This subject suggests a similar one, which was discussed 

 a few months since at the Acadamy of Sciences of Paris. 

 On January 30th last M. St. Meunier read a paper on " The 

 mode of rupture of a star, from which meteors are de- 

 rived." The author starts with .the assumption that me- 

 teors have been produced by the rupture of a world, basing 

 this assumption upon the arguments he has stated in pre- 

 vious papers. He discards altogether Sir "W. Thomson's 

 idea of a collision between two worlds, but works out a con- 

 clusion quite as melancholy. 



He begins, like most other builders of cosmical theories, 

 with the hypothesis that this and all the other worlds of 

 space began their existence in a condition of nebulous in- 

 fancy; that they gradually condensed into molten liquids, 

 and then cooled down till they obtained a thin outside 

 crust of solid matter, resting upon a molten globe within; 

 that this crust then gradually thickened -as the world 

 grew older and cooled down by radiation. I will not stop 

 to discuss this nebular and cooling-down hypothesis at 

 present, though it is but fair to state that "I "don't believe 

 a bit of it." 



Taking all this for granted a considerable assumption 

 M. St. Meunier reasons very ably upon what must follow, if 

 we further assume that each world is somehow supplied 

 with air and water, and that the atmosphere and the ocean 

 of each world are limited and unconnected with those of 

 any other world, or with any general interstellar medium. 



What, then, will happen as worlds grow old? As they 

 cool down, they must contract; the liquid inside can man- 

 age this without any inconvenience to itself, but not so 

 with the outer spherical shell of solid matter. As the 

 inner, or hotter part of this contracts, the cool outside 

 must crumple up in order to follow it, and thus mountain 

 chains and great valleys, lesser hills and dales, besides 

 faults and slips, dykes, earthquakes, volcanoes, etc., are 

 explained. 



According to M. St. Meunier, the moon has reached a 

 more advanced period of cosmical existence than the earth. 

 She is our senior; and like the old man who shows hi.s 

 gray hairs and tottering limbs to inconsiderate youth, she 



