42 



SMITHSONIAN INSTITUTION 





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Fig. 33. — A part of Mount Blanco showuig a thick bed of borax ore. Death 

 Valley in the distance. (Photograph by Grinnell.) 



Fig. 34. — Aiesa Negra and the camp of Ryan. The borax nnncs can be 

 seen to the right of the camp. The summit of the mesa is a broad flow of 

 iDlack lava. (Photograph by Grinnell.) 



