10 THE SUN. [Lesson in. 



sphere or globe, and the observations of astrono- 

 mers have proved beyond a doubt, that its axis is 

 nearly 883,210 miles, its circumference 2,774,692 

 miles, and its solidity in cubic miles 360,737,732, 

 256,5fi4,299 : viz. three hundred and sixty thou- 

 sand seven hundred and thirty-seven billions, 

 seven hundred and thirty-two thousand two hun- 

 dred and fifty-six millions, five hundred and twen- 

 ty-four thousand two hundred and ninety-nine 

 a number almost surpassing the powers of imagi- 

 nation ! 



From a cursory observation you would perhaps 

 be led to imagine that the sun moves round the 

 earth once in twenty-four hours ; but this is not the 

 case. The sun has two motions : the one is a peri- 

 odical motion, in an elliptical or very nearly a cir- 

 cular direction, round the common centre of all 

 the planetary motions. As this common centre is 

 found to be always exceedingly near the sun, and 

 most commonly within it, I shall henceforward 

 suppose this luminary to be the centre of the 

 planetary system, for in such a supposition we shall 

 not fall into any material error. The other mo- 

 tion is a revolution upon its axis, which is com- 

 pleted in about twenty-five days, as appears ob- 

 viously by paying attention to the maculce and 

 faculce, or spots upon his surface. 



The sun was supposed, by many of the ancients, 

 to be the clearest image of his Maker, <( without 

 *' spot, or wrinkle, or any such thing." To such 

 a degree had this prejudice arisen, that when Gali- 

 leo discovered several dark spots on the surface of 



the 



