174 ox THE IXTEHACTIOX OF XATUEAL FORCES. 



hold of the universe with respect to the store of force, 

 capable of action, which it possesses. 



A number of singular peculiarities in the structure of 

 our planetary system indicate that it was once a connected 

 mass, with a uniform motion of rotation. Without such 

 an assumption it is impossible to explain why all the planets 

 move in the same direction round the sun, why they all 

 rotate in the same direction round their axes, why the 

 planes of their orbits and those of their satellites and 

 rings all nearly coincide, why all their orbits differ but 

 little from circles, and much besides. From these re- 

 maininof indications of a former state astronomers have 

 shaped an hypothesis regarding the formation of our 

 planetary system, which, although from the nature of the 

 case it must ever remain an hypothesis, still in its special 

 traits is so well supported by analogy, that it certainly 

 deserves our attention ; and the more so, as this notion 

 in our own home, and within the walls of this town,^ first 

 found utterance. It was Kant who, feeling great interest 

 in the physical description of the earth and the planetary 

 system, undertook the labour of studying the works of 

 Newton ; and, as an evidence of the dejDth to which he 

 had penetrated into the fundamental ideas of Newton, 

 seized the notion that the same attractive force of all 

 ponderable matter which now supports the motion of 

 the planets must also aforetime have been able to form 

 from matter loosely scattered in space the planetary 

 system. Afterwards, and independent of Kant, Laplace, 

 the great author of the ' Mecanique celeste,' laid hold of 

 the same thought, and introduced it among astronomers. 



The commencement of our planetary system, in- 

 cluding the sun, must, according to this, be regarded 

 as an immense nebulous mass which filled the portion 

 of space now occupied by our system far beyond the 

 > Konigsberg. 



