GEOLOGY. 419 



compression increase, the internal activities become more intense, 

 and additional forms of oscillation appear, until, if the increase con- 

 tinues, the whole gamut of vibratory phases from the longest dark 

 waves to the shortest and most penetrating rays are added. It is 

 well recognized that mechanical pressure favors endothermic action. 

 The argument here goes somewhat beyond that and urges that the 

 self-stress of any intense activity tends to its own divergence into 

 varied forms to increase its modes of easement. Under this view, the 

 high intensities of heat in the interior, as well as the high pressure, 

 tend toward a maximum of divergences of energy there, a due portion 

 of which, but not all, takes a reorganizing form. This is a rather 

 distinct departure from the inherited view that all the pressure is 

 transformed into heat and that all heat remains heat. 



THE SIGNIFICANCE OF INTERNAL STATES. 



Tidal and nutational evidences concur in indicating a higher degree 

 of rigidity and elasticity in the interior, taken as a whole, than in the 

 shell. Seismic evidence is quite specific in showing higher than sur- 

 face rigidity and elasticity throughout perhaps seven-eighths of the 

 volume of the earth. The remaining central part is still the subject 

 of uncertain interpretation. Under the foregoing mterpretation of 

 the two basal types of energy, the high rigidity and elasticity of the 

 larger part of the interior seems to imply that, in the partitions and 

 divergencies of energy under increasing pressure and heat, the revolu- 

 tional or organizing type received the higher apportionment. This 

 is not in accord with the old interpretation, which gave heat the lion's 

 share of all internal transformations of energy. 



ULTRA-ORGANIZING EFFECTS. 



The most remarkaible of known exothermic effects spring from the 

 spontaneous disintegrations of radioactive substances. No evidence 

 that this disintegration has anything to do with relief of pressure 

 connected with the rise of these substances from the interior is now 

 available. So important a phenomenon can not, however, be ignored 

 in a study that involves interior density. It is logically necessary to 

 suppose that the present exothermic action was at some time, some- 

 where, and somehow, preceded by equivalent endothermic and 

 organizing action. By interpretation, the energy" now being given out 

 was previously stored in these substances in the form of minute, 

 inconceivably intense revolutional motions, for this seems to be 

 implied by the regularity and the velocity of ejection of the alpha 

 and beta particles. Perhaps the most common speculation as to the 

 place and conditions that favored the integrating action locates it at 

 some center of great stress of pressure and heat. The center of the 

 earth is a place of such stress, though it may not have the requisite 



