renewed, was resisted with a still more decided success; and since that time no farther hostilities have occurred. On the 20th February, the settlement was named, not perhaps in very good taste, Liberia, and the town Monrovia. A political constitution was formed, according to which the agent is to exercise the sovereign authority, subject to the directions of the Board; but the colonists were secured in equal rights, and in such privileges as might prepare them ultimately to govern themselves in a manner entirely independent. No white person is allowed to become a resident, the establishment being destined solely for the benefit of free men of colour. As the territory originally occupied was found too small for the growing population, they purchased more land on the river St Paul. Successive acquisitions have been since made, and eight stations established in an extent of about 150 miles along the coast, from Cape Mount to Trade Town. These are named Cape Mount, St Paul, Bushrod-island, Junk, John Factory, Rob Gruis Factory, and Young Sister. The entire population, which, in 1827, was 1200, had risen in 1830 to 1500. The inhabitants of Monrovia amount to about 700. Since that time no detailed accounts, so far as we know, have been laid before the public. We understand, however, from various quarters, and particularly from Sir James Alexander and Mr Laird, that the colony has not made the expected progress, and is at present in rather an unprosperous condition. Neither the climate nor soil has been found so favourable as was at first supposed, and few advantages are afforded for penetrating into the interior. In the United States, too, the Abolition Society has opposed the whole scheme, making it their aim to improve the condition of the negroes at home rather than to remove them. We have, however, been informed by some intelligent Americans that their endeavours to stop colonization are condemned by a numerous party, who contemplate the renewal of the measure on an extended scale. But we are not aware that any means are yet in operation for this purpose. GEOLOGY AND MINERALOGY. CHAPTER XIX. Geology and Mineralogy of Africa.* Form and Situation of Africa-Its great Natural Regions or Divisions. 1. Geology of the Atlas or Northern Region-Age of the Atlas Mountains.-2. Geology of the Sahara Region-Subterranean Villages near Tripoli; in Spain and France-Tertiary Rocks of Benioleed-Soudan, or Black Mountains-Petrified Wood in the Desert-Horrid Consequences of the Slave-trade-Human Skeletons in the Desert-Natron and Salt Lakes-Desert of Bilma-Sultan of Fezzan and a Slave-On what Formation does the Sand of the Desert rest?-Description of a Trona or Natron Lake-Fulgurite and Native Meteoric Iron in the DesertObservations on the Sand of the Desert-Moving Pillars of Sand-Sandwind-How the prevailing Winds affect the Sand of the Desert-What is the Geognostical Age of the Sahara ?-3. Geology of the Region to the South of the Sahara, and to the North of the Great Table-land-African Gold.-4. Geology of the Great Table-land of Africa-Geology of the Coast from Sierra Leone to Cape Negro-Cape of Good Hope DistrictDistribution of its Chains of Mountains, Plains, and Valleys or Kloofs --Description of the Karroo Plains-Geognosy of the Peninsula of the Cape of Good Hope-The Lion's Rump-Lion's Head-Table Mountain -Devil's Peak-To what Class of Rocks do those of the Cape Peninsula belong?-At what Period did the Cape Rocks rise above the level of the Sea?-Vegetables incrusted with Calcareous Sand confounded with Coral, and adduced as a Proof of the very recent Emergence from the Ocean of the Land supporting them-Geology of the Table-land properly so called -Account of the Sibilo of the Africans-Geological Survey of the Karroo Ground recommended-Rivers-South African Lakes-South African Springs-Remarks on the Importance of a Knowledge of the Natural History and Chemical Composition of Springs-Geology of Caffraria, Natal, &c.-Conclusion. 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 Lagullas, in lat. 34° 55′ S.; and the greatest breadth from Cape Verd, in long. 17° 31' W., to Cape Guardafui, in long. 51° 15′ E. The northern portion of this con *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. tinent 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 oases,* that extend from the termination of the Atlas to Egypt.+ 2. The Eastern Region formed by Egypt, Abyssinia, Darfur, &c. 3. The Desert Region, which is the flat, comparatively low tract of generally desert country, of which the principal portion is the Great Desert or 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 con *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 Cæsars 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. tain 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 the 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. 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 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 mountain-ranges 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 ex The Egyptian, Abyssinian, and bordering African districts, are considered in subsequent volumes of this work. tensive 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 same time. Thus the Pyrenees and Apennines, the mountains of Dalmatia and Croatia, and the Carpathians, which belong to the same system,-as may be deduced from the descriptions given of them by various geologists,-are all disposed parallel to an arc of a great circle, which passes through Natchez and the mouth of the Persian Gulf. Thus, whatever may have been the cause, the mountains in Europe, which have issued from the earth at the same period, form chains at the surface of the globe, that is to say, longitudinal projections, all parallel to a certain circle of the sphere. If we suppose, as is natural, that this rule may be applicable beyond the limits within which it has been determined, the Alleghanies of North America, since their direction is also parallel to the great circle which joins Natchez and the Persian Gulf,-would seem to belong, in respect to date, to the Pyrenean system. Elie Beaumont has been able to verify the accuracy of this inference by a careful examination of the descriptions of American geologists. It would appear from this statement, that we might venture to conclude that the mountains of Greece, the mountains situated to the north of the Euphrates, and the chain of Ghauts in India, which also come under this condition of parallelism already indicated, must have risen, like the Alleghanies, along with the Pyrenees and Apennines. If we apply this reasoning to the Atlas, which we find to have the same general direction as the Alps of Switzerland, from the Valais to Styria, and with that of the Caucasus, the Balkan Mountains, and the Himmaleh Mountains, we infer that these vast ranges, and also the Atlas, may have risen at the same period. But at what period did this elevation take place? This can be answered in a general way, by remarking, that in Switzerland the principal chain of the Alps appears to have upraised all the secondary, and also the tertiary strata; hence, according to the opinion already stated, these Swiss mountains, and consequently the Atlas and other ranges already mentioned, may have risen from below at a comparatively recent period, after the deposition of the tertiary rocks. Allowing this hypothesis to be plausible, it could be shown that an opinion of the ancients, that, namely, which maintains that the whole country between the Syrtis and the Atlantic, over which the Atlas chain extends, was formerly insulated, and in that state formed the celebrated Atlantis,-is not destitute of geological probability.* * The particular geology of the Northern Region, which includes de |