Having succeeded in settling the dispute in favour of the republic of Lucca, he was handsomely re warded by the senate with a present of 1000 se quins.* The talents of Boscovich as a negotiator, pointed him out to the Senate of Ragusa, as the fittest per son for settling a misunderstanding that existed be tween that republic and the British government. It was alleged by the latter, that the Ragusans had in fringed their neutrality by fitting out vessels for the French service ; and as there had been no just ground for this suspicion, so injurious to the commerce of his native city, Boscovich repaired to London, and succeeded in establishing the integrity of the republic of Ragusa.
On his way to London, Boscovich visited Paris, where he remained for six months, enjoying the ex quisite society which then distinguished the French metropolis. During his stay at London, he was chosen a Fellow of the Royal Society in 1760; and he published his work, De Solis ae Luner Defectibus, which he dedicated to that learned body.
The approaching transit of Venus in 1761, had at this time absorbed the attention of philosophers, and numerous parties of astronomical observers were sent to different parts of the world. Boscovich was invited by the Royal Society tosaccompany the party of its members that was going to America; but as such an expedition would have greatly retarded his return to Italy, and interfered with some other plans, he was obliged to decline the invitation, and return to his native country. At Venice he met with his friend Corner, who accompanied him to the Plain of Troy, which they on their way to Constantinople. During his residence in Constantinople, his happiness was completely embittered by a continuance of ill health, which rose to such a height that it frequently threatened his existence. After he had begun to re cover his strength, he left Constantinople in the train of the English ambassador, Sir James Porter, and tra velled through Bulgaria, Moldavia, and part of Po land, with the intention of visiting the capital of I Russia ; but the death of Peter deterred him from the prosecution of his travels. An account of this journey was afterwards published in French and Italian, but it did not add much to the fame of its author. • The return of Boscovich to [Rome was eagerly welcomed by his countrymen, and his talents were speedily called into exercise for the public good. In the spring of 1761, the Austrian governor of Milan appointed him to the mathematical chair in the uni versity of Pavia, where the mean jealousy of his col leagues forced him to defend his reputation by the publication of his Dissertationes Dioptricce, which related principally to the correction of the aberra tion of refrangibility in achromatic telescopes. The fame which be derived from this ingenious work, si lenced, for a while, the calumnies of his rivals ; but their malice havino. again broken out with increasing
violence, Boscovich sought for tranquillity in a jour ney to France and the Netherlands. When he re turned from this excursion, he was transferred from the college of Pavia to the Palatine •schools at Mi lan, where he received from the Empress queen the professorship of astronomy and optics, and was also appointed to superintend the observatory of the Royal College of Brera, which was furnished with instru ments chiefly at his own expense.
When Boscnvich had repaired to the baths of .Albano to strengthen his constitution, he received the mortifying intelligence, that several of the young Jesuits whom hi had employed as assistants, had conspired against his favourite pupil, and had pre vented the government from appointing him to some office of trust. He complained, in vain, to Prince Kaunitz and to the governor of Milan, of this in sulting . conduct ; but having received no redress, he retired to Venice, where he continued for ten months, and at last formed the resolution of spend ing the remainder of his days at Ragusa. When be was upon the eve of carrying this resolution into ef fect, his plans were completely frustrated by the suppression of the order of Jesuits in 1773.
In conseqtience of this sudden revolution, so hos tile to his temporal interests, he went to Paris along with La Bord, the chamberlain of Louis XV., and sought in a foreign country those honourable rewards of genius which had been so unjustly denied him in his own. The influence of his friend La Bord procured for him the patronage of the French, king, who ap pointed him Director of Optics for the Marine, a new office created on purpose, with two pensions, amount ing to 8000 livres. j Such. rapid promotion given to a foreigner, naturally •excited the jealousy of the French philosophers. The piety of Boscovich, the freedom of his conversation, and his personal vanity, were by no means calculated for the, meridian of Paris. The generosity of the sovereign was not se conded by the kindness of his subjects ; and Bosco vich, after all his services to science, was doomed to experience a neglect, which was the more mortify ing, when he reflected on the idolatry with which he was formerly regarded at Rome. To a man of keen 1. temper, like Boscovich, who knew his own merits, this cold treatment was unsufferable. He therefore requested leave of absence from his royal patron, and retired, in 1783, to Bassano, in the state of Venice, where he employed himself in preparing for the press a collection of his unpublished works, which he com pleted in 5 vols. 4to, entitled, Rogcrii Josephi Bos covich, Opera pertinentiaad Opticam et Astronomi am maxima ex parte Nova, et amnia hucusque in edita, in quinque iomos distributa. Bassani, 1785.