded mountains, moderating the heat and dryness of the atmosphere. More frequently the fertile countries, bounded by vast deserts, form narrow stripes along the banks of the rivers, or alluvial plains situated at their place of exit. These last

gerated. Our companions indeed affected to re late various stories of caravans that had been overwhelmed. But as neither time nor place was adduced, it would seem not unreasonable to doubt the truth of the assertion.

If caravans have been thus buried, it may be presumed that accident can only have happened after they had lost the power of moving by the influence of a hot wind, want of water and other causes. A number of men, and other ani mals, found dead, and covered with sand, would be sufficient ground for succeeding travellers to believe, or at least to relate, that the persons thus found, had been overwhelmed on their march; though the accumulation had not occurred till they were already dead. Brown's Travels, page 249. The army of Cambyses was reported to have been overwhelmed in the deserts of Lybia beneath a mountain of sand [Vide Herodotus, Tha. $26] and the story has been embellished by the poetic imagination of Darwin, but it appears more probable that they perished from thirst and fatigue. Bruce,(Vol V. p. 318,) gives the following account of some phenomena ob served in the deserts of Barabra. Here we were at once surprised and terrified by a sight, surely one of the most magnificent in the world. In that vast expanse of desert, we saw a number of prodigious pillars of sand at different distances from us, at times moving with great celerity, at others stalking on with majestic slowness; at in tervals we thought they were coming in a few minutes to overwhelm us; and small quantities of sand did actually more than once reach us; again they would retreat so as to be almost out of sight, their tops reaching to the very clouds. There the tops often separated, from the bodies; and these being once disjoined, dispersed in the air, and disappeared. Sometimes they were bro ken near the middle, as if struck with a large cannon shot. About noon they began to ap proach with considerable swiftness. Eleven of them ranged along side of us about the distance of three miles. The diameter of the largest ap peared to me as if it would measure ten feet. They at length retired from us leaving an impression upon my mind to which I can give no name, though surely one ingredient in it was fear, with a considerable mixture of wonder and astonishment.

countries, generally contained between two branches of the river diverging to form a triangle, have, from their figure received a name taken from Delta, the fourth letter of the Greek alphabet, which is a triangle. The term has been given, by way of eminence, to the flat island formed by the Nile in lower Egypt. Another class of fertile lands owes its existence to springs, which, here and there, burst forth in the midst of deserts; these spots of verdure are called oases. Even Strabo mentions them, when he says, "to the south of Atlas lies a vast desert of sand and stones, which like the spotted skin of a panther, is here and there diversified by oases; that is to say, by fertile grounds, rising like islands in the midst of the ocean.

nificant

"It is to these contrasts that Africa owes its twofold reputation. This land of perpetual thirst, this arid nursery of lions, as it was called by the ancients, was at the same time, represented under the emblem of a woman, crowned with ears of corn, or holding ears of corn in her hand. Although the character of high fertility belongs especially to the Africa propria of the ancients, that is, to the present state of Tunis, it is certain, that in this part of the world, wherever moisture is conjoined with heat, vegetation displays great vigour and magnificence. The human species find abundant aliment at a very insigof labour. The corn expense stalks bend under their load; the vine attains a colossal size; melons and pumpkins acquire enormous volume millet and holcus, the grain which is most common over three fourths of this continent, though badly cultivated, yield a return of two hundred fold; and the date tree; which is to the African what the cocoa nut and the bread fruit are in Oceanica, can withstand the fiery winds which assail it from the neighbouring deserts. The forests of Mount Atlas are equal to the finest of Italy and Spain. Those of the Cape, boast of the silver leaved Protea and some elegant trees. In the whole of Guinea, Senegambia, Congo, Nigritia, and the eastern coast, formerly denominated India, are to be found the same thick forests as in America. But in parts which are marshy or arid,

sandy or rocky, that is in one half of Africa, the natural vegetation presents a harsh and uncouth physiognomy.

