Page:Encyclopædia Britannica, Ninth Edition, v. 10.djvu/796

772 in the same direction as before. The angle through which the crystal has been turned is either 180° + 2A or 180° — :3.\, where A is the angle between the faces. The introduc- tion of the fier mirror by Degen and Lang, and of the horizontal circle with collimators, brought the instrument into its most modern form. Babinet, Malus, Mitseherlieh, I Iaidinger, Von Lang, and others have contributed towards perfecting the instrument. Recently Professor W. H. Miller (I‘ln'l. .1[ag., 1876) has described a new form of gonio- meter. In the paper quoted some useful details concern- ing the use of the instrument will be found. For further instructions how to use the goniometer the reader may refer to Phillips’s Illineralogy, or Groth’s I’ll-ysilcaliscke Ix'rystallo— graphic, Abth. iii. The modern goniometer has so much in common with the spectrometer that it is unnecessary to describe it in detail here. See.  GONSALVO. See.  GONZAGA, or, an old princely family of Italy, which traces its origin to the emperor Lothair, but first came into notice in the, after the overthrow of the imperial power in Italy, where they for some time disputed the sovereignty of M antua with the Bonaeosse. The long dispute was ended by the murder of Passerina de Bonaeossi in, after which the Gonzaga retained possession of Mantua for four centuries. Their claims were in conﬁrmed to Ludovico I. (–) by Louis the Bavarian, who nominated him imperial vicar, and gave him also the sovereignty of Reggie and other towns. l’etrino, youngest son of Ludovico, founded the countship of Novellara, which became extinct in 1728. The elder branch of the family was continued by Guido and his son Ludovico II., who, on his death in, was succeeded by his brother F raneeseo. He was followed in by his son Giovanni F raneeseo (–), on whom, for his services in the Italian wars, the emperor Sigismund in bestowed the title of marquis. Ludovico III. (–), son of the preceding, surnamed, for what reason is not quite certain, the Turk, retained a body of troops which he granted on hire to neighbouring princes. The younger sons of this Ludovico, Giovanni Francesco and Rudolpho, founded the dukedoms of Gabioneta and Castiglione respectively, which were conﬁscated in 1692. The elder branch of the family was continued by Frederick I. (–), whose son, Giovanni Francesco II. (–), was in appointed to the supreme command of the united Italian army against Charles VIII. of France, and on the 6th of July of the gained the victory of Fornovo, and took prisoner the bastard of Bourbon. His son, Frederick II. (–), received in the title of duke from Charles V., and in the principality of Montferrat. A younger son, Ferdinand, was the founder of the Guastella branch of the family, which became extinct in 1746. Of the succeeding members of the elder branch, the only notable one was Vineenzo I. (–1612), to whom the Admirable Crichton was tutor, and by whom he was murdered from jealousy in . This branch became extinct in 1627 through the death of Vineenzo IL, sixth successor of Frederick II. The nearest heir was Carlo I., duke of Nevers, who was recog- nized by the Mantuans, but his claims were contested by Ferdinand II. of Guastella, who had the support of the emperor Ferdinand II. In the war which followed, the duke of Nevers obtained the assistance of Louis XIII. of France, but in 1630 Mantua was captured and pillaged by the imperial troops, and the duke was forced to retire to the States of the Church. In 1631 a treaty was, however. con- cluded between France and the emperor, by which the duke, on making submission, was reinvested with the duchies of Mantua and Montferrat. Anna, a daughter of Carlo 1., became wife of Edward, elector-palatine of the Rhine, and after playing a distinguished part at the French court, died at Paris in 1684, leaving behind her a volume of interesting Memoirs (London and Paris, 1686). Carlo died in 1639, and was succeeded by his grandson Carlo 111., who, on his death in 1665, was succeeded by his son Carlo IV. This duke married in 1670 Anna. Isabella, eldest daughter of Ferdinand duke of Guastella ; and on the death of Ferdi- nand in 1679, he endeavoured to obtain possession of that duehy, but was compelled to relinquish his claims to Vineenzo, a cousin-german of the deceased duke. lle took part on the side of France in the Spanish succession war, and received a French garrison into Mantua. After the defeat of the French he was placed under the ban by the emperor Joseph I., whereupon Victor Amadeus of Savoy conquered Montferrat, and Austria, in agreement with France whom Carlo had offended, took possession (f Mantua. On his death without issue in 1708, the dynasty of the Gonzagas of Mantua became extinct.  GONZAGA, (1744–1809), “ the Portuguese Petrarch,” perhaps better known as DIRCEL', was born at Oporto in 1744, and received his early education there and at Bahia, where his father, after having held vari- ous judicial appointments, became a member of the supreme court in 1759. Having completed his law studies at the university of Coimbra, which he attended from 1763 to 1768, Gonzaga in the latter year returned to Brazil, and after having acted for some years as juiz de fora or local magis trate at Beja and elsewhere he ultimately was appointed a judge (ouvidor) at Villa—Rica in the province of Minus, where he highly distinguished himself it is said both by his administrative ability and by the many excellences of his private character. He appears before this time to have developed some talent for versiﬁcation, and his literary tastes soon brought him into intimate association with Claudio Manoel, Alvarenga Peixoto, and other writers of the so-ealled Minas school; but the love which makes the poet did not, in his own opinion at least, come upon him until he had made the acquaintance (about 1788) of D. Maria Joaquina Dorothea de Seixas, the “ Marilia de Dirceu” to whom all his extant poems relate. He had just been nominated a member of the supreme court of Bahia, and was on the eve of his marriage, when discovery was made of the treasonable plot of Mines, and he was arrested on suspicion of having been implicated in it. On merely circumstantial evidence, and that of a very incon elusive kind, he was condemned, 18th April 1792, to banishment for life to Pedras de Angoche, asentence which was afterwards commuted to one of ten years’ exile at Mozambique. Here he made some effort to practise as an advocate, but he never recovered from the wearing-out de- pression into which he had been thrown by his cruel lot ; an attack of nervous fever undermined his health, and after years of an ever-deepening melancholy, which ocea- sionally alternated with fits of acute mania, he died in 1809. "

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