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When a larger body than usual of light air from the 
south begins to descend upon the upper surface of the 
stream from the north, as those opposite currents in the 
atmosphere come into close proximity, their negative and 
positive electricities produce confiscations. 
The rarity of the atmosphere and the great elevation pro- 
bably prevent (at least for the most part) any sound or 
thunder being heard; and the former cause, joined with the 
manner in which the currents approach each other, may 
probably occasion the shooting, flickering movements of the 
aurora, and of the clouds formerly mentioned as being seen 
by day. 
The arches of boreal light frequently seen stretching from 
E. to W., may be produced by large masses of air, charged 
with opposite electricities, meeting each other and feeding 
the flame, quietly and continuously, on an extended front ; 
while the movements of light occasionally occurring 
throughout the length of these arches, may arise from the 
masses of vapour coming more actively into contact at 
particular points, and lighting up a corruscation, which like 
a running fire, passes along the whole line. 
When the corruscations are more than usually vivid, or 
violent in their motion, it would indicate a larger arrival 
than usual of negatively electric air from S. or S.W., which, 
in a shorter or longer time , according to its strength, first 
checks, and then overpowers the N. or N.E. wind generally 
blowing when the aurora is seen. The lower temperature 
of the atmosphere, cooled down by the recent northerly 
wind, condenses the moisture borne by that from the warm 
somewhere in one hemisphere or other, instantaneously felt through the air, 
however remote — or by conduction, or by vibration — as an earthquake is felt 
on board ship in the middle of a deep ocean, even the South Pacific.” 
The Eev. P. Secchi, Director of the Roman Observatory, in writing of 
magnetic currents in a wire in the magnetic meridian, states that disturbances 
in it indicate the approach of storms, a9 well as the barometer. 
