a 
104 FIELD Co_LuMBIAN MusEUM—GEOLOGY, VOL. I. 
says that Popocatepetl is the grandest mountain summit of the valley 
of Anahuac. To my own mind, however, Ixtaccihuatl presents by far 
the most striking scenery. 
Turning to a history of the various attempts made from time to 
time to ascend this mountain, we may find them briefly summarized 
in the work of Felix and Lenk.* 7 
‘‘The cool assertion of Father Sahagun of the 16th century,” 
say these authors, ‘‘that ‘he had been to the top’ is as little to be 
believed as is his statement that in the case of Popocatepetl he had 
reached the highest point, and won the honor of the first ascent. 
‘<The honor of having made the first attempt at ascent belongs to 
Frederick Sonneschmidt, the traveler who about the end of the 18th 
century undertook the first barometric measurements of Popocatepetl, 
and gained at least the height of the Pico del Fraile. From Sonne- 
schmidt’s description it seems quite certain that he did not ascend the 
highest or middle peak of Ixtaccihuatl, but only the lowest or south- 
ern, a conclusion which is corroborated by his barometer measurement 
of 4,516m. 
‘¢When in 1803 Humboldt carried on his trigonometric measure- 
ment of Popocatepetl in the Llano de Tetimba, he determined at the 
same time the height of Ixtaccihuatl and found it by calculation to 
be 4,786m. 
‘A long time passed after this before another traveler attempted 
to ascend the mountain. 
‘‘On the 15th of April, 1853, however, the French engineer and 
geologist, Virlet d’Aoust, again made the attempt to ascend the 
highest peak. In this he was not successful, but he reached one 
of the two ridges which separate the three peaks of Ixtaccihuatl from 
one another. Unfortunately, except for a determination from the 
boiling point of water at the Rancho de la Sienega (above Tlalman- 
alco on the west side), which gave about 3,168.5m., no measurements 
of heights were undertaken by Virlet d’Aoust. 
‘‘A. Sonntag, a member of the scientific commission which was. 
sent to make geodetic measurements of Popocatepetl, unacquainted, 
as it seems, with Virlet d’Aoust’s undertaking, spent some days in 
February, 1857, ‘on the slope of Ixtaccihuatl, and on the 5th of 
February ascended actually to the snow line.t His was the last 
*Of. cit. p. SI. 
+Felix and Lenk here state that Sonntag did not aim to reach the highest peak, but only to 
search for traces of a certain Dr. Cramfort, who, after an attempt at ascent concerning which 
nothing further is known, disappeared. In his published observations (Smithsonian Contributions 
to Knowledge, Vol. XI, p. 60), however, Sonntag makes no mention of such a search, only stating 
that he reached without much difficulty a point which he considered to be about 600 feet vertically 
below the highest peak. 
