The Sun and his real and apparent Motions. 271 



in the course of a solar day, or about 24 hours ; 

 by the other he appears to traverse that circle in 

 the heavens which is called the ecliptic, in the 

 course of the solar year. It is almost un- 

 necessary to tell you that neither of these mo- 

 tions is real. For the first depends upon the 

 eartirs rotation on its own axis, and the second 

 on her annual revolution round the sun. This 

 deception of our senses with respect to the gun 

 and heavenly bodies appearing to move, may be 

 compared to that which we experience, when 

 sailing in a vessel within sight of the shore, when 

 the trees and villages appear all moving in a con- 

 trary direction, and we ourselves to remain at rest. 

 But though the vulgar language of astronomy 

 is thus, as M. Voltaire observes, a tissue of 

 falsehood, it yet conveys no deception to those 

 who are once acquainted with the true prin- 

 ciples. Thus, though we know that the sun 

 does not change his place in the heavens, and 

 that it is the earth only which moves, yet it is 

 no absolute solecism to say that the sun is in 

 aries, or any other point of the heavens ; for with 

 respect to us he is to all intents and purposes 

 apparently there. To make this clear by a very 

 easy diagram : Let us for a moment suppose the 

 earth the centre of the system at S, (PI. XXV. 

 fig. 109.) and the sun to revolve round it in the 

 orbit ABCD ; and let EFGH represent what 

 appears to us the concave sphere of the starry 

 heavens. As the sun moves in this supposed 



