Ozanam, James

, an eminent French mathematician, was descended from a family of Jewish extraction, but which had long been convertsto the Romish faith and some of whom had held considerable places in the parliaments of Provence. He was born at Boligneux, in Brescia, in 1640; and being a younger son, though his father had a good estate, it was thought proper to breed him to the church, that he might enjoy some small benefices which belonged to the family, to serve as a provision for him. Accordingly he studied divinity four years; but, on the death of his father, devoted himself entirely to the mathematics, to which he had always been strongly attached. Some mathematical books, which fell into his hands, first excited his curiosity; and by his extraordinary genius, without the aid of a master, he made so great a progress, that at the age of fifteen he wrote a treatise of that kind, of which, although it was not published, he inserted the principal parts in some of his subsequent works.

For a maintenance he first went to Lyons to teach the mathematics, in which he had considerable encouragement; and after some time his generous disposition procured him still better success elsewhere. Among his scholars were two foreigners, who expressing their uneasiness to him at being disappointed of some bills of exchange for a journey to Paris, he asked them how much would do, and being told 50 pistoles, he lent them the money immediately, even without their note for it. Upon their arrival at Paris, mentioning this generous action to M. Daguesseau, father of the chancellor, this magistrate was touched with it; | and engaged them to invite Ozanam to Paris, with a promise of his favour. The opportunity was eagerly euibraced; and the business of teaching the mathematics here soon brought him in a considerable income: but he wanted prudence for some time to make the best use of it. He was young, handsome, and sprightly; and much aduicted both to gaming and gallantry, which continually drained his purse. Among others, he had a love intrigue with a woman, who lodged in the same house with him, and gave herself out for a person of condition. However, this expence in time led him to think of matrimony, and he soon after married a young woman without afortune, but for this defect she made amends by her modesty, virtue, and sweet temper; so that though the state of his purse was not amended, yet he experienced a long course of domestic happiness. He had twelve children by her, who all died young; and he was lastly rendered quite unhappy by the death of his wife also, which happened in 1701. Neither did this misfortune come single: for the war breaking out about the same time, on account of the Spanish succession, it swept away all his scholars, who, being foreigners, were obliged to leave Paris. Thus he sunk into a very melancholy state; under which, however, he received some relief, and amusement, from the honour of being admitted this same year an eleve of the royal academy of sciences.

He seems to have had a pre-sentiment of his death, from some lurking disorder within, of which no outward symptoms appeared. In that persuasion he refused to engage with some foreign noblemen, who offered to become his scholars; alleging that he should not live long enough to carry them through their intended course. Accordingly he was seized soon after with an apoplexy, which terminated his existence in less than two hours, on the 3d of April, 1717, at 77 years of age.

We are told that he knew too much of astronomy to give into judicial astrology; and obstinately refused all that was offered him to engage him to calculate nativities. Once indeed he submitted to the importunity of a count of the empire, whom he had sufficiently warned not to believe him. He drew up by astronomy the scheme of his nativity, and then without employing the rules of astrology, foretold him all the instances of good fortune, which ca.ne into his head. The count at the same time procured his

| horoscope to be taken by a physician, who was greatly infatuated with astrology, and who followed exactly all the rules of that art. Twenty years after the count informed Mr. Ozanam, that all his predictions were come to pass, and that none of the physician’s had their effect. This account gave him a very different satisfaction from what was intended. The count thought to compliment him upon his skill in astrology, but it only served to confirm him in his opinion of the absurdity of that pretended science.

