MA CHINEE Y OF THE HE A VENS R UNNINO D WK 419 



tern is perfect. The contingent part of this proposition 

 possesses all the significance. Neither are the planetary 

 bodies solid, nor do they move in vacuo. The effect of the 

 terrestrial liquids is apparent in a considerable lengthening 

 of the sidereal day— which, for the time being, is counter- 

 poised by the shrinkage of the earth — while the effect of 

 the resisting medium has been wrought out in the partial 

 arrest of the whole brood of comets. 



The retardation of Encke's comet is such that it would 

 lose one half of its present velocity in 23,000 years. A 

 power which can sensibly check the flight of the filmy com- 

 et can also retard, however minutely, the motion of the 

 ponderous planet. Jupiter, by far the largest of the plan- 

 ets, would lose one thousandth of his velocity in seventy 

 millions of years. The length of the period has nothing 

 whatever to do with the result. If the motion be inevita- 

 bly and perpetually toward precipitation into the sun, the 

 event is as demonstrable as the fall of an aerolite to the 

 earth. Not only are the cloud-like comets slowly ap- 

 proaching the sun in spiral curves, but every revolving 

 planet — every material particle in the solar system — is 

 borne forward by the same unalterable decree. It is the 

 presence of a resisting ether which conditions the precipi- 

 tation of that meteoric rain which retards the cooling of 

 the sun. The fall of comets and planets to the sun will 

 still farther delay the final refrigeration of that luminary, 

 without averting it. 



The proof of the existence of a resisting ether in space 

 has disclosed the decree which records the doom of the 

 solar system. Whewell says : " Since there is such a retard- 

 ing force perpetually acting, however slight it be, it must 

 in the end destroy all the celestial motions. * * * The 

 moment such a fluid is ascertained to exist, the eternity of 

 the movements of the planets becomes as impossible as a 



