508 



ANNUAL REGISTER, 1814. 



bankments, and we were often 

 obliged to clamber over them as 

 one ascends a steep wall : this lava 

 is of the same porphyritic appear- 

 ance as the masses we found in the 

 plains ; it is not covered with a thick 

 scoria, and seems never to have 

 been in a very fluid state, but to 

 haveroUed alongin large masses. — 

 The feldspar is crystalized in the 

 lava itself, which is slightly celluinr 

 at its surface, yet though I searched 

 carefully, I was unable to discover 

 any extraneous substance. The 

 whole composition of the stream 

 seems to be feldspar imbedded in a 

 brown clayey pas<e, remarkably 

 hard, of a close texture and heavy. 

 Judging from the sharp declivity of 

 the mountain, it appears surprising 

 that the lava should have flowed 

 so short a distance, as it does not 

 exceed 24 or three miles from the 

 base of the cone to the point of 

 union with the pumice hill : the 

 mass of lava as well as its depth is 

 prodigious. M. Escolar told me 

 that its greatest breadth was above 

 two miles ; its depth it is not easy 

 to determine; there are however 

 several ravines or valleys in the 

 course of the stream, some of which 

 may be from 60 to 100 feet deep. 

 The fusion of the mass does not 

 appear to have been perfect ; it is 

 very earthy, and though vitrified 

 pieces are found, there is no gene- 

 ral appearance of vitrification : 

 there are some pieces that exhibit 

 an union with the pumice, and the 

 gradation from the stony structure 

 to the vitrified, and thence to pu- 

 mice. Immense heaps of this latter 

 lie scattered on the surface of the 

 lava, some of them containing 

 large crystals of feldspar, which 

 abounds in, orroore properly forms 



the constituent part, of the lava of 

 the Mai Pais. 



We halted several times during 

 the ascent, and at last reached ii 

 spot called La Cueva, one of the 

 numerous caves that are found on 

 the sides of the mountain ; this is 

 the largest of them, and is filled 

 with snow and the most delicious 

 water, which was just at the point 

 of congelation : the descent into it 

 is difficult, it being 30 or 40 feet 

 deep. One of our party let him- 

 self down by a rope : he could not 

 see the extent of the cave, but the 

 guides declared it to be 300 feet 

 in length, and to contain thirty or 

 forty feet of water in depth. The 

 roof and sides are composed of a 

 fine stalactitic lava, similar to that 

 found on Vesuvius, and it is of the 

 same nature as that which flowed 

 on the surface. We rested here 

 about half an hour, during which 

 we had an opportunity of observ- 

 ing the rising of the sun, and that 

 singular and rapid change of night 

 into day, the consequence of almost 

 an entire absence of twilight. As 

 we ascended the north-east side of 

 the mountain this view was strik- 

 ingly beautiful : at first there ap- 

 peared a bright streak of red on the 

 horizon, which gradually spread 

 itself, lighting up the heavens by 

 degrees, and growing brighter and 

 brighter, till at last the sun burst 

 forth from the bed of the ocean, 

 gilding, as it rose, the mountains 

 of Teneriffie and those of the great 

 Canary ; in a short time the whole 

 country to the eastward lay spread 

 out as a map, the great Canary was 

 easily to be distinguished, and its 

 rugged and mountainous character, 

 similar to that of the other islands, 

 became visible to the naked eve. The 



