Marquis De Laplace. 199 



ditions which his predecessors had omitted. In the question 

 already so complex of the form and rotatory motion of the 

 earth, he has considered the influence of the waters distributed 

 between the continents, the compression of the interior strata, 

 and the secular diminution of the dimensions of the globe. ' 



Among all these researches we must particularly distinguish 

 those which relate to the stability of great phenomena ; for 

 no object is more worthy of the meditation of philosophers. 

 Hence it follows that those causes, either accidental or con- 

 stant, which disturb the equilibrium of the ocean, are subject 

 to limits which cannot be passed. The specific gravity of the 

 sea being much less than that of the solid globe, it follows 

 that the oscillation s of the ocean are always comprehended be- 

 tween very narrow limits ; which would not have happened 

 if the fluid spread over the globe had been much heavier. 

 Nature in general keeps in reserve conservative forces which 

 are always present, and act the instant the disturbance com- 

 mences, and with a force increasing with the necessity of cal- 

 hng in their assistance. This preservative power is found in 

 every part of the universe. The form of the great planetary or- 

 bits, and their inclinations, vary in the course of ages, but these 

 changes have their limits. The principal dimensions subsist, 

 and this immense assemblage of celestial bodies oscillates 

 round a mean condition of the system, towards which it is al- 

 ways drawn back. Every thing is arranged for order, perpe- 

 tuity, and harmony. 



In the primitive and liquid state of the terrestrial globe, the 

 heaviest materials are placed near the centre, and this condi- 

 tion determines the stability of seas. 



Whatever may be the physical cause of the formation of 

 the planets, it has impressed on all these bodies a projectile 

 motion in one direction round an immense globe ; and from this 

 the solar system derives its stability. Order is here kept up by 

 the power of the central mass. It is not, therefore, left, as 

 Newton himself and Euler had conjectured, to an adventitious 

 force to repair or prevent the disturbance which time may have 

 caused. It is the law of gravitation itself which regulates all 

 things, which is sufficient for all things, and which everywhere 

 maintains variety and order. Having once emanated from su- 



