22 SOUTH AMERICA— THE ANDES REGIONS. 



places by shingle, in others by fresb-fallen snow, denied their existence in these 

 tropical Alpine regions. But he was mistaken, as the observations of Whymper 

 have clearly shown. Certain great igneous cones in the Quito district have their 

 circular snowfields frmged with as many as fifteen glaciers, scored by crevasses, 

 furnished with lateral and frontal moraines like those of the European Alps. 



In the Bolivian Andes, Illimani has also its frozen rivers, and in Chili the 

 rapid lowering of the snow-lines corresponds with the appearance of numerous 

 glaciers. South of the 35th parallel every upland coomb receives its crystal 

 stream descending lower and lower towards sea-level. In the inner channels of 

 the Magellanic archipelago, a glacier may be seen issuing from every valley on 

 the mainland. Towards the southernmost point of the continent the crystalline 

 masses at last reach the seashore, where they break away in small blocks which 

 arc borne northwards by the marine current. 



YOLCANOES. 



The Andes belong to those orographic systems in which numerous volcanoes 

 have cropped out through rocks of a different formation. Nevertheless, the sub- 

 terranean fires have not found "safety valves" along the entire length of the 

 chain between the Caribbean Sea and the Strait of Magellan. On the mainland 

 the craters are grouped in three great clusters, those of Colombia and Ecuador in 

 the north, of Bolivia in the centre, and of southern Chili in the south. At least 

 sixty still active cones rise above the Andean axis, and hundreds of others now 

 quiescent formerly shared in the work of eruption. 



The line of igneous crests is even continued beyond the Fuegian archipelago, 

 away to the Antarctic lands, where navigators have seen the clouds aglow with the 

 flames issuing from burning mountains. West of the South American coast, and 

 under the same latitude as the volcanoes of Ecuador, the Galapagos Islands form 

 a short chain surging, as it were, above abysmal waters some 1,500 fathoms deep. 



But east of the Andes along the prolonged axis of the Antilles, the South 

 American continent has not a single eruptive cone. Here the igneous distur- 

 bances appear to be arrested at Trinidad and the opposite coast of Venezuela, 

 where the oil wells and mud volcanoes may perhaps stand in some relation with 

 the underground forces. 



In this respect the contrast is certainly very marked between the two sections 

 of the continent, the Andean region and that of the Guianas and Brazil. In the 

 former the planetary life manifests itself with the greater energy, and this section 

 is also the younger of the two. Formed in more recent geological epochs, it has 

 not yet completed its upward movement. The several ranges, however, appear to 

 have been upheaved in an extremely irregular manner, and some of the loftiest 

 crests are amongst those whose origin dates from comparatively modern ages. 



The Eastern Orographic System. 



Taken as a whole, the Andine crests rose above the ocean during geological 

 periods later than those that witnessed the birth of the eastern uplands in the 



