HYDROGRAPHY. I2 , 



oms (141 M.)| and 101 [2°o at a depth of 100 fathoms (188 M.)| to station 108 [i°i af the bottom, depth 

 97 fathoms (183 M)]. 



It will likewise be seen from these ciphers that the depth of the maximum temperature is 

 growing. Owing to the rotation of the earth, the sonth-going ice-water will be driven in against the 

 east coast of Iceland, that is to say, in over the aforesaid water with the slightly appreciable salinitv 

 and relatively high temperature, and the consequence will then be that the more we advance in a 

 southerly direction, the more the maximum temperature will be pressed towards the bottom. This 

 water cannot in consequence of its little degree of salinity be reckoned as belonging to the under- 

 layer, 110 more so than on account of its high temperature, it can be considered as a part of the 

 upper-layer. 



The water of the Ir minger Current must on the contrary be considered as a com- 

 ponent of the underlayer. It has been mentioned on page 117 that this current can be traced 

 in section XIV and XV. Even in section XVI, its influence can be traced on the salinities in the 

 under-layer; we see thus that there are salinities at stations 101 and 102 as high as 35*04 — 35"07, 

 while the highest salinity at station 103 is 35'03- No observations of this kind tending to 

 prove a difference of the salinity in the under-layer between the western and middle 

 parts of the section, are to be found in section XVII. Owing to this, we may take it for 

 granted that the before mentioned high degree of salinity of the under-layer in the 

 western parts of section XV and XVI cannot be due to a northerly current in the under 

 layer along the east-coast of Scotland, norcanitbe attributed to currents from the salt water in 

 the North Ocean making their way into the under-layer, as we should not, if such a thing was the case, be 

 able to account for the low degree of salinity at stations 118 and 103. Hence there is the possi- 

 bility of supposing that the high degree of salinity of the under-layer in the western part of the 

 aforesaid section may be ascribed to the branch of the Irminger Current that is flowing in an easterly 

 direction north of Iceland. It has been mentioned before how this branch is driven away from the 

 coast at the eastern coast of Iceland. Furthermore we have seen how it is spreading in the under- 

 layer in a southerly and easterly direction north-east of Iceland, gradually losing its character 

 entirely. 



Considering the East Greenland Polar Current as a surface-current flowing on top of the warmer 

 and salter water of the Irminger Current, which it is dragging with it to the southward — but very 

 likely with a velocity inferior to its own — thus we may now likewise consider the East- Ice la n die- 

 Polar Current in the same light. The warm under layer of this latter is in its 

 western part due to the effects of the eastern branch of the Irminger Current, at 

 any rate it gets its character from this current, while, on the contrary, the warm 

 under-layer of the eastern part is due to the effects of the Gulf St ream. 



i6' 



