528 



BESSBL. ON BAROMETRICAL. 



and the second section 



0*2457 



loer f 10- « ' + '^ ^* = J; ^. 



^ m — t ^ 



We obtain thereby 



logA=/r^-/r 



log B = log A + \I/ r, + log (r — r^) -f log b, 

 and a,, which is sought, = A — B. 



If we determine in this manner the values of a for two eleva^ 

 tionSj they will seldom be found of equal amount ; as the lav 



