THE EARTH. 265 



cieiit light for all the purposes of existence. However, in the 

 very midst of their tedious nights, the inhabitants are not en- 

 tirely forsaken. The tops of the mountains are often seen 

 painted v,nt.h the red rays of the sun ; and the poor Greenlander 

 from thence begins to date his chronologj'. It would appear 

 whimsical to read a Greenland calendar, in which we might be 

 told, That one of their chiefs, having lived forty days, died, at 

 last, of a good old age ; and that his widow continued for half a 

 day to deplore his loss, with great fidelity, before she admitted a 

 second husband. 



The meteors of the day, in these countries, are not less ex- 

 traordinary than those of the night : mock suns are often re- 

 flected upon an opposite cloud ; and the ignorant spectator fan 

 cies that there are often thi-ee or four real suns in the firmament 

 at the same time. In this splendid appearance the real sun is 



proceed, and we shall soon perceive the electricity forcing itself through the 

 air within it, in a visible stream. At first this stream is of a deep purple co- 

 lour ; but, as the exhaustion advances, it changes to blue ; and at length to 

 an intense wliite, \vith which the whole receiver becomes completely filled. 



This experiment would appear to establish the identity of the aurora bore- 

 alis with electric light ; and it may be mentioned as collateral proofs of this 

 identity, that the atmosphere is found, by the electrometer, to abound with 

 electricity when tke aurora shines forth ; that the aurora, when strong, is 

 accompanied with the whizzing or craekling sound of electricity ; and that 

 the magnetic needle is evidently disturbed by the aurora, as well as by the 

 action of an electrical machine, or by the natural electricity of a thunder 

 storm. The course of the aurora is uniformly from the poles towards the 

 equator ; and stipposing it to consist in a stream of electric light, the follow, 

 ing reasons may be assigned for its constantly preserving this course. Ex- 

 treme cold renders almost all bodies electric, or disposed to accumulate elec- 

 tricity ; while heat and moisture occasion a conducting power. Air, when 

 dry and cold, is powerfully electric; and heuce the beautiful phenomena of 

 the aurora are confined to the polar regions, and appear by night and not by 

 day, and in winter rather tlian in summer. The inferior part of the atmo- 

 epliere, between the tropics, is violently heated during the day time, by the 

 reflection of the sun's rays from the earth, while the superior parts retain 

 tlieir original cold. It is also impregnated with moisture exhaled by the 

 powerful heat wluch then acts upon the earth. It is therefore in the con. 

 ducting state, and readily communicates the electricity of the superior regions 

 to the clouds which float in it, or to the body of tlie earth. Hence the awful 

 electrical phenomena of the tropical regions, exhibited in thunder and light. 

 ning, water spouts, whirlwinds, and the most tremendous tempests. The 

 electrical fluid is thus conveyed in great quantities from the upper parts of 

 the atmosphere between the tropics, to the lower stratum, and thence to the 

 earth ; and the inferior and warm atmosphere, having once exhausted itself, 

 must necessarily be recruited from the upper and colder region. 



