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PROCEEDINGS 



OF THE 



AMERICAN PHILOSOPHICAL SOCIETY 



HELD AT PHILADELPHIA 



FOR PROMOTING USEFUL KNOWLEDGE 



Vol. XLVI April-September, 1907. No. 186. 



ON THE TEMPERATURE, SECULAR COOLING AND 



CONTRACTION OF THE EARTH, AND ON THE 



THEORY OF EARTHQUAKES HELD BY 



THE ANCIENTS. 



By T. J. J. SEE, A.M., Lt.M., Sc.M. (Missou.), A.M., Ph.D. (Berol.), 



Professor of Mathematics, U. S. Navy, in charge of the Naval 

 Observatory, Mare Island, California. 



(Read April 20, 1907.) 



I. On the Temperature and Internal State of the Earth. 



§ I. General Considerations. 



It is well knov^n that Fourier devoted almost the whole of his 

 life to those famous mathematical investigations by which he estab- 

 lished the laws for the propagation of heat in solid bodies. His 

 first memoir was communicated to the Institut de France in 1807, 

 but with several subsequent memoirs was allowed to rest in the 

 Archives till 1822, when all were at length published in the cele- 

 brated " Theorie Analytique de la Chaleur." Prior to this, how- 

 ever, in the Bulletin des Sciences par la Socicte Philomathique de 

 Paris, avril, 1820, pp. 58-70, there appeared an " Extrait d'un 

 Memoire sur le Refroidissement seculaire du Globe Terrestre," 

 which contains the earliest detailed statement of the secular cooling 

 of the earth (cf. " Oeuvres de Fourier," edited by Darboux, Tome 

 IL, pp. 271-288). 



PROG. AMER. PHIL. SOC, XLVI. l86 N, PRINTED SEPTEMBER 3, I907. 



