414 THYSICAL GEOGEAPHY AND CLIMATE. Chap. XX. 



Olomba ; it then sloped gradually towards tlie east, 

 with small streams running in that direction, and 

 flowing no doubt towards tJie large river mentioned 

 by the natives — a river that may be the Congo, or 

 one of its large tributaries. I should think that it 

 was about two degrees further eastward, somewhere 

 about 15° or 16° east longitude. 



After I had drawn attention to the great basin of 

 the Ogobai, the attention of the French Government 

 was attracted towards it, and two expeditions have been 

 made ; one in the year 1862, and -the other in 1864. 



Unfortunately the two expeditions chose the worst 

 time of the year for their errand^ the dry season, 

 when the rivers are shallow and full of banks. 



The first expedition did not reach the junction 

 of the Okanda and the Ngouyai ; but afterwards, 

 M. Serval, whose enterprise is an honour to the 

 French navy, from the Upper Gaboon crossed by 

 land to the Ogobai, and reached a point not far from 

 the junction.* 



* The map made by M. Serval appeared after I had started a second 

 time for Africa, and was sent to me by my friend M. V. A. Malte-Brun, 

 with a kind letter saying how glad he was that I was vindicated; for 

 some people had said in England that I had gone nowhere, and Dr. Barth 

 had done me the honour to map the ftirthest parts of my exploration as 

 only a few miles into the interior. 



I have not seen Eliva Olanga, called by Serval, Eliva Jonanga. When 

 at the Falls of Ngouyai, I heard that it was on the other side of the Ashan- 

 kolo mountains. With regard to latitude, its position would agree with 

 my map, but my astronomical observations for longitude put it more to the 

 Avcstward than M. Serval does. I should not trust, perhaps, entirely to my 

 observations while at Olenda; but at Mayolo I took a great number of 

 observations of lunar distances, and the longitude of this place may there- 

 fore be considered as well determined. 



An eliva is not properly a lake, but really a broad extension of a river 

 between ranges of hills. 



