Hydrographical Observations trom the Danmark Expedition. 423 



period varied between 10.30 and 9.42, thus on an aA^erage 10 hours 

 5 minutes. 



On 30/iv the moon was new and on 7/v in its first quarter. 



The tidal measurements at Mørkefjord and at Maroussia were 

 carried out at an interval of 2 months, but the moon was in the same 

 phase during both periods. 



The observations made show, that the tidal period at Marous- 

 sia, Danmarks Havn and in Mørkefjord was nearly the same (ca. 10 

 hours), whilst the height of the tidal wave increases from 1 meter 

 on the outer coast (Maroussia) to 2 meters in the inner fjords. 



Remarks on some harbours in N. E. Greenland. 



Our ^^'inter-harbouг proved to be very good and satisfied the 

 follo^ving conditions of a good harbour for overwintering in N. E. 

 Greenland. 



1. It was sheltered against invasion and pressure of the drift- 

 ice. The mouth of the harbour opened towards the south, which was a 

 good thing, on the one hand, because the current outside the coast runs 

 mainly towards the south and on the other, because the sun had thus 

 the best chance of affecting the ice in the harbour. 



2. It possessed a water-course opening at the head of the har- 

 bour, so that the heated water from the melting snow and ice greatly 

 helped in loosening the harbour ice from the land. 



3. At the entrance the harbour was so shallow that large ice- 

 fields and icebergs could not get in. 



4. Lastly, the harbour lay close to the outer coast, so that it 

 was easy to slip out into the current and escape being trapped by 

 the fjord-ice. 



The following harbours were examined (see PI. XIV): 



1. Danmarks Havn — 76°46'.2 N. L., 18°45'.5 W. L. 



2. Sonja Havn — 76°36'.6 N. L., 18°40'.5 W. L. 



3. Absalon Havn — 76°39.8 N. L., 18°53'.5 W. L. 



4. Dagmar Havn — 76°40'.7 N. L., 18°56'.4 W. L. 



In Danmarks Havn the "Danmark" lay anchored for nearly two 

 years without being exposed to pressure from ice, (with the stem facing 

 Southwards, both anchors out and with wire hauser moorings aft to 

 large stones and a heavy anchor on the land). 



Inside the harbour the water became ice-free in the beginning 

 of July in both years (1907 and 1908), but the fjord-ice in 1907 did 

 not break up until August 6th and a belt of drift-ice (ca. 4 — 5 km. 

 broad) then lay fast to the land and remained there into the begin- 

 ning of September, so that it is doubtful whether we should have 

 succeeded in getting out that year. 



