144 NOMOS. 



sun and moon, the tidal wave will, cceteris paribifs, 

 set equally towards every shore; for, according to 

 this view, the tide is nothing more than the agitation 

 of the edge of the ocean which is caused by the 

 alternate rising and sinking of the land, the level of 

 the ocean being always the same. In the third 

 place, the diagrams of the tides at St. Helena 

 become intelligible. It is quite natural, according 

 to this view, that the moon should be in relation to 

 the region between the tides. It is also natural that 

 she should be nearer to the tide before the moon than 

 to the tide behind the moon, and not exactly midway 

 between the two tides : for time must be required to 

 produce the necessary expansion of the land; and 

 time perhaps a longer time is also necessary to 

 allow this expansion to pass off. In a word, there 

 is an inertia of land as well as of water, which must 

 be taken into consideration. But the great difficulty 

 in the way of this theory is in supposing that the 

 moon is endowed with anything like heating powers. 

 Is she so endowed ? 



It is an unquestionable fact that the most careful 

 observations have failed to detect any sensible sign 

 of heat in the lunar rays, unless, as Sir John 

 Herschel inclines to think, the general absence of 

 clouds at the time of the full moon may be con- 

 sidered an argument that the moon has a sun-like 

 power of heating the clouds, and so rendering them 

 invisible. But still we are not at liberty to suppose 

 that there is no heat in these rays. We are not at 

 liberty to do this, because the thermometer cannot 

 be allowed to be the sole standard of judgment in 



