OCEAN CURKENTS 125 



bed and banks are of cold water, and it is to this fact 

 that we owe our national existence ; for if, instead 

 of flowing as it does over a bed and between banks 

 of cold water, it flowed over a shallow bottom of earth, 

 it would lose its heat so rapidly (earth being a far 

 better conductor of heat than water) that by the 

 time it reached our shores it would have none to 

 give us, and the conditions obtaining in Labrador 

 and Greenland would be ours. The Thames, the 

 Severn, and the Clyde would become glaciers, and 

 all that Britain stands for would be annulled. Of 

 course, the same thing would happen if, by any cata- 

 clysm, the course of the Gulf Stream could be changed 

 deflected south, let us say so that it would recurve 

 to the westward about the Azores. 



But, it may be asked, how is it that this great 

 oceanic river of water pursues its way over so many 

 miles of intervening sea without losing either its 

 direction or its distinctive characteristic ? Why does 

 it apparently obey a different law to that which makes 

 the equatorial current flow westward ? Has the rota- 

 tion of the earth upon its axis no influence upon this 

 eastward-flowing stream? Kemembering that this is 

 not a scientific treatise, but an attempt to treat the 

 great question of ocean circulation in a way that shall 

 be popular yet not misleading, I would remind the 

 reader, first of all, that cold water is heavier than 

 warm, and consequently when a body of cold water 

 strikes a body of warm water it does not, as we might 

 think, amalgamate at once, but the cold water sinks 

 as well as pushes the warm water back. But if the 

 body of warm water has a vastly greater bulk than 

 the cold, it will not be pushed back, but will continue 



