Intelligence and Miscellaneous Articles. 307 



/have used the term pores for the extremely minute openings found 

 in them. This I adopted from Sir John Herschel's description of 

 the phenomena. It may, however, be necessary to guard against 

 the supposition that these pores are always or even usually quite 

 round. When best seen, under circumstances which are unfortunately 

 of very rare occurrence, they sometimes have rather the appearance 

 of very small fissures, such as might be caused by several exceedingly 

 small dots running together into one short dark line, which is never 

 Mack, but at most of a dark grey. I have been strongly impressed 

 with the conviction that their visibility varies greatly at different 

 times, even under circumstances too similar to account satisfactorily 

 for the difference. Indeed I have on some occasions been able to 

 find none, or scarcely any* while on others, not remarkably more 

 favourable, they have come out by pretty steady views in a suffi- 

 ciently certain and positive way. 



Perhaps this variation in their visibility may be connected with 

 another fact to which I should wish to draw special attention, 

 namely, that the proportion of the area of the less luminous spaces (in 

 which the pores are sometimes found) to that of the most luminous 

 masses is subject to very considerable change. Though they are at no 

 time very small or narrow, yet of late they have struck me as occu- 

 pying a decidedly greater space than I used to assign to them. If 

 such changes really exist, and are also great, they would seem ne- 

 cessarily to produce differences in the quantity of solar light, and 

 might thus place our sun among the slightly variable stars, and also 

 afford a plausible way of accounting for the variation in others. I 

 have indulged the hope of being able to give a more decided opinion 



^ as to the actual proportion between the masses of different lumi- 



I nosity ; but I can only say that at the present time my impression is 

 that the area occupied by the less luminous masses is even greater 

 than that of the brighter ones, but that the proportion in different 



\ parts of the sun is by no means always the same at the same time. 



These conclusions may, however, be considerably modified by better 

 and more continuous observations (with this special object in view) 

 than I have been able to procure, especially during the last eight 

 months. Might it not be reasonably expected that photography 

 would here step in most efficiently to our assistance ? As an ap- 

 proximation to what is wanting, I may refer to the very remarkable 

 print of the sun's surface from an electro-copper block obtained from 

 the original negative taken by Mr. Warren De la Rue. The dark 

 interstices in that plate seem to represent the less luminous portions 

 of the surface, which may possess far less photographic power. 

 How such a picture can be reconciled with the idea of an interlacing 

 of an infinite number of willow-leaf-shaped masses of equal bright- 

 ness I am at a loss to conceive. The brighter parts are in that 

 picture, as I have always seen them, of all imaginable forms, and 

 could not possibly be produced by any such interlacing. 



I"> Another feature of these masses of different brightness may here 

 be adverted to. They certainly give the impression of an undulating / 

 surface, much like that of an orange, or of a fine head of cauliflower 



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