Studies in the Sierra 



235 



that a series of concentric shells which form a dome may be 

 cut by another series of the same kind, giving rise to domes 

 within domes and domes upon domes. 



Fig. 12 represents bricks, thirty or forty feet in height, placed 

 directly upon a smooth, well-curved dome, which dome, in turn, 

 is borne upon or rather stands out from a yet larger dome- 

 curved surface forming a portion of the east side of El Capitan 

 rock, near the top. 



The Tuolumne middle region presents a sublime assemblage 

 of glacier-born rocks, of which a general view may be obtained 

 from the summit of Mount Hoffmann. These were overswept 

 by the wide outlets of the great Tuolumne mer de glace. The 

 Tuolumne Cafion outlet flowed across the edges of the best de- 

 veloped or north 35° east vertical cleavage planes, which gave 

 rise to an extraordinary number of rocks, like Fig. 8, with their 

 split and fractured faces invariably turned down stream, and 

 round abraded sides up against the ice-current. 



This glaciated landscape is unrivaled in general effect, com- 

 bining as it does so many elements of sublimity. The summit 

 mountains, majestic monuments of glacial force, rise grandly 

 along the azure sky. The brown Tuolumne meadow, level as 

 a floor, is spread in front, and on either side a broad swath of 

 sombre pines, interrupted with many small meadow openings, 

 around the edges of which the forest presses in smooth close 

 lines. On the level bottom of the mer de glace, mountains once 

 stood, which have been broken and swept away during the ice- 

 winter like loose stones from a pavement. Where the deep 

 glacial flood began to break down into the region of domes, a 

 vast number of rock forms are seen on which their glacial his- 

 tory is written in lines of noble simplicity. 



No attribute of this glacial landscape is more remarkable 

 than the map-like distinctness of its varied features. The direc- 

 tions and magnitudes of the main ice-currents, with their 

 numerous subordinate streams, together with the history of 

 their fluctuations and final death, are eloquently expressed in 

 the specific rocks, hills, meadows, and valleys over which they 

 flowed. No commercial highway of the sea, edged with buoys 

 and lamps, or of the land, with fences and guide-boards, is so 



