18 



mining, and to such persons as, having this object in view, may 

 desire to have at least so much superficial knowledge of the subject 

 as will be useful to them in arranging their future studies in this 

 line of work, and in selecting a place where these studies can be 

 pursued. 



Chiefly to aid students in Economical Geology, certain chapters 

 in the " United States : Facts and Figures illustrating the Physical 

 Geography of the Country and its Material Resources," published 

 in 1889, and which have special reference to the subjects treated in 

 the courses indicated above, have been rewritten, considerably am- 

 plified, and brought down to the latest available date. These 

 chapters, which will be published separately, are now being printed, 

 and will be available for reference during the coming College year, 

 1893-94. 



