(5 Art. 1.— T. Terada: 



choosing as the materials those compiled by Angot and Hann in 

 their classical papers above cited and also those given in the current 

 numbers of the "Meteorologische Zeitschrift", from which the 

 diurnal amplitudes «, were taken and their dependency on the 

 distribution of land and Avater in a definite area enclosing the 

 stations was to be examined. A circle with the radius of 10° was 

 drawn, with each station in question a^ the centre, on a suitable 

 globe, and the percentage of land area was determined by means of 

 planimeter. The value of the percentage was called, the "continent- 

 ality" of the station for simplicity's sake and denoted by K. It 

 may be remarked that the area is roughly of the same order of 

 magnitude as Australia. Different stations were then classified into 

 groups according to the 10° zones of latitude to which the}^ belong. 

 For each group, a diagram was constructed in which tlie values of 

 «1 Avere plotted with the corresponding continentality as abscissa 

 (Figs. 1-6). The points thus obtained, representing different 

 stations, though rather capriciously scattered over the diagram, 

 showed still an undeniable tendency to be arranged within a certain 

 belt inclined to the axis of the continentality. Moreover, the in- 

 clination of the belt to the axis of abscissa seems to become less as 

 the latitude increases. The result shows at least that among the 

 numerous factors determining «i, the continentality as defined 

 above may play not quite an unimportant rôle. To proceed a 

 little further, a straight line was drawn in each diagram, roughly 

 representing the median line of the belt supposed. The ensemble 

 (jf such straight lines for different latitudes taken together was 

 adjusted among themselves, so as to show a regular transition 

 according to latitude. From lines reduced (the full lines in Figs. 

 ]-(*») a diagram was constructed in which the ordinate represents «i 

 and the abscissa the latitude, and the system of curves Avas drawn 

 representing the dependency of a^ on the latitude for different 

 values of the continentality. It was found that the curves may be 

 roughly repi-esented by an empirical formula of the form 



«/ = (a + 67i )cos Y — c, 

 a=0.35, 6=0.80. c^0.15 in mm., 



