CERTAIN HARMONIES OP THE SOLAR SYSTEM. 



19 



Fig. 5. 



(29) But almost always, the nebulous ring must have broken mto several masses, 

 which, moving with velocities but slightly different, would continue to circulate at 

 the same distance from the sun. 



These masses would take a spheroidal form with a motion of rotation in the direc- 

 tion of their motion of revolution (from west 

 to east), because of the inferior molecules 

 (26), having less actual velocity than the 

 superior ; and thus would soon be formed so 

 many nebulous planets. But if one of these 

 were sufficiently powerful to bring together 

 successively, by its attraction, all the others 

 about its own centre, the nebulous ring 

 would then be transformed into a single 

 nebulous spheroidal mass revolving around 

 the sun, and having a rotation in the direc- 

 tion of its revolution. This last has been 

 the most common case ; though the solar 

 system, nevertheless, furnishes an example 

 of the first case, in the small planets which 

 revolve betwee.n Mars and Jupiter, at least 

 if we do not suppose with Olbers that they 



primitively formed a single planet, which a powerful explosion divided into several 

 parts animated with different velocities. 



(30) Now if we follow the changes which an ulterior cooling would produce in 

 the nebulous planets of which we have come to conceive the formation, we shall 

 see form, at the centre of each, a nucleus incessantly increasing by the condensa- 

 tion of its surrounding atmosphere. 



(31) In this state the planet would perfectly resemble the sun in the nebulous 

 state in which we considered it. The process of cooling must then produce, at dif- 

 ferent limits in its atmospliere, phenomena similar to those which we have described; 

 that is to say, rings and satellites circulating around its centre in the direction of 

 the planet's own rotation, and turning at the same time (the satellites that is) upon 

 themselves. The regular distribution of the mass of the rings of Saturn about its 

 centre, and in the plane of its equator, results naturally from this hypothesis, and 

 without it becomes inexplicable. " The rings" (exclaims the framer of the hypo- 

 thesis) " appear to me to be an ever-present proof of the primitive extension of 

 the atmosphere of Saturn, and of its successive retreats.'" 



(32) He then proceeds to say that the singular phenomena of the small eccentricity 

 of the orbits of the planets and the satellites, of the small inclination of those orbits 

 to the solar equator, of the identity of direction of rotation and revolution of alP 



' " Me paraisseut etre des preuves toujours subsistantes de I'extension primitive de I'atmosphere 

 de Saturn, et de ses retraites successives." 



" Difference of density, etc. might cause the rotation of a satellite in a rare case to be in a con- 

 trary direction, as is true of the orbital motion of the satellites of Uranus. 



