Miscellanies. 153 
3. On shooting stars —Prov. Suximan.—Dear Sir—The trans- 
parent vapor, which was described in the last number of your Jour- 
; nal as the basis of the aurora borealis, unquestionably exists in va- 
rious tracts of the atmosphere, independently of latitude. It possi- 
bly gathers in larger quantities towards the pole, but the principal 
reason why it appears. more luminous and extensive as we recede 
from the equator, is its relative position to the solar light. 
While examining the causes of the aurora borealis, I became con- 
vinced, that shooting or falling stones are derived from the same ori- 
gin. A flake of the vapor, which forms the basis of the aurora, by 
reflecting the light of a star, vertical or nearly so to its apparent 
place, becomes an image of the star, and while it remains quiet is 
hot distinguishable from others in the hemisphere. When an aerial 
current crosses it, it is immediately removed from the direct rays of 
the particular star whose image it reflected, and disappears, or in 
fommon phrase, goes out, in the same way that the streams and 
flashes of the aurora vanish by changing their relative positions to 
the source of illumination. 
alling stars descend diagonally, unlike the aurora of these lati- 
tudes, which undulates, or shoots upwards when it moves at all; but 
a the northern regions its motions are very often lateral, and in some 
mstances it falls perpendicularly. The levity of the vapor in the 
aurora is one of its characteristics, and the increase of its specific 
Stavity so far as to causesits descegt, is an exception to its prevailing 
Condition ; in the star, ver, as in the descending aurora, the va- 
Por becomes surcharged with moisture, ‘or its elgments form some 
new combination sufticient to overcome in part, its buoyancy, and 
the resistance of the ‘atmosphere. And this is consistent with the 
laws which regulate the clouds, which at one time float in the air, 
and at another descend. We cannot follow the erratic movements 
of this vapor after it leaves the position where the lines of light dis- 
Close its existence, because it is invisible except when locally lumin- 
ous in the night; and whether it is dispersed in the expanse of the 
heavens after it disappears from our sight, or whether it combines 
mith the clouds@lBeomes itself a cloud, or whether by parting — 
ith its superfluous moistare it retains its gaseous and invisible iden- 
uty is unknown. ; 
Shooting stars increase in number and frequency towards the equa- 
‘or, as the aurora increases towards the pole. M. Humboldt describes 
a being innumerable over the seas between Maderia and Af- 
q 9? 
Vou. XX 
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