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OBSERVATIONS 
ON THE 
BAROMETER, THERM omETER, 
AND 
RAIN, 
AT MANCHESTER: 
From 1794 to 1818 inelusive. 
BY JOHN DALTON. 
(Read November 13, and December 11, 1818.) 
1, Of the Barometer. 
In along series of observations it is scarcely 
to be expected that the same instruments can 
be used throughout. Accidents are occurring 
which either derange or destroy them. It is 
expedient, therefore, to notice such occur- 
rences; as it seldom happens that instru- 
ments, particularly barometers, are replaced 
or renovated in like circumstances as before; 
and if this is not the case, they must neces- 
sarily mislead in comparison. 
During the first period of five years, I 
had a barometer consisting of astraight tube 
