ON SUNSPOTS AND TERRESTRIAL PHENOMENA. 463 



evidence of periodical changes in the appearance of the surface of Jupiter 

 is very strong. Wolf was the first to draw attention to these periodical 

 changes. More lately, Ranyard tried to show that the distinctness of the 

 belts, as well as the appearance of certain spots in the atmosphere of 

 Jupiter, pointed to a connection with sunspots. Dr. Lohse has further 

 investigated the matter, and has found a strong evidence of periodical 

 variability in the belts coincident with sunspot changes. 



The celebrated astronomer Bruhns has made a remark which, if con- 

 firmed, would throw a great deal of light on the whole matter. According 

 to him, there were fewer comets visible during this present century at 

 times of minimum than at times of maximum sunspots. As we know 

 comets to be connected with swarms of meteorites, we might perhaps 

 ultimately find the sunspot period itself to be due to the periodicity of 

 such swarms, having their perihelion close to the sun. This was first sug- 

 gested by Johnstone Stoney, 1 and I' 2 have brought forward arguments 

 in favour of this view. The remark of Bruhns has, however, been much 

 weakened by the subsequent inquiries of Wolf. Fritz, on the other hand, 

 has pointed out that the centuries in which we know that many large comets 

 have appeared have also been remarkable for the display of aurorae and 

 of sunspots, while the seventeenth century was poor alike in comets and 

 in aurorae. 



Conclusion. 



Having thus given a rapid survey of those meteorological phenomena 

 which possibly or probably may be connected with occurrences on the 

 solar surface, I must leave every one to draw his own conclusions. But 

 few, I think, will not re-echo the following eloquent remarks of Professor 

 Stanley Jevons : — 



' But why do we beat about the bush, when all that is needed is half a 

 dozen of Pouillet's heliometers with skilled observers, who will seize every 

 day to determine directly the heating power of the sun. Why do we not 

 go to the great luminary himself, and ask him plainly whether he varies or 

 not ? If he answers No, then some of us must reconsider our theories, and 

 perhaps endure a little ridicule. But if, as is much more likely, he should 

 answer Yes, then the time will come when the most important news 

 in the "Times " will be the usual cablegram of the solar power. Solar 

 observatories ought to be established on the table-land of Quito or 

 Cusco, in Cashmere, in Piazzi Smyth's observatory on the Peak of Tenerilfe, 

 in Central Australia, or wherever else the sun can be observed most free 

 of atmospheric opacity. An empire on which the sun never sets, and 

 whose commerce pervades every port and creek of the sunny South, can- 

 not wisely neglect to keep a watch on the great fountain of energy. From 

 that sun, which is truly " of this great world both eye and soul," we derive 

 our strength and our weakness, our success and our failure, our elation in 

 commercial success, and our despondency in commercial collapse.' 



1 Proc. Boy. Soo. xvii. p. 1, 1868. - Observatory II. p. 262. 



