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Sierra Club Bulletin 



by the combined Tenaya and Hoffman glaciers on the one side, 

 and by the South Lyell or Merced Glacier on the other ; the San 

 Joaquin Dome, by the combined glaciers of the middle and 

 north forks, on one side, and by the glaciers of the south fork on 

 the other. The split dome of Kings River Yosemite is a worthy 

 counterpart of the great Half Dome of the Merced Yosemite. 



Fig. 8 Fig. 9 



They occur at about the same elevation, and are similarly situ- 

 ated with reference to the ancient glacial currents, which first 

 overswept them and then glided heavily by on either side, break- 

 ing them up in chips and slabs, until fashioned and sculptured 

 to their present condition. The Half Dome is usually regarded 

 as being the most mysterious and unique rock form in the val- 

 ley, or, indeed, in the world, yet when closely approached and 

 studied, its history becomes plain. 



From A to B, Fig. lo, the height is about i,8oo feet; from A 

 to the base, 3,000. The upper portion is almost absolutely plain 

 and vertical, the lower is inclined at an angle with the horizon 

 of about 37°. The observer may ascend from the south side to 

 the shoulder of the dome at D, and descend along the face to- 

 ward A H. In the notch at F a section of the dome may be seen, 

 showing that it is there made up of immense slabs set on edge. 

 These evidently have been produced by the development of 

 cleavage planes, which, cutting the dome perpendicularly, have 

 determined the plane of its face, which is the most striking char- 



