m. de beaumont's geology of mountains. 121 



qui-qui-qui-qui. When perched after feeding, it may be heard for 

 entire hours repeating these sounds, which seem rather feeble for a 

 bird whose size is equal, by nearly one-third, to that of the GrifFard. 



The White Gos Eagle builds upon the top of tall trees. The male 

 and female take it in turn to sit. I have never met with more than 

 two eggs in the same nest. They are white, and of the size of a 

 guinea-fowl's, but rounder. When I was obliged to quit my camp, 

 I decided upon killing the old birds ; I then found the young ones 

 were covered entirely with a whitish fawn-coloured down. I at- 

 tempted to rear them, but my dogs killed them before they were 

 covered with all their feathers. Judging by those they already had, 

 the first colours of the White Gos Eagle seem to be nearly the same 

 as those of the adult bird, excepting that the brown is fainter, and 

 that all the wing-coverts have reddish borders. 



GEOLOGY OF MOUNTAINS. 



BY M. ELIE DE BEAUMONT.* 



The independence of successive sedimentary formations is the 

 most important result of the superficial beds of our globe ; and one 

 of the principal objects of my researches has been to show, that this 

 great fact is the consequence and even a proof of the independence 

 of mountain-systems having different directions. 



The fact of a general uniformity in the direction of all beds up- 

 heaved at the same epoch, and consequently in the crests formed 

 1 by these beds, is, perhaps, as important in the study of mountains, 

 as the independence of successive formations is in the study of su- 

 perimposed beds. The sudden change of direction in passing from 

 one group to another has permitted the division of European chains 

 into a certain number of distinct systems, which penetrate and 

 sometimes cross each other without becoming confounded. I have 

 recognised from various examples, of which the number now 

 amounts to twelve, that there is a coincidence between the sudden 

 changes established by the lines of demarcation observable in cer- 

 tain consecutive stages of the sedimentary rocks, and the elevation 

 of the beds of the same number of mountain-systems. 



Pursuing the subject as far as my means of observation and in- 

 duction will permit, it has appeared to me ^hat the different systems, 



* From Mr. De La Beche. 



