MARALDI (Janus Primp), in biogra phy, a learned mathematician, astrono mer, and natural philosopher, was born in the year 1665, at Perinaldo, in the county of Nice, which had been already honoured by the birth of his maternal un cle, the celebrated Cassini. We are not informed where he received his educa tion ; but we are told that after he had for some time successfully cultivated lite rature, the bent of his geniis led him to study the sublimer sciences, and particu larly the mathematics. Having made a considerable progress, when lie was twen ty-two years of age, his uncle sent for him to Paris, where lie had been settled a long time, that he might himself super intend his studies, and have the satisfac tion of witnessing the efforts of his ge nius in a country where useful and ex traordinary talents, both in natives and Foreigners, were at that time much che• rished and encouraged. Under such a tutor Maraldi made a wonderful profi ciency, and soon answered the most flat tering expectations which he had formed of him. To his uncle he implicitly re signed the direction of his studies and his manners, and conceived for him the affec tion of a son, which met with an equal re turn. When Cassini found that his ne phew's advancement in science, his ex traordinary diligence, and his accuracy, had qualified him to become an useful as sistant in his astronomical labours, by the direction of the Royal Academy of Scien ces, he associated him with himself in making observations on the celestial bodies. A wide field was now opened for the industry and ingenuity of our young astronomer. In making his observations on the planets, he found that Kepler and Bouillaud had incorrectly determined the place of the aphelion of Jupiter. Com paring afterwards his observations with those of the Chaldean astronomers, made in the third century before the Christian era, he found that the nodes of that planet had retrograded more than four teen degrees, and that owing to their natural motion ; and he observed and ac counted for other phenomena in the ap pearance of that planet and its satellites. After an assiduous attention to Mars, he acknowledged that Kepler's theory o4 that planet was so perfect, that scarcely any thing could be added to it. He cor rected, however, some trifling inaccura cies ; and he found that the parallax of the planet was less by one second, than had been determined by Cassini in 1672. During almost the whole of the year 1714, his observations were occupied by Saturn; and he sheaved how the disappearance of his ring at that time confirmed the theory of Huygens. Ile also bestowed incredible industry in perfecting the bles of Jupiter's satellites. The results of his numerous observations he commu nicated to the Academy of Sciences, to whom they afforded the greatest satisfac tion, and particularly his discovery, that the eclipses of the satellites were of dif ferent durations, even when the distance of their nodes was the same. Ile was now justly considered as entitled to rank with the most skilful astronomers.
When Maraldi first applied himself to the contemplatioirof the heavens, he con ceived the design of forming a catalogue of the fixed stars, more perfect and com prehensive than that of Bayer, an object of the greatest utility, and of the first im portance hi agronomy. For they are Considered as so many fixed points, to which the motions of the comets, and of the other planets that are under them, are referred. Hence will appear the impor tance of an intimate acquaintance with them ; the attainment of which is an ob ject of no less difficulty than it is of mo ment. However, this difficulty did not deter Maraldi, who to the great injury of his health, applied himself to observe them with the most constant attention, at all seasons of the year. By this means he became so intimate with the fixed stars, that on being shown any one of them, however small, he could immediately tell to what constellation it belonged, and its place in that constellation. He has been
known to discover those small comets which astronomers often take for the stars of the consellation in which they are seen, for want• of knowing precisely of what stars the constellation consists, when others on the same spot, and with eyes directed equally to the same part of the heavens, could not for a long time see any thing of them Whenever Maraldi found it necessary to relax in his astrono mical labours, by way of amusement he applied to the study of natural history, making observations on insects, curious petrif actions, &c. To the subject of bees lie paid particular attention, not only ac-' quainting himself with what ancient and modern writers have said concerning them, but providing himself with glass hives, that he might observe their labours and economy. On these and other sub jects in natural history, he drew up a number of very interesting papers, which were received with great applause by the Academy of Sciences, and inserted in different volumes of their memoirs. In the year 1699, Maraldi was admitted a member of that body. In 1700, lie was employed under Cassini in prolongin the French meridian to the northern ex tremity of France, and had no small share in completing it. When this business was finished, he paid a visit to Italy, where the astronomers every where glad ly availed themselves of his advice and assistance in making their observations ; And Eustachio Manfredi has made due acknowledgments of his great obliga tions to him. Being come to Rome, on the invitation of Pope Clement XL he assisted at the assemblies of the congre gation then sitting in that city, for the purpose of reforming the calendar. Bian chini also availed himself of his advice and aid, in constructing the great meri dian line at the baths of Dioelesian. While he continued at Rome, he had an opportunity of observing an eclipse of the fourth satellite of Jupiter, in the up per part of his circle, from which he was led to the conclusion, that its inclination is three minutes less than as fixed by Cas sini. In 1703, Maraldi returned to France, with a rich treasure of subjects in natural history, chiefly collected at Verona, which he presented to the Academy of Sciences. In the year 1718, he was employed, with three other academicians, in prolonging the French meridian to the southern ex tremity of that kingdom. Still, however, the greatest part of his time was occu pied within the walls of the observatory of Paris, where he was incessantly em ployed in observing every thing that was curious and useful in the motions and phenomena of the heavenly bodies, in in genious applications of the methods laid down by Cassini, in verifying theories with which it is of consequence to be ac quainted, in correcting other theories which are susceptible of improvement, and in completing his catalogue. This last mentioned great work he did not live entirely to finish ; for just after he had placed a mural quadrant on the ter race of the observatory, in order to ob serve some stars towards the north and the zenith, he fell sick of a fever, and died in December 1729, in the sixty-fifth year of his age. He is highly commended for seriousness, integrity, sincerity, a gene rous spirit, the purest morals, and an in teresting simplicity of manners. He was not proud of the rank which he held in the scientific world, and was never more gratified than when he could render ser vice to others, by communicating to them freely the discoveries and improvements which he had made, at the expense of in conceivable labour and application. He did not publish his catalogue, or any other of his productions, but communi cated an immense number of papers to the Royal Academy of Sciences, which are inserted in their " Memoirs" for al most every year from 1699 to 1729, and not uncommonly several papers in the same year.