20 STATEMENT AND EXPOSITION OF 



these bodies with that of the rotation of the sun, flow from the hypothesis which 

 he proposes, and give to it great probability.^ 



(33) If the sohir system had been formed with perfect regularity, the orbits of 

 the bodies which compose it would have been circles, the planes of which, as well 

 as those of their several equators and rings, would have coincided with the plane 

 of the solar equator. But we may conceive that the innumerable varieties which 

 must exist in the temperature and density of the different parts of those great 

 masses, have produced the eccentricities of their orbits, and the deviation of their 

 motions from the plane of that equator. 



(34) The author then goes on to show that, on this hypothesis, the comets are 

 strangers to the system, formed by the condensation of nebulous matter elsewhere, 

 but drawn in when they come into the region in which the attraction of the sun is pre- 

 dominant ; and he then proceeds further to show that this will account for all the 

 peculiarities of their motion, as well as the variety in the inclinations of their orbits. 



(35) M. Laplace then adds that, if in the zones abandoned by the atmosphere of 

 the sun there were found molecules too volatile to unite to one another, or to the 

 planets, they ought, while continuing to circulate around the sun, to present all the 

 appearances of the Zodiacal Light, without opposing sensible resistance to the several 

 bodies of the planetary system, either because of their extreme rarity, or because 

 their motion is the same with that of the planets themselves. 



(36) In all that has now been stated, which, for the most part, is a translation, 

 or else a paraphrase of M. Laplace's Note VII. to his Exposition du Sijsteme du 

 Monde, in all this, there has been no allusion to the operation of another cause, 

 which may well have produced changes in the nebulous material, antecedent to 

 those which have been already contemplated. The solar atmosphere, when at its 

 largest extent, must also have had a very oblate form, and the portions near to the 

 pole of the rotating sun, because of the superior density, and close proximity of the 

 sun's body, have been subjected to an attractive force greatly superior to that pre- 

 valent (or barely in equilibrio) in the equatorial regions. 



(37) Now a greater attractive force acting on nebulous matter increases the 

 local density where the force is thus urgent ; as is manifest from what we observe 

 in the nuclei of comets. But a greater density^ of the same sort of material is 

 accompanied by a more prof use radiation of heat. All this could not fail to produce 

 changes in the actual, as well as angular, velocity of the portions thus affected, 

 which would not conform to the changes of both, then going on, in the regions 

 nearer to, or at the equator.^ A rending of the material of the atmosphere must 

 thus result, perpetuating itself all round the sun, so long as the portions most 

 affected were not detached to the extent of "abandonment." 



There might still be a tendency in the portions thus separated by the rent from 

 those parts still closely attached, to preserve, at least rudely, an approximation, 

 even in their exterior surface, to the spheroidal form; the situation, at any given 

 distance from the axis — when once that situation has been attained — presenting 

 the same ratio there of centripetal and centrifugal forces ; since, in so far as density 



' Verisimilitude rather — " vraisemblance." 



" To say nothing of the molecular changes which might be superinduced by the condensation itself. 



