288 Mr. Bennet on the Island of Tenenffe, 



point itself being very low and projecting as a promontory into the 

 sea. The declination of the strata is similar from the Peak to Puerto 

 de los Christianos. This south-westerly chain is broken into many 

 abrupt ridges, and is cut nearly perpendicular down to the sea. I 

 could not perceive any base or shelf as on the other sides of the 

 Peak, from which the cone arose, but the fall is regular though steep. 

 From Puerto de los Chr'istiauos to Santa Cruz, comprising the south- 

 ern and south-eastern sides of the island, the form is similar to that 

 in the vicinity of Orotava^ but it is barren and desolate, laid waste 

 by streams of lava. In the short space of a few leagues I counted no 

 less than seven cones of extinct volcanoes, and the country is covered 

 with scoria, exhibiting no appearance of culture, and hardly any of 

 vegetation ; it is more broken into ravines and more intersected by 

 lava torrents than on any of the other sides of the island. Numerous 

 peaked and conical mountains rise upon the slope of the chain, and 

 the whole country is covered by scoria, and is one continued stream 

 of lava. The Montana Roxa itself is a singular example of the dis- 

 location of strata so commonly found in countries of volcanic for- 

 mation ; it is evidently a slip or fall of semi-columnar lava, and 

 slopes into the sea at an highly inclined angle. 



The ordinary strata of the island are as follows, reckoning 

 from below upwards : 1st. the porphyritic lava covered by scoria 

 and sometimes by pumice. This lava is composed of hornblende 

 and feldspar, and contains no other substance. The next stratum 

 graduates into what the Spaniards call Roccaverde ov greenstone^ and 

 is composed of feldspar and hornblende ; upon this is generally a thick 

 stratum of pumice, and last of all towards the surface is the basaltic 

 lava covered also by tufa and ash. This lava decomposes the soonest. 

 It also contains the greatest variety of extraneous substances, and is 

 sometimes divided by a layer of large crystals of olivine some inches 



