H 2 



HYDROGRAPHY. 



from the land in 1896 than in 1895, and in so far as the last year is concerned at a distance of 30 

 miles from the coast, while due west of Iceland, it has remained unaltered from one year to the 

 other. (The chart on plate III). In 1895 the observations north-west and west of Iceland were made 

 at the beginning of June, while, on the other hand, in 1896 they were made a month later at the 

 same places. According to this, it seems to appear that the Irniinger Current, when looked 

 upon as a surface-current, most frequently does not flow round Cape North at all. 

 According to the statements given by Cpt Wandel in his work «Bemaerkninger til Besejlingen af Is- 

 lands Kyster», the northern coast of Iceland is on an average within a period of 10 years blocked up 

 with large masses of ice during 7 of these ten years, and it is of course entirely out of the question 

 that there can be a warm surface-current where the surface is consisting of ice. 



The isohaliues 33-50 and 34-00 in the region of the sea Iceland— Jan Mayen proceed from 

 Iceland, first in an easterly and afterwards in a north-easterly direction, until in 67 30' L. N. they 

 change this latter into a north-westerly one. Owing to this, the surface-layer of the Polar-current had 

 in this latitude its greatest extent from the east to the west at the end of July 1896. It will be seen 

 when comparing this statement with what is said on page 122, that these two statements concerning the 

 breadth of the Polar-current do not agree at all. Formerly we have found that at this place the 

 Polar-current had its smallest extent to the eastward. This discrepancy proves, however, only that 

 the heated surface-layer of the ice-water can have a motion, which, to a certain 

 degree, is independent of that of the main body of the ice-water. The surface-layer has 

 namely a very slight specific gravity, so that in consequence of this, it will be apt to spread over 

 large areas, which in reality it is also doing. And it is just this part of the sea-water that can be 

 directly acted upon by the wind, in consequence of which it is led away from the actual Polar-current, 

 the characteristically distinctive mark of which is the cold ice-water under the here mentioned heated 

 surface-layer. 



On the route south of Greenland in 1895, the cold fresh water did not on the voyage out 

 stretch so far to the eastward as it did on the voyage home. The isohaline 35-00 has from the 20* 

 of June to the 3d of August moved from 39 L. W. to 34 L,. W., which very likely means that the 

 Polar-current during the said period has moved a similar distance to the south-eastward, or that it 

 has grown so much in breadth. West of these confines, we do not, through any of the determinations 

 that have been made, find a higher salinity than 3505; it has everywhere been subject to a reduction 

 on account of the melting of ice that is taking place in the Davis Strait and south and east of Green- 

 land. As usual in the ice-water, the salinity varies also here quite irregularly, but it appears distinctly 

 that it is decreasing in the Davis Strait the more we advance to the northward. North of about 

 62 L. N., the salinity in this strait sinks as a rule below 34-00, but in return it is nearly everywhere 

 above 33-50, when not, of course, the determinations have been made between hummocks of ice or 

 close to the land. 



It will be seen from the chart of the stations, plate III, that the routes followed during the 

 voyage to and from Godthaab, and south of Greenland, nearly coincide. The determinations of salinity 

 which have heen made at nearly the same places, at the interval of a month, vary but little. From 

 the beginning of the voyage in June till the voyage home in August, the salinities have on an average 



