132 LAPLACE. 



iu reality, are twenty-two years of labor to Lim who is about to become 

 the legislator of worlds; who shall iuseribe his name iu iuefi'aceable 

 characters upou the frontispiece of an immortal code; who shall be 

 able to exclaim in dithyrambic language, and without incurring the 

 rei)roaeh of any one, "The die is cast; I have written my book ; it will 

 be read either in tiie present age or by posterity, it matters not which ; 

 it may well await a reader, since God has waited six thousand years for 

 an interpreter of his works!"* To investigate a physical cause capable 

 of making the planets revolve iu closed curves ; to place the princii)le 

 of the stability of the universe in mechanical forces, and not in solid 

 supports, such as the spheres of crystal which pur ancestors had dreamed 

 of; to extend to the revolutions of the heavenly bodies the general 

 principles of the mechanics of terrestrial bodies, such were the ques- 

 tions which remained to be solved after Kepler had announced his dis- 

 coveries to the world. 



Very distinct traces of these great problems are perceived here and 

 there among the ancients as well as the moderns, from Lucretius and 

 Plutarch dowu to Kepler, Bouillaud, and Borelli. It is to Xewton, 

 however, that we must award the merit of their solution. This great 

 man, like several of his predecessors, conceived the celestial bodies to 

 have a tendency to approach toward each other in virtue of au attract- 

 ive force, deduced the mathematical characteristics of this force from 

 the laws of Kepler, extended it to all the material molecules of the solar 

 system, and developed his brilliant discovery in a work which, even in 

 the present day, is regarded as the most eminent production of the 

 human intellect. 



The heart aches when, studying the history of the sciences, we per- 

 ceive so magnificent an intellectual movement efi'ected without the 

 cooperation of France. Practical astronomy increased our inferiority 

 The means of investigation were at first inconsiderately intrusted to 

 foreigners, to the prejudice of Frenchmen abounding in intelligence and 

 zeal. Subsequently intellects of a superior order struggled with courage, 

 but in vain, against the unskillfuluess of our artists. During this period 

 Bradley, more fortunate, on the other side of the Channel, immortalized 

 himself by the discovery of aberration and nutation. 



The contribution of France to these admirable revolutions in astro- 

 nomical science consisted, in 1740, of the experimental determination of 



* TliPse celebrated laws, known in astronomy as the laws of Kepler, are three in number. 

 The first law is, that the planets describe ellipses aronnd the sun in their common focus; 

 the second, that a line joining the planet and the sun sweeps over equal areas in equal times; 

 the third, that the squares of the periodic times of the planets are proportional to the cubes 

 of their mean distances from the sun. The first two laws were discovered by Kepler in the 

 course of a laborious examination of the theory of the planet Mars ; a full account of this 

 inquiry is contained in his famous work De Stella Martis, published in 1 609. The discovery 

 of the third law was not effected until several years afterward. Kepler announced it to the 

 world in his treatise on Harmonics, (1628.') The passage quoted below is extracted from 

 that work. — Transl.^tor. 



