42 MADEIRA METEOROLOGIC. PART iv. 



aurora is positively an electrical phenomenon, notwith- 

 standing these two grievous difficulties ; viz. first, he 

 cannot explain how, why, or whence so much electricity 

 got into that part of the earth's atmosphere ; and second, 

 the aurora's light invariably shows in the spectroscope a 

 certain citron -coloured line, which has never yet been 

 seen in any electrical spark or discharge in any natural- 

 philosophy-electrical apparatus throughout all the lecture 

 rooms of all the universities in existence. 



Now M. Gaston Plante's theory supplies the first of 

 these two difficulties, though not the second. And in 

 supplying the first it seems to suggest a process of 

 nature in the tropical belt of our earth, somewhat of a 

 comparable but complementary kind to auroral evolution 

 near the poles ; and only too much alike at the present 

 epoch of scientific history in this, viz. that some of the 

 greatest men of the day have each suggested that elec- 

 tricity has the chief part of the work to perform, and yet 

 they cannot quite prove, by experiments with their 

 chamber apparatus, that there is any electricity there at 

 all, of that instrumental kind. 



M. Plante's theory, but which each person interested 

 in the matter should read for himself in the French 

 volume already named, is shortly, that the earth-ball at 

 Creation received a full charge of cosmical electricity, 

 and became an " electrical storage " of the grandest kind, 

 sufficient to last myriad ages, even with a large annual 

 leakage. This leakage he considers to be in a manner 



