[ 21 3 ] 
of thefe effects, and the frequency of die caufes, 
which might produce them. 
We fee, therefore, how important it is to defcribe- 
exactly the phenomena we obl'erve : other wife, how 
long may it be, before we can deduce any real in- 
ftruction from thole, which we have been informed 
of in a negligent and fuperficial manner ? We have 
heard all our lives of St. Helmo’s fire, of thole which 
the antients call Caftor and Pollux, and of the coma-- 
zants of our mariners. But, from what we have 
had related to us, and from what we have read, who * 
could have been prevailed upon to range them with 
electrical phenomena ? We have heard them repre- 
fented, as thin lambent finning lights, a kind of phof- 
phoreal vapour : but there is a paffage in the memoirs 
of the Count de Forbin, quoted by our author, 
wherein mention is made of St. Helmo’s fire ; which 
if any one, well verfed in the phenomena of elec- 
tricity, had carefully attended to and confidered a 
few years ago, he might have prognofticated fuccefs 
to Mr. Franklin, when he propofed his experiment 
upon thunder. " In the night (fays the author of 
“ thofe memoirs) on a fudden it became exceed- 
“ ingly dark, and thunder'd and lightened moll dread-- 
“ fully. As we were threatened with the fHip’s 
u being torn to pieces, I ordered the fails to be taken 
“ in : We faw, upon different parts of the fhip, above 
« thirty St. Helmo’s fires: Among the reft, there was 
one upon the top of the vane of the main-maft, 
tf which was more than a foot and half in height. 
<< I ordered one of the failors to take it down: When 
“ this man was on the top, he heard this fire ; its 
“ noife refembled that of fired wet gunpowder : I 
11 ordered 
