346 



the four formulas; for the reasons already given, the fifth and 

 most correct formulas cannot be used in practice : — 



Table II. 













Range of Barom. 





I. 



II. 



in. 



IV. 



from 10, a.m., to 



4, P.M. 



1 



155-30 



156-54 



156-38 



157-63 



-•029 



2 



159-13 



160-88 



15739 



159-12 



+ 013 



3 



156-56 



157-81 



155-93 



157-18 



+ •094 



4 



159-00 



160-43 



159-22 



160-65 



+ •026 



5 



156-61 



157-86 



150-30 



151-50 



+ •044 



6 



157-25 



157-51 



160-25 



161-53 



-•092 



7 



156-70 



15811 



153-19 



154-57 



-■061 



8 



158-76 



159-87 



160-41 



161-53 



+ •034 



9 



160-87 



163-28 



15912 



161-50 



-•157 



10 



157-53 



159-26 



157-49 



159 22 



-■069 





157771 



159-155 



156-968 



158-443 





On examining column I. of these observations, it is plain 

 that they may be divided into two distinct groups, of which 

 Nos. 1, 3, 5, 6, 7 are below the average, and Nos. 2, 4, 8, 

 9, 10 are above the average. Of the latter, Nos. 2, 4, 9 were 

 made on wet days; Nos. 8, 10, on windy days, and in all, the 

 state of the atmosphere may be considered as unsettled ; al- 

 though, so far as the change in the barometer is considered, 

 Nos. 2, 4, 8 will bear comparison with the fine days. 



If we take the mean results of the observations on settled 

 and unsettled days, we obtain the following Table : — 



Table III. 





I. 



II. 



III. 



IV. 



Settled, 



Unsettled, .... 



156-484 

 159-058 



157-566 

 160-744 



155-210 

 158-726 



156-482 

 160-404 



Column III. is less than I. for the reason already given. 

 Comparing columns I. and IV., it is interesting to observe 



