1152 
2.1. The two groups of fluctuations show a phasedifference of 2 
or 3 months. 
34. The origin of the Gulfstream lies under the Equator, the 
North-Atlantie current is a direct offshoot of the Gulfstream and 
is the connection between the Gulfstream proper and the North-Sea, 
the Baltic, the Norwegian and the Barents-Sea. 
4th. Breireusz was in 1904 the first to point out the direction in 
which we had to look for the solution of this problem. 
3. We mentioned before that VAN per Stok and Wirrine thought 
the water-raising power of the local wind or of that near the entrances 
of the North-Sea and the Baltic responsible for the fluctuations in 
the waterlevel. 
We do not know how Wirtine proceeded; from mean monthly 
windresultants, as calculated but not published by Van DER STOK 
for Swambister, Bergen, Skudeness, Helder and Flushing, we derived 
a mean monthly “North-Sea-wind” (Table IV). 
TABLE IV, 
Fe Me vi v | vi | vir | vi 1x xox |x 
1 
| 
F 
i 
| 
199 / 
| Direction| 206° | 207 | 220 | 278 | 314 | 321 | 282 | 256 | 235 | 216 | 196 | 
| Fost 
ee p.s. 2.69/2.15/1.88 0.58 1.80 1.90 2.05 2.03, 2.06 Loo 2.42 2.85, 
| | | | | 
The first thing necessary to cause a rise of the waterlevel on a’ 
coast is a motion of the water or a current perpendicular to that 
coast. The direction of the Dutch, Danish, and Norwegian coast is 
about SSW—NNE; a maximum rise of the water will be caused 
by an ESE-ly current. Wirtinc has shown that between wind and 
winddrift in inland seas as the Baltic, a difference in direction exists 
of 25° to the right (southern latitude to the left); the most favour- 
able winddirection to cause a rise of the water, is in our case 
N 268°0O E. 
In order to judge of the waterraising-power of the different monthly 
windresultants of table IV we project them on the direction N 268° E. 
and consider the squares of the projections; we get the following 
monthly values and departures from the mean {Table V 4 Fig. 1). 
The minima in spring and autumn in waterlevel and raising-power 
coincide; the maximum raising-power between July and August is 
