overcome the obstacles which had hitherto baffled the most strenuous efforts of individuals. Accordingly, by mutual agreement, concluded on the 8th August, 1807, and carried into effect on the 1st January following, the settlement was surrendered into the hands of the crown, and placed on the same footing with the other British colonies. From this time a new and much more copious source of population was opened. Since the year just mentioned, Britain had prohibited her own subjects from carrying on the slave-trade, and she had afterward obtained an assurance from other countries, that they would discontinue it along all the coast northward of the Line. She even received permission to treat as pirates such of their subjects as within those limits might be found employed in the conveyance of slaves. In her zeal for the abolition of this odious traffic, she has maintained a number of ships constantly watching those seas, and capturing every vessel thus unlawfully laden. The liberated negroes are brought to Sierra Leone, where they are located in the surrounding villages. For some time they receive rations, and are kept in pretty strict subordination; but, after a certain period, they obtain assignments of ground, from which to earn their own subsistence. On the 31st March, 1827, the slaves thus liberated amounted to 11,878, of which there were 4701 males above and 1875 under fourteen; 2717 females above and 1517 under that age; besides 1068 settled in Freetown, or employed on the river in the timber trade. On the 31st December, 1828, the number had been increased by new arrivals to 16,886. Unfortunately, neither their progress in industry and civilization, nor the general prosperity of the colony, has answered the sanguine expectations once so fondly cherished. The efficiency of the government has been much impaired by various errors and unfortunate circumstances, and above all by the singularly deleterious influence of the climate on European constitutions. This, it is supposed, is owing not so much to the mere heat, as to the noxious exhalations arising from an ill-regulated town, and an uncultivated country, covered with such a mass of brush and jungle as to impede the necessary venti lation. The result is, a remittent fever, so malignant that almost all Europeans are attacked with it, and not one in three recovers These circumstances have oftener than once led to the consideration whether Sierra Leone ought not to be entirely relinquished. An attempt has even been recently made to establish in its room a colony at Fernando Po, a small island in the Gulf of Benin; but the expectations formed from its climate have also been entirely disappointed. Meantime, it is considered that the absolute abandonment of Sierra Leone would leave full scope for the contraband slave-trade, and frustrate all hopes of establishing a centre whence civilization might hereafter spread throughout Africa. The latest accounts from the governors, Colonel Denham, in 1827 and 1828, and Major Ricketts, in 1829, express a decided opinion that a spirit of improvement is at last beginning to be manifested, that the inhabitants show a disposition to cultivate the ground, and an anxiety to be able to purchase European luxuries, and that in the villages, particularly of Wellington and Waterloo, good churches, and a few stone houses, have been erected. annual expenditure has been reduced to about 40,000l., of which 17,000l. is for liberated Africans; and government seems desirous to retain the settlement, till the natives shall be so far improved as to be able to conduct their own administration, and to afford an example of industry and order to the neighbouring states. The CHAPTER XVII. Geology of Africa.* AFRICA is distinguished from the other continents by its nearly insular form, being connected with Asia merely by an inconsiderable neck of land or isthmus, viz. that of Suez. It extends from the equator to about the average latitude of 35° north, and also to the same degree of latitude south. The greatest length from north to south is from Cape Serrat in Algiers, in lat. 37° 18′ N., to Cape * According to some authors, the name Africa is derived from a, neg., and frigus, cold; while others trace it from a small Carthaginian district, named Frigi-A-frikc-a. Laguillas, in lat. 34° 55′ S.; and the greatest breadth from Cape Verde, in long. 17° 31′ W., to Cape Guardafui, in long. 51° 15′ E. The northern portion of this continent is fully twice the size of the southern portion, and may be considered as about equal to South America; while the southern half is contracted to half the breadth of the northern part, and is nearly about the size of New-Holland. The shape of the corresponding coasts of Africa and America would induce us to infer that the two continents of Africa and America were once united, the projecting or salient part of the former fitting exactly to the Gulf of Mexico; and the bulging part of South America, about Paraiba and Pernambuco, being about the size and shape to fill up the Gulf of Guinea. This great continent has but comparatively few gulfs, bays, arms of the sea, and promontories; and hence, notwithstanding its nearly insular form, its extent of coast is much less in proportion to its area, than in other quarters of the globe. The condition of man, the distribution of the lower animals and plants, even the climate of Africa, are intimately connected with this limited extent of coast. On viewing Africa from its northern boundary on the shores of the Mediterranean, to its southern boundary at the Cape of Good Hope, the following natural divisions or regions present themselves to our attention : 1. The