XIII.~ON THE SCIENTIFIC INVESTIGATION OF THE BALTIC SEA 

 AND THE GERMAN OCEAN.* 



By G. Kaksten. 



The following lines are designed to call attention to the investigations 

 of the Baltic Sea and German Ocean, which have been in progress sev- 

 eral years, and which are of especial interest in opening up a new field 

 of observation, to which hitherto but little attention has been paid. 

 The extensive experiments of the Americans and Englishmen have in- 

 creased our knowledge of the physics of the ocean and its organisms, but 

 not being made with the view to continued systematic investigations, they 

 have resulted only in discovering for the time being certain relations for 

 given points ; the variations, be they of a i)eriodical or a non-periodical 

 nature, for one and the same locality could not be ascertained during the 

 rapid passages through the ocean. But just these variations are of 

 special significance, since upon them depends our knowledge of the phe- 

 nomena of the currents and of the relations between the i3hysical con- 

 ditions and the i^henomena of life, as in meteorology, where the final con- 

 clusions are not drawn from a few isolated observations but from a 

 knowledge of the limits between which the variations take place. With 

 this view, Dr. H. A. Mayer made extensive investigations of the physi- 

 cal conditions of the western part of the Baltic, hoping thereby to gain 

 information regarding the variable character of the organic world, a fact 

 established by his own observations as well as by those of E. Mobius. 

 The observations of Dr. Mayer have shown that the western portion of 

 the Baltic offers fluctuations in all the physical elements — in the height 

 of the water, its temperature, and the proportion of salt — fluctuations 

 which vary with the seasons and likewise in different years. These ob- 

 servations gave a sufficient explanation of the character of the currents, 

 but in order to properly fix the laws of these currents the co-operation 

 of a number of savans was found necessary, since only by simultaneous 

 observations at many points the enterprise could be made a success. 



The impulse to make the present investigation was given by the Ger- 

 man Society for Fish -culture, which, fully comprehending its impor- 

 tance, requested the Prussian Government to have the work estabhshed. 

 The government acted in accordance with this petition, and entrusted 



" Translated by Dr. Oscar Loew. 



