82 Messrs. W. 1ST. Shaw and E. W. Cohen. On the Seasonal 



metrical process. Thus, if the length of AB, in fig. i, represents the 

 amplitude of the resultant curve, AC, CB, the amplitudes of the two 

 components, then, upon forming a triangle of the three, as in the 

 figure, the angle BCC will represent the phase difference of the two 

 components, BAG will represent the phase difference between the 

 resultant and the first component, and ABC the phase difference 

 between the resultant and second component. 



FIG. i. 



F. 



C' 



Applying these to the case under consideration, AC may be re- 

 garded as representing the temperature oscillation undisturbed by the 

 effect of the sea temperature, CB the effect of the sea and AB the result- 

 ant effect or the actual temperature oscillation observed at the station. 

 The angle ABC will represent the number of degrees of phase differ- 

 ence between the sea curve and the station curve, i.e., practically, the 

 number of days between the time of maximum on shore and on sea, 

 and so on for the other angles. Of such a triangle for any station, 

 the following elements are known : the resultant amplitude AB, the 

 lag of the sea effect behind the land curve, i.e., the angle ABC. The 

 position of C is indeterminate because we do not know the actual 

 magnitude of the sea effect BC, nor the magnitude or epoch of the 

 undisturbed effect. But we know the extreme position of AC : it 

 cannot correspond to a curve with an earlier maximum than June 21, 



