34 
“ On the Electrical Properties of Clouds and the Pheno- 
mena of Thunder Storms,” by Professor Osborne Reynolds, 
M.A. 
The object of this paper is to point out the three folio wing- 
propositions respecting the behaviour of clouds under con- 
ditions of electrical induction, and to suggest an explanation 
of thunder storms based on these propositions and on the 
assumption that the sun is in the condition of a body 
charged with negative electricity : an assumption which I 
have already made in order to explain the Solar Corona, 
Comets’ Tails, and Terrestrial Magnetism. 
1. A cloud floating in d,ry air forms an insulated electri- 
cal conductor. 
2. When such a cloud is first formed it will not be charged 
with electricity but will be ready to receive a charge from 
any excited body to which it is near enough. 
3. When a cloud charged with electricity is diminished 
by evaporation, the tension of its charge will increase until 
it finds relief. 
I do not imagine that the truth of these propositions will 
be questioned, but rather, that they will be treated as self 
evident. However, as a matter of interest I have made 
some experiments to prove their truth, in which I have 
been more or less successful. 
Experiment 1 was to shew that a cloud in dry air acts the 
part of an insulated conductor. The steam from a vessel of 
hot water was allowed to rise past a conductor, the apparatus 
being in front of a large fire, so that the air was very dry. 
When the conductor was charged the column of vapour was 
deflected from the vertical to the conductor both for a posi- 
tive and negative charge. 
Experiment 2 was made with the same object as Experi- 
ment 1. A gold leaf electrometer was charged so that the 
leaves stood open and then a cloud made to pass by the insu- 
lated leaves. As the cloud passed they were both attracted. 
