226 SOUTH AMERICA— THE ANDES REGIONS. 



shoulder or on any lateral crevasse, but on its summit, a large crater, which is 

 still in constant commotion. At all epochs since the arrival of the white man in 

 the country, history speaks of its eruptions. 



The great disturbances, which take place at intervals of centuries, are dreaded 

 far more for their torrents of mud than for their showers of stones. In 1877 the 

 deluge of slush, water, ice, and rocks rushed down to the plains with a velocity of 

 over half a mile a minute, sweeping away houses, bridges, and all other obstacles 

 along its passage, and reaching the sea 280 miles distant on the very day of 

 the eruption. The catastrophe had been heralded the day before by a huge column 

 of black ashes which was projected to a height of 18,000 feet above the crater, 

 and which, swaying with the east wind, was diffused widely over the Pacific. 

 The steamships plying along the coast between Guayaquil and Panama found 

 themselves suddenly wrapped in the darkness caused by the dense clouds of dust, 

 and when the black shroud was lifted streams of molten red lava were seen boiling 

 over the rim of the crater, melting the ice and snows and suddenly changing them 

 to avalanches of mud and slush. Blocks of ice transported to the Latacunga 

 plain, 30 miles away, remained on the ground for months, while the summit of 

 the volcano, usually white with snow, became black and calcined except at some 

 points left like islands amid the boiling sea of lavas. On previous occasions 

 Cotopaxi belched forth flames which, according to La Condamine, shot up in 

 1743-4 to a height of at least 2,000 feet above the top of the mountain. 



Cotopaxi, the flanks of which were figured by Humboldt with an exaggerated 

 incline of about 50°, has a mean slope of not more than 30*^ on the north and 

 south, and 32° on the east and west sides. Hence it may easily be scaled by 

 climbers capable of resisting mountain-sickness. Moritz Wagner had to retrace 

 his steps in 1858, but several have succeeded since the ascent of Reiss in 1872; 

 and Whymper passed a whole night on the edge of the terminal crater in order 

 to study the physiological effects of rarefaction on the human organism at an 

 altitude of nearly 20,000 feet. 



The surface heat was very perceptible on the outer wall of the crater, where 

 the snow melted in manj^ places as it fell. Consequently everj' snowfall was fol- 

 lowed by vapours ascending in puffs from the slopes of the volcano, which seemed 

 to smoke as if in a state of combustion. Nevertheless, a few narrow glaciers were 

 formed in the ravines round about the cone, and these were here and there covered 

 and blackened by a layer of volcanic scoriae. 



" At intervals of about half an hour the volcano regularly blew off steam. It 

 rose in jets with great violence from the bottom of the crater, and boiled over the 

 lip, continually enveloping us. The noise on these occasions resembled that which 

 we hear when a large ocean steamer is blowing off steam. It appeared to be pure, 

 and we saw nothing thrown out ; yet in the morning the tent was almost black 

 with matter which had been ejected. Steam unquestionably plays a leading part 

 ill the operations of Cotopaxi, and sometimes the quantity that issues is enormous. 

 One morning in the following April, when encamped, at the height of 14,760 

 feet, onCayambe, at a distance of about 60 miles to the north-north-east, just after 



