What We Learn from the Sun 



hemispheres during the night which followed; 

 and the whole frame of the earth seemed to 

 thrill responsively to the disturbance which had 

 affected the great central luminary of the solar 

 system. 



The reader will now see why I have discussed 

 relations which hitherto he may perhaps have 

 thought very little connected with my subject. 

 He sees that there is a bond of sympathy be- 

 tween our earth and the sun ; that no disturbance 

 can affect the solar photosphere without affecting 

 our earth to a greater or less degree. But if our 

 earth, then also the other planets. Mercury 

 and Venus, so much nearer the sun than we are, 

 surely respond even more swiftly and more dis- 

 tinctly to the solar magnetic influences. But 

 beyond our earth, and beyond the orbit of moon- 

 less Mars, the magnetic impulses speed with the 

 velocity of light. The vast globe of Jupiter is 

 thrilled from pole to pole as the magnetic wave 

 rolls upon it; then Saturn feels the shock, and 

 then the vast distances beyond which lie Uranus 

 and Neptune are swept with the ever-lessening 

 yet ever- widening disturbance- wave. Who shall 

 say what outer planets it then seeks? or who, 

 looking back upon the course over which it has 

 travelled, shall say that the planets alone have felt 

 its effects ? Meteoric and cometic systems have 

 been visited by the great magnetic wave, and 

 upon the dispersed members of the one and the 

 subtle structure of the other effects even more 

 important may have been produced than those 

 17 



