C 632 ] 
tus, of which I formerly gave an account to the 
Royal Society. 
I have great reafon, my lord, to think that the 
mifchiefs arifing from thunder and lightning, happen 
always near the place, where the explofion is made ; 
as thofe perfons, who have been prefent, when great 
mifchiefs have been done, univerfally agree, that 
when thefe accidents have happened, the report of 
the thunder has indantly fucceeded the Hath of 
the lightning. As the progrefs of light is nearly in- 
dantaneous, and' that of. found fomewhat more than 
1 1 00 feet in a fecond of time, the thunder and 
lightning happening in the fame indant proves the ex- 
plolion to have been very near. 
We are therefore to guard againft the thunder- 
clouds, which are near us. The mad; of every dfip, 
which is befet on its tops with thofe bright lights, 
which our mariners call comazants, and are th z fcic 
St. Ebne of the French, and were the Cajlor and Pol- 
lux of the ancients, is within the fphere of adhon of a 
thunder cloud. Anciently, when thefe were feen, they 
were only confidered as the attendants of a dorm, and 
no confequence was- drawn from them; but now, 
(fince Dr. Franklin 's admirable difcovery of conduct- 
ing lightning from the clouds, we know them to be 
no other than a modification of the fame meteor, 
which conditutes thunder and lightning) they de- 
mondrate that danger is near, and therefore we diould 
do our outmod to prevent its effedts. This in my 
opinion would be done, if a wire of iron or any other 
metal were connedted with the fpindles and iron work 
at the tops of mads of fhips, and condudted down the, 
fides of the mads, and from thence in any con- 
s’ venient 
