]^^ Art. fj. — T. Torada,, M. Isimoto and M. luiauaura : 



of the region I and II, was taken (Table VI) for successive years. 

 Then the points on the vector diagram were classified according as 

 the above difference of the ]H)th sides is positive or negative. 

 Carrying out the procedure, it was found that the points belonging 

 to the two classes may be separated by a boundary line dividing 

 the area of the diagram into two halves. Though the line of 

 demarcation is more or less sinuous, it may be compared for very 

 rough approximation with a straight line making an angle of about 

 20° or 30° with the axis of x. 



This latter result is exactly what may be expected from our 

 previous elementary theory, except that the angle expected from 

 the calculation w^as IS'' instead of 20 or 30°. The fact that the actual 

 angle is decidedly larger than the calculated, points to the 

 conclusion that the difference of the angles between the Avind and 

 the barometric gradient on land and sea must be assumed much 

 larger than in the previous paper. This discrepancy may probably 

 be explained if we consider that the angle between the gradient 

 and the wind increases generally with the height and also that in 

 calculating the vertical displacement of air caused by the disconti- 

 nuity of the horizontal flow on the boundary of land and sea, it is 

 reasonable to take the data of calculation from a certain mean or 

 ' ' effective ' ' height froih the sea level. If the years of observation 

 be multiplied several times, we may obtain sufficient numl)er of 

 points on the vector diagram for drawing a more definite line of 

 demarcation and thence deduce something about the effective height 

 above mentioned. IMoreover, it seems quite possible that the 

 sinuosity of the boundary curve may have a real significance, since 

 the " effective height" may l>e a function of the velocity of wind 

 as well as the direction of wind determined by the irregularity of 

 topography. These latter points of interests nuist be postponed to 

 a future when a sufficient materials would have accumulated. 



9. In passing, it may be observed that vector diagram above 

 described is very convenient U)y investigating the sensibility of 

 different stations with respect to the barometric gradient, or in 

 other worlds the mode and degree in -which the topographic 

 conditions affect the precipitation of the stations. Taking the 



