330 THE POPULAR SCIENCE MONTHLY. 



Dilolo, a small body of water, reached February 20, 1854, is the source 

 of the Lceba. It was only on his return that Livingstone ascertained 

 this. But the courses taken by the different streams he crossed struck 

 him; and the observations he made on his journey back impressing 

 him with the conviction that the Dilolo country was the water-shed of 

 the streams running east and west, led him to confirm the theory of 

 Sir R. Murchison, of which he had not heard at the time, that the form 

 of the interior of the South African Continent is that of an elevated, 

 saucer-shaped plateau. In other words, that the country is gi-adually 

 depressed toward its centre, sloping from an inner environing moun- 

 tain-ridge toward which the land rises from the coast. The western 

 ridge was crossed at a spot called Tala Mungongo, lat. 9 42' 31" S., 

 and, by carefully noticing the course of the various streams flowing 

 thence to the centre, and forming his judgment from what Arab trad- 

 ers had told him subsequently confirmed by his own observation 

 that the rivers set inland from a similar ridge on the eastern side of 

 the continent, the conclusion forced itself on Livingstone's mind, that 

 these river systems, uniting at last, pass out to the north and south in 

 two main drains ; the northern finding its way to the Atlantic as the 

 Congo on the west coast, and the southern to the Indian Ocean as the 

 Zambesi on the east. The configuration of the oountry alluded to will 

 account for the course of the Leeba from the lake being about S. E., 

 while the Leeambye joins it flowing west from the eastern ridge of the 

 central plateau. But Livingstone also speaks confidently of " a sort 

 of elevated partition in the great longitudinal valley " between the 

 latitudes about 6 and 12 S. It would not be fair to him to suppress 

 the fact that, considering this peculiar configuration of the country, 

 and hearing: from some Zanzibar Arabs of the existence of a lake Tan- 

 ganyenka (Tanganyika) and Nyanja (Nyassa) to the east of Londa 

 where he then was, he was led to the probable conjecture that the 

 res-ion about them would be found to be the water-shed of the Nile to 

 the north, as it was that of the Zambesi to the south. Thus his saga- 

 city brought him to anticipate the existence of facts which have since 

 been confirmed by the travels of Burton, Speke, and Grant, and Sir S. 

 Baker ; and which only remain to be thoroughly investigated and de- 

 fined in the completion of those researches the exciting story of whose 

 partial accomplishment we have recently heard. 



A few words must dispose of Livingstone's westward journey. 

 Passing various tribes as he wends along, chiefly on oxback, accompa- 

 nied by his faithful Makololo, he encounters no opposition, but the con- 

 trary, till he enters the territory of the Chiboque. There, however, 

 he gets on the track of the Mambari, or half-caste Portuguese slave- 

 traders, from whom the native chiefs exacted heavy tribute, and the 

 hostilities with which he is threatened, on his stanch refusal to submit 

 to their impositions, were avoided simply by his firmness and tact. 

 On his arrival at Loando, May 31, 1854, he was well received by the 



