412 THOMAS C. CHAMBERLIN 
67. The protracted rescrutiny of the cosmological postulates 
back of the planetary comparison was made to see if the results 
of that comparison needed any serious modification or qualification. 
It was found that the total self-compression should be placed 
somewhat higher than the high figures given by the comparison, 
on account of the larger proportion of light material which the 
larger bodies gathered in. As the amount had previously been 
found to be unexpectedly large, the correction may be treated 
simply as a margin of safety. The trustworthiness of the compara- 
tive method seemed to be greatly strengthened by the rescrutiny; 
the deductions from the planetary comparison are therefore 
regarded as firm groundwork for further study. 
THE DIASTROPHIC RESOURCES OF A PLANETESIMAL EARTH 
68. An earth built of planetesimal dust settling from the air 
in a mixed state would retain, to an almost ideal degree, its latent 
resources for subsequent chemical combination and _ physical 
reorganization. It would retain also about as much as possible of 
its potential energy of position, for the accessions would be very 
loose as first laid down. In strong contrast to this, the resources of 
a molten earth would be dissipated in large measure while still in 
the fluid state. The molten globe spent its energies in a hot 
youth; the cooler planetesimal earth conserved its resources for 
its later life. 
69. In a molten earth, the high heat would be the master 
factor; its rate of dissipation would set the pace of progress. 
In a planetesimal earth, the strength of the solid material would 
be the ruling factor. Self-compression would take place only as 
this was overcome. Heat, of course, would be developed, but 
only as the yield of the solid matter permitted; it would be merely 
an incident of the process and would help to stay the process until 
it was taken care of. 
70. In a dust-built earth, self-compression began as soon as a 
new layer was laid on an old one. Thereafter, compression con- 
tinued by stages and intervals as long as loading continued. Dias- 
trophism therefore ran through the whole formative history and 
was doubtless more active during the stages of growth than since. 
