136 



sion that it is a product resulting from atmospherical 

 agitations of oxo -hydrogen. We will analyse first those 

 symptoms which accompany this phenomenon. 



And first we remark that the Aurora appears on the 

 horizon only after the sun has crossed the line of the 

 autumnal equinox, and continues till early spring before 

 the sun crosses the equinoctial line. 2) Its direction is 

 always from S. E. to N. W. 3) Lying in a level mass 

 on the far North, on the South it moves in waves which 

 always roll towards the North, and never in the oppo- 

 site direction. 4) During its appearance there is an 

 audible noise clearly distinguishable in quiet weather in 

 regions near the poles. 5) It invariably produces distur- 

 bance of the magnetic needle, and consequently is clearly 

 a product of electric energy Finally, after its disappea- 

 rance the sky is always clouded. What can we gather 

 from an analysis of these facts? 



The Northern Lights always begin after the autumnal 

 equinox, that is at the time when the equatorial ecliptic 

 passes to the southern hemisphere , a time, therefore, 

 when the North Pole is evidently moving farther from 

 the sun. Meanwhile the oxo hydrogen, distilled and break- 

 ing out sun ward from under the pressure of azote, 

 must fly in the nature of the cosmic arrangements to- 

 wards the sun. but encountering the general cosmic tide 

 it is turned again towards the earth. This tide of gas 

 outside the planetary atmosphere does not, I assume, 

 flow always in one straight line ; if then the direction of 

 the current should be diverted towards the earth; the 

 oxygen would be still more effectually pressed upon the 

 atmosphere at its maximum elevation. The phenomenon 

 is two-fold; fist the initial impetus of oxygen towards 

 the sun i. e. from S. E. to N. W. and secondly the 

 friction of this oxygen against our upper air which, pre- 

 senting a spherical surface like the globe which it sur- 

 rounds, imparts a corresponding bend to the stream of 

 gas. This stream runs like a bent bow ower our atmo- 

 sphere to which it forms a kind of roof, and supplies 



