186 THE POPULAR SCIENCE MONTHLY. 



Jupiter, and the Sun representing stages of development separated 

 by vast intervals of time, certain regions north and south of their 

 equators are the scene of violent disturbances in their fluid shells or 

 envelopes. But it will not do to liken these phenomena upon the 

 three different globes too closely to one another, for they unquestiona- 

 bly differ not merely in magnitude but in kind and in mode of opera- 

 tion, and this is specially true as to the earth and the sun. We may 

 speak of a sun-spot as a solar cyclone, but we must not forget that it is 

 very different from our West Indian cyclones or East Indian typhoons. 

 The point is that in each case that of a solidified globe like the earth, 

 surrounded by a comparatively rare atmosphere ; that of a partially 

 cooled globe, like Jupiter, enveloped in a dense atmosphere of great 

 depth ; and that of a completely gaseous globe like the sun, possessing 

 a sort of shell of partly condensed gases certain regions near the 

 equator are those in which the greatest disturbance is visible, and in 

 every case, probably, the force of rotation is a powerful factor in the 

 production of these zones of commotion. This shows a sort of sur- 

 vival of the action of certain causes under changed conditions, as a 

 globe proceeds in the process of cooling and condensation from the 

 condition of a sun to that of an unsolidified planet, and so on to the 

 condition of a crusted or solid earth. So, then, we may with some 

 show of reason suggest that the half -belted appearance of the sun last 

 summer was in a certain sense prophetic of its future condition, and 

 that in time its spot-zones will be succeeded by continuous belts re- 

 sembling those of Jupiter. But no human eye will ever behold the 

 sun thus robbed of his majesty, with his glorious light extinguished 

 by bands of gloomy vapors ; for, long before he could reach such a 

 condition, life would cease in the solar system, from want of his vivi- 

 fying radiations. 



The picture of Jupiter here given possesses some interest in itself, 

 as it is a representation of the planet as it appeared in September, 

 1879, when the celebrated red spot was a very striking object. The 

 spot is seen at the left hand edge of the disk, just above the great 

 southern belt which is narrowed, or indented, in a very singular way, 

 opposite the spot. The red spot is no longer visible, and as it was, 

 perhaps, the most remarkable marking, except the belts themselves, 

 ever seen upon Jupiter, pictures of it will possess great interest in 

 the future. 



