416 CARNEGIE INSTITUTION OF WASHINGTON. 



there was an end of compression. But if atoms are revolutionary 

 organizations, as open as a planetary system, compression of the minute 

 flying constituents to the point of contact is out of the question, at 

 least in the case in hand. The problem of compression takes on the 

 form of a reduction of the orbits of revolutionary bodies, a purely 

 dynamic question, very like those of celestial mechanics. A reduction 

 of volume of 50 per cent or some such measure, as implied by the 

 higher density of the earth's interior, can not be supposed to change in 

 any radical way the revolutionary nature of the atoms that form the 

 earth. The new view pictures the earth as an almost infinite assem- 

 blage of revolutionary systems pulled together by their own attrac- 

 tions. These attractions, however, are opposed by the centrifugal 

 components of the orbital motions and the quasi-repellant effects of 

 the interior heat. As the revolutional energy embodied in the organiza- 

 tion of the constituents is immensely superior to the vibratory thermal 

 energy, the crux of the problem of their cooperativ^e function in com- 

 pression lies mainly in deciphering the modes by which the orbits of 

 the constituents are reduced, readjusted, or reorganized. As the actual 

 field is ultra-microscopic, some general considerations from the very 

 tangible celestial world were found helpful. 



THE TWO BASAL TYPES OF KINETIC ENERGY. 



There are two leading forms of kinetic energy in the great tangible 

 world: (1) that embodied in continuous, orbital, or revolutional motion, 

 and (2) that embodied in discontinuous, to-and-fro, or vibratory 

 motion. The first functions in constructive work, giving rise to rela- 

 tively permanent organization ; the second functions in dissolution and 

 dispersion. But this tells only the outstanding part of the story. 

 These contrasted aspects are linked together by numerous intermediate 

 forms of motion. Besides, though contrasted, they are often cooperative 

 in constructional work. Agitation prepares the way for reorgani- 

 zation. The relative values of the energies of the two types, as em- 

 bodied in the known part of the cosmos, are usually much misjudged, 

 because the first type is singularly unobtrusive, while the second type 

 is as singularly demonstrative. The smooth, steady gliding of a planet 

 in its course gives little hint of its kinetic energy, Vv'hile a mental effort 

 is required to realize its potential energy. On the other hand, the 

 radiant energies of hot bodies sharply stimulate the senses and have an 

 impressive effect. The energy embodied in revolutional motion is, 

 however, a high multiple of that expressed in vibratory motion, as 

 already shown in the case of the earth. 



If the analogies of the celestial world are carried into the ultra- 

 microscopic world, where our problem lies, a similar vast preponder- 

 ance of unobtrusive revolutional energy is scarcely less demonstrable. 

 One may easily give this concrete form by selecting a familiar body, 



