PEAR-SHAPED EARTH 47 



lar interest for us in the speculations of Mr. Jeans, since 

 they throw fresh light on that very difficult question, the 

 origin of the ocean.* 



The conclusion which Mr. Jeans reaches, as the result 

 of a train of mathematical reasoning, is that immediately 

 before consolidation our planet may have possessed a 

 form somewhat similar to that of a pear (Fig. 4). It 

 looks as though, after giving birth to the moon, the earth 

 was on the way to eject a second satellite, but stopped 



FIG 4. 



short of this, perhaps, on account of completed solidifica- 

 tion. If the earth had at this juncture a pear-like form, 

 then Mr. Jeans says: "It is easy to see that enormous 

 stresses would be set up in the interior of the earth after 

 consolidation. An equilibrium figure depends in general 

 upon the compressibility of the material ; and a con- 



* " On the Vibrations and Stability of a Gravitating Planet," by 

 J. H. Jeans, B.A., Fellow of Trinity College, Cambridge, Phil. 

 Trans. A., vol. 201, pp. 157-184, 1903. 



