TISSERAND. 307 TITANOSAURUS. mechanics. In 1892 he succeeded Mouchez as director of the Paris Observatory. Besides the generalisation of the method of Delaunay which he continued till his death, he made observations for the determination of planetary orbits, on the ring of Saturn, on the perturbations of Pallas, the origin of comets and their capture by the larger planets, and gave also a valuable criterion for identifying a pe- riodic comet. He also observed the shifting of the orbital plane of Neptune's satellite as a re- sult of Nejitune's ellipsoidal shape. In conse- quence of this shifting of orbit, the retrograde motion of the pole of the satellite completes a cycle in 500 years. His principal work, Traitd de mecaniqnc celeste (1889-90). gives a complete account of the state of knowledge of that branch of astronomy up to the time of his death. Since 1SS4 he edited the Bulletin astronomiqiie. His other writings include: Uecueil d'exereises stir le calcul infiniicsimal (1870; 2d ed. 1890). Con- sult PoincarS, "La vie et les travaux de F. Tis- serand," in Revue generate des sciences for 1896. TISSOT, tls'so', Jame.s Joseph Jacques ( 1836- 1902). A French painter, born at Nantes. He studied at the Ecole des Beaux-Arts under La- mothc and Flandrin, and first exhibited in 1859. After the Comnuuie. in which he was accused of having taken part, he went to London and spent twelve years in England, where he became known as an etcher and a painter of portrait and genre subjects. LTntil he was iifty years old Tissot's work dealt principally with the worldlj' aspects of Parisian life. The drawing in these works is always careful, and the coloring exact and finished. Examples of this style are "Faust and ^Marguerite" (Luxembourg) and "La Femme a Paris." Experiencing a change in his religious views about 1886, he left Paris and passeii ten years in Palestine. The results of this were the 300 and more water-color studies representing the life of Christ, which are now in the possession of the Brooklyn Institute. It is an attempt to portray the real environment of Christ, the cities, buildings, and habits of the country, as they must really have been in His time, instead of their ordinary conventional treatment by artists. The details are painted with miniature faithfulness. and the Oriental character of the subject is fully carried out. At the time of his death Tissot had begim a similar set of illustrations from the Old Testament. TISSUE, Animal. See Histology. TISZA, tis'so, Kalmax (Koloman) (1830- 1902). An Hungarian statesman, born at Geszt, Count.v of Bihar. He studied law and entered the Government service. In 1855 he accepted a semi- ecclesiastical position in the Reformed Church and in 1859 lie vigorously combated the attempt of the Austrian Minister of Public Worship. Count Leo Thun. to curtail the autonomy of the Protes- tant Church in Hungary. In 1801 he Vas elected to the Diet from the city of Debi-eczin and soon became the recognized leader of the opposition. Long opposed to the Ausgleich, Tisza finally, in 1875, united his followers with the Deak party and organized the new Liberal Party, which recognized the existing situation and sought to make the most of it for Hungary. In the Wenckheim Cabinet he assimied the portfolio of the Interior (March, 1875), becoming Premier in October. He held this positi()n for fifteen years, having at his back a more harmonious po- litical support than any other leader in the dual monarchy. He retired from the -Ministry in 1890, but continued his political leadership and was regularly returned as a Deputy from the city of Grosswardein until 1901. His leadership through- out his administration was conspicuously suc- cessful. He was an upright patriot and an able financier, and to him more ])erliaps than to any other one man was due the industrial and finan- cial progress of his countrv. Consult his biog- raphy by Visi (Budajjest, 1886). TITA'NIA. (1) An epithet of Latona, as the daughter of the Titan CVus. Ovid uses the name of Diana and of Pyrrha, daughter of Epimethcus. (2) In Shakespeare's iiidmimmer i'iglit's Dream, the fairy queen, wife of Oberon. TITANIC IRON ORE. See Ilitenite. TITANITE (from /i7a)ii!/)H). A mineral cal- cium-titanium silicate crystallized in the mono- clinic system. It has a resinous lustre, and is brown or black in color. It usually occurs in crystals embedded in granite, gneiss, mica schists, granular limestone, or in beds of iron ore and vol- canic rocks. It is found in the Saint Gotthard region, in Switzerland, Finland, and Ireland. In the United States it occurs in numerous locali- ties along the Appalachian Mountains from Maine to North Carolina. The name titanite is usually given to the brown or black varieties in distinction from the lighter colored titanite called sphene. The transparent and colorless varieties are frequently cut as gem stones. TITANIUM (Neo-Lat., from Lat. Titan, from Gk. Tirdy, Titan). A metallic element dis- covered by Gregor in 1789. It is not found na- tive, but as the oxide in vhe minerals anatase, brookite, and rutile; in combination with iron as ilmenite, and as the silicate with calcium in titanite. In smaller quantities it also occurs in other minerals. It is prepared by heating the potassium titanofluoride (obtained from rutile) with potassium or sodium out of contact with air. Titanium (symbol, Ti ; atomic weight. 48.15) is a dark-gray amorphous powder resembling re- duced iron, with a specific gravity of 1.25. When heated to redness in the air it burns with an in- tensely brilliant white light. It decomposes boiling water, and is soluble in dilute acids. Metallic titanium is distinguished from almost all other elements by its peculiar capacity for rmiting with nitrogen at a high temperature. This promises a cheap means of preparing am- monia direct from the atmosphere. Titaiiiiun gives hardness Rnd toughness to steel and a fine lustre to silver, while added to carbon used for arc lamps, it increases the brilliancy of the light. It combines with oxygen to form a di- oxide, a trioxide. and a sesquioxide. Of these the dioxide is found native and combines with bases to form titanates. TITANOSAURUS, or Atlantosaitrus. A genus of extinct, sauropodous, herbivorous dino- saurs (([.v. ). found fossil in the Jurassic rocks of the Rocky iloimtain region and Dakota, whose species were among the most gigantic land ani- mals that ever existed, one specimen, exhumed in Colorado by O. C. Marsh, measuring about 00 feet long and standing about 30 feet high. The
