The Astronomical Outlook 



Lately, also, it has become pretty clear that in 

 the study of solar physics we have to do with 

 conditions not permanent, but transitional; that 

 certain phenomena which have long most per- 

 plexed us, like the peculiar acceleration in the 

 motion of the sun's surface in the regions near its 

 equator, are mere "survivals" and have their 

 origin and explanation not in causes now oper- 

 ating, but in the far-distant past. We study in 

 the sun a process rather than a thing; or, if a 

 thing, one that is not permanent and stable, but 

 in a state of flux and change, and this guiding 

 thought, newly acquired, will probably aid 

 greatly in the interpretation of the facts of ob- 

 servation. Doubtless, also we shall by-and-by 

 have instruments which will enable us to follow 

 out in a way now impossible the daily and hourly 

 changes in the solar radiation and co-ordinating 

 these results with those of visual and photo- 

 graphic observation, we shall gain an insight 

 into the now most puzzling phenomena of sun- 

 spots and prominences. Then, too, the more 

 detailed study of the solar spectrum under var- 

 ious conditions and its comparison with the 

 results of laboratory work are sure to throw light 

 in both directions to give us on the one hand a 

 better understanding of the sun and its conditions 

 and on the other to make more intelligible the 

 nature and behaviour of molecules and molecular 

 forces. It is to be hoped, also, that the faithful 

 observation of eclipses will in time solve the 

 numerous and intensely interesting problems pre- 

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