TIDAL ACTION BELOW EARTH'S SURFACE. 47 



from asserting that all the phenomena presented by 

 earth's surface are the result of lateral pressure, we 

 stated that the outer crust of the earth must be 

 under the dominion of the same forces as are the 

 ocean and the atmosphere. If, then, the interior of 

 the earth be in a state of liquid incandescence, 

 that liquid mass must heave and throb with tidal 

 movements analogous to those of the ocean and the 

 atmosphere. It must stream around; and sway to 

 and fro against the inner surface of earth's hardened 

 crust, with an action more or less similar to that of 

 the ocean and atmosphere against the outer surface 

 of that crust. The force of its pressure against any 

 given part of earth's crust will be subject to diurnal 

 and annual variations in accordance with the changes 

 of its position in relation to the various tidal forces. 



In the sketch of the action of lateral pressure, 

 contained in the third chapter of our first volume, 

 we supposed that we were advancing what was in a 

 great measure a new theory of the causes of the 

 undulations of earth's surface. It appears, however, 

 from the tenth edition of Sir Charles LyelPs ' Prin- 

 ciples of Geology,' the first volume of which has just 

 issued from the press, that there is no novelty in 

 those views; but that they originated with M. Elie 

 de Beaumont, and have for many years been elabo- 

 rately supported by him. We therefore fall back on 

 the authority of M. Elie de Beaumont in maintaining 

 that the contortions of the outer crust of the earth 