Ozanam was of a mild and calm disposition, a cheerful and pleasant temper, endeared by a generosity almost unparalleled. His manners were irreproachable after marriage; and he was sincerely pious, and zealously devout, though studiously avoiding to meddle in theological questions. He used to say, that it was the business of the Sorbonne to discuss, of the pope to decide, and of a mathematician to go straight to heaven in a perpendicular line. He wrote a great number of useful books; a list of which is as follows 1. “La Geometric-pratique, contenant la Trigonometric theorique & pratique, la Longimetrie, la Planimetrie, & la Stereometric,” Paris, 1684, 12mo., 2. “Tables des Sinus, Tangentes, & Secantes, & des Logarithmes des Sinus & des Tangentes, & des nombres depuis T unite jusqu’a dix mille, avec un traite de Trigonometric, par de nouvelles demonstrations & des pratiques tres faciles,” Paris, 1685, 8vo reprinted, with additions, in 1710. 3. “Traite des ‘Lignes du premier genre, de la construction des equations, et des lieux Geometriques, expliquees par une methode nouveile & facile,” Paris, 1687, 4to. 4. “L‘usage du Compas de proportion, explique & demontre d’une maniere courte & facile, & augmente d’un Traite de la division des champs,” Paris, 1688, 8vo, reprinted in 1700. 5. “Usage de l’instrument universel pour resoudre promptement & tres-exactement tous les problemes de la Geometric- pratique sans aucun calcul,” Paris, 1688, 12mo; reprinted in 1700. 6. “Dictionaire Mathematique, ou Idee generale des Mathematiques,” Paris, 1690, 4to. 7. “Methode Generale pour tracer des Cadrans sur toutes sortes de plans,” Paris, 1673, 12mo, reprinted and enlarged in 1685. 8. “Cours de Mathematiques, qui comprend toutes les parties de cette science les plus utiles & les plus necessaires,” Paris, 1693, 5 vols. 8vo. 9. “Traite” 4e la Fortification, contenant les methodes anciennes & | modernes pour la construction & defense des Places, & la maniere de les attaquer, expliquees plus au long qu‘elles n’on jusqu’ a present,“Paris, 1694, 4to. 10.” Recreations Mathematiques & Physiques, qui contiennent plusieurs problemes utiles & agreables de PArithmetiquej de Geometric, d’Optique, de Gnomonique, de Cosmographie, de Mechanique, de Pyrotecnie, & de Physique, avec un Traite des Horloges elementaires,“Paris, 1694, 2 vols. 8vo. There was a new edition, with additions, at Paris, in 1724, 4 vols. 8vo; and in 1803, Dr. Hutton published a very enlarged edition, in 4 vols. 8vo, with Montucla’s and his own additions and improvements. 11.” Nouvelle Trigonometric, oil Ton trouve la maniere de calculer toutes sortes de Triangles rectilignes, sans les tables des Sinus, & aussi par les Tables des Sinus, avec un application de la Trigonometric a la mesure de Lignes droites accessibles & inaccessibles sur la terre,“Paris, 1699, 12mo. 12.” Methode facile pour arpenter ou mesurer toutes sortes de superficies, & pour toiser exactement la Ma^onnerie, les Vuidanges des terres, & tous les autres corps, avec le toise du bois de charpente, & un traite dela Separation des Terres,“Paris, 1699, 12mo; reprinted, with corrections, in 1725. 13.” Nouveaux Elemens d’Algebre, ou Principes generaux pour resoudre toutes sortes de problemes de Mathematiques,“Amsterdam, 1702, 8vo, Mr. Leibnitz, in the Journal des Savans of 1703, speaks thus of this work of our author:” Monsieur Ozanam’s Algebra seems to me greatly preferable to most of those which have been published a long time, and are only copies from Des Cartes and his commentators. I am well pleased that he has revived part of Vieta’s precepts, which deserve not to be forgotten.“14.” Les Elemens d’Euclide, par le P. Dechales. Nouvelle edition corrigee & augmentee,“Paris, 1709, in 12mo; reprinted in 1720. 15.” GeometriePratique du Pieur Boulanger, augmentee de plusieurs notes & d‘un Traite de l’Arithmetique par Geometric, par M. Ozanam,“Paris, 1691, 12mo. 16.” Traite de la Sphere du Monde, par Boulanger, revu, corrige*, & augmente, par M. Ozanam,“Paris, 12mo. 17.” La Perspective Theorique & Pratique, ou Ton enseigne la maniere de mettre toutes sortes d‘objets en perspective, & d’en representer les ombres causees par le Soleil, ou par une petite Lumiere,“Paris, 1711, 8vo. 18. * e Le Geographic & Cosmographie, qui traite de la Sphere, des Corps celestes, | des differens Systmes du Monde, du Globe, & de ses usages,” Paris, 1711, 8vb. 19. In the Journal des Ssavans, our author has the following pieces I. “Demonstration de ce Theoreme que la somme ou la. difference de deux quarre”-quarrez ne peut etre un quarre-quarre,“Journal of May 20, 1680. II.” Response a un probleme propose“par M.'Comiers,” Journal of Nov. 17, 1681. III. “Demonstration d’un problSaie touchant les racines fausses imaginaires,” Journal of the 2d and 9th of April, 1685. IV. “Methode pour trouver en nombres la racine cubique, & la racme sursolide d’un binoine, quand ii y en a une,” Journal of April 9th, 1691. 20. In the “Me mo ires de Trevoux,” he has this piece, “Reponse aux principaux articles, qui sont dans le 23 Journal de Paris de Tan 1703, touchant la premiere partie de son Algebre,” inserted in the Me. noire* of December 1703, p. 2214. And lastly, in the Memoirs of the Academy of Sciences of 1707, he has Observations on a Problem of Spherical Trigonometry. ¹