On the Effect of Topography on the Precipitation in Japan. J J 



monthly value of precipitation and the barometric gradient. 

 Table VII gives the mean monthly gradient to be compared with 

 the precipitation given above in Table II. In Table VIII, the 

 differences of the percentage anomaly, obtained in similar manner 

 as in Table VI are given. The vector diagrams plotted in exactly 

 same manner are given in Fig. 3. Here also the months with 

 more than usual excess of precipitation on the Japan Sea side, are 

 distributed on the one side of a line of demarcation, similar as in 

 the case of the yearly amount. 



From the results thus far obtained, it seems certainly worth 

 while to apply the vector diagram method to the relation of the 

 precipitation and barometric gradient of each month of each year, 

 instead of taking the monthly or the yearly means, since as is well 

 known the fluctuation of the monthly means of the both elements 

 are considerable. At present, we must refrain from the task on 

 account of the want of time, with a hope that in some days we 

 will be able to resume the investigation. 



11. In section 3, we have already alluded to the peculiar 



distribution of the precipitation of the different regions in different 



seasons. We will now make an attempt to interprète or analyse 



the actual distribution in terms of the elementary theory proposed. 



Let us put at first for a trial : 



i\ = B2 + C2, Vi = Ä2 — C'L (A-) 



where c,, C2, Ci etc represent the effects of the topography which 

 will be considered as some functions of the barometric gradients, 

 varying from month to month, i^i, Ro, R^ represent the principal 

 terms which will prevail in absence of the topographical influence. 

 It seems plausible to assume that the c's are proportional to c''s, if 

 not equal, so that we will put 



The factor a must vary with season, but it must be generally 

 positive if our theory be valid. Further, on the basis of the 

 approximate equality of the annual amounts of n + rs and n+^e, we 



