On Mean Sea Level and its Fluctuations. 



31 



Stations. The Swedish results (1887-1900), though somewhat irre- 

 gular, can be show?i to resemble those of the Scottish Stations at least 

 in their most conspicuous featui'cs and theii- general trend. While, 

 lastly, the Milford Haven I'esults (1880-1892) can also, apparently. 

 be correlated with the Scottish, if we allow for one year's retardation 

 of phase. 



Having arrived, then, at the conclusion that the apparent 

 variation in Mean Sea Level from year to year is not a mere local 



phenomenon, but is common, in greater or less detail, to widelv 

 separated stations, let us look more closely at the longest set of avail- 

 able data, viz., those for Aberdeen, in order to see whether the varia- 

 tion shows signs of any regular periodicity. 



Let us begin by examining, not the Mean Sea Level, but the 

 Intertidal Range, — the mean difference between ]\Iean High Water 

 and Low. AVe have not dealt hitherto with the fluctuation in this 

 quantity fiom month to month, foT-. as we might of course expect, 



