23 r 



gr But over and above this motion on his own axis, 

 * f We are not sure, "says Mr. lluygens, "whether the sun 

 be a solid or liquid globe. I rather think it liquid, 

 which the equal distribution of his light to all parts is 

 an argument for. That very small inequality on his sur- 

 face, discovered by the telescope, which has made some 

 men imagine they saw huge mountains of fire, is en- 

 tirely owing to the trembling motion of the vapours 

 our atmosphere is full of, particularly near the 

 earth. And this is likewise the cause of -the -stars twink- 

 ling. 



" The dark spots in the sun I have often seen : but 

 Ihose bright spots of which many speak, I never was 

 able to discover : so that 1 cannot but doubt of their 

 existence. Nor do I apprehend there is any thirtg in or 

 upon the sun, brighter than the sun itself. Indeed it is 

 not pretended that these bright spots are any were, but 

 just about the dark ones. And it is no wonder the parts 

 which are near the dark should appear somewhat 

 brighter than the rest. 7 ' 



And hence it is, that those spots being viewed ob- 

 liquely, near the edge of the sun, appear narrow and ob- 

 long. He is supposed to be abundantly larger than the 

 earth. When the moon passes between the earth and 

 the sun, so as to intercept his rays, he is said to be 

 eclipsed. This happens only at the time of the new 

 moon, because ; it is then only she passes between the sun 

 and the earth. Yet not at every new, moon, because 

 she generally declines either to the north or south. 



No solar eclipse can be universal, the moon beiu^ too 

 little to overshadow the- whole earth. Nor does any 

 eclipse appear the same in all places, but is total in one, 

 and partial in another. In most solar eclipses, the moon 

 Is covered with a faint, dawning light, which is owing to 

 the rejection of the light from the illuminated parts of 

 the earth. In total eclipses the moon's edge is seen sur- 

 rounded by a pale circle of light, which is at least a pro- 

 bable indication of a lunar atmosphere. 



'//hen the earth is interposed between the moon and 

 the sun. then the mooii is eclipsed. This is only at the 



