138 NOMOS. 



equal, or nearly equal, to the expansion which is 

 caused in the region diametrically opposite to this, 

 by the direct action of the solar heat (see p. 130), 

 because the heat of the focus is simply the sum of 

 the heat communicated to the earth on the other 

 side. 



According to these views, then, the solar heat 

 must produce a very marked and peculiar action 

 upon the earth. It must produce a constant bulging 

 out in the region of the equator, and it must produce 

 a double bulging of a transitory character, of which 

 one part is the exact counterpart of the other, a 

 bulging in the region immediately underneath the 

 sun, and a bulging in the region diametrically opposite 

 to this. Such is the conclusion to which we are led 

 by these considerations. 



But, it may be asked, is this conclusion supported 

 by other than mere abstract considerations ? Has it 

 any foundation in sober fact ? We think it has, and 

 we think so because it seems to afford the clue to 

 the interpretation of certain great difficulties in the 

 history of the tides and comets, and in the past 

 history of the earth. And first of the tides. 



Notwithstanding the immense labour which has 

 been expended upon the interpretation of the tides, 

 The tides ^he subject is still involved in much 

 support the obscurity. The theory of Newton that 



idea that the * , 



soiar heat the sun and moon combine to raise the 



acts upon the , i i 



earth in the ocean under them into a great tidal wave, 



