CURRENTS AND STREAMS 17 



the fact remains that we really know very little 

 of the sea or its inhabitants and that many of 

 the ocean's greatest mysteries still remain un- 

 solved. 



Standing upon the shore or on the deck of 

 a ship, and gazing upon the great expanse of 

 water that stretches to the horizon, it is very 

 hard for us to realise that the ever-restless 

 surface before us is composed of countless 

 great rivers, some flowing in one direction and 

 some in another. 



These ocean rivers, many of which are thou- 

 sands and thousands of times as large as the 

 Amazon, are known as "Ocean Currents," and 

 many of them flow in courses almost as defi- 

 nite and as regular as the rivers on land, 

 although their banks are only water which 

 cannot be distinguished from the rivers them- 

 selves. 



If you sail east or southeast in a steamer 

 from New York or Boston you will ruotice that 

 a day or two after leaving port the dull, green- 

 ish water changes to a clear and sparkling 

 indigo-blue, and if you have set sail during 

 cold weather you will find that as soon as your 



