HYDROGRAPHICAL INVESTIGATIONS 203 



Stockholm University) and Cleve (of Upsala) have 

 long been associated with the physico-biological 

 investigation of the North Atlantic, the North 

 Sea, and the Baltic. In the investigations carried 

 out by these hydrographers and their colleagues, 

 two objects have apparently been kept in view : 

 (i) the investigation of the movements of the 

 water in these seas from the point of view of 

 the fisheries — the migration of the herring to 

 and from the fishing grounds, for instance ; and 

 (2) the elucidation of the conditions affecting 

 the climate of the countries bordering on the 

 Skagerack, the Cattegat, and the Baltic Sea, 

 After much preliminary work, in which results 

 of great importance were obtained, Pettersson 

 and Ekman, in 1892, formulated a scheme for 

 an international survey of the North Sea and the 

 entrance to the Baltic. To obtain results on a 

 large scale was beyond the resources of any one 

 State, and it was seen that only by the simultaneous 

 employment of a number of surveying vessels 

 could the condition of such an extensive area 

 be ascertained. The co-operation of Norway, 

 Sweden, Denmark, Germany, and Great Britain 

 was fortunately obtained. Great Britain was 

 represented by the Scottish Fishery Board, and 

 Germany by the Kiel Kommission. The survey 

 was carried out in the months of May, August, 

 and November of 1893, and in May of 1894, 

 and the results of this, the first international 