"The animal kingdom presents still greater variety and more originality. Africa possesses most of the animals of the old continent, and, in some species, the most vigorous and the most beautiful varieties. Such are the horse of Barbary, the Cape buffalo, the Senegal mule, and the zebra, the pride of the Asinine race. The African lion is the only lion worthy of the name. The elephant and the rhinoceros, though of less colossal dimensions than those of Asia, have more agility, and perhaps more ferocity, though the African elephant is said to fly at the sight of that of Asia. Several very singular animal forms appear to be peculiar to this part of the world. The unwieldy hippopotamus inhabits the south, from the Cape of Good Hope to Egypt, and to Senegal. The majestic giraffe, the prototype of the seraphim, which the Arabian mythology yoked to the chariot of the lord of thunder, roams from the Niger to the Orange River. The gazelle, or antelope genus, peoples Africa with numerous species and varieties; some lighter and handsomer than others, and perhaps all differing from those of the table lands of Asia. Africa, filled with monstrous apes and disgusting baboons, is probably deficient in many species of monkeys which seem reserved for Oceanica, as the ourangoutang; or for America, as the sapajoo. The winged race of Africa is equally peculiar. The flamingo, in his scarlet robe, the paroquet, clad in emerald and saffron hues, the digretta, of elegant plumage, might have imparted sufficient interest to the descriptive pen of Vaillant, though he had added no imaginary birds. The ostrich is peculiar to Africa, as the cassowary is to Oceanica, and the tooyoo to South America; but among the walking birds, or those which have no true wings, that of Africa is the largest and most perfect."-Malte

Brun.

Though the modern travellers, who have visited Africa, have thrown much

This does not appear to be strictly correct, the ostrich being found amid the sandy deserts of Arabia, and, formerly at least, much further eastward.-Edin. Eucy. art. Ornithology.

light on the geography of that continent, and communicated much interesting information concerning the condition and character of its inhabitants; though they have confirmed many facts which had been mentioned by the ancients; ascertained many circumstances which were formerly doubtful; and introduced to our notice several new countries and nations, yet, notwithstanding all their exertions, there is a space of many hundred miles, in the interior of Africa, north of the equator, that remains unexplored; while the inland country south of the line, is almost wholly unknown.

Africa, as at present known to Europeans, may be divided, in general, into north, south, west, east, and central Africa.

North Africa contains the following countries, viz: Egypt, Barca, Tunis, Tripoli, Algiers, Morocco, Fez, Tafilet, Biledulgerid, and the Sahara. These countries are inhabited chiefly by Moors, descended from the Arabs, and intermingled with the different nations, who at various times have established colonies in Africa. These Moors have overspread the habitable parts of the desert; extended their conquests and colonies towards the south, and driving before them the negro aborigines, have forced them, in several instances, to retire beyond the great rivers. Yet the negroes, addicted to agriculture, probably never possessed any considerable portion of the desert, which is much better adapted to the wandering and pastoral life of the Moors.

West Africa contains the two great divisions of Guinea and Congo; the former of which may be subdivided into North Guinea, or Senegal, containing the country of the Jalops and Foulahs, and the kingdom of the Mandingoes. Within this subdivision is situated the English colony of Sierra Leone.* South Guinea, containing the Pepper coast, the Ivory coast, and the Gold coast. Within this subdivision is the new American colony of Liberia, or Mesurado. East Guinea, or

*The Lion Mountains. The term Sierra being given to the mountains on account of their broken summits, supposed to have some resem. blance to a saw.

the Slave coast, in which are the kingdoms of Whidah, Ardra, and Benin. In Congo are comprehended the kingdoms of Loango, Congo, Ango, Matamba, and Benguela.

South Africa, or Caffraria, contains the country of the Namaquas, the country of the Hottentots, and the English colony of the Cape of Good Hope. Eastward of the Cape, we find on the south eastern coast the kingdoms of Inhambanc, Manica, Sabia, Sofala, and Mocaranga, or as it is sometimes called, Monomatapa. East Africa has been divided into the coast of Zanguebar, the coast of Ajan, and the coast of Adel. In Zanguebar are comprehended the kingdoms of Mozambique, Mongalla, Quilao, Montbaza, Melinda, and the country of the Monoemugi. Ajan contains the republic of Brava, and the kingdom of Magadoxa. Adel is an extensive kingdom, stretching 160 leagues from east to west, and 72 from north to south.

