BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 32, pp. 211-226 JUNE 30, 1921 



THE GREATER EARTH ^ 



BY T. C. CHAMBERLIN 



{Read before the Society December 29, 1920) 



CONTENTS 



Page 



The material earth and the dynamic earth 211 



The earth's sphere of gravitative control 212 



The Roche limit 218 



Tidal zones 218 



Division between the collisional and ultra atmospheres of the earth 219 



An upper turbulent atmospheric zone 220 



The surficial diastrophic zone 221 



The gravity -pull within the earth 222 



The gravitative pressure within the earth 223 



The spheroid of anomalous effects on seismic waves 224 



The core of the earth 224 



Discussion 225 



The material Earth and the dynamic Earth 



The earth, like ourselves, has a material organization and a d_ynamic 

 organization. In the early history of our race we gave chief attention to 

 physical affairs, but the time came at length when we began to gather 

 together, as we do here today, to exchange the products of our dynamic 

 personalities. I think you will agree that the latter is the greater phase 

 of man. So the physical aspects of the earth have received chief atten- 

 tion thus far ; but the time has come, I think, when the study of the earth 

 should turn more largely to the dynamic. Very naturally the outer and 

 more intangible phases of the dynamic earth have received scant atten- 

 tion, either from geologists, concerned primarily with the eartli-body 

 itself, or from astronomers, concerned primarily with the more fascinat- 

 ing displays of the distant heavens. The inner, invisible heavens, into 

 which the outer reaches of the dynamic earth penetrate, have lain neg- 

 lected as the borderland between two more tangible domains — as a sort 

 of "turn-row" between two better cultivated fields of absorbino; interest. 



1 Manuscript received by tiie Secretary of the .Society February 'A, 10-Jl. 



(Ull) 



