474 



DISCUSSION OF BAROMETRIC OBSERVATIONS. 



of Wolf's series (that is, the mean of Wolf's numbers for 1836 and 1837 

 is taken as the sun-spot luimber for the year 1836-'37, the mean of the 

 given numbers for 1837 and 1838 as the number for 1837-'38, etc.). In 

 this comparison the observations for the years 1836 to 1853, hitherto 

 omitted from this discussion, are included ; for though in respect to the 

 absolute values of pressure these observations are not comparable with 

 the later ones, they may be considered as fairly comparable as far as 

 range is concerned, though less accurate. 



Table VII. 

 Variation of the Armual Barometric Range. 



In this table a relation bet'ween the mean range and the sun-spot 

 numbers is obvious at a glance, not a single maximum or minimum of 

 the latter series failing to fall on the same year with an opposite phase 



"Years of miuimum suu-spots, and maximmn barometric range, 

 t Years of maximum sun-siiots, and miuimum barometric range. 



