Summit of the Peak of Teneriffe in February 1 829. 1 99 



no doubt belonged to the main body. Towards the W.S.W. 

 the foot of the Peak is much lower than on the sides next the 

 Canadas, and the surface is totally different; it likewise has no 

 circular chain of mountains, nor any remains, that I could 

 observe, of ridges of mountains springing from them. 



I think the Canadas formerly were circular, and consider- 

 ably higher than they are now, but that they have sunk from 

 the immense quantity of matter they have thrown out ; and it 

 is very probable that the W.S.W. side was surrounded by a 

 similar chain to that on the opposite point, but it was possibly 

 destroyed by some violent convulsion of nature at the same 

 period that the chasms were formed in the present circular 

 chain round the Canadas. 



Appearances strongly indicate that the whole island at one 

 period gradually sloped on all sides from the Canadas to the 

 sea, and that the beautiful valleys of Orotava and Icod were 

 formed by a sinking of the strata in the centre of them. What 

 makes this apparent is, that the mountains called Pedrogil, 

 La Florida, and La Resbala, which form the eastern boundary 

 of the valley of Orotava, are nearly on the same level and 

 inclination as the opposite mountains of Tigayga, and Icod- 

 el- Alto, which form the western limit : as the upper part of 

 the sides next the valley are almost perpendicular, or, what is 

 practically the same thing, form an angle in some places of 60 

 or 70 degrees, and as they are covered with a luxuriant vege- 

 tation, I was not able to discover whether the strata of both 

 ridges have the same succession. 



Several minor volcanos are scattered in different parts of 

 the Canadas, which from the top of the Peak look like so 

 many large hillocks on a sandy plain ; the craters of two of 

 them are very distinct, and the side which discharged the lava 

 is evident. The surface of this immense crater is dotted over 

 with masses of lava, which at a certain distance from the Peak 

 is of a gfUnsteinic character; some are only a few inches above 

 the surface, and others are several yards : at first sight they 

 appeared to be without order, but upon closer inspection I 

 found that they were generally disposed in concentric circles. 

 It is difficult to account in a satisfactory manner for this ap- 

 pearance, unless they were formed after the general sinking of 

 the Canadas, when fresh eruptions breaking out in the centre 

 formed new craters, which fell in one after another, and were 

 ultimately covered over with a thick bed of pumice thrown out 

 by the Peak or some of the numerous volcanos on the surface. 



Besides these before-mentioned masses of lava there were 

 immense blocks upon the surface of the pumice, some of them 

 12 feet high and nearly 40 in circumference ; some of them 



were 



