APPENDIX A; PETTERSSON 



10 — 



the Swedish, Dutch and German water-gauges and represent the annual fluctuation in 

 the waterlevel at the North Sea, the Kattegat and the Baltic coasts. 



So long as only Swedish and German observations were at hand, this fluctuation 

 was ascribed to the riverine supply of fresh water to the Baltic. In opposition to this 

 conjecture stood, however, the synchronism which the Baltic and Kattegat level fluctua- 

 tions evinced with one exception (the nonappearance of the maximum in February) by 

 the water-gauge at Varberg (Kattegat). 



If, on the other hand, only Dutch observations had been accessible, the inferences 

 drawn from them would certainly have pointed to the wind as originator of the fluctu- 

 ations. Now, since a comparison of facts has shown the analogy of the fluctuations in 



Fig. 6. Gulfstream-circulation in March and November 1899 



the North Sea, the Baltic, and the Kattegat i, such inferior explanations are excluded, and 

 we must acknowledge the fluctuations to be the outcome of a general pulsation of the 

 ocean, extending from the tropics to the Polar Sea. The fluctuation of the north- 

 ern seas is analogous with that of the Atlantic. 



1 A very interesting paper on this subject is H. Geelmuyden's "Resultater af Vandstandsobservationer 

 paa den norske Kyst". VI. (Norske Gradmaalings Kommissionen). On page iS the following quotation is 

 to be found: "The fluctuation (in the waterlevel) displaying its minimum in spring and a corresponding 

 maximum in autumn is very marked at all the Norwegian stations. Towards north, however, the appear- 

 ance of both is delayed." Prof G. explains the fluctuation as being the result of atmospheric pressure, 

 winds etc. 



It is a wellknown fact, that in Bohuslän on the Skager Rak the water annually attains its highest level 

 in October and its lowest in spring. 



