ON SUNSrOTS AND TBnRESTRIAL PHENOMENA. 



463 



tity of 



nine in 

 9 i^■, of 

 I have 

 le dlCB- 



9 cotn- 

 to deny 

 suspend 

 3 ample 



1 crises, 



I years is 

 the sun- 

 lS misled, 

 ) sunspot 

 and there 

 or tiiree 



10 former, 

 different 

 to be no 



length we 

 regularity. 

 9 an argu- 

 If is rather 

 lienoniena, 

 spots, \vAi-- 

 t curves, 

 .estion wiis 

 . determine 

 Lich, during 

 ay all over 

 9 ought to 

 id not here 

 ,ooth down 

 it the price 

 ^and and in 

 at countries 

 [he yielil of 

 this i« <i"^- 

 inf"" widely 

 [lowever, no 

 [pots, except 

 of impoi't** 



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 appeai-ance 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 snnspot changes. 



The celebrated astronomer Pruhns lias 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 bo connected with swarms of meteorites, we might perhaps 

 ultimately find the snnspot 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,' and I^ have brought forward arguments 

 in favour of this view. The remark of 13ruhns 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 boon remarkable for the display of auroroa and 

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

 in aurora). 



Conclusion. 



Having thus given a rapid survey of those meteorological phciiomeiia 

 which po.ssibly or probably may bo connected witli occurrences on the 

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

 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 necided is half a 

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

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

 go to rlie great luminary himself, and ask him plainly whether ho varies or 

 not P If he answers No, then some of ns must recon.sider our theories, and 

 perhaps endure a little ridicule. Jiut 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 

 Casco, in Cashmei*e, in Piazzi Smyth's observatory on the Peak of Tenei'iffe, 

 in Central Australia, or wherever else the sun can bo 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 suc(n>ss and our failure, our elation in 

 commercial success, and our despondency in commercial collapse.' 



' Proc. Itoy. Soc. xvii. p. 1, 1SG8. 



Observatory II. p. -'02. 



rial matters*, 



are operat- 



.stem. The 



240. 



