PROCEEDINGS 



OF THE 



AMERICAN PHILOSOPHICAL SOCIETY 



HELD AT PHILADELPHIA 

 FOR PROMOTING USEFUL KNOWLEDGE 



Vol. LIV Octobee-December, 1915 No. 220 



SYMPOSIUM ON THE EARTH: ITS FIGURE, DIMEN- 

 SIONS AND THE CONSTITUTION OF ITS 

 INTERIOR. 



{Concluded from page 308.) 



iv. 



VARIATIONS OF LATITUDE: THEIR BEARING UPON 



OUR KNOWLEDGE OF THE INTERIOR OF THE 



EARTH. 



By frank SCHLESINGER. 



To review even hastily the contributions that astronomy has made 

 to our knowledge of the figure and dimensions of the earth and the 

 constitution of its interior, would consume more time than I can 

 fairly claim as my share this afternoon. Let me therefore pass over 

 those points that are on accepted ground and are matters of general 

 agreement from the different points of view represented in this sym- 

 posium; and let me dwell instead upon certain recent developments 

 especially in need of consideration, concerning which the astronomer 

 desires the criticism and help of the geologist, the seismologist, the 

 physicist, and the meteorologist. These developments have come to 

 us directly or indirectly through a study of latitude variations, so 

 that most of what I shall have to say will deal with this subject. 



Although variations of latitude are in a sense a very recent addi- 



PROC. AMER. PHIL. SOC, LIV. 220 X, PRINTED FEBRUARY 25, I916. 



