Ou Diurnal Variation of Barometric Pressuro. 'J 



wiiero <f denotes the latitude, K tjie continentality. a/ Ijeconies 

 negative for <f near 00°, which means that for a higher hititude, the 

 phase of the variation is inverted. The calculated value ci\ was 

 then compared with the actual value «i. The differences a^—a^'=J 

 are generally considerable as miglit have been expected from the 

 outset. Nevertheless, it may be scarcely hoped that any empirical 

 formula in which the term depending on the continentality is put 

 out of account, will show a less discrepancy than here met with. 

 In Fig. 7 the actual values of «i is plotted against the calculated 



ax 



Fig. 7. 



observed amplitude of the diurnal component, 

 calculated value. 



0-2 o-'.- 0-6 o-e 10 j-z«*/ 



value c</. It will l)e seen that the great majovity of the points lie 

 within the belt with a breadth of 0.2 mm. on both sides of the line 

 «i'=cï], while the value of «i varies from 0.1 to 1.0. 



Next, on plotting the values of J for different stations upon a 

 cliart, it was found that for European stations negative J's remark- 

 ably predominate, in other words the variation is of the oceanic 

 type : 



