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IV. A Letter from Granvile Wheler^ Efq-j to 
L)r. Mortimer, Seer, R. S. containing fome 
Remarks on the late Stephen Gray, F. R. S. 
his Eledrical Circular Experiment, ^ 
SIR, 
S OME odd Circumftances led me to make Mr. 
Gra/s circular Experiment in the following 
Manner. While I excited a Cake of Rofin and Bees- 
wax ten Inches Diameter, by clapping with my Hand, 
I let my ivory Ball continue in a Baftn of Watery 
then fliaking off the Drops, placed it in the Centre, 
and with my right Hand held a fine Thread, about 
eight or nine Inches long, having one End rolled up 
into a little Ball, and the other, for about an Inch, 
reduced to its greatefl; Finenefs, to only one Fibre, 
myfelf and Hand being fupported on the Back of a 
Chair. The Succefs was, 1 had a great many Revo- 
lutions, to the Number of Fifty, from Weft to Eaftj 
but at firft not fo regular as towards the laft, at firft 
deferibing only about one third Part of the Circum- 
ference at a time, and after Banding Bill a little, 
deferibing another third Part. I might probably 
have had a great many more Revolutions, but being 
tired, 1 was forced to reft myfelf, which I did for ten 
Minutes, then took up the Thread again. The 
Thread flood repelled at fome Diflance, without 
making any Revolutions, and at laft only made half 
an one the contrary way to what it did before; but 
upon wetting it, by drawing it two or three times 
* Sc&PhilofophicalTravfa{iions^ 220 . and 44.4, />. 400. 
of the Revolutions of pendulous 'Bodies by Electricity. 
over 
