282 SOUTH AMERICA— THE ANDES REGIONS. 



East of lea the Cordillera ramifies into two branches. The scarp of the 

 plateau continues its south-easterly trend parallel with the coast, while the inter- 

 Andean space is traversed by a connecting ridge, which usually takes the name 

 of the Vilcanota knot. This series of meandering heights, however, is not a true 

 Cordillera ; it deviates from the normal direction of the sj^stem, and is, in fact, 

 merely a divide, left uneroded between two drainage areas — on one side the 

 Amazonian slope with the thousand sources of the Apurimac and Urubamba ; on 

 the other the Pacific slope, divided into several secondary basins by numerous 

 long but waterless gorges furrowing the whole face of the outer cordillera with 

 deep fissures. 



The chief summits of the water-parting rise along the southern prolongation 

 of the Andean ranges here eroded by the running waters. Thus, Vilcanota 

 (17,390 feet), which gives its name to the whole divide, stands exactly in a line 

 with the axis of the main Andean range. Azungato, also south-east of Cuzco, 

 from which its snowy peak is visible glittering in the sun, lies in the normal 

 direction of another Andean crest. 



The Southern Cordilleras. 



In its southern section the Western Cordillera is distinguished from the other 

 Peruvian chains by the presence of igneous cones, which make their appearance 

 at a distance of about 1,240 miles from those of Ecuador. Their appearance may 

 perhaps be a recent phenomenon analogous to the formation of the fluvial valleys 

 which rise farther east, and which continue to traverse the range, despite the 

 barriers of molten matter by which they must have often been obstructed. 



The MiSTi and Omate Volcanoes. 



The first group of these volcanoes, all exceeding 13,000 feet — Sara-Sara, 

 Achatayhua, Coro Puna (comparable to Chimborazo in the extent of its snow- 

 fields and the beauty of its crest), Ampato, Chachani (19,820 feet) — are all 

 quiescent and snow-clad for a great part of the year, or even permanently. The 

 famous Misti (Sucahuaya), whose superb snow-streaked cone rises immediately to 

 the north-east of the Arequipa plain, owes its celebrity more to its imposing 

 aspect and conspicuous position on the great Bolivian trade route rather than 

 to its geological importance and altitude, though this is considerable enough 

 (18,500 feet). 



From time immemorial Misti has been in repose, and at present its crater 

 contains nothing but ashes and snow. Yet from this focus appear to be pro- 

 pagated the earthquakes from which Arequipa has so often suffered, and by which 

 it was almost entirely destroyed in 1868. Misti was first ascended by "VVeddell in 

 1847, and since that time the exploit has been often repeated, but always on the 

 north side, facing Chachani. Ryder and Pothwell perished in the attempt to scale 

 it on the west side in order to explore its crevasses. Henceforth, Misti cannot 



