sound philosophy, and is therefore un- 

 worthy of consideration. 



The inevitable enlargement of the sun's 

 dimentions which would occur from the 

 accretions resulting from this method, 

 would also prove fatal to this hypothe- 

 sis. An exact knowledge of the sun for 

 centuries has not in the slighest degree 

 disclosed a change of radius in the 

 earth's orbit; a necessary consequence 

 of any change in the sun's bulk. 



The third hypothesis, "the contrac- 

 tion of the solar mass," implying a pro- 

 gressive diminution of that body, finds 

 the same objections which lie against its 

 progressive augmentation. 



The fourth, "the dissociation of com- 

 pound bodies in the sun's substance," 

 depends upon the process of combus- 

 tion, (SECCHI. "Le Soleil"} and is there- 

 fore open to the objections already 

 named. 



Each of the foregoing hypotheses 

 stands in direct opposition to the inexor- 

 able law of conservation of force. Ac- 

 cording to the decree of that law, what- 

 ever is received by the earth from the 

 sun, an equivalent for the same must 

 again* be returned from the earth to 

 the sun to the uttermost fraction. Each 

 recognizes the presence of a vast flood 

 of light, heat and magnetic force, (grav- 

 ity) incessantly issuing from the great 

 solar mass, and proceeding therefrom 

 with inconceivable velocity to the earth. 

 Yet neither makes provision for the re- 

 tro-acting, or returning force, which un- 

 der that law becomes indispensable. 



No hypothesis based upon any other 

 foundation can stand. 



Each assumes the actual and indis- 

 pensable presence of light and heat at 



