ATTRACTIVE FORCE OF THE MOON. 349 



great multitude of phenomena, but the public will thereby 

 be exposed to new and terrible catastrophes. 



Mankind may rest assured : Laplace has proved that 

 the equilibrium of the ocean is stable, but upon the ex- 

 press condition (which, however, has been amply veri- 

 fied by established facts), that the mean density of the 

 fluid mass is less than the mean density of the earth. 

 Every thing else remaining the same, let us substitute 

 an ocean of mercury for the actual ocean, and the sta- 

 bility will disappear, and the fluid will frequently sur- 

 pass its boundaries, to ravage continents even to the 

 height of the snowy regions which lose themselves in 

 the clouds. 



Does not the reader remark how each of the analyti- 

 cal investigations of Laplace serves to disclose the har- 

 mony and duration of the universe and of our globe ! 



It was impossible that the great geometer, who had 

 succeeded so well in the study of the tides of the ocean, 

 should not have occupied his attention with the tides of 

 the atmosphere ; that he should not have submitted to 

 the delicate and definitive tests of a rigorous calculus, 

 the generally diffused opinions respecting the influence 

 of the moon upon the height of the barometer and other 

 meteorological phenomena. 



Laplace, in effect, has devoted a chapter of his splendid 

 work to an examination of the oscillations which the 

 attractive force of the moon is capable of producing in 

 our atmosphere. It results from these researches, that, 

 at Paris, the lunar tide produces no sensible effect upon 

 the barometer. The height of the tide, obtained by the 

 discussion of a long series of observations, has not ex- 

 ceeded two-hundredths of a millimetre, a quantity which, 

 in the present state of meteorological science, is less than 

 the probable error of observation. 



