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Africa, considered in relation to her place on the map, forms an extensive continent, situated nearly in the centre of the earth, and obstructing the great highway across the ocean. Her coasts form the chief barrier to a direct maritime intercourse between the distant extremities of the globe. To perform the vast circuit of her shores, and to round her stormy capes, has tried the courage and hardihood of the greatest navigators. Could Africa cease to exist, great facilities would be afforded to the communication between the other continents, and many new channels of commerce would be opened up. As she, however, has an existence likely to be coeval with theirs, our concern is with her actual condition, presenting as it does many peculiar claims to interest in the eyes of the philosopher and politician.
The physical peculiarities which distinguish Africa seem to depend chiefly on the circumstance that almost her whole territory is situated within the tropics. The other portions of the earth's surface, which lie directly beneath the solar influence, consist generally either of sea, or of narrow and insular lands, refreshed by breezes from the ocean. But the greatest breadth of Africa is under the immediate power and dominion of the sun; and most of her people see that great planet, in its annual progress from tropic to tropic, pass twice over their heads, and thus experience a repetition of its most intense and perpendicular rays. The highest blessings of this sublunary world, when carried beyond a certain limit, become its deadliest bane. That parent orb, which cheers and illumines the rest of the earth, glares on Africa with oppressive and malignant beam, blasting the face of Nature, and covering her
with barrenness and desolation. Sometimes it converts the soil into a naked desert, sometimes overspreads it with a noxious excess of animal and vegetable life. The soil, when not watered by copious rains or river-inundations, is scorched and dried up, till it is converted into a dreary waste. Hence it is, that in Africa plains of sand form a feature so truly alarming. The Great Desert, with the exception of the narrow valley of the Nile, reaches across the entire continent, exhibiting an expanse of burning surface, where for many days the traveller finds not a drop of water, nor sees the least vestige of animal or vegetable nature. He pursues his dreary route amid loose hills, continually shifting, and leaving no marks to guide his course. Every breeze is filled with dust, which enters the mouth and nostrils, and penetrates between the clothes and skin. Sometimes it drives along in clouds and whirlwinds, beneath which it was once thought that caravans and even armies had been buried; but it is now ascertained that the numerous bones which whiten the desert are merely those of travellers who have sunk under famine, thirst, and fatigue; and that the sand, which continually blows, has accumulated above them. Travellers over these tracts of shingle have been impressed with the idea of their being the bed of an ancient ocean. This is not the place to enter into a speculation on the formation of the earth. That every part of its surface lay once beneath the waters is sufficiently apparent; but there is at least no historical proof that Africa emerged later than other continents. The earliest records represent her deserts to have been as extensive as they are in our days, and to have pressed equally
close upon the cultivated belt along the northern coast. In general, all regions between the tropics, when not copiously watered, moulder into sand, alternating with a hard and impenetrable stratum of clay. The central wastes of Asia, those of Arabia, and of Sindetic Hindostan, though inferior to those of Africa, are yet of similar character, and of immense extent.
In order to obviate the extreme effects of the tropical sun, which produces a desolation so dreadful, Nature has provided suitable remedies. Every. country under this latitude has its rainy season, when, amid the blaze of lightnings and the noise of thunders rending the sky, Heaven seems to open all her windows to pour an unbroken flood upon the earth. The ground is covered as with a deluge, and the dry beds of the rivulets are converted into torrents; yet so intense are the sun's rays, that the moisture thus lavished upon the surface is quickly dried up. Great rivers which, swollen by the rains, overflow their banks, and lay the surrounding country under water, or at least afford the means of artificial inundation, are the principal source of that luxuriant fertility, that mighty growth of vegetable forms, which singularly characterize the tropical climates. It is to the waters which descend from the lofty precipices and eternal snows of the Himmaleh, that the plains of Hindostan and China owe their amazing fruitfulness. Africa, too, has elevated mountain-chains, which give rise to several rivers of great magnitude and most fertilizing influence. Atlas, along its northern border, presents, even in so hot a climate, pinnacles wrapt in everlasting snow. Still more extensive is that central range, which, amid its various local names, is most generally known
under the poetical appellation of "The Mountains of the Moon." Yet these chains, besides being not altogether so gigantic as those of the other continents, labour under the peculiar disadvantage of extending across the breadth only of Africa. The Andes and the Himmaleh, those stupendous heights of America and Asia, as they traverse these continents in the direction of their length, cover a much greater surface, and thus create fertility in the more limited plains which intervene between the mountains and the ocean. But the largest of the African rivers, directing their course through a vast extent of low land, reach the sea only by a very circuitous course. Several of them, too, diffusing their waters into lakes or marshes, expire in the very heart of the continent. The result is, that the enormous breadth of the Sahara, or Great Desert, is scarcely irrigated even by a streamlet. It depends entirely on the periodical rains; and these sink into the sandy and porous surface till, being arrested at the depth of eight or ten feet, they form that "sea under ground" which has been traced over a large portion of the waste.
Vegetable life, in consequence of this absence of moisture, is scantily diffused over a great extent of the continent. In the heart of the mountains, however, and in the kingdoms along their border, the soil is most profusely watered, and, under the influence of a tropical sun, produces, perhaps, beyond any other part of the world, that luxuriant growth, and those gigantic vegetable forms, which distinguish the equatorial regions. The baobab, or great calabash, appears to be the most enormous tree on the face of the earth. Adanson assures us, that the circumference in some cases is equal to thirteen fathoms, as measured by his arms clasped round the trunk, that
is, varying from seventy-four to seventy-seven feet. Branches extending horizontally from the trunk, each equal to a large tree, make the baobab a forest as it were in itself. The mangrove, too, which rises on the borders of rivers or inundated spots, diffuses itself in a manner truly remarkable. The branches, dropping down upon the watery bank, strike root and grow; hence the original plant, spreading farther and farther, forms over the stream a species of natural arcade. These mighty trees do not stand alone, but have their interstices filled up by numberless shrubs, canes, creeping and parasitical plants, which intersect and entwine with each other till they form a thick and impenetrable mass of underwood. To cut even a narrow path through these dense forests is a laborious process; and as shoots are continually protruding inwards on each side, the track, without constant travelling and the diligent use of the axe, soon becomes impassable.
As we approach the confines of the Desert, these giants of the wood disappear, and vegetation presents a different and more pleasing aspect. It exhibits now the light and gay form of the acacia, whole forests of which rise amid the sand, distilling those rich gums that afford an important material of African commerce. The lotus, a celebrated and classical shrub, the tamarisk, and other small and elegant trees, afford agreeable and nutritive 'berries, which constitute the food of several nations. Various flowering shrubs, of the most delicate tints, rising in wild and spontaneous beauty, embellish the precincts of the waste. Thus the Desert, in its first approaches, and before vegetable life begins to expire, does not assume its sternest character, but wears even a peculiarly pleasing and smiling aspect.