20 



of land areas, and in changes in position of the polar 

 axis, and in the orbital eccentricity of the earth. Some 

 of these are beyond the range of analysis and investi- 

 gation, and others are of local and minor influence, and 

 may be left out of consideration in a discussion of the 

 fundamental principles. 



If the eras of climatic evolution which our planet has 

 undergone have herein been referred to their proper 

 laws and sequence, the questions involved may not 

 be the fearful "glacial nightmare" that some would 

 make them; but rather the means whereby we recognize 

 the Ice Age as one of these eras, during which the land 

 areas were made smoother and more stable, and the 

 soils more uniform in composition and fertility. 



If new light has been thrown on the grand problems 

 of terrestrial physics, much remains to be done. The 

 worshipers who bow at the altars of science will have a 

 stronger faith to cheer them on; and if some of their 

 early structures have been rudely struck, it is hoped 

 that in their stead grander and more stately temples 

 will be reared whose foundations rest upon everlasting 

 truth. 



