Chap. XX. RIVEIl SYSTEMS. 413 



but it runs, according to wbat I heard, from a north- 

 east direction ; the latter from a south-east direction. 

 The Ngouyai I had seen and crossed in my journey 

 to the Apingi country. My further explorations this 

 time have led me higher up the stream, and proved 

 that my former conclusions were correct. 



These two rivers are the only ones that break 

 through the coast chains of mountains, and thus we 

 must not wonder at the tremendous amount of water 

 they throw into the sea, in despite of the enormous 

 absorj^tion by radiation, when we consider the very 

 great amount of rain falling in the interior. 



Between the Niger and the Congo there is no 

 river that brings down such a quantity of water as 

 the Ogobai. The enormous amount of rain that falls 

 in these equatorial regions will account at once for 

 the greater volume of water of this river, which 

 has a far greater basin than all the other rivers 

 between the Congo and the Niger. 



The first table-lands of the interior gradually slop- 

 ing down eastward, form a valley. In this valley 

 from the north-east the Eembo Okanda glides gra- 

 dually southward, increasing by numerous streams 

 until it unites with the Rembo Ngouyai. I have 

 heard that the Okanda has several rapids. 



The Rembo Ngouyai comes from the south-east, and 

 flows northward, gradually increasing by its tributa- 

 ries ; it breaks through the range of mountains, forms 

 a series of falls and rapids, unites with the Olcanda, 

 and then the two rivers take the name of Ogobai. 



Going eastward in my present journey the land 

 rose higher and higher until we reached Niembouai 



