3E YOSEMITE. 277 



tend to return to the static condition in basins and at other 

 points of maximum interruption of channel base, so the 

 reduced glaciers in turn of the Alps and the Polar Regions 

 tend to return to the crystalline solid condition during the 

 present stage of reduced ice volume, and they appear as 

 crevassed and granular masses whose upper portions are 

 constantly shorn over the lower ones. Because of the 

 stagnation and incompetence thus evidenced, we are now 

 seriously told that this is the motion peculiar to ice gener- 

 ally, whether in flood or in low level stages. This point of 

 view had perhaps better be considered merely as a phase 

 of glacial motion peculiar to decadent, not to eorrasive 

 stages. 



But enough has here been brought forward to prove the 

 importance of the psychological factor in the discussion on 

 ice action — the suspension of judgment on matters scientific 

 when opposed to the direct evidence of the senses. A 

 summary of conclusions based on the mechanics of stream 

 action has been given elsewhere by the writer. 1 



Topography of the Yosemite Locality.— The formation 

 of the cirque, the valley "step" and the intcrstep "tread:' 

 In the present paper the floor of the Yosemite Valley of 

 California is considered as a magnificent example of an 

 aggraded "tread" of a valley "step," while the rough 

 broken ledges which separate the Yosemite Valley proper 

 from the Upper Merced Valleys are considered as a suc- 

 cession of "steps" or modified cirques." Thus both the 

 Nevada and the Vernal Falls are fine examples of valley 

 "steps." 



The peculiarities of the Yosemite topography are the 

 width and flatness of the valley floor, the characteristic 



•ToF.M 



VaUey. Infor! 



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