222 THE OCEAN. [Book X. 



matter is the source of gravitation, through the action 

 of which the apparent motion of every star must 

 affect the ocean in the same manner as the corre- 

 sponding motions of the sun and moon. 



Just as the lunar tide follows the apparent motion 

 of the moon, so also a similar action of the gravita- 

 tion of every star draws the water in the direction of 

 its apparent motion ; but as the stars are distributed 

 all round the earth, the combined action of their 

 innumerable tidal forces causes the equable system 

 of circulation on which the lunar and solar tides are 

 excrescences, on account of the irregularity of the 

 action of these latter bodies on different meridians not 

 beiQg balanced by the action of bodies at the same 

 distance on other meridians. 



Thus the ocean moves in concert with every 

 motion of every star, just as it moves with the move- 

 ments of the sun and moon, so that every movement 

 in the universe is, as it were, reflected by a corre- 

 sponding movement in the ocean. 



The object of this Book will be to endeavour to 

 trace in the heavens the action of the force wliich 

 forms the connecting link between the ocean and 

 every part of those distant realms. 



