300 cosmos. 



fully 60 feet. The view of the columns of smoke Avas most 

 remarkable early in a cool morning. Toward midday, and 

 even after 11 o'clock, they had become very low, and were 

 visible only from their immediate vicinity. In the interior 

 of many of the hornitos we heard a rushing sound like the 

 fall of water. The small basaltic hornitos are, as already 

 remarked, easily destructible. When Burkart visited the 

 Malpais, 24 years after me, he found that none of the hor- 

 nitos were still smoking, their temperature being in most 

 cases the same as that of the surrounding air, while many of 

 them had lost all regularity of form by heavy rains and me- 

 teoric influences. Near the principal volcano Burkart found 

 small cones, which were composed of a brownish-red con- 

 glomerate of rounded or angular fragments of lava, and only 

 loosely coherent. In the midst of the upheaved area, cover- 

 ed with hornitos, there is still to be seen a remnant of the 

 old elevation on which the buildings of the farm of San 

 Pedro rested. The hill, which I have indicated in my plan, 

 forms a ridge directed east and west, and its preservation at 

 the foot of the great volcano is most astonishing. Only a 

 part of it is covered with dense sand (burned rapilli). The 

 projecting basaltic rock, grown over with ancient trunks of 

 Ficus indica and Psidium, is certainly, like that of the Cerro 

 del Mirador and the high mountain masses which bound the 

 plain to the eastward, to be regarded as having existed be- 

 fore the catastrophe. 



It remains for me to describe the vast fissure upon which 

 a series of six volcanoes has risen, in the general direction 

 from south-southwest to north-northeast. The partial direc- 

 tion of the first three less-elevated volcanoes situated most 

 southerly is S.W. — N.E. ; that of the three following near 

 S. — N. The fissure has consequently been curved, and has 

 changed its strike throughout its total length of 10,871 feet. 

 The direction here indicated of the linear but not contiguous 

 mountains is certainly nearly at right angles with the line 

 upon which, according to my observation, the Mexican vol- 

 canoes follow each other from sea to sea. But this differ- 

 ence is the less surprising if we consider that a great geog- 

 nostic phenomenon (the relation of the principal masses to 

 each other across a continent) is not to be confounded with 

 the local conditions and direction of a single group. The 

 long ridge of the great volcano of Pichincha, also, is not in 

 the same direction as the series of volcanoes of Quito ; and 

 in non-volcanic chains, for example in the Himalaya, the 



