THE IMPENETRABLE SEA 



the waters before they emerged from the Gulf is evidently 

 the cause of this. Off Cape Hatteras the Stream wriggled 

 around like a snake released from a box, enjoying its 

 newly-found freedom, sometimes getting off its course 

 as much as eleven miles in a day's wandering. In the 

 surveyed area, the Stream was found to have a tempera- 

 ture of seventy-five degrees, and to be about fifteen miles 

 wide and a mile deep, carrying over a thousand times as 

 much water in its course as the mighty Mississippi. 



We have followed the south equatorial current over 

 one part of its journey only. Before the vast body of water 

 is forced onward into the Atlantic it twists and turns and 

 doubles back in a curiously sinuous course. In the Gulf of 

 Mexico the pressure of its volume is so great that its level 

 is eight inches higher there than it is on the Atlantic 

 coast of Florida. Through the ninety-mile gap between 

 Florida and Cuba this irresistible ocean river pours more 

 than 100,000 million tons of water every minute. 



Its beneficent influence on the climate of Western 

 Europe, without which Britain would suffer ice-bound 

 winters, must not blind us to the potential malevolence of 

 this mighty equatorial current if its waters were reinforced 

 by the melting of the ice-caps in any considerable measure. 



Before we consider the extraordinary whirlpool of 

 weeds, populated by all kinds of interesting creatures, 

 which lies in the centre of the Gulf Stream's circular 

 course and is known as the Sargasso Sea, we must exam- 

 ine some of the ocean's tides and tidal waves. 



Tides are caused by the co-operation of the gravita- 

 tional influences of the sun and moon on the world's 

 waters. The partnership is a strange one. Our earth and 

 the moon, separated by (roughly) a quarter of a million 

 miles, are of course mutually attracted, and in their 

 mutual attraction they waltz like a couple on a dance 

 floor, circling each other and also moving in a vast circle 

 around the sun, which is pulling at them both. 



It is a well-known fact that the gravitational force of 



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