4^ 0. Nordgaard. [No. 8 



in the sur face salinity. A comparatively fresh upper layer acts as 

 a screen to ward off the effects of the atmosphere on the lower 

 lavers, because it hinders the rising of the vertical current. On 

 the other hand, a stretch of fiord with high surface salinity would 

 more easily influence the variations of temperature. And observa- 

 tions prove that the surface water in the By Fiord is, on an aver- 

 age, more mixed, than that of the Hjelte Fiord. 



Maxima and minima of temperature and their movements. 



Professor dr. Mohn r ) has, on the basis of measurements made 

 in the innermost part of the Vest Fiord, as well as in the Alten 

 Fiord, described the most important phenomena which take place 

 in the distribution of heat in the upper layers of water. My 

 measurements, made in the western fiords, on the whole show 

 corresponding conditions to those observed in the Vest and Alten 

 Fiords. In January, February and March, the minimum temperature 

 is found at the surface, and the maximum, if not always at the 

 bottom, so, at any rate, at a great depth. In April there is a 

 change, the surface begins to be warmer, the minimum moves down- 

 wards, the surface becomes the seat of the maximum temperature. 

 And in May, June, July and August the maximum is still at the 

 surface, the minimum meanwhile being found farther and farther 

 down. 



In September, a change again begins, and the surface begins 

 to lose heat, the maximum now starts on a corresponding course to 

 that tåken by the minimum in the spring. 



In October, November and December, the autumn maximum 

 will be found deeper and deeper, while the minimum will move to 

 the surface at the moment when the cooling process has produced 

 a correspondingly low temperature to that which is the average 

 constant at the bottom. 



This is, without doubt, of earlier occurrence the farther one 

 gets from the outer coast. For instance, on Nov. 25th 1902, in 

 the By Fiord, the minimum (1.5) was at the surface, while in the 

 Hjelte Fiord the minimum (6.95) was found at a depth of 200 m. 



The observations made in the western fiords have given op- 

 portunities for a more exact judgment of the movements of the 



1 ) The North Ocean, its depths, temperature and circulation. 



