Senhor Graça visited Matiamvo. If I knew that any one else had done more, or that any European had ever before crossed the continent, I would certainly mention it'. I cannot find a trace of a road from Caconda either."

The historical results of these labours and triumphs are necessarily future. Already some pages are added to authentic history by what he has done. Half a century hence will probably revolutionize the records of the African continent, and of the race of Ham, as a direct consequence of these labours. It were idle to speculate as to what these results may be. We have every reason to conclude that, sooner or later, AFRICA WILL BE IMMEASURABLY RAISED IN THE SCALE OF THE HUMAN FAMILY; GENERAL SCIENCE AND COMMERCE THEREIN EXTENDED; THE SLAVE-TRADE DESTROYED; AND THE GLORIOUS STANDARD OF THE GOSPEL OF PEACE PLANTED WHERE HEATHENISM NOW REIGNS.

SECTION II.-Dr Livingstone's Labours, Explorations and Discoveries considered as to their extent and results in their SCIENTIFIC ASPECT.

"And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith." Eccles. i. 13.

THE subjects embraced in this section are so vast, that we have to be mindful of suggesting principles rather than of giving detail. It is thought well to arrange these materials under those heads which occur the most obviously in connexion with this scientific aspect.

It must be remembered that the information here given refers in particular to the new regions traversed by Dr Livingstone, and not to Africa in general.

1 See Mr Macqueen's Papers, Royal Geographical Society's Journal, Vol. XXVI.

GEOGRAPHY.

"The earth is the Lord's, and the fulness thereof." Psalm xxiv. 1.

In this science henceforth the map of Africa is greatly altered; the immense sandy plains of some philosophers speculating at home, in which rivers were asserted to be lost, and no life, animate or inanimate, was declared to flourish, are proved by our traveller to exist only in the fertile brains of those worthies; while facts replace these plains with peopled and productive regions.

The following theories propounded by celebrated men, will, when compared with Dr Livingstone's revelations, prove the undoubted superiority of fact over theory.

Buffon imagined that central Africa consists of great longitudinal chains of mountains.

Lacépède so far refined on this idea, as to lay down these chains; and gravely to belt them with fiery girdles of sand. Malte-Brun doubted these assertions.

Professor Ritter advanced a theory singularly in accordance with the facts evolved. by Sir R. I. Murchison, from geological data, and proved by Dr Livingstone from actual observation. We will now discuss these facts.

South Africa an oblong basin, with depressed centre and raised sides.

This is one of the most interesting features of Dr Livingstone's discoveries. Sir R. I. Murchison's great inductive feat in connexion with this fact puts one in mind as an inductive effort, of Mr Adams' celebrated à priori demonstration of the position of the planet Neptune. The former gentleman, in a presidential address to the members of the Royal Geographical Society, in 1852, stated his conviction that central South Africa is a depressed plateau, having elevated ridges running down the eastern and western coasts'.

1 The following is the passage occurring in this address:-"Such as South Africa is now, such have been her main features during countless past ages, anterior to the creation of the human race. For the old rocks

geological map of Mr Bain, and some former discoveries of Dr Livingstone and Mr Oswell, were probably the germ of this idea. Dr Livingstone at this time was in central Africa, far away from all communication with Europeans. He by observation arrived independently at the same conclusion, and on reaching Linyanti, on his return from Loanda, received Sir R. I. Murchison's demonstration in the box sent him by Mr Moffat. The notice of the following facts first led him to arrive at the same conclusion. In passing northwards to Angola, the presence of large Cape heaths, rhododendrons, Alpine roses, and especially the sudden descent into the valley of the Quango, near Cassangé, led him to believe that they had been travelling on an elevated plateau. This conviction was confirmed by observations made with a thermometer and boiling water, whereby he took altitudes at various points1. Moreover, he found that several rivers which

which form her outer fringe, unquestionably circled round an interior marshy or lacustrine country, in which the Dicynodon flourished, at a time when not a single animal was similar to any living thing which now inhabits the surface of our globe. The present central and meridian zone of waters, whether lakes or marshes, extending from Lake Chád to Lake Ngami, with hippopotami on their banks, are therefore but the great modern residual geographical phenomena of those of a mesozoic age. The differences, however, between the geological past of Africa and her present state, are enormous. Since that primeval time, the lands have been much elevated above the sea-level-eruptive rocks piercing in parts through them; deep rents and defiles have been suddenly formed in the subtending ridges through which some rivers escape outwards.

