SCENOGRAPHICAL GEOLOGY. 609 



The suggestion has been made of the existence of a fault in ancient 

 times, which lifted this range abruptly above the Saco valley, on the 

 side of Mt. Webster. The change from the Androscoggin valley is 

 less abrupt to Madison, there being a gradual descent through the inter- 

 vening Pine hill, not shown in the last figure. The action of the Andros- 

 coggin river has deepened the gap naturally existing between Pine hill 

 and Mt. Hayes ; but we have here no evidence of an upthrow or down- 

 throw on either side. 



There have been not less than three attempts of the forces of nature 

 to throw up this range. The first evidently produced a wave-like ridge, 

 much like its present form, but not so elevated. One of the others acted 

 in the same direction, and therefore cannot be distinguished from the 

 first in its effects. But the third force pushed from a direction at right 

 angles nearly to the others. Its effects can be conceived by imagining 

 an ocean wave to become fixed, while it is allowed to have a plastic con- 

 stitution. Supposing, now, that some force pushes this plastic material 

 in the direction of its length, it is clear that there will be a ridging up 

 which will tend to elevate disproportionately certain parts of the wave. 

 Such action has taken place in this range, as its indications are manifest 

 in the contortions of the strata, and its effects must have been perma- 

 nently impressed upon the figure of the mountain. 



I am disposed to think that Washington, Jefferson, Adams, and Madi- 

 son owe their conical shapes to the crushing action of the last mentioned 

 of the three forces of elevation. If you examine carefully the positions 

 of the strata upon these summits, you will perceive great irregularity and 

 constant variation, just as if the plastic material had been crowded into 

 heaps. But all the notches have been intensified by erosion, as well as 

 the valley of the west branch of the Peabody river, shown conspicuously 

 in Figs. 63 and 70, and less so in Figs. 79 and 85. 



Another marked feature of the higher regions is its plateau character. 

 It is best seen in the heliotype view of Mt. Washington from the south- 

 east. On descending to the Lake of the Clouds, the explorer will find a 

 very flat region, running out easterly into Boott's Spur, and northerly 

 along the east side of Washington. The Great Gulf, between Washing- 

 ton and the three contiguous peaks of Jefferson, Adams, and Madison, is 

 only a gorge cut out of the plateau, as we can easily imagine on looking 

 VOL. i. 79 



