318 COSMOS. 



Hambato, and Riobamba. The small knot of mountains of the 

 Altos of Chisinche separates the two basins like a dam ; and, 

 what is remarkable enough, considering its smallness, the 

 waters of the northern slope of Chisinche pass by the Rios 

 de San Pedro, de Pito, and de Guallabamba into the Pacific, 

 while those of the southern declivity flow through the Rio 

 Alaques and the Rio de San Felipe into the Amazons and 

 Atlantic Ocean. The union of the Cordilleras by mountain 

 knots and dikes (sometimes low, like the Altos just mention- 

 ed ; sometimes equal to Mont Blanc in height, as on the road 

 over the Paso del Assuay) appears to be a more recent and 

 also a less important phenomenon than the upheaval of the 

 divided parallel mountain chain itself. As Cotopaxi, the 

 greatest of the volcanoes of Quito, presents much analogy in 

 its trachytic rock with the Antisana, so also we again meet 

 with the rows of blocks (lines of fragments) which have al- 

 ready occupied us so long, even in greater number upon the 

 slopes of Cotopaxi. 



It was especially our business, when traveling, to trace 

 these rows to their origin, or rather to the point where they 

 arc concealed beneath the perpetual covering of snow. We 

 ascended upon the southwestern declivity of the volcano from 

 Mulalo (Mulahalo), along the Rio Alaques, which is formed 

 of the Rio de los Banos, and the Rio Barrancas, up to Pan- 

 sache (12,066 feet), where we inhabited the spacious Casa 

 del Paramo in the grassy plain (El Pajonal). Although up 

 to this time much snow had fallen at night, we nevertheless 

 got to the eastward of the celebrated Cabeza clel Inga, first 

 into the Quebrada and Reventazon de lasMinas, and after- 

 ward still farther to the east, over the Alto de Suniguaicu, 

 to the chasm of the Lion Mountain (Puma-Urcu), where the 

 barometer only showed an elevation of 2263 toises, or 14,471 

 feet. Another line of fragments, which, however we only 

 saw from a distance, has moved from the eastern part of the 

 snow-clad ash-cone toward the Rio Negro (an affluent of the 

 Amazon) and Valle vicioso. It is uncertain whether these 

 blocks were all thrown out of the crater at the summit to a 

 great height in the air, as glowing, scoriaceous masses fused 

 only at the edges (some angular, some rounded, of six or 

 eight feet in diameter, rarely conchoidal like those of Anti- 

 sana), falling on the declivity of Cotopaxi, and hastened in 

 their movement by the rush of the melted snow-water ; or 

 whether, without passing through the air they were forced out 

 through lateral fissures of the volcano, as the word revcnta- 



