CHANGE OF SCENERY. 245 



nearly approaching to the vertical. It is, I believe, a 

 portion of the original rock skeleton that formed the 

 axis of the Andean chain during the long ages that 

 preceded the great volcanic outbursts that have 

 covered over the framework of the western side of 

 South America. Like most peaks of a similar form, 

 I am disposed to believe that in the course of gradual 

 upheaval the flanks have been carved by marine 

 action to the nearly vertical form which impresses the 

 beholder. Although snow-covered mountains suffer 

 a certain limited amount of denudation in the channels 

 through which glaciers flow, there is reason to hold 

 that they are far less subject to degradation than 

 those which are not protected from the main agencies 

 that wear away rocky surfaces. It is by alternations 

 of temperature, by frost, and the action of running 

 water, that rocks are rapidly eaten away, and from 

 these a snow-covered mountain is to a great extent 

 secured. 



A few miles east of Cape Froward the coast of the 

 mainland trends nearly due north for a distance of 

 fully sixty miles, and a marked change is perceived in 

 the aspect of the shores. Instead of the bold outlines 

 to which our eyes had become accustomed, the coast- 

 line lay low, fringed with forest on the side of the 

 mainland, which now lay to our west, and on the 

 other hand showing bare flats, here and there flecked 

 with fresh snow. The land on that side at first 

 belonged to Dawson Island ; but later in the day, as 

 we approached our destination, the dreary flats formed 

 part of Northern Tierra del Fuego. 

 ..The weather was thick as we passed Port Famine, 



