LAPLACE, PIERRE SIMON, MARQUIS DE, the greatest of recent physicists, was born March 23, 1749, at Beaumont, near Pont l'Evêque, in Lower Normandy. His father, a small farmer in the Vallée d'Auge, was too poor to send him to school, but some rich friends took an interest in the young scholar and sent him to the college of Caen, and afterwards to the military school of Beaumont. Though mathematics were at this time his favourite study, he seems to have paid a good deal of attention to theology. In his eighteenth year he went to Paris, furnished with introductions to D'Alembert and others. D'Alembert took no notice of his letter, till Laplace sent him an essay involving some of the higher principles of mathematics, when he invited him to his house, and shortly afterwards procured him a mathematical mastership in the military school of Paris. Laplace soon justified his choice by his papers read before the Academy of Sciences, of which, in 1773, he became an associate, and in 1786 a member. Before he was thirty years of age he had begun that career of discovery which only terminated with his life. It is not necessary here to recapitulate the details of his studies and their results, which are given in full in the PRELIMINARY DISSERTATIONS of Sir John Leslie and Professor J. D. Forbes. When the Revolution broke out, Laplace became ambitious of political distinction. In 1796 he was one of the deputation which, in presence of the Council of Five Hundred, swore eternal hatred against royalty. A little later he dedicated to this same body his Exposition du Système du Monde. On the return of General Bonaparte from his campaigns in Italy, Laplace paid his court to him and secured his admission into the Institute. His good will was rewarded at a later period with the portfolio of the interior. But, as Napoleon afterwards said, "he carried into government the principles of
the calculus," and managed matters so ill, that after six weeks of office it was found necessary to promote him to a sinecure in the senate. This occurred in 1799. Four years later he was made successively vice-president and chancellor of that body. Though he had sworn eternal hatred against kings and tyrants, he cheerfully took the oath of allegiance to Napoleon when he mounted the throne in 1804. His complaisance was rewarded with numerous honours. He received the grand-cordon of the Legion of Honour in 1805, the title of count in 1806, the cross of grand-officier of the Legion of Honour in 1813, with many other distinctions. Yet when his benefactor's power began to wane, Laplace was among the first who voted for the overthrow of the imperial throne, and the restoration of the Bourbons. He even displayed a spirit of pusillanimous ingratitude to his fallen patron. He had dedicated to him, in very fulsome terms, his Théorie des Probabilités; in 1814, on the downfall of the empire, he suppressed this dedication. Shame or remorse for this time-serving may perhaps have prevented him from visiting the Tuileries during the Hundred Days. It is all the more creditable to him, however, that he did not go, as he had been assured of a kindly welcome. He carried a somewhat similar spirit into his writings, in which he withheld nearly all mention of any who had preceded him in his own branch of science, though liberal enough of praise to the great names in other departments of inquiry. On this point, however, it is unnecessary to dwell, as it has been already discussed in Professor Forbes' DISSERTATION. In 1816 Laplace was named by Louis XVIII. president of a commission for the reorganization of the Polytechnic School, and in the following year became president of the Academy of Sciences. Before this date he had been elected a member of all the leading learned societies of Europe. At the time of his death, March 5, 1827, exactly a century after that of Newton, he had nearly completed his 78th year. The last words he was heard to utter were, "Ce que nous savons est peu de choses; ce que nous ignorons est immense."
The following list of Laplace's works is taken chiefly from La France Littéraire, by M. Quéret, and includes not only his separate publications, but also numerous memoirs, with which, during a period extending to rather more than half a century, he enriched the collections of the Academy and the Institute, and the Journal of the Polytechnic School:—
Laplace. sident Bochart de Saron, who only caused 200 copies to be struck off, for the purpose of being distributed gratuitously.
7. Traité de Mécanique Céleste, in sixteen books, Paris, 1799-1825, in five volumes 4to, with four supplements published at different times. The first book treats of the general laws of the equilibrium of motion; the second, of the law of universal gravitation, and the motion of the centres of gravity of the heavenly bodies; the third, of the figure of the heavenly bodies; the fourth, of the oscillations of the sea and the atmosphere; the fifth, of the motions of the heavenly bodies around their proper centres of gravity; the sixth, of the theory of the planetary motions; the seventh, of the theory of the moon; the eighth, of the theory of the satellites of Jupiter, Saturn, and Uranus; the ninth, of the theory of comets; the tenth, on different points relative to the system of the world; the eleventh, on the figure and rotation of the earth; the twelfth, on the attraction and repulsion of spheres, and the laws of the equilibrium and motion of elastic fluids; the thirteenth, on the oscillation of the fluids which cover the planets; the fourteenth, on the motions of the heavenly bodies around their centres of gravity; the fifteenth, on the motions of the planets and comets; and the sixteenth, on the motions of the satellites. A second edition of the first two volumes of this work was published at Paris in 1829, 1830. In this country no attempt has yet been made, so far as we know, to translate the Traité de Mécanique Céleste into English; but, in 1830, an English translation of the first volume, with a commentary, was published at Boston, in the United States of America. Both the translation and the commentary are by Dr Bowditch of Boston; but the amount of the latter is out of all proportion to the text, being intended to enable persons but moderately skilled in the mathematics to comprehend the profound analytical investigations of the great astronomer, and to follow him to his beautiful and striking results.
