64 THE OCEAN 



body exerts a force of gravitation upon the 

 water the sun must also attract the sea, al- 

 though, owing to its greater distance from the 

 earth, it exerts only a very little force as com- 

 pared with the moon. When, however, the 

 sun and moon both act together the highest 

 tides are formed, which are known as ^^Spring 

 Tides" or "Perigee Tides," and when the two 

 planets are opposed and exert their forces in 

 different directions "Neap Tides" or very 

 low tides result. 



If you visit various points on the seacoast 

 you may be surprised to find that the amount 

 of rise and fall of the tide varies a great deal. 

 In one spot the tide may rise and fall for six 

 or eight feet while in another locality, only a 

 few miles away, there may be a rise and fall 

 of but two or three feet. In reality the tide 

 itself rises and falls the same amount in both 

 places but the water rises and falls more or 

 less according to the surrounding shores, the 

 bottom of the ocean and the wind. I have 

 already told how the tides on some of the 

 West Indian islands rise and fall but a few 

 inches on one side of an island and five or six 



