214 THE OCEAN. [Book IX. 



axial rotation from any axis to a new axis at right 

 angles to the position of the old axis. And, in fact, 

 if in this sketch I have correctly described the action 

 of the forces brought into play, then it would appear 

 from the actual conformation of the outer crust of 

 the earth that such a change of the axis of rotation 

 as above mentioned has occurred, not once only, but 

 many times. In such case the wave-like conforma- 

 tions observed by Admiral Fitzroy must have been 

 formed since the occurrence of the last change of 

 axis : these comparatively modern undulations inter- 

 secting older similar undulations, and obliterating, to 

 a greater or lesser extent, the traces of their original 

 conformation. 



Let us consider how such a change of axis as 

 that just mentioned would aifect the configuration of 

 the globe which we have been describing. By such 

 a change the position of the poles of the new axis 

 would be in opposite points of the old equator : and 

 the new equator would intersect the old at points 

 ninety degrees from each of those poles. The equa- 

 torial diameter between those points would then be 

 greater than that at right angles to it ; for this latter 

 would be the line of the former axis of rotation. 

 And centrifugal force, carrying the water to the 

 equatorial regions, would cause it to accumulate in 

 two great oceans whose central points would be over 

 the poles of the former axis : and those oceans would 

 be separated meridionally by a belt of land lying 



