HYDEOGKAPHY OF PEEU. 



291 



tere and there by the so-called " Incas' bridges," the Maranon is eoon tripled in 

 volume by the Napo, from the slopes of the Cordillera, below the confluence of 

 which ic trends north-west as if to fall into Guayaquil bay. For a distance of 

 nearly 600 miles it continues to traverse the deep longitudinal valley of the 

 Andes, swollen by a lateral torrent at every gorge opening from the mountains on 



Fig. 112. — PoNGO DE Manseeiche. 

 Scale 1 : 1,000,000. 



Gold-mines. 



25 Miles. 



both banks. Here again the narrows are spanned by suspension bridges made of 

 huaros, oroyas, or other lianas, though most of the tracks on the opposite sides are 

 connected only by balsas, or rafts formed by three or four trunks of trees firmly 

 lashed together and boarded over. All these ferries are called puertos, " ports " or 

 "harbours," like those on the seaboard. 



