254 FROM NEBULA TO NEBULA 



system, but forge onward into space, distancing the solar 

 gravity, as it were, and finally cross the border line of 

 neighboring systems, there to become the cometary and 

 meteoric vassals of other suns and stars. Inasmuch as 

 the repulsive force is single, and the ether of space op- 

 poses no resistance, we should naturally expect that the 

 outer planets would be fed proportionately more of the 

 lighter materials of the solar carcass, and vice versa as 

 to the planets nearer him. At any rate, this accords well 

 with the physical facts, for the superior planets are by 

 far the least dense. 



The violence of the ordeal ended, the nuclei origi- 

 nally, and now the matured planets, under the gyratory 

 rule of the Prime Resultant, continue on in the even tenor 

 of their way and proceed to sweep up by their gravita- 

 tional suctions the nebular material littering their re- 

 spective orbital zones. It is quite true that the nebula, 

 under the principle of systemal equilibrium, tends from 

 the first to accomodate itself to the Keplerian law of 

 areas, in which case, if that goal were immediately 

 realized, the ingathering process would be defeated ; but 

 it is also true that this adaptation requires a long period, 

 during which the differentiation of orbital speed between 

 the coursing planets and the relatively stagnant medium 

 immensely facilitates the gleaning process. In spite of 

 this advantage, however, wisps of the most tenuous mat- 

 ter will always remain uncaptured and continue to litter 

 the zone of the ecliptic indefinitely. These wisps, being 

 illuminated by the sun outside the boundaries of the 

 earth 's shadow, are responsible for the phenomena known 

 as the Zodiacal Light and Gegenschein. 



When I say that the planets devour this nebular mat- 

 ter, I do not mean to exclude from the cannibalistic feast 

 the asteroids, satellites, or even the meteors, that help to 

 make up our system. All of these share impartially, ac- 

 cording to their respective gravitative voracities. Fur- 

 thermore, they stand the same risk of being struck by 

 the flying missiles. This suggests the question as to 

 what should be the direct effect upon terrestrial life were 



