576 The Andes and the Amazons. 



rose immediately above, appearing very huge, but not very 

 high. The border of the crater showed itself as a broad 

 line, with a lofty rock on the north end, and another on 

 the south. An immense stream of lava came down the 

 cone, and near the place of encampment divided, entering 

 the two quebradas, or ravines, mentioned. The lava was 

 still warm, clouds of vapor rising along the whole extent 

 o^ the stream. During the afternoon the thermometer 

 had stood at freezing-point ; but in the night it fell to 25°. 

 The next day Dr. Eeiss attained all his hopes. The 

 top stood out clear, while at his feet the accumulated 

 clouds looked like a sea of cotton wrapping the mount- 

 ain up to the altitude of 12,000 feet, leaving here and 

 there an islanded peak or promontory. Cropping out of 

 the lava-stream, but mainly disposed along the borders of 

 it, were numerous rough stones, upon which he advanced 

 as on the rounds of a ladder. The greatest width of the 

 lava current before it divided was about 3000 feet, and 

 the estimated thickness 150 feet. The lava was entirely 

 black and warm in all its course ; its temperature being 

 from 68° to 91°, while that of the atmosphere was 32°. 

 This elevated temperature explains the absence of snow on 

 this part of the slope. The gaseous exhalations from the 

 crevices seemed to be nothing more than air mixed with 

 vapor. This is doubtless the lava-stream -which flowed in 

 1854:, and which, by melting vast quantities of snow, 

 caused much devastation in the valley by floods. These 

 sudden floods, caused by fresh eruptions of lava on the 

 mountain side, are the terror of the villages at the foot of 

 Cotopaxi. Sometimes, however, the cone, especially on 

 the east side, appears black, owing not to absence of snow, 

 but to a covering of black ashes. No fissure or accumu- 

 lation of scoriae indicates the source of the lava-stream. 

 But the altitude of the point of departure is 18,700 feet. 



