180 On, the Assumption of a Solar Electric Potential. 
the hitherto cairn overcooled aerial sea is thrown will now in- 
duce in it a sudden formation of water and ice. The whirlings 
with horizontal axis of rotation may at the same time acquire 
a great diameter and hurl up the grains of ice repeatedly into 
the ice-region, until they have grown too heavy and fall to the 
ground as hailstones or, after passing through lower warm 
air, as cold drops of rain. By this copious formation of rain 
in a short time the water particles of the path of cloud are 
brought so close together up to the highest air-strata, that it 
becomes a Conductor of electricity and is consequently exposed 
to electrical distribution. If at any place it is in conductive 
connexion with the earth, the earth's electricity must flow 
into it ; and it then receives the same electricity. If it is not 
so, it becomes charged in the vicinity of the earth with the 
contrary electricity, while the similar electricity escapes by 
the conductive vortex-cloud into the higher regions. Where 
the conduction of the cloud is imperfect, it is temporarily 
restored by lightning-flashes springing between the layers of 
cloud insulated from one another, or between cloud and earth; 
and finally, on the whirling storm passing away, and the cloud 
formed by it breaking up, the whole of the electricity will 
again equalize itself with the earth's electricity by flashes of 
lightning, or will in part pass into the air as atmospheric 
electricity. 
Many observations of the formation of thunder-storms have 
been made from the summits of high mountains or from 
balloons ; and almost all of the observers have spoken of 
several layers of clouds one above another, either joined to- 
gether or between which flashes of lightning sprang. The 
most instructive description is that given by M. Wite *, who ob- 
served from a balloon the rise of a heavy thunder-storm. He 
saw "two layers of cloud, one about 2000 feet above the other, 
of which the upper one sent snow, rain, and hail to the lower. 
Between the two passed noiseless undulating masses of yellowish 
light. Electric discharges, with lightning and thunder, oc- 
curred always in the lower layer ; yet the thunder-storm was 
far more violent above both layers than below them. The 
upper layer was strongly agitated by a west wind." That the 
observer could see only two clouds, one above the other, is 
explicable, since his balloon was at the altitude of the interval. 
It is to be presumed that several more such layers of cloud, up 
to the highest region of the atmosphere, were present, between 
which the observed precipitation and processes of electric con- 
duction took place. By the heavy rain falling from the upper 
cloud layer, especially from its middle, the two were conduc- 
* Fortschr. der Physik, 1852, p. 7(52. 
