THEOEY or THE TIDES. 



97 



moment of its aplpearance, they depend on the obstacles of every 

 kind which the rocks, islands, continents, oceanic currents, and 

 winds oppose to the free circulation of the waters. 



Nevertheless, the moon is not the only heavenly body whose at- 

 traction is manifested in a sensible manner on the waves of the ocean. 

 The sun, which draws the moon in its immense orbit across the hea- 

 vens, is near enough to our planet to raise the liquid particles of our 



Fig. 28.— Syzygy tide, during full Moon. 



ocean also. The total attraction exercised by the sun on the earth 

 is even 162 times greater than the total attraction of the moon, and 



