EDITORIALS. 299 



Another class presumably involve superficial loading and unload- 

 ing, as, for example, the accumulation and dissipation of conti- 

 nental glaciers. These are less radical in nature and less 

 general in applicability, but perhaps offer greater hopes 

 of early solution. There are few problems in geology more 

 difficult of satisfactory elucidation, even by hypothesis, than the 

 moderate but widespread oscillations of the ©arth's crust. The 

 problem of mountain building, though more obtrusive, seems 

 really less difficult than that of plateau formation, and that of 

 plateau formation, in turn, less unpromising than that of the 

 common widespread crustal oscillations. 



The writer has become interested in these questions in con- 

 nection with some studies of the earth's crust and interior, and 

 would welcome contributions to the subject either for publication 

 or for personal information. T. C. C. 



