356 J. F. KEMP STRUCTURAL AND PETROGRAPHIC GEOLOGY 



letters of Peter and Susaii Lesle.y"; "Life of James Dwight Dana," and 

 the memorial volume issued to the finest spirit produced b}^ American 

 geology, Clarence King, by his fellow-members in the Century Associa- 

 tion in New York. Latest of all, the incomparable "Eeminiscences" of 

 our venerable past President, Eaphael Pumpelly, whom I describe as 

 venerable, although I: well know that he has partaken of the spring of 

 eternal youth. 



These works are no less important in a course which will stimulate 

 investigators than is the last word in magmatic differentiation, in meta- 

 morphism, or in the isostatic equilibrium of the earth. 



