On Diurual Variation of Baromotric rrossure. 15 



along the European coast. Take the origin of x at 30 E^., corres- 

 pondmg to the assumption that tlie aniphtude of tlie temperature 

 variation is minimum at tlie centre of Atlantic Ocean. Tn (12), we 



assume a=5°C. and 1=-^-. 



Then 



, \ f I >. \- i-x , , 



Carrying out the numerial calculation for each ten degree of longi- 

 tude, we obtained the second line of the following Table, in which 

 the observed value of «i, as the mean values for different stations 

 included within successive strips with the breadth of 10^ are given 

 in the third line. In the fourth line, the number of stations taken 

 for evaluating the third line is given. 



Some parallelism is to be observed between the second and the 

 third lines, if we put range 20°-30°E. out of account, in which the 

 number of stations is scant3\ 



G. For the next trial, we chose all stations falling within 

 the zone of latitude 20°-60°N. and the mean value of the observed 

 a, were calculated for successive areas with the breadth of 20' in 

 longitude. To compare this with the result to be expected from 

 the present theory, it will be most natural to take for « the mean 

 value of the amplitude of daily temperature ^-ariation for each area 



■J J'o 



mentioned and estimate the coefficients -^ and -^- from these 



