THE GREATEST VOLCANOES OF MEXICO 753 



NO. 14. the: white surface in the i^oreground is not white, but sulphur 



crystals: ORIZABA 



Photo No. 5. Iztaccihuatl, "The 

 Woman in White," is the fitting com- 

 panion of Popo. Its resemblance to a 

 human form is remarkable, and the 

 rugged, abrupt sides are in marked con- 

 trast with the graceful lines of the snow- 

 covered body. It is located about 10 

 miles directly north of Popo and about 

 40 miles east of the city of Mexico. It 

 rises to 15,082 feet above sea-level at 

 its highest point, being, as will be seen 

 from the above photograph, oblong in 

 shape. Amecameca, the base of supplies, 

 where horses, guides, etc., are obtained, 

 and from where the start for the climb 

 to both Popo and Iztaccihuatl is made, 

 is seen in the foreground. 



Photo No. 6. Iztaccihuatl, seen from 

 the rim of Popo's crater. What appear 

 like patches of grass on the sides of the 

 mountain are in reality forests of the 

 largest trees. 



The great superstition of the natives 

 has made them give all the rocks and 

 peaks religious names. 



Photo No.- 7. M. Rossi and guides. 

 Showing the steep but even slope when 

 heavily snowed. 



Popocatepetl, although considered an 

 extinct volcano, is in reality only dor- 

 mant, as is proven by its great sulphur 

 and steam vents. However, its great 

 eruptions date as far back as 1548, and 

 the last were recorded 108 years ago, in 

 1802. Iztaccihuatl is entirely extinct, its 

 activity having ceased since the 17th 

 century, and it is a matter of doubt 

 whether it was then really active. 



The mean altitude of the plains sur- 

 rounding both mountains is about 7,500 

 feet, so that their absolute height above 

 the valley is 8,000 feet for Iztaccihuatl 

 and 10,000 feet for Popocatepetl. They 

 form a more or less isolated chain, the 

 so-called valley of Mexico lying on the 

 west and the Puebla Valley on the east. 

 North of Iztaccihuatl the plains are con- 

 spicuous, and south of Popocatepetl a 

 great depression occurs, reaching to the 

 "hot country," thus allowing a magnifi- 



