HYDROGRAPHY. ll j 



be the ease, when the whole body of water is subject to motion, all these little regulating currents 

 left apart. If there was a constant current, either at the surface or in the depth, the state of things 

 would be otherwise, the isohalines woidd have to adopt other forms. As now the isohaline 35-00 

 has the expected form here, we must come to the conclusion that all the parts of the water move 

 as a body, so that there is no special current, neither at the surface nor in the depth, lengthways of 

 section XIII. On the other hand, there is nothing in the foregoing to prove that there should not 

 be currents perpendicular on the direction of the section. It can easily be seen, however, that such 

 a regular current towards and from the laud, neither will be able to arise or to be maintained. 



According to this, the eastern branch of the Irminger Current must be a bottom- 

 going current, that is to say, a current in which the water has almost the same 

 motion from surface to bottom. It is not long in losing its characteristic feature, as the 

 Polar-water, which it is drawing with it, gathers round about it. It is in the nature of things that 

 an Atlantic Current which is getting into Polar-water, sooner looses its characteristical marks, than a 

 Polar-current would do when it is falling in with Atlantic-water; the East Greenland Polar Current 

 serves as a good example of this. The fact is that the Polar-water will flow on top of the warmer 

 and Salter Atlantic-water, and on account of the different specific gravity of these two strata, they will 

 but slowly and not without difficulty be mixed together. An Atlantic current will, on the contrary, 

 when falling in with Polar-water, be surrounded by this on all sides, and easily get mixed with the 

 not much heavier under-layer of the Polar-water. 



The stations 123 and 122, situated far to the eastward in section XIII, show still lower sali- 

 nities than station 128, which serves as a new proof of how rapidly the eastern-going branch of the 

 Irminger Current is weakened. From the temperatures at station 123, the maximum-temperature of 

 which is 3°5 below the surface, we might be tempted to conclude that the said current for all that 

 still shows an appreciable influence so far to the eastward, for so high a maximum temperature has 

 nowhere been found in Polar-water. The salinity is, however, remarkably small, at a depth of 100 

 fathoms (188 M.) only 34'04, that is to say, less than at a corresponding depth farther East and North. 

 The high temperatures cannot therefore be directly attributed to the influence of 

 the Irminger Current, but it is more likely to be supposed that they are due to 

 vertical currents. 



SECTION XIV. 

 From station 123 and northward. 



In this section, station 123 is again remarkable by its high temperatures in connection with a 

 small degree of salinity. Water in possession of these qualities, appears otherwise only as the upper- 

 most stratum in the ice-water, and it is produced when the fresh surface-layer is heated by the sun 

 in the summer time. It is therefore likely to be supposed that such surface-water is flowing in the 

 direction of station 123, and that it is sinking down at this station. As, however, the afflux neither 

 can take place from the westward or the eastward, as the surface-water on both of these sides has a 

 higher salinity and specific gravity than the water at station 123, it must come from south or north. 

 It might be supposed, however, that it came from the southward, that is to say from the land. The 



