HYDEOGEAPHY OF PEEU. 



295 



direction from south-east to north-west, enclosing right and left the Carabaya 

 Andes and their prolongations. 



A well-marked parting-line between two perfectly distinct fluvial systems is 

 indicated by the confluence of the Tambo with the Quillabamba at an elevation of 

 860 feet above sea-level. Above the confluence the streams are in the nature of 

 mountain torrents, rushing wildly between their rocky walls, or disappearing in 

 deep romantic gorges ; below the mainstream flows sluggishly in a broad winding- 

 channel, whose banks are everywhere covered with continuous forest growths. In 



Fig. 115. — Mantaeo, Pampas and Apurimac Valleys. 

 Scale 1 : 2,000,000. 





WesLoh Gre 



this section of its course the Ucayali, still within the political frontiers of Peru, 

 although presenting the normal aspect of the Brazilian rivers, is joined by only 

 one considerable affluent, the Pachitea, which is swollen by the Palcazu, and, like 

 the Perene, appears destined to become one of the main commercial highways 

 of Peru. 



All these watercourses descending to the Ucayali and to the Huallaga have 

 been the object of numerous hydrographie surveys by Tucker, Werthemann and 

 other engineers in the service of Peru. At the Mantaro confluence the Apurimac 

 has a mean discharge of about 42,000 cubic feet per second. 



