a. Waterlevel Dutch coast. b. Raising-power wind Dutch coast. 
c. Equatorial Current. 
The correlation between waterlevel, trade-wind and water-raising 
power is 0.82. 
If it were possible to make a trustworthy prognostication about 
the ‘North-Sea wind’, we should be able to forecast with a fair 
certainty the level to be expected, for during two years we have 
known fairly well the behaviour of the trade winds from month 
to month,’) a progress made by international coöperation on VAN DER 
Srok’s instigation. 
The correlation between fluctuations in the Equatorial current and 
the waterlevel is far greater viz. 0.85. It will be tried to secure 
current observations in time in sufficient quantity, for in our opinion 
1) Kon. Ned. Meteor. Instituut 1074 and 107. Monthly Meteorological Data for 
ten-degree squares in the Atlantic and Indian Oceans. 
1074 Computed by the Royal Netherlands Meteorological Institute from Swedish 
and Dutch Observations 1900—1912 and from international observations January— 
June 1913. 
107 Computed by the Royal Netherlands Meteorological Institute from inter- 
national logs and observations I’! January—June 1913, 1? July—December 1913, 
Utrecht 1914. 
