REBTTLAR HYPOTHESIS. 



211 



iide9 towards a central region ; which is virtually equiva- 

 lent, m a mechanical point of view, to what we witness 

 so frequently, both on a small and large scale — the meet- 

 ing and intermingling of opp6site gentle currents of water. 

 Now what do we find on occasion of such a meeting ? 

 Herschel's keen glance lighted at once on this simple 

 phenomenon, and drew from it the secret of one of the 

 most fertile processes of Nature ! In almost no case do 

 streams meet and intermingle, without occasioning, 

 where they intermingle, a dimple or whirlpool ; and, in 

 fact, it is barely possible that such a flow of matter from 

 opposite sides could be so nicely balanced in any case 

 that the opposite momenta or floods would neutralize 

 each other, and produce a condition of central rest. In 

 this circumstance, then — in the whirlpool to be expected 

 where the nebulous floods meet — is the obscure and sim- 

 ple germ of rotatory movement. The very act of the 

 condensation of the gaseous matter as it flows towards a 

 central district, almost necessitates the commencement 

 of a process, which, though slow and vague at first, has, 

 it will be found, the inherent power of reaching a perfect 

 and definite condition . . ."* 



The exception presented by the satellites of Uranus to 

 the otherwise uniform orbitual movements of the plane- 

 tary bodies, is brought forward as a startling difficulty.f 

 It is, in reality, only a trifling objection, seeing that so 

 many other movements follow one rule, and that we may 

 any day be able to fix upon a cause for this exception, 

 perfectly in harmony with all the associated facts. There 

 W T as once a similar difficulty in geology — strata uppermost 

 where they ought to have been lowermost; but it was in 

 time cleared. Geologists found that there had been a fold- 

 ing over of the strata, so as to reverse their proper and 

 original positions. May we not rest in hope that a similar 

 exception in astronomy may find a similar solution ? I 

 have thrown out the hint of a possible bouleversement of 

 the whole of that planet's system : it has been scoffed at; 

 but it is only the supposition of a greater degree of ob- 

 liquity in the inclination of the axis of the planet to the 

 plane of its orbit than what we find in several others. 

 The same causes which made the inclination of the axis 



* Views of the Architecture of the Heavens. First edition, 83? 

 \ Edinburgh Keview, No. 165, p. 24. 



