84 FieLp CoLumMBiAN MusEUM—GEOLOGY, VOL. I. 
‘In 1781 Antonio Alzate, the Mexican naturalist, again attempted 
the ascent, but reached only the snow line. Overcome and exhausted 
by the effort, he declared that to reach the summit of the mountain was 
simply impossible. This opinion, accordingly, was commonly held 
in Mexico for a long time thereafter, and probably aided in deterring 
Humboldt from attempting the ascent, as well as leading him to doubt 
the feats reported by Ordaz and his contemporaries. Humboldt.did 
not himself ascend the mountain, but made his measurements of its 
height trigonometrically from the plain of Tetimba near Cholula. 
‘¢In 1827 two Englishmen, Messrs. F. and W. Glennie, with Mr. 
Taylor, undertook the ascent, and succeeded after much difficulty, on 
the 2oth of April, in reaching the actual summit. They are, therefore, 
the first known to have scaled the height. Their ascent, it is inter- 
esting to note, was made on the southern slope of the mountain, 
which was at that time free from snow. 
‘In the same year a German, S. Birbeck by name, took barometric 
observations at the crater. His measurements indicate that he also 
reached the highest point of the mountain, but unfortunately, beyond 
his measurements of altitude, nothing is known further of the trip. 
‘On April 27, 1834, Baron Frederick von Gerolt, Baron L. 
Gros and Fl. Egerton, having previously failed on May 26th of 
the preceding year to get beyond the Pico del Fraile, succeeded 
in ascending to the crater. They obtained a measurement of the 
height of the Pico del Fraile, but were unable to make further 
observations on account of losing their barometers. One impor- 
tant result of their expedition was, however, the tidings of what 
had been known before, but apparently forgotten, the fact of the 
existence of large deposits of sulphur in the crater. It was not long 
after, therefore, before measures were taken to turn to practical 
advantage these somewhat inaccessible mineral treasures. In 1836, 
according to Laverriere, a resident of Ameca named Ignacio Reyes 
formed a plan to mine the sulphur. His plan was first put into exe- 
cution in 1849 by a certain Juan Mugica, of Puebla, after a brave 
engineer, Antonio Garcia by name, had allowed himself to be lowered _ 
‘into the crater by a rope and had investigated the deposits. Mugica, 
through his administrador Perez, constructed at the crater’s edge a 
windlass (malacate) for conveying the miners to and from the crater, 
and near the snow line on the mountain at the so-called Ranch of 
Tlamacas erected some rude buildings for refining the sulphur. The 
demand for the product seems at this time to have been very lively, 
for travelers visiting the mountains in the years following devote con- 
siderable space to a description of this peculiar industry, the pursuit 
of which at such a height is without a parallel on the globe. 
