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XXVI. An Account of a new: FleStrometer^ 
contrived by Mr. William Henly, and of 
fever al FleSlrical Experiments made by 
him , in a Eetter from Dr . Prieftley, F.R.S « 
to Dr. Franklin, F. R. S. 
Dear Sir, 
Read May THINK myfelf happy in an oppor- 
j[ tunity of giving you a fpecies of plea- 
fure, which I know is peculiarly grateful to you as 
the father of modern eleCtricity, by tranfmitting to 
you an account of fome very curious and valuable 
improvements in your favourite fcience. The author 
of them is Mr. Henly, in the Borough, who has- 
favoured me with the communication of them, and 
has given me leave to requeft, that you would pre- 
fent them to the Royal Society. 
In my hiftory of eleCtricity, and elfewhere, I have 
mentioned a good electrometer, as one of the greateft 
defiderata among practical electricians, to meafure 
both the precife degree of the electrification of any 
body, and alfo the exaCt quantity of a charge be- 
fore the explofion, with refpedt to the fize of the 
electrified body, or the jar or battery with which it 
is connected ; as well as to afcertain the moment of 
time, in which the electricity of a jar changes, when, 
without making an explofion, it is difcharged by 
giving 
