CHARACTERS. An Account of the Life and Writings of Father Boscovich. OBERT Joseph Boscovich, an eminent mathematician and natural philosopher, was born of very respectable parents, in the free city of Ragusa, on the coast of Dalma. tia, the 18th of May, 1711. He was the youngest of nine children, and his mother lived to the extraordinary age of 103. Six sons received the best education that their father's circumstances could afford; and all of them, particularly the eldest, who became a priest, were distinguished by a happy vein for poetry. Having finished his grammatical course with applause, the young Boscovich, prompted by the example of his brother, in his fifteenth year took the habit of the noviciate, and entered the Jesuits' college at Rome. There the original bent of his genius discovered itself by the enthusiastic ardour with which he plunged into the study of the mathematics. His progress in that important branch of knowledge was so rapid as to astonish, and soon outrun his preceptors. Under their instruction he acquired the elements of geometry and algebra, but was left to the exercise of his own ap plication in prosecuting the higher parts of mathematics. He studied by himself the principles of the differential calculus; and thus prepared he began the Principia of Newton, and devoured that immortal work with the most eager avidity. He was transported by the vast display of new and splendid truths which were unveiled; and while, with the torch of geometry, he traced the secret links of nature's operations, and seemed to penetrate the councils of heaven, he felt his passion for distinction wonderfully enflamed: nor in the warmth of his temper could he suppress the movements of self-gratulation, which the consciousness of his powers and acquirements excited in his breast. By his persuasion, Noceti, his master in philosophy, was induced to re-print a small poem on the rainbow, and another on the aurora borealis, both of which Boscovich enriched with ingenious notes and illustrations. The publication of this tract spread his fame beyond the precincts of the college, and beyond the Alps. Mairan, whose opinion concerning the aurora borealis he had espoused, noticed it with loud commendation, in the second edition of his dissertation; and the praises bestowed by the 3 B4 French French philosopher, with the title conferred on him of correspondent of the Academy of Sciences, could not fail to prove highly gratifying to his youthful vanity. After Boscovich had completed the usual course of philosophy, he was obliged, by the rules of the institution, to teach grammar and the classics; but he never lost sight of his favourite studies, and he was invited by his mathematical master to defend annual theses, and deliver dissertations on such subjects as occasion suggested. These being printed in succession, extended farther his reputation. The first appeared in 1736, and contained a theory of the solar spots, very similar to that which was afterwards so ingenious ly supported by professor Wilson of Glasgow. It supposes the sun to have two atmospheres, the lower being dense, and sometimes sprinkled with clouds; the upper rare, and subject to variation of height. Next year produced two dissertations; one on the transit of Mercury, and another on a remarkable aurora borealis. Five years had Boscovich spent in the drudgery of teaching latin, and three more were consumed in the unprofitable study of scholastic theology, when, by a very singular indulgence, he was exempted by his superiors from the fourth year's attendance, and permitted to relinquish that dark and thorny path, and thenceforth employ his talents in exploring nature's wide domain. His situation now, as supernumerary prefect of the Roman college, was entirely suited to his taste. To communicate mathematical instruction was to him a delightful task; and he prepared, for the use of his pupils, a short system of geometry, was which comprised all the capital truths of that science, in fourteen propositions. In the selection of the materials, in their disposition and arrangement, he exhibited the clearness, the precision, and noble elegance, formed after the model of the ancients. He composed the elements of trigonometry with the same purity of taste. But the capital part of the system, his theory of the conic sections, reared by repeated efforts, and at distant intervals, and was not pub. lished until the year 1755. Boscovich considered these curves as described in plano, and assumed, for his generic definition, the beautiful property of the directrix, which is commou to them all, the parabola being only its simplest case. In the eclipse, the ratio of a line drawn from any point to either of the foci, is to a perpendicular from the same point to the directrix, in the ratio of a less to a greater; in the hyperbola, it is that of a greater to a less. But the author did not stop here; he likewise investigated the properties derived immediately from the section of the cone. He supposed it cut by a moveable plane, and showed how the several curves would thence be successively produced. The same luminous idea he transferred to the cylinder, the spheroids. His imagination