FOR HIGH LEVELS IN THE EARTh's ATMOSPHERE. 57 



If the value E-^]^ — 7 620, viz., the number of level surfaces of gravity pre- 

 viously found to lie between the isobaric surfaces jj = 28.0 and p — 27.5, be added to 

 the value 25 930 just found for Fago, then we obtain the quantity ViT,^ — 33 550, or 

 the total number of level surfaces of gravity lying between sealevel and the isobaric 

 surface jj = 27.5 inches. Again by adding 'E^i = 7 800 to F27.5 = 33 550, we obtain 

 Kjy.o = 41 350 ; by repeating this process the following values of Vp result : 



Under static equilibrium in the atmosphere the values of U\\, ji,-, EJJ;, and Vp are 

 constants at all points and at all times. Therefore a single balloon ascension, worked 

 up in the manner just described, would suffice to determine for all time the relative 

 positions of the isobaric surfaces and the level surfaces of gravity throughout the 

 whole mass of static atmosphere. 



