62 



THE OCEAN 



does not reach the coast of North America 

 until it is thirty-six hours old. Strangely 

 enough a second tidal wave is formed on the 



Of Sat f-^ &Afoon 



5rca/f/a.ry y\^ir(^ 



HOW THE MOON CAUSES TIDES 



side of the earth opposite the moon and at first 

 thought this would seem to refute the theory 

 that the moon really causes the tides. To 

 explain this second tide is far more difficult 

 than to account for the first and several well- 



