for the year 1870. xxxi 



The spectrum obtained from the red streamers consisted 

 of a strong red band or line (which I estimated was rather 

 more refrangible than C line), and bands in the green, which 

 I believe to be the same as described by Angstrom. The 

 spectrum of the green light which formed the lower arch of 

 the aurora, however, contained no red band, and the appear- 

 ance of it as the spectroscope was passed up and down, so as 

 to receive the light from the streamers or green arch, was 

 very marked indeed. I am not aware of this red band or 

 line having been noticed by any previous observers ; and 

 had it not been so clear and prominent, far brighter than the 

 green ones — and had I not proved that it belonged to the 

 red streamers, and not to any other of the auroral light, by 

 the method referred to — I might have been doubtful as to 

 the real existence of a line not hitherto noted in the spectra 

 of aurora. 



It is to be regretted, but it is nevertheless true, that 

 meteorology is still in the dark — an occult science. After 

 years of careful observing, and the accumulation of hundreds 

 of ponderous volumes of observations, the laws which 

 govern the weather are almost as deeply hidden from us as 

 ever, in astronomy, phenomena can be predicted centuries 

 beforehand, yet it cannot be foretold what shall be the 

 weather to-morrow. But, admitting this, careful observers 

 cannot divest themselves of the belief that the greater 

 climatic events, such as dry or wet, hot or cold, seasons, 

 recur in cycles, or are brought about by some great telluric 

 or more general cosmical causes, which may yet be traced 

 out. Nor do I think there is anything unreasonable in the 

 belief. If such causes are ever traced, I think they will be 

 found extraneous to our globe, and probably in the varying 

 conditions of the sun itself Every time the more violent 

 disturbances take place in that body the earth's magnetic 

 forces tremble in sympathy — the normal electric conditions 



