MAUPERTUIS (Peter Louis Morceau de)

, a celebrated French mathematician and philosopher, was born at St Malo in 1698, and was there privately educated till he attained his 16th year, when he was placed under the celebrated professor of philosophy, M. le Blond, in the college of la Marche, at Paris; while M. Guisnée, of the Academy of Sciences, was his instructor in mathematics. For this science he soon discovered a strong inclination, and particularly for geometry. He likewise practised instrumental music in his early years with great success; but fixed on no profession till he was 20, when he entered into the army; in which he remained about 5 years, during which time he pursued his mathematical studies with great vigour; and it was soon remarked by M. Freret and other academicians, that nothing but mathematics could satisfy his active soul and unbounded thirst for knowledge.

In the year 1723, he was received into the Royal Academy of Sciences, and read his first performance, which was a memoir upon the construction and form of musical instruments. During the first years of his admission, he did not wholly confine his attention to mathematics; he dipt into natural philosophy, and discovered great knowledge and dexterity in observations and experiments upon animals.

If the custom of travelling into remote countries, like the sages of antiquity, in order to be initiated into the learned mysteries of those times, had still subsisted, no one would have conformed to it with more eagerness than Maupertuis. His first gratification of this passion was to visit the country which had given birth to Newton; and during his residence at London he became as zealous an admirer and follower of that philosopher as any one of his own countrymen. His next excursion was to Basil in Switzerland, where he formed a friendship with the celebrated John Bernoulli and his family, which continued till his death. At his return to Paris, he applied himself to his favourite studies with greater zeal than ever. And how well he ful-| filled the duties of an academician, may be seen by running over the Memoirs of the Academy from the year 1724 to 1744; where it appears that he was neither idle, nor occupied by objects of small importance. The most sublime questions in the mathematical sciences, received from his hand that elegance, clearness, and precision, so remarkable in all his writings.

In the year 1736, he was sent to the polar circle, to measure a degree of the meridian, in order to ascertain the sigure of the earth; in which expedition he was accompanied by Mess. Clairault, Camus, Monnier, Outhier, and Celsus the celebrated professor of astronomy at Upsal. This business rendered him so famous, that on his return he was admitted a member of almost every academy in Europe.

In the year 1740, Maupertuis had an invitation from the king of Prussia to go to Berlin; which was too flattering to be refused. His rank among men of letters had not wholly effaced his love for his first profe<*>ion, that of arms. He followed the king to the field, but at the battle of Molwitz was deprived of the pleasure of being present, when victory declared in favour of his royal patron, by a fingular kind of adventure. His horse, during the heat of the action, running away with him, he fell into the hands of the enemy; and was at first but roughly treated by the Austrian Hussars, to whom he could not make himself known for want of language; but being carried prisoner to Vienna, he received such honours from the emperor as never were effaced from his memory. Maupertuis lamented very much the loss of a watch of Mr. Graham's, the celebrated English artist, which they had taken from him; the emperor, who happened to have another by the same artist, but enriched with diamonds, presented it to him, saying, “the Hussars meant only to jest with you, they have sent me your watch, and I return it to you.”

He went soon after to Berlin; but as the reform of the academy which the king of Prussia then meditated was not yet mature, he repaired to Paris, where his affairs called him, and was chosen in 1742 director of the Academy of Sciences. In 1743 he was received into the French Academy; which was the first instance of the same person being a member of both the academies at Paris at the same time. Maupertuis again assumed the soldier at the siege of Fribourg, and was pitched upon by marshal Coigny and the count d'Argenson to carry the news to the French king of the surrender of that citadel.

Maupertuis returned to Berlin in the year 1744, when a marriage was negotiated and brought about, by the good offices of the queen mother, between our author and madamoiselle de Borck, a lady of great beauty and merit, and nearly related to M. de Borck at that time minister of state. This determined him to settle at Berlin, as he was extremely attached to his new spouse, and regarded this alliance as the most fortunate circumstance of his life.

