434 
ELECTRICITY OF THE AIR. 
M. Quetelet observes that we have no precise ideas of the 
absolute force of electricity^ and that we do not know whether 
its intensity is greater in the north than in the south, although 
if the upper stratum of the air is not so high, the electricity 
must be stronger, as seems to be shown by the auroras. 
“ The earth is generally regarded as solid throughout all its 
extent, although many physicists consider that it is only solid 
in its exterior portion. They say, and, as we think, with reason, 
that the interior portion, in a state of greater or less fluidity, 
may have its own movements, which may occasion magnetic 
variations, and also the electric variations that are intimately 
connected with them.^^ 
The great laws of the distribution of atmospheric electri¬ 
city are often masked by secondary causes. Thus, especially 
during the summer, we notice the formation of strata of 
clouds carrying an electricity which M. Quetelet denominates 
accidental^ and which gives rise to storms. These clouds 
may be the origin of hail, which finds itself attracted and re¬ 
pelled by the upper stratum of the air, until it falls by force 
of gravityor there may be a direct electrical action upon 
the earth in the shape of storms. Negative electricity is 
more frequent in the atmosphere during the summer, the 
space between the earth and the stationary portion of the at¬ 
mosphere being then greater, and also being drier and better 
able to accommodate clouds which assume “a supplementary 
electricity.” The tranquil passage of electricity towards the 
earth is more frequent in winter, but in the summer, by 
reason of the greater dryness, it is less continuous and more 
violent. Thunder storms are more common in summer than 
in winter, but those of the latter season are often extremely 
dangerous. One, for example, in the winter of I860, struck 
twenty clock towers within the limits of Belgium, and in the 
course of a few hours; and in the night of April 14th, 
1718, twenty*four towers were struck in France, along the 
coasts of Brittany. Summer storms are usually less destruc¬ 
tive on the surface of the earth, and their action limited to a 
smaller space. AVinter storms act over a wider range. 
M. Quetelet gives numerous details of the great storm of 
the 19lh February, I860, to which allusion has just been 
made, and which surpassed in violence any ever known to 
have occurred in Belgium. It began on the evening of the 
Sunday in question, and followed the route usually taken by 
such scourges in that country. About seven oVlock it burst 
over Rolleghem and Courtroy; an hour afterwards it reached 
Ghent, Brussels, and the neighbourhood of Antwerp; and by 
nine it was at Liege, carrying devastation as it went, and 
