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VII. An Account of an Experiment made before the 
d(pyal Society , touching the proportion of the Weight 
of Air , to the Weight of a like Bulk of Water , with- 
out knowing the Quantity of either. By Mr Fra. 
Hauksbee, F. $(. S. 
Jt Took a Bottle fomewhat of an Oval form, ( which 
X I had purpofely caus’d to be made fo, that it might 
with more eafe Librate in Water.) It held more than 
three Gallons, ( but how much we have no occafion 
to know. ) Into this Bottle I put as much Lead as 
would fink it under the furface of the Water, and was, 
when weigh’d in that Element, Ballane'd by a fmall 
Weight in- the Scale on • the other end of the Beam, I 
chofe to include my Weight, to prevent the Inconve- 
niency of Bubbles of Air, which I knew would plenti- 
fully adhere to and lurk in the Irregular Body of the 
Weight, had it been fixt on the outfide c, and muft 
( I think) of neceffity make an Error ftf an Experiment 
winch requires fo great a Nicety as this. Thus provided, 
the Bottle being clos’d with Common Air, was by a 
Wire fufpended at one end of a very good Ballance, and 
being in the Water, was Counterpois’d by a Weight of 
385 Grains and a half in the Scale hanging on the other 
end. Then being taken out and (crew’d to the Pump, 
it was in 5 minutes of Time pretty well exhaufted, the 
Mercury in the Gage being Elevated to near 29 inches 
and a half. It was then taken off the Pump, but| firft, 
by Turning a Cock that Screw’d both to it and the 
Pump, the Air was prevented from Returning into it. In 
S3 Q this 
