148 NOMOS. 



ray is 180 times hotter than the lunar ray. Suppos- 

 ing, then, that the solar ray is 180 times hotter than 

 the lunar ray, the effect will be to raise by so much 

 the value of the part which the sun plays in causing 

 the tidal expansion of the earth ; and, therefore, the 

 value of the part which the sun plays in this matter 

 as compared with the value of the part played by 

 the moon will no longer be as 12 ^ 00 to -J^, but as 

 1 *%g , that is -gig, to -^. In other words, the pro- 

 portion between the lunar and solar tidal expansion 

 will be very nearly that which Newton calculated 

 as existing between the lunar and solar tidal waves. 



It is no extravagant stretch of fancy, therefore, to 

 suppose that the moon may expand the earth in the 

 same manner as the sun, and cause the land to bulge 

 out on the side which faces the moon, and on the 

 side diametrically opposite to this, and that this 

 action, together with the corresponding action of the 

 sun, is the cause of the tides, the land contracting 

 and sinking down at high water, and expanding and 

 rising up at low water. And assuredly such a theory 

 is more in harmony with the facts of the case than 

 the theory which supposes the tide to be a wave 

 raised up by the attraction of the sun and moon. 



Themeta. It appears, also, that the same expan- 



s i ye process is exhibited in certain unex- 

 plained changes in the form of comets, 



heat may act an( j this is the point we proposed to con- 



in the man- f * . 



ner which sider after having discussed the question 



has been 



supposed. of the tides. 