loved to contemplate the fine mutation and transition of mathematical figures, and to trace the series of successive, yet apparently connected changes, which have suggested the law of continuity. On that metaphysical principle, as elucidated by the transformation of geometrical loci, he gave an exquisite dissertation Other dissertations, remarkable for their inge nuity', nuity, were successively delivered to a crowded audience, at the annual examination of his school. These treated on various difficult points on geometry, astronomy and optics; on osculating circles, the nature of infinitesimals, trajectories, the inequality of gravity over the earth's surface, the centre of magnitude, the laws of bodies, living forces, the flux and reflux of the sea, the annual abberation of the fixed stars, the limits of astronomical observations, the uses of lenses and dioptric telescopes, and a new method of employing the observation of the phases in lunar eclipses, on the determination of a planet's orbit by help of catoptrics, and on the atmosphere of the moon, which he held to be very different from that of the earth, and more analogous to water. In one of these dissertations he pointed out a mistake of the famous Daniel Bernouilli, who had hastily concluded, that the tides of the atmosphere must rise higher, in proportion to its rarity, than those of the occan; in another he shewed that the question concerning the measure of forces, which then so vehemently agitated the scientific world, as it generally happens, was merely a dispute of words; in a third, he sketched the outlines of that bold structure, which has obtained such deserved celebrity among the learned-his sublime theory of the constitution of matter. While Boscovich was thus usefully and honourably engaged in directing the studies of youth, and enlightening the world by his elegant and ingenious writings, the pleasure of his conversation was eagerly courted at Rome. In every house of note he was always a most welcome guest, and he reigned in every society by Be. the ascendancy of his talents. fore mixed companies he would freely talk of his own speculations, which he had a singular felicity in rendering intelligible and interesting to the most ordinary minds; and though, on these occasions, he was not accustomed to conceal his inward satisfaction, or decline bestowing upon himself the merited encomiums, these frequent sallies of vanity seemed to flow merely from the warmth of his character, and were effaced in the general blaze of admiration entertained for his superior talents. Nor was his ambition confined within the circle of abstract science; indulging the excursive flights of fancy, he often sacrificed to the muses. He composed latin verses on a great variety of subjects, and which, conse quently, possessed very different degrees of merit. Every occurrence, he was ready to seize, whether public or private, serious or comic; wars, nuptials, jocular and domestic incidents, were indiscriminately his theme. He had a wonderful knack in composing those verses, with a memory not less astonishing for retaining them; and at the tables of his friends, he took pleasure in reciting elaborate passages. Surrounded by his disciples and partial admirers, the sort of idolatry which he received, appears, however, to have had rather an unfortunate effect on his character, by tempting him to overate the measure of his powers, and extent of his attainments. Once, and once only, he entered the lists with his illustrious cotemporaries. It was in answer to the question proposed by the academy of sciences at Paris, to determine the inequalities produced by the mutual action of Jupiter and Saturn, especially near the time of their conjunction. His memoir was returned with much application was made by the court commendation, and very few mathematicians, assuredly, would have felt themselves lowered in yielding the premium to the great Euler. But Boscovich was piqued at what he conceived to be an unfair decision, and would never afterwards engage in any public competition. A philosopher, residing in Rome, amidst the venerable remains of ancient splendour, was powerfully drawn to examine these monuments. Boscovich wrote several dissertations on the subject of antiquities, two of which were printed, and the rest circulated in manuscript. His zeal, activity, and fondness of applause, rendered him at all times accessible, and in a multitude of cases, his advice was ardently sought by individuals. Benedict XIV. a great patron of learned men, and his enlightened minister, cardinal Valenti, consulted him on various objects of public œconomy, the clearing of harbours, and the constructing of roads and canals. On one occasion he was joined in a commission with other mathematicians and architects, invited from different parts of Italy, to inspect the cupola of St. Peter's, in which a crack had been discover. ed. They were divided in opinion, but the sentiments of Boscovich, and of the marquis Poleni, prevailed. In stating, however, the result of the consultation, which was to apply a circle of iron round the building, Poleni forgot to refer the idea to its real author, and this omission greatly