FOSSOMBRO'NI, VITTO'RIO, born in 1754, at Arezzo in Tuscany, of a noble family, studied at Piss, and applied himself especially to the mathematical sciences, for which he showed a particular aptitude. In 1782 he was appointed, by the Grand-Duke Leopold I., inspector of the property of the military order of San Stefauo, and in 1785 he was made commendatory of that order. In 1792 he was consulted by the Grand-Duke Ferdinand III. on the subject of the corn-trado and corn-laws, upon which he wrote a treatise, which has not been published. In 1794 he was appointed hydraulic superintendent of the Val di Chiana. Fossombroni had previously studied the ground attentively, and had written a learned treatise on the causes which had led to the encroachment of the waters over that low but fertile district, and had pointed out the means of draining the country : • Illemorie Idraulico•atoriche copra la Val di Chiana,' 1789. He pro moted tho works for that object, which having been continued through a succession of years, at last restored the valley of the Chiana to fertility and salubriousness. In 1796 Foasombroni was appointed Minister for Foreign Affairs of the Grand-Duke of Tuscany. When the French took violent possession of the country in 1799, Fossom. broni accompanied his master to Vienna, where the grsud•duke gave him leave to return home to attend to his own affairs. After Tuscany wars transformed into a kingdom, the new queen of Etruria appointed Fossombroni in 1801 member of the Commission of Finance. In April 1805 he was sent, jointly with the Prince Corsini, to Milan, to compliment Napoleon on his assumption of the crown of Italy. When Tuscany was annexed to the French empire, Napoleon mado Fossombroni a member of the Legion of Honour, and appointed him president of the commission for the improvement of the Campagna of Rome and the drahaago of the Pomptine Marshes, on which he wrote a report for the emperor. On the restoration of the Grand Duke Ferdinand to his paternal dominions, Fossombroni was one of the first persons employed in the now ministry. He was made president of the legislative commission, councillor of state, minister for foreign affairs, with the presidency of the other departments of the government. These offices he retained till his death, which took place in 1844, when he was ninety years of age, having retained all his mental faculties to the last. In 1832, when he was seventy-eight years of age, he married a lady of a noble family of his native town, Arezzo.
Besides the works already mentioned, Foseombroni published the following works on hydraulics : 1, • Memoria aopra la Distribuzione dells Alluvioni ;' 2, ‘Memoria sulla Resistenza ed Urto dei Fluidi ;' 3, 'Illustrazione di un Antico Documento relative all' originario Rapporto trii le Acque dell' Arno e della Chianti,' 1826 ; 4, ‘Memoria walla Relazione hit to Acque dell' Arno e quelle della Chiana,' 1839.
In these last two papers he explained the remarkable change that has taken place in the course of ages in the declivity of the bed of the Chiana, which in Ancient times afforded a water-communication between the Arno and the Tiber. He also adverted to the danger to which the city of Florence and the surrounding country were exposed, in consequence of the alluvial deposits which are carried by the Chiana and numerous other streams into the Arno, and which tend to raise the bed of the Arno; 5, 'Saggio sulla Bonifionzione dells Paludi Pontine ;' 6, ' Mennoria sul Lago di Fuccechio,' another marshy district of Tuscany, in the valley of tho Lower Arno ; 7, Rclazione sops 1'Incanalamento di un Treace del Fiume Arno ;' 8, Memoria sulle Illarernme Toscano;' 9, Memoria eopra la Inclinazione Fossombroni wrote numerous other memoirs on hydraulio subjects, which are inedited; among the rest, a memoir on the lagoons of Venice, for the Emperor of Austria, which was used for the works in that quarter, and another memoir for Mehemet Ali, pasha of Egypt, concerning the construction of a basin at Alexandria. Fos sombroni also wrote several treatises on mathematics and mechanics, among others a 'Sages) eopra it Moto degli Animali e eopra i Tres porti ;' a treatise Sopra Is Mieura delle Form Muscolari ; ' another, 'Sops la Valutszione della Forza o degli Attriti; ' and a Mcmoria copra ii I'rincipio dells Velocith Virtuali; published iu 1796, and which was highly praised by Lagrange, Lacroix, Laplace, and other eminent mathematicians.
As a statesman, Fossombroni was enlightened and unprejudiced.
Jealous of the independence of his native country, he asserted its rights upon every occasion during the long and occasionally critical period of his administration ; he maintained the freedom of commerce, which has greatly contributed to the prosperity of the country; he advocated toleration of opinions, and he strove to render Tuscany a model of a paternal but enlightened government. His system appears to have been to govern without bustle and noise, to let society move on with as little apparent interference as possible ou the part of the governing powers, a task in which he was assisted by the disposition of the people, the smallness of the state, and by his own tempera ment. It is generally admitted that during Fossombroni's adminis tration Tuscany was the happiest country in Italy.
(Rivista Ligurc, and other Italian journals for 1844; Communications from. Italy, and the works of Fossombroni quoted above.)