THUKDZX AND LISHTNING. 
447 
"Uinber of judicious experiments made by bim, 
‘to concludes that the clouds serve as coiiduc- 
cojiv, 
the electric fluid from those parts of tlie 
W- 
are overloaded with 
The same cause by 
it, to those where it is 
which a cloud is first 
^ »t\^ ortllJC CtlUsC Uj d la Hi at- 
i, ''se '’opours dispersed in the atmosphere, draws to 
- 
are already formed, and still continues to 
'’''cs, till the whole collected mass extends so far 
V^ifi ® J’ort of the earth where there is a deficiency of 
_ St ^tiid, and w'here the electric matter will dis- 
'tin/ tbe earth. A channel of communication 
fi-Q* P‘'oduced, a fresh supply of electric matter is 
overloaded part, which continues to be 
I'Ofl '’V 
'flit, 
l|,|" fl^j /. 'be medium of the clouds, till the equilibrium 
'l(i, Restored between the two places of the earth. 
that as the wind constantly blows from 
Sl'''"^'ti thunder cloud proceeds, the sudden 
ih?"' a prodigious quantity of vapours must 
repel it on all sides. Indeed, many 
descent of lightning confirm his theory 
‘ f\f rtf' . . r •. r. I r .. _ 
its ascent;, for it often throws before it the 
' \ tiigjj^'^'^'big bodies, and distributes them along the 
Hr '“'s - 'brough which it must force its passage; 
'be longest flashes of lightning seem to 
( 1 ’ by its forchis: in its way part of the vai 
: vapours in 
s ij ‘'s of the chief reasons why tire report of these 
f,, ‘iiuch protracted, is the vast length of the 
\ by the passage of the electric matier ; foi 
^'v'^'br'^ *^°bapses the moment after it has passed, 
>K on which the sound depends, commences 
when the flash is directed towards 
'tid hears the report, the vibrations excited at the 
\ b'Onj . 'be track will reach his ear much sooner than 
Nr ''^tiiote end, and the sound will, without any 
I- ‘cussion, continue till all the vibrations have 
(Sii bim. The rattling iK)ise of the thunder, 
\ * y ^uein as if it passed through arches, or were 
^'Cd^lPon^"’ ** probably owing to the sound being 
1 dir p,^ .^b>uds hanging over one another, and the 
oi^ bregularly between them. 
precautions pointed out by Doctor Franklin, 
'o those who happen to be in the fields, at 
