11 



Appendix was also added, in which the subject of the geo- 

 graphical discovery of the Cordillera Region was treated at some 

 length, and a sketch was given of the methods and results of 

 hypsometrical measurements in the United States, with special 

 reference to the probable accuracy of the results obtained. Fur- 

 thermore, the subject of the cartography of the country was 

 discussed in some detail. 



The work done in preparing definitions of technical terms in 

 physical geography, geology, mining, and metallurgy for the 

 Century Dictionary has occupied a very considerable amount of 

 time, and as five parts of the encyclopedic work are now before 

 the public, bringing it down to D, those who are interested can 

 judge for themselves of the nature and value of the material 

 contributed in the branches of science specified. 



Some field-work has also been done in continuation of the 

 investigation of the surface and glacial geology of North Amer- 

 ica, to which allusion has been made in preceding Reports. 

 The regions visited were the southern and eastern portions of 

 Long Island and the adjacent mainland, and the valley of the 

 St. Lawrence. 



