MARY WHITNEY. 207 



produced by eruptions from the interior, these elevated 

 ridges are seen under less absorption from the solar at- 

 mosphere than the surrounding photosphere. Near the 

 border the photosphere is observed through a deeper 

 layer of atmosphere than at the centre, and there is a 

 perceptible darkening. The faculse show by contrast. 

 Near the centre the contrast between elevated ridge and 

 average surface being less apparent the faculse are not 

 generally seen. 



Faculse are pretty surely known to be £>rominences in 

 the atmosphere, because, viewed on the sun's edge with 

 a sufficiently high power, they have been seen to project 

 like teeth. 



In spots of regular form the faculse incline to radiate 

 with considerable regularity from the spot umbra. In 

 irregular spots their distribution is likewise irregular. 

 I have observed that faculse are much more frequently 

 seen behind the spot than in advance of it. In eleven 

 hundred thirty-seven observations made at the Kew 

 observatory, live hundred eighty-four spots pre- 

 sented faculse following, five hundred eight gave a 

 comparatively regular arrangement, and only forty-five 

 gave faculse preceding. Secchi notices that they are 

 smaller and more brilliant when preceding, more numer- 

 ous and extended when following. 



Faculse often exist independently of spots, and their 

 distribution is more extended. Spots are rarely seen be- 

 yond 30° of heliocentric latitude. One spot as near the 

 pole as 50° has been reported by Peters (when in Naples i, 

 but this is exceptional. Faculse, however, are not un- 

 commonly seen as near the pole as 60°. Still, they 

 abound where spots abound. 



Besides the belt of July, 1883, several other remarka- 

 ble spot phenomena of the past three years have been 

 noted in our records. The most striking single group 

 appeared in November, 1882. At first the nucleus 



191 