8. Besides the works which we have just enumerated, M. de Laplace is also the author of a series of very important Mémoires, in which, from 1772 to 1823, he published the collections of the old and the new Academy of Sciences, that of the Institute, and the Journal of the Polytechnic School. The subjects of these Mémoires are exceedingly various. We give the following list in the chronological order of their impression, viz.:-1. On the Particular Solutions of Differential Equations, and on the Secular Inequalities of the Planets, 1772; 2. On the Integral Calculus, and on the System of the World, 1772; 3. On the Integral Calculus of Partial Differences, 1773; 4. On recurring Series, and their Uses in the Theory of Chances, 1774; 5. On the Probability of Causes afforded by Events, 1774; 6. On some Points in the System of the World, 1775 and 1776; 7. On the Integration of Differential Equations with Finite Differences, 1776; 8. On the Mean Inclination of the Orbits of Comets, id.; 9. On the Use of the Calculus of Partial Differences in the Theory of recurring Series, 1777; 10. On the Precession of the Equinoxes, id.; 11. On the Integration of Differential Equations by Approximation, id.; 12. On Probabilities, 1778; 13. On Series, 1779; 14. On the Determination of the Orbits of Comets, id.; 15. On Heat, id.; 16. On the Electricity which Bodies absorb when reduced to Vapour, 1781; 17. On the Approximations of Formulae which are functions of very great numbers, 1782, 1783; 18. On the Figure of the Earth, 1783; 19. On the Births, Marriages, and Deaths at Paris from 1772 to 1784; 20. On the Population of France, and the Number of Inhabitants in the Country, 1783-1788; 21. On the Secular Inequalities of the Planets and of the Satellites, 1784; 22. Theory of Jupiter and of Saturn, 1787; 23. On the Secular Equation of the Moon, 1786; 24. On the Theory of Saturn's Ring, 1787; 25. On the Secular Variations in the Orbits of the Planets, id.; 26. Theory of the Satellites of Jupiter, 1788, 1789; 27. On the Theory of the Satellites of Jupiter, 1789; 28. On the Flux and Reflux of the Sea, 1790; 29. On the Determination of a Plane which remains always parallel to itself, in the movement of a system of bodies acting upon each other in any manner whatsoever, and free from all foreign action, 1793; 30. On Mechanics, id.; 31. On the Motions of the Heavenly Bodies round their Centres of Gravity, id.; 32. On the Secular Equations of the Motions of the Moon, of her Apogee, and of her Nodes, 1799; 33. On the Motion of the orbits of the Satellites of Saturn and Uranus, 1801; 34. On the Theory of the Moon, id.; 35. On Different Points of Analysis, 1809; 36. On the Motion of Light in Diaphanous Media, id.; 37. On the Approximations of the Formulae which are functions of very great numbers, and on their application to Probabilities, id.; 38. On the Figure of the Earth, 1817; 39. On the Flux and Reflux of the Sea, 1818; 40. Addition to the Mémoire on the Figure of the Earth, id.; 41. On the Developments of the true Anomaly, and of the Elliptical Radius Vector, in series, arranged according to the powers of the eccentricity, 1823. Lastly, the Marquis de Laplace contributed, in the mathematical department, to the Leçons de l'École Normale.
(See Éloge Historique de M. le Marquis de Laplace, by Baron VOL. XIII.
Fourier, in the Mémoires de l'Académie Royale des Sciences de l'Institut de la France, tom. x., p. lxxxii.; Quérad, La France Littéraire, art. LAPLACE; Revue Encyclopédique, tom. xxxiii., p. 889; Edinburgh Review, vol. xi., p. 249, et seqq., vol. xv., p. 395, et seqq., and vol. xxiii., p. 320, containing masterly criticisms on the Mécanique Céleste, the Exposition du Système du Monde, and the Essai Philosophique sur les Probabilités; and Dissertations Fourth and Sixth, prefixed to the present work.) (J. E.—E.)