48 REPORT—1840. 
the atmosphere to be lighter; that the greater quantity of rain falling 
on the earth than at any elevation in the same locality, is occasioned 
by each falling drop of rain attracting to itself every particle of invi- 
sible vapour which may be floating within the sphere of its electrical 
attraction, and thus increasing its bulk. 
The paper concludes with proposing the experiment of raising elec- 
trical conductors to the regions of the clouds by means of balloons; 
which, in the author's opinion, would withdraw the electricity, and cause 
clouds and rain to be formed. 
On the Cause of the Aurora, §c. By G A. Rowe tt. 
The phenomenon of the aurora is explained thus :—The vapour 
rising at the equator, being greatly expanded, ascends to a great height 
with a great accumulation of electricity ; is thence carried by the cur- 
rents of air towards the poles, where the electricity again escapes to the 
earth and rushes along its surface, and the vapour in the lower parts 
of the atmosphere towards the equator is again carried off, thus cau- 
sing currents of electricity ; this circulation continues freely while the 
air at the poles is damp; but during the severe frosts of winter in the 
frigid regions, the air, near the earth’s surface, is nearly or quite dry, 
and the aurora is exhibited by the electricity passing through this 
non-conducting medium. 
By these currents, and the supposition that magnetism is owing to 
the attraction which the magnet has for electricity, which from some 
peculiarity can pass through it in one direction only, and that there be 
two sorts of electricity, one predominating in each hemisphere, the va- 
rious phenomena of magnetism are explained thus:—The direction 
of the needle is owing to its being attracted in the direction from which 
the streams passing through it are derived, the streams in this hemi- 
sphere converging to the north pole, and diverging or escaping from 
the south pole to gain their equilibrium ; that the dip is caused by the 
currents derived from the earth being stronger than those from the 
air and vapour above the needle; that the variation is owing to the 
greater quantity of electricity received by the earth at the magnetic 
poles, diverging east and west to gain its equilibrium in passing towards 
the equator; that the probable cause of the great quantity being re- 
ceived at these parts of the earth, is from the height of land conduct- 
ing the electricity to the earth, or because the temperature is constantly 
lowest at these points of the earth, thus causing a draught of air, vapour, 
and electricity, from the warmer parts of the earth through the upper 
parts of the atmosphere ; and that the daily variation is occasioned by — 
the greater or lesser formation of vapour, according to the direct action 
of the sun on different parts of the earth. 
The repulsion of similar and attraction of opposite poles of the 
magnet is thus explained :—The needle is kept in its magnetic meridian ¥ 
t 
by the converging streams to the north pole: now if the north pole of 
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