Physical Geography of the Great Oceans 103 



so completely screens the water below, that the temperature 

 of the layer between 20 and 80 fathoms is 17 lower than at 

 the neighbouring station No. 270. The surface water at both 

 stations is moving away rapidly, and the deeper and colder 

 water, which rises to supply a portion of the deficiency, cools 

 -urfurr water at both stations; but at station 267, however 



Mean temperature of different layers of water. 



Observed density (at 60 F.) of water at different depths at 

 the same stations. 



much the surface water be cooled, it -till floats on the surface, 

 while at No. 270, on being cooled to the sain< t< mperature 



'trr inin ink- tliiou-li it. carrying 



deeper. 

 The study of the 1 i ^i<>n< \vuil 1 



