1886, ] Ascent of the Volcano of Popocatepetl. 119 
The transition was thrilling. Here we were on the summit of 
the highest mountain between Mt. St. Elias in Alaska, and Chim- 
borazo in Peru! The sky was well-nigh cloudless, a few cottony 
masses hung over Iztacihuatl to the north of us, partly obscuring 
its peaks; the plains of Anahuac and the Puebla valley bathed in 
the sunlight, and wrapped in a warm, soft haze, stretched for hun- 
dreds of miles away west and east; the volcano of Malinche to 
the north-east seemed like a pigmy cone; the city of Puebla 
could be distinguished, but Cholula and its pyramid, which lay 
nearer, were lost in the haze; we could not detect the city of 
Mexico and its adjoining lakes, nor could I make out the volcano 
of Orizaba, which lay to the eastward 150 miles. 
But our interest centered in the crater. In comparison with 
that of Vesuvius or Mt. Shasta it was, it must be confessed, tame. 
Many have looked down into the crater of Vesuvius; that of Mt. 
Shasta is a funnel-shaped chasm over a thousand feet in depth, 
the snow fields extending from the rim to the bottom, in which 
lies a frozen lake. The view into it was memorable. 
Descending a few feet to a rock overhanging the chasm now 
before us, we could take in the entire basin. It seemed to us to 
be about 500 feet deep and from 1000 to 1500 feet across at the 
mouth, but according to Gen. Ochoa’s measurements it is a thou- 
sand feet deep, and the floor is 200 meters in circumference. It 
1S Not an irregular chasm like that of Vesuvius, but like a vast 
cauldron in shape, the steep sides visible all around, and the bot- 
tom broad and somewhat flat, with no large, deep fissures visible. 
n. Ochoa told Mr. Ober that there are more than sixty sol- 
paras or smoking vents in the crater, one of them over fifty feet 
in circumference ; he called the vents respiradores. 
The northerly rim is of loose volcanic sand which has been 
blown up out of the crater. Perhaps two-thirds of the rim was 
of Solid lava more or less jagged and irregular, the highest por- 
tion on the south-east side. Looking across from the northerly 
Side one is confronted by three well-marked layers of vertically 
columnar basalt marking three successive overflows, while a less 
regular fourth layer indicated an additional eruption. The rock 
composing the sides of the crater, the mountain itself and the 
sand lying on its flanks is a tough, black basalt, slightly por- 
Phyritic. 3 
ear the rim of the crater on the west side is a sulphur fuma- 
