396 



THE POPULAR SCIENCE MONTHLY. 



ERUPTIVE PROMINENCES. 



Three figures, of the same prominence, 

 seen July 25, 1872. 



Fig. 6. 



As SEEN AT 2.15 P. M. 



Fig. 9. 



Spikes. 



Fig. 7. 



Fig. 10. 



Sheaf and Volutes. 



As seen at 2.45 p. m. 



Fig. 11. 



Fig. 8. 



AS SEEN AT 3.30 P. M. 



100,000 miles to the inch. 



Jets. 



sub-classes or varieties, between which, however, it is not always easy 

 to maintain the distinctions. 



The quiescent prominences in form and texture resemble, with al- 

 most perfect exactness, our terrestrial clouds, and differ among them- 

 selves as much and in the same manner. The familiar cirrus and 

 stratus types are very common, the former especially, while the cumu- 

 lus and cumulo-stratus are less frequent. The protuberances of this 

 class are often of enormous magnitude, especially in their horizontal 

 extent (but the highest elevations are attained by those of the erup- 

 tive order), and are comparatively permanent, remaining often for 

 hours and days without serious change ; near the poles they some- 

 times persist through a whole solar revolution of twenty-seven days. 



