MA CHINEE Y OF THE HE A YENS R TINNING D WN. 41 7 



CHAPTER XXXIX. 



THE MACHINERY OF THE HEAVENS RUNNING DOWN. 



LET the earth have frozen ; let the bright sun have been 

 extinguished ; let the moon and stars " wander dark- 

 ling in the eternal space." Will this, then, be the end of 

 matter's history ? Is this the consummation of which phi- 

 losophers, and poets, and patriarchs have dreamed and 

 prophesied? From the pinnacle on which we stand we 

 can discern the course of Nature still wending onward. 

 There must be progress even after the funeral of the sun. 

 As that bright luminary shines on after the fall of genera- 

 tions of men — as he shines serenely and undisturbed even 

 in dead men's faces, so will gravitation continue to prose- 

 cute its work even among the corpses of planets and suns. 



Hark ! from the highways of the comets come tidings of 

 friction in the machinery of the heavens. The filmy wan- 

 derer encounters resistance in his long journey to the con- 

 fines of the solar system. He plows his way through a re- 

 sisting medium. The balance of centripetal and centrifu- 

 gal forces is destroyed; the central attraction preponder- 

 ates ; he falls toward the sun ; his orbit is diminished ; his 

 motion is accelerated, and he comes back to his starting- 

 point earlier than the time which astronomy had appointed. 

 Here we get the first disclosure of the existence of a sub- 

 tile material fluid pervading space. 



This remarkable retardation was first observed in the 

 successive returns of Encke's comet. This comet has at 

 present a period of about 1210 days, and it returns each 

 time two hours and forty-five minutes sooner than calcula- 



