DATA OF VARYING PRESSURE. 

 TABLE 8. Data 1 corresponding to table 7 for larger ranges of dp. 



21 



1 Color distortion. The value of s corresponds to g y at least. 



2 Fog chamber cleaned of water nuclei after each observation. 



13. Explanation. It will next be necessary to endeavor to coordinate 

 the two curves for [dp^ and [dp}'. If the absolute temperatures of the 

 air within the fog chamber before and after exhaustion are T and r l 

 (adiabatic pressure p t ) then apart from the condensation of water vapor 

 at the original vapor pressure x at T, we may write as one extreme case, 



With a large vacuum chamber the difference between p l and p 3 is very 

 small relatively to p l and p 3 , so that for the present purposes p p d = 

 pp l = dp (nearly), whence 



T I I dp(7:7i: l )Y k ~ c)/h 

 r"' = \ prc 



Similarly we may write as a second extreme case, 



or the degree of sudden cooling from a fixed temperature r to the adia- 

 batic temperature r l depends primarily on dp /p. This would in any case 

 be permissible for comparison in table 6, where a continuous series of 

 experiments is made at the same temperature. The moisture error is 

 thus a constant throughout. Hence the apertures of coronas s, and the 

 nucleation n, will be a function of dp/p to the degree specified. 