Central Africa, according to this division, includes Nigritia, or Soudan, Nubia, and Abyssinia. Under the name of Nigritia, is included that extensive tract of country, south of the Sahara, which stretches almost across the African continent, on both sides of the Niger. It contains the empires of Houssa, Tombuctoo, the country of the Agudez, the kingdoms of Ludamar, Bondou, Bambour, and other smaller principalities recently discovered by Mungo Park; and towards the east, the kingdoms of Bornou and Darfur. Nubia, an extensive country between Egypt and Abyssinia, comprehends Turkish Nubia, with the kingdoms of Dongola and Sennaar. As Africa lies chiefly within the torrid zone, winter, according to the apprehension of a native of the temperate zones, must be there almost wholly unknown. The seasons are, however, marked by other peculiarities. The most prominent distinctions of the African seasons, are the rainy and the dry.

SOME ACCOUNT OF THE PERIODICAL WINDS AND RAINS OF THE TORRID ZONE.

As the most remarkable feature of

the African year is its division into the rainy season and the dry, both much more strongly marked, than in almost any part of the temperate zones, a brief account of these periodical changes, and the winds which generally prevail in the torrid zone, and a few degrees beyond the tropics, may probably be acceptable to such of our readers as have been but little conversant with the peculiarities of that region of the globe.

In the Pacific and Atlantic Oceans, at a distance from land, it is well known that a wind, nearly constant, blows from the east, throughout the year, over that great belt of waters included between the parallels of 27 or 28 degrees north, and as many south. This wind, as we recede from the equator, is still further deflected from its eastern direction, towards the nearest pole. This phenomenon is caused by the rarefaction of the air, in those places to which the sun is nearly vertical, and the consequent movement of the colder and denser air towards the regions where the rarefaction has occurred.

To this general current of air, called by mariners the trade wind, is to be attributed those remarkable aqueous currents, which have been observed on the shores of the Mexican gulf, along the coast of North America as far as Newfoundland, and near the western shores of Europe and Africa. On these currents a few observations will be offered.

The trade winds sweeping across the Atlantic, in the neighbourhood of the equator, impart to the mass of waters, a westerly motion, towards the shores of South America; where the situation of the land, directs the current toward the Isthmus of Panama. The waters thus accumulated in the Gulf of Mexico, are supposed to rise considerably above the level of the Pacific, on the opposite shore. The current having followed the bendings of the Mexican coast, from Vera Cruz to the mouth of the Rio del Norte, and thence to the mouths of the Mississippi and to the shoals to the west of the southern extremity of Florida,-takes there a direction towards the north, and drives with impetuosity into the Gulf of Florida. Its celerity was there

observed by Humboldt, in 1804, to be five feet per second, though a north wind was then blowing, with great violence. At the end of the Gulf of Florida, in the latitude of Cape Carnaveral, the gulf stream flows to the north east with a velocity, which is sometimes as great as five miles an hour. The pilot may judge of his proximity to Charleston, Philadelphia, or New York, by his arrival on the borders of the gulf stream; for the elevated temperature of the waters, their strong saltness, indigo colour, the shoals of sea weed which cover their surface, as well as the heat of the surrounding atmosphere, all indicate this remarkable stream. Its breadth increases toward the north at the same time that its rapidity decreases and its waters cool. The temperature of the water in the latitude of 40° and 41°, was found to be 72°; when in the same latitude beyond the limits of the stream, the heat at the surface was only 63. Consequently the temperature of the gulf stream, in the parallel of New York, is nearly the same as that of the ocean in the parallel of Porto Rico, and the islands of Cape Verd.

