Hydrographical Observations from the Danmark Expedition. 311 



Remarks : The observations were made after leaving the Færoes 

 on July 14th 1906 every four hours on the out-voyage until mid- 

 night of August 9th ; thereafter they were taken less frequently, the 

 areometer used for the salinity determinations being broken. 



As the variations in the surface temperature and salinity in 

 among the ice-fields proved to be irregular owing to quite local oc- 

 currences of melting ice, however, it was also of no great importance 

 to continue the investigations here at intervals of 4 hours. 



From August 9th to 13th, when we reached the coast of Green- 

 land, no other surface observations were taken than those included 

 in the hydrographical series. 



On the return voyage surface observations were taken three 

 times in the 24 hours during the voyage from the ice-edge over to- 

 Avards the Norwegian coast. The samples of the surface water were 

 titrated after returning home at the Hydrographical Laboratory in 

 Copenhagen. 



The surface observations taken on the voyage out show decreas- 

 ing temperature and salinity from the Atlantic water in towards the 

 Polar Current, the variations being frequently very abrupt. There 

 was no sudden transition from Atlantic to Polar Current water, so 

 that the surface observations of the salinity could not indicate a def- 

 inite boundary between the two regions. 



Between the drift-ice in over the Continental Bank the salinity, 

 with quite few exceptions, was below 32 "/po and the water cooled 

 down below 0°. Near to the coast the salinity was even somewhat 

 lower (ca. 31 "/qo) owing to mixture with river water from the coast 

 in the summer. 



On the return A^yage the surface salinities were on the whole 

 lower (28 %o — 31 "/oo) aid the temperature higher (up to + 3'15°) 

 than on the way out, though the return voyage was earlier in the 

 summer, and the fresh-water had been flowing from the land for a 

 shorter time. 



After getting out of the ice the above-mentioned surface observa- 

 tions were made three times in the 24 hours. They show, how both 

 the surface salinity and temperature increase greatly from the ice- 

 edge out towards the Atlantic water. The changes in the salinity 

 were very irregular, those of the temperature more uniform. 



