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traced, to show that though, at first, it produced a rise of the 
barometer, afterwards, when it was condensed in the upper 
regions, by heating them, it caused a fall of that instrument ; 
and this condensation also accounted for the reduced tension 
of vapour in the lower regions. The vapour having parted 
with its heat, that heat expanded the gases, and thus reduced 
the weight of the atmosphere, while the conversion of vapour 
into water diminished vapour tension. Improved methods of 
recording the changes of the two thermometers were then 
suggested, for the purpose of showing more palpably the very 
important movements of the aqueous vapour, which so greatly 
disturbs the atmosphere. 
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