To the east of Boston, the current is nearly eighty leagues in breadth. Here it turns to the east, so that its western edge as it bends, skirts the extremity of the great bank of Newfoundland, which Volney calls the bar of the mouth of this enormous sea river. The cold waters of this bank, which, according the observations of Humboldt, were at the temperature of 48 or 50 degrees, present a striking contrast with the waters of the torrid zone, driven to the north by the gulf stream, the temperature of which is from 70 to 72 degrees. In these latitudes the caloric is distributed in a singular manner throughout the ocean; the waters of the bank are 17° colder than the neighbouring sea, and this sea is 5° degrees colder than the current.*

To this diversity in the temperatures of contiguous portions of water, must, doubtless, be attributed the prevalence of fogs on the banks of Newfoundland. The air reposing on the waters of the stream, and thence acquiring an elevated temperature, becomes charged with vapours, nearly to its point of saturation. This sir becoming mixed with colder portions of at

From the banks of Newfoundland to the Azores, the gulf stream continues its course towards the east. The waters still preserve a part of the impulsion which they had received, at a distance of nearly a thousand leagues. On the meridian of the Isles of Corvo and Flores, the most westerly of the Azores, the breadth of the current is 160 leagues.

From the Azores, the current turns towards the Straits of Gibraltar, the Isle of Madeira, and the Canary Islands. The opening into the Mediterranean, contributes, no doubt, to accelerate the motion of the waters towards the east ;* but if this strait had not existed, vessels sailing to Teneriffe, would, probably, have been driven to the south east by a current, whose cause must be sought in the regions of the equator, and on the shores of the western world. To the south of Madeira, the current may be traced to the south east and south south east, towards the coast of Africa, between Cape Cantin and Cape Bajadoz. In these latitudes, a vessel becalmed, is

liable to be carried on the coast at a time when the crew, relying on their reckoning, suppose themselves far to the west. In the parallel of Cape Blanc, the current mixes with that of the tropics to begin anew its course to the west.

The trade wind of the great Pacific Ocean, must necessarily produce a correspondent movement in the zone of waters over which it flows, but the circumstances of this sea river do not appear to have been observed with the same attention as those of the Atlantic. To this we may, with great plausibility, if not absolute certainty, attribute the elevation of the waters in the Arabian gulf, and doubtless in the

mosphere, or coming in contact with the colder waters, is itself so far cooled as to precipitate its vapours in mists and fogs.

Dr. Halley instituted an inquiry into the cause of the current which is found always flowing from the Atlantic into the Mediterranean. He ascertained by experiment, the quantity of water evaporated in a given time, from a surface of known extent, at the usual temperature of that sea, and making a liberal allowance for the quantity discharged into it by the rivers, found a large excess on the side of the evapora tion, quite sufficient to account for the current in question.

adjacent seas above the level of the Mediterranean.t

These general winds are always modified, or totally changed, in the vicinity of the shores, by the situation and character of the land.

Along the western coast of Africa, the wind is generally directed from the ocean toward the land, assuming of consequence, various directions, according to varieties of the coast. This is readily explained by observing that the air which rests on the burning sands of Africa, must be generally more rarefied than that on the adjacent ocean. In the Atlantic ocean, at no great distance from the African shore, there is a tract, which is subject to calms, occasionally broken with violent storms, attended with terrible thunder, and torrents of rain. This region appears to be the dividing line between the currents which flow toward the African coast, and the general trade wind which moves to the west. The air being here attenuated by those opposite currents, is, no doubt, replenished, by strata descending from the higher and colder regions of the atmosphere, which, mingling with the saturated strata at the surface, produce those tremendous electrical phenomena, and rapid depositions of water, by which this tract of the ocean is marked.

A wind, which though not altogether peculiar to the torrid zone, is more remarkable there than any where else, is that called the sea and the land breeze. This breeze is most observable where the land, at no great dis tance from the coast, is of considerable elevation; as in the islands of Jamaica, Cuba, and others, in the West Indian seas. During the greater part of the day, a breeze sets from the ocean toward the land, which in the evening dies away, and is soon succeeded by a current from the land toward the sea. The air reposing on the lands which are exposed to the fervours of a tropical sun, becomes, during the day, much more rarefied, than

†The level of the Mediterranean is 30 feet lower than that of the gulf of Suez. The level of the water of the Nile, at Cairo, when lowest, in 1798, 1799, and 1800, was nine feet lower than the gulf at low water. But the Nile when highest is nine feet above the level of the gulf at high water.-M. Brun.

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