INVESTIGATION OF BALTIC SEA AND GERMAN OCEAN. 291 



But only by a long series of observations it can be determined to what 

 extent these differences decrease at the different points of the German 

 Ocean in contradistinction to the temperatures of the Baltic, what in- 

 fluence is brought to bear by the currents in different seasons, and what 

 relations in greater depths the period of higher temperatures will show. 



It will be seen from the following series of one year's observations 

 at Heligoland that in the German Ocean, the temperatures of the waters 

 of all strata are subjected to greater changes than the temperatures of 

 the waters of the Irish coast although these changes are much smaller 

 tlian those of the Baltic^. 



