CHAPTER X. 



SUN-SPOTS. 



Grave Doubts. 



HERBERT SPENCER says : " At present 

 none of the interpretations of the sun-spots 

 can be regarded as established." 



How numerous and how strange have 

 been the theories promulgated as to the 

 character of the manifestations called sun- 

 spots. The dark spots in the sun have been 

 supposed to be " solid bodies revolving very 

 near its surface," * " Smoke of volcanoes ; " 

 " Scum floating upon an ocean of fluid mat- 

 ter ; " " Clouds ; " " Opaque masses floating 

 in the fluid matter of the sun, dipping down 

 occasionally," " Fiery liquid surrounding the 

 sun which, by its ebbing and flowing, the 

 highest parts of it were occasionally uncov- 

 ered, and appeared under the shape of dark 

 spots, and by the return of the fiery liquid, 

 they were again covered, and in a manner 

 successively assumed different phases ; " " In- 



