430 APPENDIX V 



fact that the curves of the isotherms and isohalins are more 

 marked in the more southerly of our two sections than in the 

 more northerly one, which lies 10 or 15 degrees nearer the 

 Equator. 



But the probability is that the curves are due to the formation 

 of eddies in the currents. In an eddy the light and w^arm water 

 will be depressed to greater depths if the eddy goes contrary to the 

 hands of a clock and is situated in the southern hemisphere. We 

 appear to have such an eddy around Station 19, for example. 

 Around Station 2 an eddy appears to be going the other way; 

 that is, the same way as the hands of a clock. On the chart 

 of currents we have indicated some of these eddies from the obser- 

 vations of the distribution of salinity and temperature made by the 

 Fram Expedition. 



While this, then, is the probable explanation of the irregularities 

 shown by the lines of the sections, it is not impossible that they 

 may be due to other conditions, such as, for instance, the submarine 

 waves alluded to above. Another possibility is that they may be a 

 consequence of variations in the rapidity of the current, produced, 

 for instance, by wind. The periodical variations caused by the 

 tides will hardly be an adequate explanation of what happens 

 here, although during Murray and Hjort's Atlantic Expedition in 

 the Michael Sars (in 1910), and recently during Nansen's voyage 

 to the Arctic Ocean in the Veslemoy (in 1912), the existence of 

 tidal currents in the open ocean was proved. It may be hoped 

 that the further examination of the Fram material will make these 

 matters clearer. But however this may be, it is interesting to 

 establish the fact that in so great and deep an ocean as the South 

 Atlantic very considerable variations of this kind may occur 

 between points which he near together and in the same current. 



As we have already mentioned in passing, the observations show 

 that the same temperatures and salinities as are found at the 

 surface are continued downward almost unchanged to a depth 

 of between 75 and 150 metres; on an average it is about 