offended the Ragusan geometer. Other incidents had occurred to mortify his pride: he became at last disgusted with his situation, and only looked for a convenient opportunity of quitting Rome. While in this temper of mind, an of Portugal to the general of jesuits, for ten mathematicians of the society to go out to Brazil, for the purpose of surveying that settlement, and ascertaining the boundaries which divide it from the Spanish dominions in America. Wishing to combine with that object the mensuration of a degree of latitude, Boscovich of fered to embark in the expedition, and his proposition was readily ac cepted. But cardinal Valenti, unwilling to forego the lustre reflected by a man of such distinguished abilities, commanded him, in the name of the Pope, to dismiss the project, and persuaded him to undertake the same service at home in the papal territory. In this fatiguing, and often perilous operation, he was assisted by the English jesuit, Mayer, an excellent mathematician, and was amply provided with the requisite instruments and attendants. They began the work about the close of the year 1750, in the neighbourhood of Rome, and extended the meridian line northwards across the chain of Appenines as far as Rimini. Two whole years were spent in completing the various measurements, which were performed with the most scrupulous accuracy. In the intervals, while this great work was carrying on, the active disposition of Boscevich sought amusement and occupation in other pursuits. At night he was busy in drawing out his elements of conic sections; and in the mornings and evenings, during his excur sions to and from the remote stations among the mountains, he composed on horseback the greater part of his elegant latin poem on eclipses. This singular fact reminds us of what is reported of the late Dr. Darwin, who is said to have framed, in his mind, the beautiful and harmonious episodes of the Botanic Garden, while driving in his chariot, on visits to his country patients. This important operation of measuring two degrees on the surface of Italy, is elaborately described by Boscovich, in a quarto volume, written in his usual diffuse manner, and full of illustration and minute details. But the book is rendered the more valuable by the addition of several opuscules, or detached essays, relating to the subject, and which display great ingenuity conjoined with the finést geometric taste. We may instance, in particular, the discourse on the rectification of instruments, the elegant synthetical investigation of the figure of the earth, deduced both from the law of attraction, and from the actual measurement of degrees, and the nice remarks concerning the curve and the conditions of permament stability. This last tract gave occasion, however, to some strictures from D'Alembert, to which Boscovich replied, in a note annexed to the French edition of his works. The arduous service which Boscovich had now performed was but poorly rewarded. From the Pope he only received a hundred sequins, or about forty-five pounds sterling, a gold box, (and abundance of praise). He now resumed the charge of the mathematical school, and, besides, discharged faithfully the public duties of religion which are enjoined his order. A trifling circumstance will mark the warmth of his temper, and his love of precedence. He had recourse to the authority of cardinal Valenti, to obtain admission into the oratory of Caravita, from which his absence excluded him, and which yet did afford only the benefit of a free, but frugal supper. In presiding at that social repast, the philo sopher relaxed from the severity of his studies, and shone by his varied, his lively, and fluent conversation. He lived in habits of intimacy with his colleagues, and especially with his compatriot, Benedict Stay, known to the learned world by an excellent didactic poem, entitled, "Philoso"phia Recentior," and which he elucidated by notes, containing, in a very neat compressed form, the elements of mechanics. At this time a dispute arose between the little republic of Lucca, and the government of Tuscany, on the subject of draining a lake. A. congress of mathematicians was called, and Boscovich repaired to the scene of contention, in order to de fend the rights of the petty state. Having waited three months in vain, expecting the commissioners, and amused with repeated hollow promises, he thought it better for the interest of his constituents, to proceed at once to the court of Vienna, which then supremely directed the affairs of Italy. The flames of war had been recently kindled on the continent of Europe, and Boscovich, like a true courtier, took occasion to celebrate the first successes of the Austrian arms, in a poem, of which the first book was presented to the empress Theresa; but the military genius of Frederick the great of Prussia soon turned the scale of fortune, and our poet was reduced to silence. More honourably did he employ some leisure in the composition of his immortal work,- Theoria philoso"phiæ naturalis reducta ad unicam "legem virium in naturâ existen"tium," printed at Vienna, in the year, 1758. This he drew up, it is alledged, in the very short space of |