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OBSERVATIONS in METEOROLOGY, 
PARTICULARLY WITH REGARD TO THB 
DAW e2POMTD 
Or quantity of Vapour in the Atmosphere ; 
MADE ON THE MOUNTAINS IN THE 
NORTH OF ENGLAND, 
From 1803 to 1820. 
——I IN FS 
BY JOHN DALTON, F.R.S. &c. 
(Read Feb. 9th, 1821.) 
ne ti 
In my paper on Meteorology, vol. 3, page 
509, I mentioned my intention of drawing 
up a memoir on the subject of vapour or 
steam in the atmosphere, particularly with 
regard to the idea of a distinct vapour at- 
mosphere, mechanically blended with the 
common one, but acting by its own tension 
or elasticity, and being subject to conden- 
sation by cold exactly in the same manner as 
an insulated atmosphere of steam would be. 
/The following collection of observations and 
—— 
