HANGING VALLEYS OF THE YOSEMITE 553 



the origin of the Yosemite valley itself (by stream erosion before 

 the glacial epoch) and of the influence of the nature of the rock 

 and of rock joints upon the topography." 



Unfortunately the large and constantly increasing number of 

 visitors to the valley are misled by so excellent a guide as 

 Baedeker's U. S. Handbook, edition of 1899, p. 509, which still gives 

 as the accepted explanation of the origin of the Yosemite valley 

 the fault theory advanced by Whitney many years ago. It is 

 very desirable that the U. S. Geological Survey should bring out 

 as soon as possible Mr. Turner's Yosemite folio and set the question 

 at rest in the popular mind. 



J. C. Branner. 



^ H. W. Turner, "The Pleistocene Geology of the South Central Sierra Nevada, 

 with Especial Reference to the Origin of Yosemite Valley," Proc. Calif. Acad. Set., 3d 

 sen, Vol. I, pp. 262-321. 



