T. Torada : 27 



for any (listribiiti(jii of tciuperaturo, provided it is maintained 

 stationary by any cause. In tiie present particular case, the curve 

 of equal B will be parallel to the isotherms and be straight, if 

 G=br, and R will increase toward the direction of the increasing 

 T. When G=const. and for example T=T,—Gy, the curves will 

 be given by f[T„ — Cij)/\/x- + y'-=const. in Cartesian coordinates, 

 which are generally concave toward the direction of increasing T. 

 This will liold within the limit of the inner region and the effect 

 will in any case tend to shift the centre of precipitation area 

 toward the direction of the increasing temperature. 



The quantity B is, however, not the only one in determining 

 the precipitation. When the air proceeds from Q to F, the 

 temperature must vary, due to the assumjittion that the isotherms 

 are stationary. It will be easily seen from the figure that the 

 temperature decrease is given by 



COS^ 



when T=l\ — Cy. Hence the unit volume of air, in proceeding 

 unit distance along /•, condenses out an amount of water given by 



clE clT _ df(T) c_sin(t^=E' - u) 



(IT dr dT cosç-'' ■ ^^ 



Tbis will 1)0 zero for d = <J', positive for d = - + </' to 2- + ^^-, and 

 negative (i.e. evaporation instead of condensation) for ^ = ^ to 



Tbe total ])i'ecipitation will then be proportional to B + Ii' in 

 which tlie effect of B' is in ;my case to shift the centre of the 



heaviest })recipitation toward the (hi'ection 6 — — + </'■ In the 



above, it has been assumed tliat Ji at any place is merely due to 

 the condensation caused by the vertical current at tliat very spot. 

 In the actual case, however, the ascending air is transported 

 leewards by the horizontal current to an extent depending on the 

 ratio of the horizontal vel()City to the vertical an<l also t(_) tlie 

 height of the cloud layer. 'J'bis effect will result in deforming and 

 twisting the isohyets as a whole m counterclockwise sense. 



