160 FRIDTJOF NANSEN. 



a tendency to flow in the opposite direction, but this water may 

 also be exposed to forces going in other directions which are 

 still more effective. 



Section IV, PI. 14, demonstrates very well the vertical di- 

 stribution of density in the North Cape Branch of the Gulf 

 Stream. The water near the Norwegian coast is conspicuously 

 lighter than the water to the north, and has consequently a very 

 strong tendency to I'ise and spread northward, which is however, 

 more or less checked by the Earth's rotation, as before men- 

 tioned. If the effect of the boyancy of the coast-water be cal- 

 culated according to Prof. V. Bjerknes' s theory^ and by the 

 methods invented by Bjerknes and Mr. Sandström,^ we find 

 that in the section between Station 57 and the Norwegian coast, 

 and between m. and 200 m. there are 7500 solenoids (c. g. s), 

 which would make the water of this section circulate [i. e. flow 

 from the coast near the surface, and towards the coast at 200 m). 

 with a mean acceleration of 40 cm. per second every 24 hours, 

 the friction of the water not being considered. If, however, the 

 water at the surface of the sea flows eastward with a velocity 

 which is greater by 7 cm. per second (= 6000 m. in 24 hours) 

 than the velocity of the water at 200 m., this difference, on 

 account of the Earth's rotation, is sufficient to check the effect 

 of the force with the above acceleration, and will keep the light 

 water in position on the right side of the current.^ 



In Section V (PL 14) across the Gulf Stream east of Bear 

 Island, there seems to have been a small bulk of heavy sinking 

 water at 600 m. at Stat. 63, wdiich has probably arised from 

 cooling of the saline Gulf Stream water. Our observations on 



' Y. Bjerknes, 'Videnskabsselskabets Skrifter', Christiania, 1898. Idem. 



K. Svenska V.et.-Akad. Handl. vol. 31, No. 4, Stockliolm, 1898. See 



also 'Meteorologische Zeitschrift', 1900. 

 - A description of this method will shortly be published. 

 ^ Mr. Walfrid Ekman has had the great kindness to make the above 



calculations. I take this opportunity of offering him my sincere thanks. 



