414 PHYSICAL GEOGRAPHY AND CLBIATE. Chap. XX. 



Olomba ; it then sloped gradually towards tlie east, 

 with small streams running in that direction, and 

 flowing no doubt towards the large river mentioned 

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

 one of its larcre tributaries. I should think that it 

 was about two degrees further eastward, somewhere 

 about 15° or IG"" east longitude. 



After I had drawn attention to the great basin of 

 the Ogobai, the attention of tlie French Government 

 was attracted towards it, and two expeditions have been 

 made ; one in the 3^ear 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 m<ade 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 l^r. Barth 

 had done me the honour to map the furthest 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 Ngouj-ai, 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 

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

 observations while at Olenda; but at Mayolo 1 took a great number of 

 observations of lunar distances, and the longitude of this place mi^y there- 

 fore be considered as well determined. 



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

 between ranges of hills. 



