PENTAGONAL DODECAHEDRON 57 



An objection to all speculations of the kind in which 

 we have just engaged will naturally arise in the 

 mind of every geologist : it is to be found in the fact that 

 nearly all the land which now rises above the sea has at 



FIG. 7. Elie de Beaumont's pentagonal dodecahedron unfolded to show 

 its correspondence with the symmetry of a pear-shaped earth. 



some time or other been submerged beneath it, and, 

 indeed, that the larger part of the existing land is com- 

 posed of marine sediments. This objection might very 

 easily prove fatal were it not equally the fact that these 



