54 



CONSTRUCTION OF ISOBARIC CHARTS 



Table 10. — Concluded. 

 The Values of Ilr"^ '° °°°=i>r— Pro. 



Table 11. 

 The Values of 115° ™S =Pi8 55o— P»o 



As an illustration of the way in which Tables 9, 10 and 11 are to be used let it be 

 supposed that the following values of tr have been deduced from balloon observations 

 made during static atmospheric conditions : 



Between T'= 

 « F= 



1 8 550 and 

 20 000 " 

 30 000 " 

 40 000 " 

 50 000 " 



20 000, t = 67.0 

 .30 000, f = 69.5 

 40 000, / = 73.0 

 50 000, t^ = 74.0 

 60 000, i^ = 73.5 



