PHYSICS OF THE GLOBE. 



By CLEVELAND ABBE, 



Of tiie Weathek Bureau, Washington, D. C. 



THE EARTH. 



INTERNAL CONDITION. 



The remarkable address of Sir William Thomson at the 

 Glasgow meeting of the B. A. A. S. in 1876, in which he re- 

 nounced the views so Ions: entertained bv him as to the inter- 

 nal fluidity of the earth, and gave in his adherence to Hop- 

 kins's conclusion as to its solidity, has been followed by a 

 paper by Gen. J. G. Barnard, in which he differs from some 

 of the points taken by Thomson. 



INTERNAL TEMPERATURE. . 



In reference to temperatures observed deep within the 

 earth, Mr. Oswald Foster has communicated to the Cam- 

 bridge Philosophical Society a memoir in which he main- 

 tains that the abnormal temperatures observed in the arte- 

 sian well 4000 feet deep at Sperenberg might be accounted 

 for by vertical currents, while the average rate of increase is 

 1 Fahr. for every sixty feet of descent. 



The very delicate and exact and convenient method of 

 observing temperatures at points underground, or otherwise 

 of difficult access, by means of the so-called electro-thermom- 

 eter, as used by Becquerel at Paris, deserves to be introduced 

 at some of the physical laboratories of America. Observa- 

 tions have been made daily for many years at Paris, the 

 results of which have lately been communicated to the 

 Academy of Sciences. 



VOLCANOES. 



Of general work on vulcanicity we make especial mention 

 of the investigations of Mr. G. K. Gilbert, of Powell's Geo- 

 logical Survey of the Western Territories, who by the study 

 of peculiar formations among the Henry Mountains, of Utah, 



