Maupertuis, Peter Louis Morceau De

, a celebrated French mathematician and philosopher, was born at St. Malo in 1698, and at first educated there. In 1714 he studied in the college of La Marche, at Paris, where he discovered a strong inclination for mathematics. He fixed, however, on no profession until he arrived at his twentieth year, when he entered into the army, and during the space of five years in which he remained in it, pursued his mathematical studies with great vigour. In 1723 he was received into the royal academy of sciences, and read his first performance, a memoir upon the construction and form of musical instruments. When he commenced his travels, his first visit was to England, and during his residence at London he became a zealous admirer and follower of Newton. His next excursion was to Basil in Switzerland, where he formed a friendship with the celebrated John Bernouilli 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 fulfilled the duties of an academician, may be seen in the Memoirs of the academy from 1724 to 1744; where the most sublime questions in the mathematical sciences, received from his hand that elegance, clearness, and precision, so remarkable in all his writings. In 1736 he was sent to the polar circle to measure a degree of the meridian, in order to ascertain the figure of the earth; in which expedition he was accompanied by Messrs. 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 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 profession, 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' singular 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 1744, when a marriage was negociated and | brought about by the good offices of the queen mother, between our author and mademoiselle 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 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 same time Jie had, it seems, a strange inquietude of spirit, with a dark atrabilious 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 vohime 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, although they had been apparently upon the most amicable terms. 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 Jong been considerably impaired by the great fatigues of various kinds in | which his active mind had involved him; though, from the amazing hardships he had undergone in his northern expedition, most of his bodily sufferings may be traced. The intense 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 twelve 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 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 to 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 sixty-one 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 Rest. 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 1724 to 1749; and in those of the academy of Berlin, from 1746 to 1756. ¹