82 NOTES ON THE SOLAR SYSTEM. 



sound one, and all space is pervaded by a resisting 

 medium, is it so, that the velocity of light is not 

 uniform is the light, as it is projected from a fixed 

 star, of greater velocity than the light of that star as 

 it nears the earth ? 



147. How is it, that when the occultation of a 

 star takes place behind the limb of the moon, the 

 projection of that star upon the moon's disc is 

 sometimes apparent ? Is it because the velocity of 

 the light which is reflected from the moon, is greater 

 than that of the star which is about to be eclipsed, 

 and therefore the star is apparent upon the moon's 

 disc after the limb of the moon is intercepted 

 between that star and the earth ? 



