1836.] Ascent of the Volcano of Popocatepetl. 113 
Mexico. We met trains of pack mules and donkeys coming 
from Puebla, and it added no little zest to our ride to recall the 
memorable march of the Spanish conquistador from the plains of 
Puebla to the then famous Aztec capital of Tenochtitlan. 
In his Essai politique sur le Royaume de la Nouvelle-Espagne, 
Humboldt refers to this road or trail, which was first opened by 
the ancient Aztec couriers from Mexico to Puebla by way of 
Amecameca 
The plains over which we trotted were evidently an old lake 
bottom. The road now ascended between low rounded hills 
which had every appearance of moraines; they were composed 
of loose sand and gravel, with boulders of black basalt like that 
forming the volcano, and sloped gradually down to the plain. 
One very regular mound which we passed on our right, which 
rose abruptly from a corn or wheat field, seemed to have 
been artificial in its origin. It is Tetepetongo, “the hill of the 
round stones,” and according to tradition, says Ober, was for- 
merly used as a place of sacrifice. But the zone of moraine-like 
hills we were now passing over contrasted strikingly with the 
broad flat plains beneath us and with the ragged volcanic foothills 
of Iztacihuatal far above us on our left. Though this peak was 
capped with clouds, the larger part of the snowy dome of Popo- 
catepetl was in full view, and from it two glacier-like streaks of 
snow led down the valleys, losing themselves in the ragged lava 
streams at the base of the cone. As we pass onward and upward 
conical tumuli of loose débris from the mountains above confront 
us, and well-marked lateral moraines extend out upon the plain 
on each side of the trail. We should judge that the level at 
which we saw the lowest moraines was about 9000 feet above the 
sea; from that level they were observed up to or near the snow 
line, the height of which above the sea, in the latitude of the 
City of Mexico, Humboldt puts at 4600 meters or 15,333 eet 
Je were unable to see such good clear natural sections of a 
1 : : 
A Lorsqu’au mois d'octobre de le l’année 1519, le corps d'armée des Espagnols et 
es Tlascaltéques marchoit de Cholula a Tenochtitlan, il traversa la Cordillére 
t aang, qui réunit la Sierra Nevada ou Iztacihuatl à la cime volcanique du Popo- . 
‘Satepetl, Les Espagnols suivirent & peu prés le méme chemin que prend le courier 
Ms Mexico pour aller a la Puebla par Mecameca, et qui se trouve tracé sur la carte de 
miler de Tenochtitlan, L'armée couffrit à la fois au froid et de Vextreme impté- 
des vents qui régnent constamment sur ce plateau.—Essai politique, etc., H, 
