318 COSMOS. 



which, according to the universal testimony of the Indians, 

 the district had undergone within 20 years, I found the 

 temperature in the fissures of the hornitos to range between 

 199 and 203 ; and at a distance of twenty feet from some 

 hills, the temperature of the air was still 108'5 and 116 0> 2, 

 at a point where no vapours reached me ; the true tem- 

 perature of the atmosphere of the Playas being at the same 

 time scarcely 77. The weak sulphuric vapours decolo- 

 rized strips of test paper, and rose visibly, for some hours 

 after sunrise, to a height of fully 60 feet. The view of 

 the columns of smoke was most remarkable early in a cool 

 morning. Towards midday, and even after 11 o'clock, they 

 had become very low and were visible only from their imme- 

 diate vicinity. In the interior of many of the hornitos we 

 heard a rushing sound like the fall of water. The small ba- 

 saltic hornitos are, as already remarked, easily destructible. 

 When Burkart visited the Malpais, 24 years after me, he 

 found that none of the hornitos 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 meteoric influences. Near the 

 principal volcano Burkart found small cones, which were 

 composed of a brownish-red conglomerate of rounded or 

 angular fragments of lava, and only loosely coherent. In 

 the midst of the upheaved area, covered 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 (burnt 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 before 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-south-west to north-north-east. The partial 

 direction of the first three, less elevated volcanoes situated 

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



