-02 COSMIC nilLOSOPIIY. [pt. n. 



rcsultin rhythms will be simple and long-enduring. Never- 

 theless the processes still going on in our system are such 

 as to forbid the conclusion that this apparently permanent 

 equilibrium is destined really to be permanent. The con- 

 centration of matter and concomitant dissipation of mole- 

 cular motion, which has gone on from the beginning, must 

 still continue to go on until it has reached its limit. That 

 consolidation and accompanying refrigeration which has 

 changed the earth from a nebula into an incandescent star, 

 and from a star into nn inhabitable planet, must continue 

 until a state of things is inaugurated for which we must seek 

 a parallel in the present condition of the moon. So, too, 

 the contraction which generates the prodigious quantity of 

 heat daily lost by the sun, cannot go on forever without 

 reducing the sun to a solidity incompatible with the further 

 generation of radiant energy. 



Thus the moon appears to afford an example of the 

 universal death which in an unimaginably remote future, 

 awaits all the members of the solar system. It then be- 

 comes an interesting question whether this cosmic death 

 will be succeeded by Dissolution, — that is, by the rediffu- 

 sion of the matter of which the system is composed, and 

 by the reabsorption of the lost motion or its equivalent. 

 We shall find it difficult to escape the conclusion that such a 

 Dissolution must ultimately take place. 



If, along with the dissipation of molecular motion already 

 described, the planets are also losing that molar motion to 

 which is due their tangential momentum, this loss of motion 

 must ultimately bring about their reunion with the sun. 

 Upon such a point direct observation can help us but little ; 

 but there are two opposing considerations, of a force which 

 none will deny, and based on facts which none can dispute. 

 Two sets of circumstances are struggling for the mastery,— 

 the one set tending to drive the planets farther and farther 

 jiway from the centre of the system, the other set tending te 



