GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 1 39 



if Ihcy were a disturbing element in the scenery. Tliese are the Eagle 

 cliffs, which are entirely composed of this rock. At the Profile house 

 they tower high up above the observer, shutting out from his observa- 

 tion a considerable portion of the sky. The finest view of them is pre- 

 sented in a heliotype in this volume, taken from a little rise of ground 

 two and a half miles south of the Profile, near the site of the former 

 Lafayette house, and the turning off to the east of a bridle-path up Mt. 

 Lafayette, almost upon the south line of Franconia. The central part of 

 the view is occupied by this range. The eastern wall is composed of the 

 same rock. On the left the eastern precipice of Profile or Cannon moun- 

 tain bounds the view in that direction. The other view of Eagle cliff 

 upon the same plate was taken from Echo lake. The land falls in both 

 directions from this central ridge of Eagle cliff. 



The following observations will illustrate the nature of these rocks, 

 and their disturbances between the Lake of the Clouds and Echo lake. 

 At the upper lake porphyritic gneiss has been observed, as stated upon 

 page 100. The steep hill-side east of Profile lake seems to be composed 

 of the breccia. At the notch between Eagle cliff and this eastern moun- 

 tain, where the new road up Lafayette passes, great sheets of granite dip 

 50° S. 48° E. On passing up the cliff to the west of the road we find 

 ledges of hard gneiss dipping 50° N. 63° W. On top the layers are 

 nearly horizontal. In this neighborhood I obtained a piece of a pebble 

 of porphyritic gneiss in the breccia, which was twelve inches long, also 

 an interesting oval concretion of mica. On top of the middle Eagle cliff 

 the rock is entirely composed of the cementing material. The grain is 

 fine, except a few crystals of mica and of feldspar of unusual size, sug- 

 gesting very faintly the Concord rock, and when weathered it shows a 

 tendency to crumble. There are many fragments in this paste. At the 

 third cliff there are both the fine feldspathic and the common coarser 

 gneissic rock. Here is also a large vein of very coarse granite like that 

 on the "Nubble," described on page iii. Still farther on the dip is N. 

 33° W., and the rock is more like the porphyritic gneiss. On reaching 

 the cliff, on the north side of Echo lake, the most conspicuous projection 

 seen in the heliotype, we find it composed of porphyritic gneiss, under- 

 laid by an igneous mass of the Franconia breccia, containing fragments 

 of the former rock. It is likely that the breccia is not found any farther 



