SCENOGRAPHICAL GEOLOGY. 



60 1 



view down the valley from Mt. Willard. Fig." 72 also illustrates this ten- 

 dency to split, less perfectly than some others ; but the steep sides show 

 where ^eat masses of granite have been excavated, and the fragments 

 washed down the tributaries of the Pemigewasset. The contrast in the 

 kind of rock may be seen by the presence or the scantiness of vege- 

 tation, as well as by the position of the granitic piles in the background. 

 The bare rocks exhibit many harmonies of color, offsetting the grays 

 with neutral hues of blue and white, which, at sunrise and sunset, are 

 intensified. 



This tendency to split does not extend very deeply into the rock. It 

 seems to be induced largely by the action of the weather, and has been 

 observed about the Quincy (Mass.) quarries by Shaler, and also by Hunt. 

 Perhaps a similar action is that made of practical service in removing 

 boulders from a field. The farmer builds a hot fire over the granite 

 blocks he wishes to remove. Then, by throwing water upon them while 

 heated, large flakes scale off, and thus rocks too large to be transported 

 bodily can be removed in a very little while. The flaking off always 

 conforms to the surface of the stone, very much like the clearing of the 

 larger masses from cliffs. I understand the arrangement of the Con- 

 cord and other 

 granites, in flat 

 sheets, as seen 

 in the quarries, 

 to be quite a dif- 

 ferent phenome- 

 non. 



In Fig. 73 the 

 granitic slopes 

 observable from 

 the Flume house, 

 upon the western 



side of Mts. La- 

 fayette, Lincoln, ^ig. 73.-lafayette range, from the flume house. 



and Liberty, are represented. The very apex of these mountains is 

 composed of compact feldspar, which disintegrates the same as granite, 

 and therefore has not varied the typical form of the decomposition. 



VOL. I. 78 



