OCEAN CURRENTS 



183 



A Belgiaii drift-bottle experiment was carried out by 

 Gilson off the West Hinder Lightship, 20 miles west-north- 

 west from Ostend, From December, 1899, on the first day of 

 each month for 18 months 100 bottles were set out, half with 

 the flood-tide and half with the ebb. The bottles drifted 

 almost exclusively north-east towards the German coast, some 

 even reaching Jutland and South Norway. 



Gilson deduced from his experiments that the currents in 

 this région of the North Sea were directly dépendent on the 

 winds. 



Current observations hâve also been made from the Dutch 

 lightships in the North Sea of late years by Van der Stok. 

 The results were analysed and the tidal streams eliminated, so 

 that what remained was attributed to the North Sea Current. 



NORTH SEA CURRENTS, 1898-1899. 

 RcsuUs of Observations from Dutch Liglitsliips. 



N.B. — 5 centimètres per second is équivalent to one-tenth of a knot. 



At the first two lightships the current is influenced in 

 direction by the présence of narrow banks in the vicinity ; at 

 the others the current runs seaward from the coast. The 

 increase in velocity northward at the first four stations is 

 attributable to the influence of the mouths of the Rhine and 

 other rivers. At the three northern lightships the influence of 

 the spring flooding of the Rhine is clearly discernible, since 

 from April to July the velocity increases much beyond the 

 annual average. At the Maas in April it is 857 centimètres 

 per second, at Haaks 884 in July, and at Terschelling Bank 

 1093 in April. 



