GREAT SUN SPOTS. 



305 



absorptive qualities of that atmosphere, that were it 

 suddenly stripped off, the sun would shine not only 

 with greatly increased brightness, but with a bluish 

 violet colour. In a very short time indeed that colour 

 would seem white again to our eyes, grown accustomed 

 to the change ; after which, the sudden restoration of 

 the absorbing atmosphere would change the sun to an 

 orange-red orb, which only after awhile would seem 

 to our eyes a white globe as before. But while the 

 general absorptive action of the sun is wonderful, the 

 story is still more wonderful which the spectroscope 

 has to tell about the specific absorptive effects due to 

 its constitution. We find that, whereas in our air the 

 vapour of water is present (to condense into water 

 drops and form clouds at certain levels, and to change 

 to ice-crystals and form cirrus at higher levels), in the 

 sun the atmosphere is laden with the vapours of iron, 

 copper, zinc, sodium, magnesium, and like elements, 

 to form clouds of metallic drops, great gatherings of 

 metallic crystals, while the rains that pour down towards 

 the concealed true globe of the sun are mighty showers 

 of molten metal. When a hurricane occurs in the sun, 

 the clouds which form the sun's surface are swept 

 along, or whirled around, not at the rate at which we 

 measure our storms, but with a velocity compared 

 with which their swiftest motion is as rest. The solar 

 tornadoes rage, not over a few hundred square miles, 

 but over regions as large as the whole surface of the 

 earth, over hundreds, even thousands of millions of 

 square miles ; and they travel over these enormous 



III. X 



