THE SUN'S WORK. . 349 



sidered as a whole, is a new and somewliat ambitious term which is 

 striving to obtain a footing in science ; and, as the Sun evidently plays 

 one of the leading parts in it, we naturally ask what is his line of action 

 and what he does. And our inquiries are advancing not only under 

 the guidance of more extended views, but by the help of bold and 

 patient research already resolutely carried out. Astronomers lono- 

 concentrated (with great success) their talents within the limits of 

 our solar system, ignoring the rest of the universe, as if it were neces- 

 sarily excluded from the domain of positive knowledge. The first 

 step taken out of those narrow bounds was Fourier's conception of 

 the important influence of the temperature of interstellar space, due 

 to the heat given out by the stars. 



Fourier's notion has recently been amplified by the account which 

 has been taken of the chemical radiations that reach us from the same 

 source. On beholding tiny stars imprint their image on the photog- 

 rapher's sensitive plate in less time than the Moon herself, we cannot 

 help believing that the actinic power of these myriads of distant stran- 

 gers outsiders to our system though they be must exert some kind 

 of influence upon our world. 



Do not meteorites and shooting-stars put us in daily relation witli 

 cosmic materials, which reach us straight from the depths of space, or 

 which have not formed part of our system for more than a few cen- 

 turies ? Moreover (and it is another view of the question), within 

 our system itself we observe phenomena whicli we cannot attribute to 

 the ordinary action of solar heat, and w})ich, nevertheless, are evi- 

 dently connected with the sun. From which we draw the obvious 

 conclusion tliat the Sun has active powers of which we are ignorant ; 

 that the same is the case, perhaps, with the planets themselves \ in 

 short, that we have yet to investigate a multitude of relations between 

 the earth and other heavenly bodies, of whatever kind. We naturally 

 hope to prove the mutual influence of the stars, more particularly in 

 respect to terrestrial magnetism and the electricity of our globe as a 

 striking instance of which may be cited M, Becquerel's happy hypothe- 

 sis of the solar origin of atmospherical electricity. The only fear is, 

 lest, once embarked in this line of speculation, we should be tempted 

 to carry it too far. 



There is less danger of error in studying certain actions of the sun 

 which, though still mystei'ious, are constant and undeniable. By fixing 

 our attention on the sun himself, the source of all energy here below, 

 we run less risk of being led astray. For example : do we find, in 

 known solar phenomena, any reason to believe that the Sun has other 

 means of action besides his' attraction, his heat, and his light ? The 

 answer, " Yes," is ready. The Sun possesses and exercises a plainly- 

 marked repulsive power, of which meteorology has hitherto taken no 

 account, although our atmosphere must experience its eflects. Of the 

 existence of this special force no doubt is entertained by astronomers 



