ON THE FORMATION OF NEBULAE. 345 



This is the general rule for the formation of secondary bodies in all 

 systems. In our system there seems to have been one exception to 

 this general rule, viz., the asteroids. From some cause most probably 

 from external disturbance this ring did not collect into a single mass, 

 or, if so, was dashed into many fragments afterward by some meteoric 

 or cometary body which, thrown out from some previously-formed neb- 

 ula, had been wandering through space till it reached our system. 



There are indications in other parts of the system of such external 

 disturbances, notably in the satellitious system of Uranus. 



From the manner in which the solar system has been formed, it 

 seems most probable that all the bodies in it should both revolve and 

 rotate in the same plane and direction that the sun does, had there been 

 no external disturbance to prevent it. 



Having examined the mode in which a planet is formed, and thus 

 learned how a solar system may be formed out of nebulous matter, and 

 having discovered that the system must be contracting into smaller 

 dimensions from some sufficient cause, let us next inquire what conse- 

 quences are most likely to follow the operation of such cause. 



Consequences of Contraction. It has been shown, by the fore- 

 going investigation, that our system is expending its life-giving energy 

 on some resisting medium which causes this contraction. 



This, at first sight, seems saddening to contemplate ; but there may 

 be another point from which to view it. For, while it is seemingly 

 wasting its life-giving power in this struggle with resistance, it may, in 

 reality, be storing up a new supply of potential energy, by which a 

 future activity may be insured. Or, in other words, it may be forming 

 a new bud, which, when properly vivified by another one, may blossom 

 forth with the most brilliant rainbow hues, and finally ripen into plane- 

 tary fruit which shall become the happy home of future intelligent 

 races. 



Modus Operandi op Conservation. It is well known that the 

 stars are not fixed, but that they are moving in various directions with 

 various velocities, relatively to our galaxy, at least. 



Now, if the stars be moving, it is very probable that some of them 

 are moving in such directions that they will finally meet, either in pairs 

 or otherwise. 



Let us direct our attention to two of them which are very like our 

 star in mass and attendants, or we may suppose our sun to be one of 

 them, and that they are so moving as to approach each other at the 

 very slow rate of one mile a week ; and let us further suppose that, 

 before meeting, each will have arrived at that state of quiescence to 

 which all systems are tending. 



The object of assuming such slow original motion for the meeting 

 bodies is to make a test case, as it were, in order to show clearly that 

 the gravitative force of two such large bodies is sufficient to convert 

 them both into a nebulous mass, besides throwing large portions of 



