Preface. 



ix 



Society for similar favours. I am also indebted to 

 Mr. Darwin, Librarian of the U. S. Geological Sur- 

 vey, for valuable data, and to Mr. Joy Lichtenstein, 

 Assistant Librarian of the Free Library of San 

 Francisco, for the appended bibliographical list. 



C. F. H. 



Pasadena, Cal., September, 1892. 



