2Q On the Distribution of Cyclonic Precipitation in Japan. 



where ^,„ is the mean kititude and ;/ the coefficient of friction in 

 Guldberg and Mohn' s sense. The flux across the circle with the 

 radius ;■ is ^7:rücos,</> where v is the resultant velocity of wind at P, 



given by 



_ Gcos</> 



in which G is tlie gradient aecelaration : 



dr 



where B is tlie barometric pressure and K a constant,''^ The excess 



of the llux across the circle with the radius r-^-dr is 



o / d(rv) 7 o cos-ç^/^ , dG \ , 



'2-cosc^— ^ — ^ dr=-^~ ^(G-^r-^ — )dr. 



dr n dr 



Hence the total amount of the ascending current per unit length of 

 the circular belt with the breadth fZ/-is 



cos'YVr' I dG^n 

 }•>( dr' 



If the air is kept artihcially always in saturation corresponding to 

 the momentary temperature as assigned hj the given temperature 

 distribution, the condensation of water vapor due to the ascending 

 current will be proportional to the mean absolute humidity or 

 nearly to the mean maximum vapor tension E between P and Q. 

 The latter is well known as the function of temperature 



E=ÂT) say. 

 Hence the condensation per unit liorizontal area at P will be pro- 

 portional to 



B = I^±l{G + r^'-^) cosV- (1) 



;//■ dr 



;//• dr 

 It lor example, G = co)ist. = G^, A = ^^^^— — -^ , (2; 



}cr 



or it G = br, B = ^^^-^ -> (3) 



in which f{T) may always be regarded as the function of the space 

 coordinates of P, since T is given as such. Tliis holds indeed 



* Though of course, in actual cases, K involves the temperature of the air column, 

 the above assumption may be allowed for the present purpose. 



