The Representation of Oceanic Movements and Kinematics 381 



these values gave the relationships (calculated) /' = 1-03 /, u = 0-465 /, u = 0-449 / 

 and u = 1-07 u. Current measurements gave the relations (observed) /' = 1-06 /, 

 u = 0-55 /, u = 0-449 / and u' = 1-22 u. 



Considering that the observational values were obtained from only a few individual 

 measurements and that meteorological factors have an appreciable influence on water 

 transport through the Bosporus the agreement is very satisfactory. 



A generalization of the Knudsen relations has been given by Witting (1906) in 

 his study of the Gulf of Bothnia ; here an attempt was made to consider in the calcula- 

 tion changes in sahnity during the observational period, although one is mostly forced 

 by the observations to be satisfied with the simpler equations (XII. 19). The investiga- 

 tions of Gehrke (1907) on the current conditions west of Ireland and the British Isles, 

 where the Atlantic current flows north-east were also based on these relationships; 

 they are an example of how similar ideas can be applied to corresponding problems 

 concerning the oceanic circulation, even then, when no upper and lower current flowing 

 in opposite directions are present. 



All these investigations are based entirely on the continuity equation for the water 

 and salt contents and of course yield information only on mean conditions ; they do 

 not give any information about the internal structure of the c urrents or on the causa- 

 tive connections between them. 



