CAUSE OF INTERNAL HEAT OF THE EARTH. 125 



magnetic poles, as to melt the compound metal, 

 which the experimenter poured out on the table 

 of a laboratory. 



This experiment is somewhat analogous to the 

 rotation of the earth opposite to the two polarized 

 electro-magnetic bodies of the sun and mpon ; 

 whereby the internal heat of the earth may be 

 similarly excited to fuse crystallized rocks into 

 melted lava, at times poured out from the tubes 

 of volcanic craters on adjacent table-lands, as the 

 fusible metal on the table of a lecture-room. 



This experiment indicates that the interior mol- 

 ecules of bodies are excited by their rotation, as 

 well as the exterior molecules on the surface ; and 

 that while the orbital revolutions of the planets in- 

 duce the solar reaction, warming the surface of the 

 earth, its axial rotation warms the interior, as 

 manifested by the eruptions of volcanoes. The 

 intensity of the excitation of the interior of the 

 earth is found to be regularly increased about i 

 Fahr. for each sixty feet of depth ; so that by very 

 deep boring for an Artesian well, an abundant 

 discharge of hot water of the temperature of 1 70 

 has been obtained, in a German city, for public 

 baths. The Geysers amid the frozen regions of 

 Iceland, and in the valleys of Northwestern Amer- 

 ica, send forth continually columns of hot water 

 to great heights. 



These facts corroborate the general law of diffu- 

 sion of electro-mechanical action by the axial and 



