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* SOME years ago I difcovered, by Mr. Canton’s 
electrometer, defcribed in the Philof. Tranfattions, 
Vo!. XLVI 1 I. p. 783. that the air of Ireland is, 
during the winter feafon, in almofl a conflant flate 
of pofitive electricity ; which, however, is fo weak, 
that, in order to oblerve it fatisfadlorily, I have al- 
ways found it neceflary to have the cork-balls fuf* 
pended from threads of a middling finenefs, fix or 
(even inches in length, quite ft reight, and to avoid, as 
much as poffible, any interruption from the wind. 
1 have likewife had frequent recourfe to the fol- 
lowing contrivance, by which I was enabled, within 
doors, to purfue my inquiries with greater accuracy 
and advantage : having procured a (lender tapering 
piece of wood, about five feet long, to the fmaller 
end of which an electrometer was affixed, by means 
of a fmall hook ; I placed it out from an open garret 
window, and fattened the other end with a lmall 
hafp to one of the jambs : I had alfo at hand another 
piece of wood, in the ends of which, a fmall glafs 
tube and a flick of fealing-wax had been inferted. 
Either of thefe was occafionally excited, and applied 
near the cork-balls, in order to determine more pre- * 
cifely the kind of eledlricity with which they might 
happen to be affedled ; and I was always careful in 
-* I commenced my experiments on the air in the year 1761, 
and thofe on the clouds in the year 1762. I continued them un- 
remittingly, as opportunity offered, till the year 1770, when 
my occalions brought me to England. I have repeated my ex- 
periments, with regard to the common air, in different places 
here, and find it the fame as that in Ireland. 
making 
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