30 T. Terada 



SUMMARY. 



1. The geographical distribution of the diurnal component a^ 

 of daily barometric change is compared with the distribution of 

 land and water, a quantity called ' ' continentality ' ' being in- 

 troduced which is the percentage of land in a definite area sur- 

 rounding each station. 



2. A linear relation between the amplitude and the con- 

 tinentality was assumed and a systematic discrepancy was dis- 

 covered. 



3. An elementary theory based on a number of simplifying 

 assumptions is proposed and applied to actual examples. 



4. The variation of the amplitudes and phases as functions 

 of longitude could be explained in its essential features. 



5. The inversion of phase near the pole is explained. 



6. The minimum of amplitude near coast is pointed out and 

 explained. 



7. The influence of geographical conditions on the seasonal 

 variation of amplitude is discussed and different possibilities point- 

 ed out. 



8. A method of investigating the complicated variety of the 

 seasonal variation under the light of the above theory is suggested, 

 referring to some examples. 



Published. November 20Lh, 1917. 



