HYDROGRAPHY. I2I 



stratum of water, in which the degree of salinity changes from its minimum point in the deep to its 

 maximum-point, is the layer of transition. Still it is to be observed that the maximum-point often is 

 somewhat below this layer, consequently in the under-layer. 



Matters are very simple in the under-layer, as the temperature is decreasing towards the bottom, 

 first rapidly, and afterwards, specially in large depths, very slowly. Even at the largest depths, it is 

 seldom getting below — i°, a temperature which is higher than that af the coldest ice-water. The 

 salinity in the under-layer varies but slightly. It will often be difficult, even impossible, to indicate 

 the position of the aforesaid maximum-point. It seems to be a rule that the salinity is slightly de- 

 creasing towards the bottom. 



The typical distribution of the strata of water, each with its special properties, which has been 

 pointed out above, is found for all the stations in sections XIV, XV, XVI and XVII, including 

 the special circumstances that manifest themselves at the coasts, and it is specially characteristic for 

 the Polar-water, by which is to be understood here, not only the water (the upper-layer) at the surface 

 of which freezing of water or melting of ice has taken place or takes place, but also the under-layer. 

 The stratum of water which here is called the upper-layer, has therefore often in the foregoing been 

 called the ice-water. 



The Polar-water east and north of Iceland, forms a Polar Current (see C. Ryder and K. Rordam : 

 Hydrografiske Undersogelser udforte paa den ostgronlandske Expedition 1891 — 92. «Meddelelser 0111 

 Gronland» XVII, page 205). The larger Polar Current, the breadth of which reaches from 

 the east-coast of Greenland to the other side of Jan Alayen, divides itself as already 

 mentioned into two smaller branches, one of which forming the East Greenland 

 Polar Current, while the other one runs south along the east-coast of Iceland, and 

 therefore with full justice may be called the East Icelandic Polar Current. 



This East Icelandic Polar Current must flow athwart of the sections XV, XVI and XVII. It 

 has already been pointed out before, when speaking about the different sections separately, that 

 they reach about as far as to the eastern limit of the found ice-water, which just is 

 constituting the said current. Thus it will be seen that it has a very large extent, 

 expanding itself more than 160 miles east oil c eland, and carrying with it such large 

 masses of ice-water, that this latter has exercised its influence up to depths of more 

 than 100 fathoms (188 metres). The velocity of the current cannot be directly found by the 

 measurings, but these show at any rate that the velocity of the current is great enough to impart 

 to these seas all the properties peculiar to a Polar Current. By means of current-bottles that have 

 been thrown overboard, we have got an idea of the movement of the surface-water, but still we dare 

 not from this draw any conclusion concerning the velocity of the whole of the ice-water layer. Ac- 

 cording to the drift of the ice, we may be led to believe that the velocity of the East Icelandic 

 Polar Current cannot by far be so large as that of the East Greenland Polar 

 Ctirrcnt. 



Like all other Polar Currents, this one has a very cold and fresh upper-layer, which 

 evidently has such a low temperature and slight salinity, because a great deal of ice has been melted 

 in it. The ice-water produced by this, will try to cool and make the under-layer less salt, and thus 



The Ingolf-Expedition. I. a. 



