SCIENCE 



Friday, Mat 15, 1914 



CONTENTS 

 Isostasy and the Size and Shape of the Earth: 

 William Bowie 697 



Safeguardmg the Health of College Students: 

 Professor Joseph E. Eaycroft 707 



The Government of Learned Societies: Pro- 

 fessor H. Austin Aikins 711 



Stanford University 716 



Foreign Students at American Colleges and 

 Universities 717 



The George Washington Memorial 717 



Scientific Notes and News 718 



University and Educational Neics 720 



Discussion and Correspondence: — 



A Note on the Accessory Chromosomes of 

 Man : Professor Michael F. Guyer. Moral 

 and Seligious Training in a State Univer- 

 sity: Henry K. White 721 



Scientific Boohs: — 



The Eastman-Zittel Paleontology : Dr. John 

 M. Clarke. Bapeer on School Eealth Ad- 

 ministration : Professor Lewis M. Terman. 723 



Investigations in the Atlantic Ocean: Pro- 

 fessor Harry C. Jones 726 



Special Articles: — 



The Poor Nitrifying Power of Soils a Pos- 

 sible Cause of "Die-hacic" in Lemons: Dr. 

 Chas. B. Lipman. The Water Content of 

 the Embryonic Nervous System: Professor 

 Otto Glaser 728 



Conference on Individual Psychology: Pro- 

 fessor E. S. WOODWORTH 731 



MSB. Intended for publication and books, etc., intended for 

 review should be sent to Frofeesor J. McKeen Cattell, Garrison- 

 On-Hudson. N. Y. 



ISOSTASr AND THE SIZE AND SHAPE OF 

 THE EABTHi 



It is the speaker 's desire, in this paper, to 

 touch briefly on some phases of geodesy 

 which should be of general interest to the 

 physicist. 



Geodesy is one of the oldest sciences; 

 probably second in this respect to astron- 

 omy alone. What is the extent of the earth 

 in the horizontal plane, to what depth does it 

 extend, and what is on the other side are 

 questions which must have been asked by 

 men of the earliest times. The history of 

 geodesy will have to be passed over, for 

 lack of time, although it would be interest- 

 ing to follow the accumulation of data as to 

 the shape and size of the earth. 



Before one can study eiBeiently the great 

 geophysical facts and comprehend them, 

 he must know the shape and size of the 

 earth with considerable accuracy. For 

 some time before the end of the seventeenth 

 century, it was taken for granted that the 

 earth was a true sphere. 



The announcement by Newton in 1687 of 

 his theory that the earth was an oblate 

 spheroid added much interest to the sub- 

 ject of its exact shape. 



A meridional are of about 81 degrees, ex- 

 tending north and south of Paris, was 

 measured by J. and D. Cassini between the 

 years 1683 and 1716. The results of the 

 first computations of this arc indicated that 

 the length of the degree was less at the 

 northern than at the southern end. This 

 gave to the earth the shape of a prolate 

 spheroid. A great controversy arose over 



1 Bead on December 30, 1913, before Section B 

 of the American Association for the Advancement 

 of Science, at Atlanta, Ga. 



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