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CHAPTER IX. 



NORMAL POSITIONS OF THE TIDES IN RELATION TO 

 THE FORCES BY WHICH THEY ARE RAISED. 



The position which the ocean would have under the 

 sole influence of terrestrial gravitation is modified by 

 the gravitation of other bodies in space, which tend 

 to draw the water to the parts of the surface of the 

 earth turned towards them. 



The sun, the moon, and the planets all tend, more 

 or less, to draw the water to those parts of the earth's 

 surface turned towards them. And by the earth's 

 motions the parts of the surface of the earth turned 

 towards the foreign bodies respectively are being 

 constantly changed. The gravitation of those bodies 

 constantly tends to hold the water in the position 

 which they tend to give it, whilst the earth's gravi- 

 tation as constantly tends to carry the water away 

 from that position, together with the surface on which 

 it rests. 



Let us now suppose all other bodies of the Solar 

 System to be so far removed from the earth that the 

 individuality of their forces of gravitation on the 

 earth may be lost in that of the remaining force — 

 which is, in fact, that of the stars, or, as we have 

 before termed it, astral gravitation. 



