503 



separate peaks. Their elevation in general does 

 not surpass one hundred and twenty toises ; but 

 their situation in the midst of a small plain, thtir 

 steep declivities, and their sides destitute of ve- 

 getation, give them a majestic character. They 

 are composed of enormous masses of granite, of 

 a parallelopipedal figure, but rounded at the 

 edges, heaped one upon another. The blocks 

 are often eighty feet long, and twenty or thirty 

 broad. They would seem to have been piled up 

 by some external force, if the proximity of a 

 rock identical in it's composition, not separated 

 into blocks but filled with veins did not prove, 

 that the parallelopipedal form is owing solely to 

 the action of the atmosphere. These veins, two 

 or three inches thick, are distinguished by a fine- 

 grained quartz granite, crossing a coarse-grained 

 granite almost porphyrinic, and abounding in fine 

 crystals of red feldspar. I sought in vain in the 

 Cordillera of Baraguan for hornblende, and those 

 steatitic masses, that characterize several gra- 

 nites of the high Alps in Switzerland. 



We landed in the middle of the strait of Ba- 

 raguan, to measure it's breadth. The rocks pro- 



* Their direction is generally, hor. 3. I also saw a great 

 number of these veins following the directions hor. 6 — 11, in 

 the winter harbour ( Puerto de invierno ) of Atures. These con- 

 tain no vacuities, no vestige of druses. They are, as at Bara- 

 guan, veins of fine-grained granite traversing coarse-grained 

 granite. 



