MOUNTAINS OF ECUADOR. 229 



from the interior of the mountain, whose explosions appear to alternate with those 

 of Cotopaxi. When one is agitated, the other, say the natives, is in repose ; thus 

 each of these vents would appear to become in its turn a sort of safety-valve for 

 the whole district. 



But of the two, Sangay is by far the more violent. From Guaranda, CO miles 

 distant, with the thickness of the plateau intervening, Whymper heard every 

 morning, always between seven and eight o'clock, a dry sound like the rattle of 

 musketry platoon-firing. In clear weather the cone is visible from the top of 

 Chimborazo to a height of about 4,000 feet, and from this point is ejected, at 

 intervals of 20 or 30 minutes, a jet of steam scarcely visible owing to its high 

 temperature, but rising to a height of some 6,000 feet. At this altitude it 

 expands into mushroom-like clouds with horizontal base, and then disperses south- 

 wards. Not a s]3eck is seen in the azure sky, when a fresh jet starts up, which 

 in its turn slowly dissolves in the same direction. Whymper calculates that 

 these jets are projected into space at a velocity of no less than 22 miles per 

 minute, while the southward drift shows the temporary, if not permanent exist- 

 ence of a current of air 22,000 to 23,000 feet above the sea, steadily setting due 

 north and south. From another eminence of the Quito Andes, Reiss saw the 

 outrush from the volcano, which was itself invisible. The vapour assumed the 

 aspect of a black column, rising like a prodigious tower above the horizon ; then, 

 under the influence of the trade wind, drifting away to the Pacific. 



From the top of Nagsangpungo, the "Mirador del Sangay" (13,235 feet), 

 Stiibel also obtained a near view of the smoking mountain. The mass of ashes 

 ejected by the crater during its explosions would appear to represent an enormous 

 cube equal in bulk to several large mountains. The country round about is 

 covered to a great thickness with a grey dust, while the shifting dunes of this 

 volcanic ash attain a height of over 300 feet. At times the rocky surface is swept 

 by furious gales, revealing the mica-schist escarpments which form the primitive 

 backbone of the cordillera. At times scoriae are wafted from Sangay as far as 

 Guayaquil, and on the plateau the pastures are often poisoned by the fall of 

 volcanic dust. Patches of fresh snow are formed round the edge of the crater, 

 and the ravines radiating from the upper cone are filled with blackened glaciers. 

 Lava-streams also overflow down to the virgin forests clothing the eastern slof»es 

 facing the Amazons basin. Stiibel assures us that the Indians of Macas see 

 these rivers of fire for years together lighting wp the western horizon during the 

 night. The earthquake which destroyed Hiobamba in 1797 is said to have been 

 propagated from beneath Sangay. 



South of this volcano the Eastern Cordillera, though interrupted by the 

 valley of the Rio Paute, is still dominated by a few lofty summits, such as 

 Quinoaloma and, farther on, the mountains with which is connected the transverse 

 Azuay or Pucaloma ridge. It was recently supposed, on the authority of Hum- 

 boldt, that no volcanic formations occurred farther south than this group, and 

 that the mountaii)s of the surrounding region consisted of sedimentary rocks. 

 But such is not the case. Reiss and Wolf have determined the existence of old 



