

PHOTOGRAPHS OF THE CORONA. 113 



has ever been photographed. The bases of the synclinal groups 

 on the western side do not reach so near the equator as on the 

 east, and the mass of equatorial rays on the western side is, 

 therefore, the larger, but it is similar in character. 



The north and south polar rifts are broad the northern rift 

 occupying about 40 along the limb, and the southern about 60. 

 They are pretty symmetrically arranged about the sun's axis, and 

 are filled with rays of the characteristic polar type straight and 

 radial in the centre of the rift, and on either side becoming 

 more curved towards and inclined to parallelism with the great 

 synclinal groups. The latter, in fact, appear to attract all other 

 rays in their neighbourhood towards themselves. 



The corona of 1898 resembles none in its general aspect so 

 completely as that of 1868, as drawn by Capt. Bullock, in 

 Celebes. Indeed, had the north-western and south-western 

 rays in this drawing been interchanged, it would have been in 

 all its main features an excellent representation of the corona 

 of 1898. 



Compared with that of 1896, it may be said that the corona 

 of 1898 shows less tendency than might have been expected 

 towards change to the characteristic sun-spot-minimum type. 

 On the east side the depression of the synclinal groups towards 

 the equator approximates to the character presented by that 

 type, but the radial direction of the corresponding groups on the 

 west shows marked divergence from it. At the same time it 

 must be noticed that in 1896 the equatorial regions were of 

 singular interest, showing a very contorted and perturbed 

 appearance, in marked contrast with 1898, when the same 

 regions seemed extremely quiescent. This appears to me a 

 sign of approach to the type of corona generally associated with 

 a period of sun-spot minimum. 



I have carefully examined the photographs for traces of the 

 dark markings which were so interesting a feature of the corona 

 of 1896. I have failed to find any, except that a few of the rays 

 in the north polar rift appear to be faintly outlined on their 

 sides with dark lines (light on the negatives). This is a region, 

 however, in which it is very difficult to distinguish between real 

 dark markings and mere spaces between the bright rays, so I do 

 not like to speak very positively upon the matter. 



W. H. WESLEY. 



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