J. Orton on the Andes of Ecuador. 247 
Porous trachyte, with augite crystals, (common.) 
Porphyroid trachyte, dark base, e 
* “= reddish, 
“c “ ; TA , 
Very compact sconk-ei gray, 
Sulphur, seen only in the crater, where it is abundant 
either pure or forming a conglomerate with cinders, “ 
grained trachyte, iron-stained, rare.) 
Porous, granular trachyte, iron-stained, “9 
Soft, friable trachyte, yellowish, 
Fine-grained, decaying trachyte, with seams of flint, 
orphyroid trachyte, disintegrating, 
Granular trachyte, ” 
Thirty-five miles 8.E. of Pichincha is the extinct volcano 
of Antisana, loftier than Cotopaxi, and overtopped only by 
Chimborazo and Cayambi. Humboldt mentions three lava 
. e discovered a fourth on the north side, reaching 
“é 
that the rock is porous and perhaps cavernous. In the same 
Cellular vitreous trachyte, black with few crystals, (common.) 
Fine grained, porphyroid trachyte, dark,* i 
C arse a4 cc re dish, : 
Compact trachyte, gray, found at snow limit, ri 
Porphyroid “ ~  iron-stained, “ o 
Fine-grained “ # (rare). 
orous 2 dark, . 
Fine-grained “ with augite crystals, . 
Pumice, 
Fifteen miles §,W. of Antisana rises Cotopaxi, the loftiest 
and most symmetrical active voleano on the globe. Every rep- 
resentation, excepting the photograph taken by Farrand, is er- 
toneous. Humboldt made the south slope 52°, and the nortl 
50°. Guzman made the slope 69° 30’! Villavicencio in his 
Geografia makes it 40° ; and in a view drawn by Salas, the 
first artist in Quito, the slope is 35°. Spruce makes 1t 29° 
di haracteristic of the “lava streams.” 
Vv 
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Cnatacue 
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