northern region, formed by the Atlas range of mountains, hills, and plains, that extend from the coast of the Atlantic to the Gulf of the Syrtis,-and by the range of fertile hills and dales, and valleys mixed with deserts, in which are some insulated spots of verdure, known under the name oase,* that extend from the termination of the Atlas to Egypt.t 2. The eastern region, formed by Egypt, Abyssinia, Dai fur, &c. The word Oasis is Egyptian, and synonymous with Auasis and Hyasis (Strabo, lxxiii. p. Alm 1140). Abulfeda names the Oasis Al Wahat. In latter times the Cesars banished criminals to the Oases. They were sentenced to expiate their crimes on the islands of the Sandy Sea, as the Spaniards and English send their criminals to the Malouin islands and New-Holland. The latter could more easily escape by the ocean, than the former across the surrounding deserts. †The Atlas of Homer and Hesiod, according to Bory St. Vincent, is the Peak of Teneriffe; the Atlas of the Greek and Roman geographers the African Atlas range of mountains. 3. The Desert region, which is the flat, comparatively low tract of generally desert country, of which the principal portion is the Great Desert of Sahara, which lies between the 29th and 16th parallels, or about 780 miles in breadth, and extending across the continent from the Atlantic to the borders of Nubia. 4. The Region of Soudan, Nigritia, or the Country of the Negroes, extending in a belt across the continent as far as Abyssinia, and from the 16th to the 5th parallel, or about 600 miles in breadth. It is a rich and fertile region, yielding, with little labour, all the valuable productions of the tropical countries. 5. Great Table-land of Africa, or High Africa. This, in all probability, very interesting part of Africa extends from the zone of Nigritia to the Cape of Good Hope. It appears to contain a lofty and extensive table-land, from which acclivities, supporting ranges of mountains, decline on the east and south towards the Indian Ocean; on the west to the Atlantic; and on the north to the Country of Soudan or Nigritia. Unfortunately the whole of this great region, with exception of the Cape of Good Hope and the Portuguese settlements on the east and west coasts, between which they are said to keep up a communication, is unknown to us; so that there still remains a tract of country, at the least 30 degrees of latitude by 25 of longitude, or about 2,600,000 square geographical miles, of which nothing whatever is known. Now that the thirst for Arctic discovery has been quenched, and the public feeling has set strongly against expeditions to Central Africa, we trust that our government will be the first to engage in the exploration of the great table-land of Southern Africa. Having premised this short account of the general features of Africa, we shall now state what is known of its geology and mineralogy, following in our account the great natural divisions already pointed out. 1. Geology of the Atlas, or Northern Region of Africa.*— The northern division of Africa is principally characterized by the Atlas chain of mountain-ranges, on some of the loftiest points of which there is perpetual snow, which gives them a height of 12,000 to 13,000 feet above the level of The Egyptian, Abyssinian, and bordering African districts will be considered in one of the succeeding volumes of this work. the sea. In it there are rocks of the primitive class, as granite, gneiss, mica-slate, and clay-slate. Copper and lead mines, said to occur in the primitive parts of the range, were worked by the ancients in Morocco and Algiers, but are at present neglected; and the same is also the case with the antimony and tin (?) said to have been discovered in these mountains. In Tunis, rock-crystals, graphite, or black-lead, and also iron and galena, are met with in the same kinds of rock. Although in extensive mountainranges the older rocks, or those of the primitive class, generally predominate, such, according to travellers, is not the case with the Atlas, where the most extensive deposites are of a calcareous nature. This calcareous formation consists principally of secondary limestones, associated with deposites of sandstone. The limestone abounds with organic remains, as of shells, corals, and even fishes; and is said to be referable to the various limestones extending from the lias, or even the magnesian limestone, to chalk inclusive. Hence in this limestone-range there are magnesian limestones, oolite limestones, lias limestones, Jura limestones, and soft limestones resembling some kinds of chalk. Resting upon these limestones, or where they are wanting, as is the case at Algiers, there are deposites of tertiary rocks; these are marly clays and limestones, with organic remains resembling those met with in the tertiary deposites on the north shore of the Mediterranean. Salt springs and gypsum are mentioned as occurring in different parts of the range. These may be connected either with the secondary or tertiary, or with both classes of rocks. Trap-rocks, of a modern date, also make their appearance among the rocks of the northern African zone. The most extensive display of these Plutonian masses is in the limestone in some districts to the south of Tripoli, where these rocks alter the position and change the characters of the limestone. Age of the Atlas Mountains.-It is conjectured, by some geologists, that the great ranges of mountains of the earth have risen from below, through rents in previously existing strata, and not all at once, but at different times; and further, that all mountain ranges having the same general direction have made their appearance from below at the |