(2J) HYDROFRAPHY. 



temperature is to be found, will be a measure for the time during which the under- 

 layer has been acted upon, or, if we like to call it so, a measure for the rapidity 

 with which the under-layer is renewed. 



This measure, however, is not very correct. In case of the ice-water expanding sidewards, the 

 maximum point will at the same time rise towards the surface. It would be far better to use the 

 distance between the position of the minimum point and that of the maximum point as a measure. 

 To obtain only a tolerably exact determination of the position of these two points, requires, however, 

 a far greater number of observations at a station, than it has been possible to get, and it can be seen 

 from the temperatures, plates XII — XIX, that where the position of the maximum point has been 

 approximatively correctly determined, it is as a rule impossible to determine the place of the minimum 

 point and vice versa. 



In the chart, table XXX, above the maximum temperature and its depth, is therefore besides 

 the maximum temperature, which is marked in bhie ciphers, likewise — in black ciphers to the right, 

 and below the number of the station — noted the distance from the surface to the place of the 

 maximum temperatures, expressed in Danish fathoms. According to this, the signification of the blue 

 and that of the black curves can easily be understood. These curves show that the maximum 

 temperature attains its smallest value in a belt that is stretching along the east- 

 coast of Iceland in a southerly direction in longitude 9 W. of G. about 120 miles 

 east of Iceland. According to this, the influence of the East Icelandic Polar 

 Current is greatest in this belt, what by the intensity of its action, and the time 

 during which the under-layer has been exposed to its cooling influence. 



The stations 128 and 123, at which the state of matters is different, have been mentioned on 

 page 115. It might perhaps have been expected that the depth of the maximum temperature should 

 be extremely small near the confines of the current, but it can be seen that this is not the case in 

 any notable degree, see for inst stations 104, 112 and 113. It is therefore likely to be supposed that 

 at these stations the under-layer has been in contact with the ice-water for a very long time. 



SECTION XXII. 



From station 1 (near the Faroe islands) in a north-westerly direction. 



The many isotherms as well as isohalines that are going from the surface to the bottom, 

 show that the south-eastern part of this section is situated in Atlantic-water, while the north-western 

 part has got its character from the Polar-water. 



The whole section is lying on the Faroe-Iceland ridge, at which we must look for the bound- 

 ary between Atlantic-water and Polar-water. The determinations that have been made do not show 

 us an)- trace of the existence of the Ice-water near the surface, which, however, cannot be taken as a 

 proof, as the number of the observations was very limited. On the other hand we do not only see 

 the under-layer but also the manner in which it passes into the Atlantic-water. Looking at the form 

 of the isotherms and the isohalines, it cannot escape our attention that Atlantic-water from the 

 western part of the section is spreading over the under-layer, while this latter, from the eastern part 



