a 
POPOCATEPETL AND [XTACCIHUATL—FARRINGTON. 107 
iby him, which he estimated as only 500 feet below the summit, he 
positively determined with a hand level that he had not, by some 
distance, yet reached the height of the Pico del Fraile on Popocate- 
petl. The altitude of this peak, by Sonntag’s own determination, is 
only 16,570 feet (5,050.1 m.). 
It is evident that until further determinations can be made the 
question as tothe height of Ixtaccihuatl must be- left undecided, 
though the writer is inclined to accept the higher altitude as probably 
the more nearly correct one. It is to be hoped that with modern 
facilities an attempt at ascent may soon be made which will prove 
successful in fixing this important datum. 
TABLE OF DETERMINATIONS OF ALTITUDES ON IXTACCIHUATL. 




METERS.| FEET. 
Northern Peak (Za Cadbeza)..| 4,595 15,076 | Saussure. 
5,080.9 | 16,670 | Sonntag, 1857. 
Middle Peak (La Panza or 
Mae V OF Vc 5551p oes 20, e'e, ac 45785 15,699 | Humboldt, 1803. Trig. Meas. 
4,816 15,861 | Felixand Lenk, 1894, 500 feet 
estimated. 
5,168 16,958 | Heilprin, 1890, 225 feet esti- 
~*mated. 
5,205 17,076.9| Sonntag, 1857, Trig. Meas. 
5,326.6 | 17,476 | Almazan. 
Southern Peak (Los Pies) ....| 4,512 14,803 |. Saussure. 
4,516 14,817 | Sonneschmidt, 1770. 
5,077.3 16,658 | Sonntag, 1857. 

While Ixtaccihuatl is usually spoken of as a volcano, I am 
mclined to agree with other writers* that it may be incorrect to apply 
this term to the mountain. I am aware that this is a much disputed 
point, but Iam not convinced that any explorations have thus far 
proved the existence of a localized center where volcanic activity 
took place, or have shown that the mountain possesses the pericen- 
tric character which belongs to the true volcano. Sonntag states} that 
the appearance of the northern side of the mountain favors. the 
hypothesis that there has formerly been a crater between the middle 
and northern peaks, the walls of which are now broken down and 
have. filled up the cavity, but he was not able to approach near 
enough to verify his opinion. 
Whitehouse,{ who made an ascent November g, 1889, says 
that ‘‘the crater, although entirely filled with ice and snow, is clearly 
distinguishable, forming a cup with gently sloping sides between the 
- three almost equally high summits.”’ 

*O. H. Howarth, Geographical Journal, Vol. VIII, No. 2, p. 140. 
+OPZ. cit. p. 60. 
tRef. in the Geographical Journal, Sept. 1896, p. 305. 
