VEGA- EXPEDITION ENS VETENSKAPLIGA AU BET EN. 251 



fresh strata will of course tend to accelerate the diffusion, 

 but on the other hand it must be remembered, that water- 

 strata of different origin can exist isolated for a very long 

 time över väst spaces of the open ocean, without exchanging 

 their individual properties. Besides, in the arctic sea there 

 is a mighty force at work to coiinteract the diffusion of the 

 waters, viz. the extreme cold of the winter season, which 

 can ses the water to freeze soHd on a larger scale than any 

 where else. The water once transformed into ice is naturally 

 exempt from the further influence of diffusion, and moreover 

 the brackish water, which has been formed in summer, is di- 

 vided b}'' freezing into salt water and ice, which contains Httle 

 or no salt. 



Whether the ice is formed entirely from salt water as in 

 the sea between Greenland, Spitzbergen and Novaya Zemlya or 

 from the fresh or brackish water forming the upper layers of 

 the Siberian sea, the freezing process has the same tendency 

 to make the difference between the original constituents of 

 the seawater still more marked. 



Neither does the melting of the sea-ice tend in any high 

 degree to unite again the fresh and salt water. It is a well- 

 proved fact, that a great deal or perhaps the most part of the 

 arctic ice never melts at those latitudes, wdiere it was formed, 

 but is carried away with the great arctic current along the 

 €ästern coast of Greenland and America, until it melts in the 

 relatively warm part of the Atlantic, Avhich is crossed by the 

 Gulf-stream. There is every reason to suppose, that the ice 

 of the Siberian sea also partakes of this great circulation. 

 The ice drift current here must exist at latitudes hitherto 

 little explored, but nevertheless the ships of the two most 

 hazardous expeditions of låter years, the Tegetthoff, of the 

 Austrian, and the Jeannette of the American expedition were 

 caught by the mighty ice drifts of this current and carried 

 away to the north-west, Tegetthoff from 78° 42' Lat. 73^ 18' Long. 

 E. G. to the shores of Fmnz Josef Land at 79° 43' Lat. 60° 23' 

 Long. E. G., where she was abandoned in the ice; ^ Jeannette 



* *Ganz bestimmt zeigen uns unsere Erfahruiigen, dass im Siiden von 

 Franz-Josef-Land ein fortwährender Abfluss von Eis von Ost gegen West. 

 also aus den Sibirisehen Gewässeni, Statt findet. Ans den Winden des 

 letzten Winters habe ich die Uberzeugung gewonnen. dass wir im Norden 

 von Spitzbergen wieder zum Vorschein gekommen wären, wenn sich nicht 

 unser Feld bei der Wilczek-Insel am Landeise festgelegt hatte.» 



Schiffslieutn. AVeypi-eclits Vortrag iiber die von ihm geleiteten wissen- 



