360 LAPLACE. 



indefinite stability of the rings would have required a 

 regularity of structure throughout their whole contour, 

 which is very improbable. Each of them accordingly 

 broke in its turn into several masses, which were plainly 

 endued with a movement of rotation, coinciding in direc 

 tion with the common movement of revolution, and 

 which in consequence of their fluidity assumed spheroi 

 dal forms. 



In order, then, that one of those spheroids might ab 

 sorb all the others belonging to the same ring, it will be 

 sufficient to assign to it a mass greater than that of any 

 other spheroid. 



Each of the planets, while in the vaporous condition to 

 w hich we have just alluded, would manifestly have a cen 

 tral nucleus gradually increasing in magnitude and mass, 

 and an atmosphere offering, at its successive limits, phe 

 nomena entirely similar to those which the solar atmos 

 phere, properly so called, had exhibited. We here 

 witness the birth of satellites, and that of the ring of 

 Saturn. 



The system, of which I have just given an imperfect 

 sketch, has for its object to show how a nebula endued 

 with a general movement of rotation must eventually 

 transform itself into a very luminous central nucleus 

 (a sun) and into a series of distinct spheroidal planets, 

 situate at considerable distances from each other, revolv 

 ing all around the central sun in the direction of the orig 

 inal movement of the nebula ; how these planets ought 

 also to have movements of rotation operating in similar 

 directions ; how, finally, the satellites, when any of such 

 are formed, cannot fail to revolve upon their axes and 

 around their respective primaries, in the direction of rota 

 tion of the planets and of their movement of revolution 

 around the sun. 



