IIFA'KLATIOXS OF THE Y08EMITE VALLEY 



77 



Bridal Veil* Falls; and Typical Hanging Valley. 



Background. 



The Three Graces in the 



serve," he notes, "two very distinct kinds of structure in the granite 

 of this region . . . which determine all the forms about this wonderful 

 valley, . . . the concentric structure and a rude, columnar structure, or 

 perpendicular cleavage." By these differentiations he traced the sculp- 

 ture of every ragged spire or rounded dome. Later, he confirmed his 

 observations by demonstrating the effect of dynamic forces upon the 

 separate formations, showing the processes of sculpturing, whether by 

 quarrying along the least resistant lines of perpendicular Assuring, or 

 the exfoliation of concentric layers of onion-like granite. Coming in 

 close association with John Muir, he accepted his theories of glacial 

 erosion. Following the ancient trough of the grand Tuolumne glacier, 

 he traced its tangential branch which overflowed southward and poured 



