XXI.] 



THE SUN, 



367 



high : such brilliant patches generally appear as streaks near 

 the margin of the solar disc, and are termed /««//i^.^ 



Above the luminous photosphere is another envelope, 

 which is known as the ckremosphere. During a total solar 

 eclipse, when the sun is obscured by the moon's shadow, 

 the dark disc is seen to be surrounded by a " glory," or 

 fringe of radiant light, which is called the £orona (Fig. 121). 

 Within tlie corona, around the margin of the disc, variously 



Fro. 121. — The corona and solar prom ne.ices as seen during a totr.I eclipse in 

 1851 (Dawes). 



coloured prominences may be detected ; and fantastically- 

 shaped tongues of red flame may be seen to dart forth, 

 sometimes to the extent of 70,000 miles or even to greater 

 distances. Under ordinary circumstances, these effects are 

 not visible, in consequence of the overpowering light of the 

 photosphere. But a method has been devised by M. 



1 Facula, a little torch, diminutive of Lat. fax. 