"Travellers will eventually ascertain whether the basin-shaped structure, which is here announced as having been the great feature of the most ancient, as it is of the actual geography of South Africa (i. e. from primeval times to the present day), does, or does not, extend into Northern Africa. Looking at that much broader portion of the continent, we have some reason to surmise that the higher mountains also form, in a general sense, its flanks only.”—p. cxxiii. President's Address, Royal Geographical Society, 1852.

1 Letter, dated Linyanti.

rise in this western ridge, run towards the centre of the continent. With reference to the opposite eastern ridge, in the letter dated Hill Chanyuné, 25 Jan. 1856, he says, "That the same formation exists on the eastern side of the country appears from the statements of Arabs, or Moors, from Zanzibar. They assert that a large branch of the Leeambye flows from the country of the Banyassa (Wun'yassa) to the south-west, and passes near the town of Cagembé; it is called Loapola."

From the longitudes he estimates the distance from top to top of these ridges to be about 600 geographical miles.

In the letter last quoted he further says, "The eastern ridge seems to bend in to the west at the part I crossed, and then travels away to the north-east, thereby approaching the east coast. If the space between the ridges is generally not broader than 600 miles, instead of calling the continent basin-shaped, it may be proper to say that it has a furrow in the middle, with an elevated ridge on each side, each about 150 or 200 miles broad, the land sloping on both sides thence to the sea." This watery central plateau is elevated above the level of the sea, at the same time that it is below the subtending eastern and western ridges.

These facts at once account for the apparent impossibility of rivers running in opposite directions. A stream which has its origin in one of the ridges may run down inland; while another main artery may be carrying off the water-shed of the central plateau in a zigzag, and find an outlet through some gorge into the ocean. For instance, the branch of the Leeambye here mentioned runs south-west, while the Leeambye itself flows due east, or south-east. The Coanzo and Quango flow from west to east towards the centre of the continent; while the northern Lotembwa runs N.N.W. The one set runs from the ridge to the plateau; the other from the plateau to the ocean.

Henceforth travellers in South Africa may at once probably know where to look for the source of a river, by observing the general direction of its current.

The country about Lake Dilolo seems to form a partition

in the basin; hence the contrary direction of its drainage to the east and west. It appears to be a correct conclusion that the rivers rising in both ridges become collected into two great drains in the central trough, the one flowing to the north, and the other to the south; the northern drain finding its way out by the Congo to the west, and the southern by the Zambesi to the east.

The KALAHARI DESERT.

p.

This desert has been partly described in the Lectures. See 146. It extends from Lake Ngami to lat. 29° south; and from 24° east long. to the west coast. It contains no running water, and but few wells. Great quantities of grass and tuberous roots grow on it. It is not by any means useless as a tract of country, sup porting much animal life; but it is dangerous from its great want of water. Dr Livingstone, with Mrs Livingstone and family, crossed it to Lake Ngami, in 1849, accompanied by Messrs Oswell and Murray. Several large salt-pans are found in it; and the mirage sometimes appears on its horizon with great perfection. It is covered with large quantities of grass, and a great variety of creeping plants, together with bushes and trees. The soil is soft light-coloured sand, nearly pure silica, with alluvial mould in the ancient river-beds. The animals found in this desert are elephants, lions, leopards, panthers, hyenas, goats, jackals, dogs, cats, antelopes, and the rhinoceros.

This desert has been for ages a refuge for oppressed and fugitive tribes. It is remarkable for little rain, and yet abundant vegetation.

LAKES and RIVERS.

According to Sir R. I. Murchison's geological demonstrations, and to Dr Livingstone's observations, central South Africa was, ages ago, almost one vast lake. The lakes now remaining are residua of this; while the great rivers, such as the Zambesi, are the natural drains of the great central plateau, the bed of the former lake system. Our traveller considers that the drain was commenced when the fissures were made at the Victoria Falls,