228 LIGHT SCIENCE FOR LEISURE HOURS. 



names at every stage where some new influx changes 

 the size and character of either. And the title ' Gulf 

 Stream' has, in like manner, advantages in point of 

 convenience, which are likely to prevent geographers 

 from rejecting it yet awhile. It may mislead some few 

 into supposing that the whole of the great north- 

 easterly current has passed through the Grulf of Mexico, 

 just as we can conceive that some few students of geo- 

 graphy might imagine all the water which flows past 

 Cologne or Coblentz to have come from the Orisons, or 

 all that flows past Nikopolis to have come from Baden. 

 Almost every convenient name, however, is open to 

 some such disadvantage ; and the student of oceanic 

 circulation who finds he has been to some degree misled 

 by a name must not mistake the detection of his error 

 for a great geographical discovery. 



Majora canamus. 



We have hitherto considered surface-currents only. 

 We have not, indeed, considered all the surface currents 

 which traverse the North Atlantic ; but the principal 

 streams have been indicated. We must now direct our 

 attention to submarine currents. 



It is impossible to consider carefully the nature and 

 distribution of the surface circulation without recog- 

 nising the fact that there must be currents beneath 

 the surface. It is true that one can conceive the 

 existence of a complete system of oceanic circulation 

 without any movement in the depths of the sea ; but 

 when we examine the actual surface currents we find 

 that either the commencement or the prolongation of 



