146 FROM NEBULA TO NEBULA 



port the huge blocks of stone that compose those struc- 

 tures; but just which of those methods was actually 

 adopted Ave shall probably never learn. So when we 

 behold the solar system. Although we may know the 

 secrets of centripetal and centrifugal motion, and of 

 gravistatic eruptions, we have yet to deduce the pre- 

 cise mode among the several possible, in which these 

 operated to bring about our particular planetary 

 scheme. As to this mode I have not as yet formed a 

 final conclusion, although I incline more and more to 

 the belief that the sun is his own legitimate successor. 

 That is to say, that his erstwhile disruption was not 

 total but only partial ; that the planets are fragments 

 of his former self; and that he himself is the chief frag- 

 ment. This view seems to me best to coordinate the 

 facts, first, that the outermost planets are the least 

 dense, second, that the planetary orbits, generally, are 

 so nearly circular, and third, that the retinues of the 

 planets are more extensive as we proceed outAvard from 

 the sun. Thus: first, the outer layers of the original 

 body being for several reasons naturally lighter, would 

 be apt to fly farthest ; second, the fragments destined to 

 become planets, being shot out radially, would yet be 

 held back by the recalling pOAver of the residual sun 

 and finally brought gently to a full stop, in Avhich state 

 of exhausted motion they AA^ould be more amenable to 

 the persuading power of the Prime Resultant that un- 

 forgettinsrly seeks to impose orbital circularity ; and 

 lastly, the expelled spray Avould be apt to be most finely 

 divided and scattered at those points farthest from the 

 seat of the eruption. It is quite true that Uranus and 

 Neptune do not appear to be so plentifully attended by 

 satellites as do Jupiter and Saturn, and to this extent 

 the fact seems to militate against my surmise. How- 

 ever, let it be remembered that those two orbs are so 

 distant as to be themselves invisible to the naked eye, 



