DIASTROPHISM AND THE FORMATIVE PROCESSES 683 
When this atomic energy, which is even more unobtrusive 
than the energies of celestial revolution, is added to the macroscopic 
energies, the disparity mounts up to a very high figure. The 
agitative energies that so deeply impress our senses are really 
little more than trivial, relatively, in the true cosmic scale. 
Now, the resistance that is offered to the compression of an 
earth made up of solid matter springs mainly from the forces that 
determine the constitution of this matter. The analysis of these 
constitutional energies, as now interpreted, involves the electronic 
revolutions, together with the fields of force and the polarities 
that spring from them. These may not be all the forces involved— 
very likely they are not all—but they form the truest picture now 
available and they may be taken as representative. They are 
herein made a working-basis, subject to correction as additional 
light is disclosed. 
THE RELATIVE ENERGY-VALUES OF THE POSTULATED 
EARTH-FORMING NEBULAE 
In estimating the potential energy of the nebular matter which, 
by hypothesis, was condensed to form the earth, in each of the two 
representative views, the planetesimal and the gaseous or quasi- 
gaseous, it is assumed, in both cases, that the earth was formed in 
essentially its present position and relations in the solar system. 
In Article XIII of this series, a conservative estimate of the 
belt occupied by the planetesimals that were later to form the 
earth, gave it a space-value of 9 X10” cubic miles. The gaseous 
nebula that was to form the earth, measured at the time it first 
came into self-control and was most extended, had a volume less . 
than 3.5 x<10'° cubic miles. The ratio is about 250,000 tox. The 
vastly superior space occupied by the planetesimals, however, does 
not carry proportional value in potential energy. Its importance 
chiefly lies in the mode of support of the planetesimals and in their 
modes and rates of assemblage. 
CONTRASTED MODES AND RATES OF ASSEMBLAGE 
The modes of concentration were radically different. The 
planetesimals were sustained in their orbits by velocities of a 
t Jour. Geol., Vol. XXVIII (1920), p. 678. 
