8 Fishery Board for Scotland. 



In the annual wave of Mean Sea Level, the total amplitude is 

 less at Aberdeen than at Dundee, viz. about -65 ft. as against -81 ft. ; 

 but the phase, so far as can be seen by inspection, is identical. In 

 the case of Mean Low Water, the phase is apparently a little earlier 

 at Aberdeen, the minimum being in April instead of May ; the ampli- 

 tude is considerably less, viz. ■82 ft., as against 1-06 ft. at Dundee. 

 In the case of Mean High Water, the phases are alike, and the ampli- 



Mr. J jy. 



FEET 



-■5 



Fjg. 3. — Mean Low Water Level : Dundee and Aberdeen. 



tudes also are all but identical, viz. -58 ft. at Aberdeen and "56 ft. 

 at Dundee. 



Such differences as there are between the two stations are not 

 without a strildng, and periodic, regularity. If we examine them 

 as they are set forth in the above Table, and especially when the 

 successive monthly values are " smoothed " (by taldng the successive 

 means of three adjacent months), we see that the differences between 

 the monthly values at Dundee and Aberdeen, in the case of Mean 

 Sea Level and Mean Low Water, approximate in each case to a sine 

 curve, showing identical values at the two stations about February 