In the year 1746, Maupertuis was declared, by the king of Prussia, President of the Royal Academy of Sciences at Berlin, and soon after by the same prince was honoured with the Order of Merit. However, all these accumulated honours and advantages, so far from lessening his ardour for the sciences, seemed to furnish new allurements to labour and application. Not a day passed but he produced some new project or essay for the advancement of knowledge. Nor did he confine himself to mathematical studies only: metaphysics, chemistry, botany, polite literature, all shared his attention, and contributed to his fame. At the fame time he had, it seems, a strange inquietude of spirit, with a dark atrabilaire humour, which rendered him miserable amidst honours and pleasures. Such a temperament did not promise a pacific life; and he was in fact engaged in several quarrels. One of these was with Koenig the professor of philosophy at Franeker, and another more terrible with Voltaire. Maupertuis had inserted in the volume of Memoirs of the Academy of Berlin for 1746, a discourse upon the laws of motion; which Koenig was not content with attacking, but attributed to Leibnitz. Maupertuis, stung with the imputation of plagiarism, engaged the academy of Berlin to call upon him for his proof; which Koenig failing to produce, his name was struck out of the academy, of which he was a member. Several pamphlets were the consequence of this measure; and Voltaire, for some reason or other, engaged in the quarrel against Maupertuis. We say, for some reason or other; because Maupertuis and Voltaire were apparently upon the most amicable terms; and the latter respected the former as his master in the mathematics. Voltaire upon this occasion exerted all his wit and satire against him; and upon the whole was so much transported beyond what was thought right, that he found it expedient in 1753 to quit the court of Prussia.

Our philosopher's constitution had long been considerably impaired by the great fatigues of various kinds in which his active mind had involved him; though from the amazing hardshipa he had undergone, in his northern expedition, most of his bodily sufferings may be traced. The intehfe sharpness of the air could only be supported by means of strong liquors; which helped but to lacerate his lungs, and bring on a spitting of blood, which began at least 12 years before he died. Yet still his mind seemed to enjoy the greatest vigour; for the best of his writings were produced, and most sublime ideas developed, during the time of his confinement by sickness, when he was unable to occupy his presidial chair at the academy. He took several journeys to St. Malo, during the last years of his life, for the recovery of his health<*> and though he always received benefit by breathing his native air, yet still, upon his return to Berlin, his disorder likewise returned with greater violence. His last journey into France was undertaken in the year 1757; when he was obliged, soon after his arrival there, to quit his favourite retreat at St. Malo, on account of the danger and confusion which that town was thrown into by the arrival of the English in its neighbourhood. From thence he went to Bourdeaux, hoping there to meet with a neutral ship to carry him to Hamburgh, in his way back to Berlin; but being disappointed in that hope, he went to Toulouse, where he remained seven months. He had then thoughts of going to Italy, in hopes a milder climate would restore him to health; but finding himself grow worse, he rather inclined towards Germany, and went no Neufchatel, where for three| months he enjoyed the conversation of lord Marischal, with whom he had formerly been much connected. At length he arrived at Basil, October 16, 1758, where he was received by his friend Bernoulli and his family with the utmost tenderness and affection. He at first found himself much better here than he had been at Neufchatel: but this amendment was of short duration; for as the winter approached, his disorder returned, accompanied by new and more alarming symptoms. He languished here many months, during which he was attended by M. de la Condamine; and died in 1759, at 61 years of age.

The works which he published were collected into 4 volumes 8vo, published at Lyons in 1756, where also a new and elegant edition was printed in 1768. These contain the following works:

1. Essay on Cosmology.—2. Discourse on the different Figures of the Stars.—3. Essay on Moral Philosophy.—4. Philosophical Reflections upon the Origin of Languages, and the Signification of Words— 5. Animal Physics, concerning Generation &c.— 6. System of Nature, or the Formation of bodies— 7. Letters on various subjects.—8. On the Progress of the Sciences.—9. Elements of Geography—10. Account of the Expedition to the Polar Circle, for determining the Figure of the Earth; or the Measure of the Earth at the Polar Circle.—11. Account of a Journey into the Heart of Lapland, to search for an Ancient Monument.—12. On the Comet of 1742.— 13. Various Academical Discourses, pronounced in the French and Prussian Academies.—14. Dissertation upon Languages.—15. Agreement of the Different Laws of Nature, which have hitherto appeared incompatible.—16. Upon the Laws of Motion.—17. Upon the Laws of R<*>st.—18. Nautical Astronomy.—19. On the Parallax of the Moon.—20. Operations for determining the Figure of the Earth, and the Variations of Gravity.—21. Measure of a Degree of the Meridian at the Polar Circle.

Beside these works, Maupertuis was author of a great multitude of interesting papers, particularly those printed in the Memoirs of the Paris and Berlin Academies, far too numerous here to mention; viz, in the Memoirs of the Academy at Paris, from the year 1724, to 1749; and in those of the Academy of Berlin, from the year 1746, to 1756.