LENZ, OSKAR (1848—). A German geogra pher and explorer. born in Leipzig and educated in the university there (1866-70). Asa member of the Austrian Geological Institute he went on geological expeditions in Croatia, Hungary, and Bohemia. and assisted Hochstetter in preparing Die zweile deutsche Nordpolfahrt (1874). In 1874 lie went on a scientific expedition for the German African Company and spent three years in West Africa. On a second journey, in ISSO, lie crossed the western Sahara in the disguise of an Arab merchant, reaching Timbuktu. In 1886 lie undertook an expedition for the relief of ,Tunker, Casati, and Lupton, who were penned up by the 11andi revolt. On this journey lie made valuable discoveries in East Africa, espe cially around the sources of the Nile. lie re turned to Austria in 1887 and became professor of geography in the German University of Prague. His African tours are described in: Skizzen ausllestafrika (1878) ; Timbuktu. Reisc durch Marokko, die Sahara and den Sudan, which contains many valuable contributions to our knowledge of the Sahara; and Wanderungen in Afrika (1895). His later works are: Die sogennanten Zu>crgtulker A frikas (1S94) ; Ueber Geld bei Naturvolkern (1895) ; Ophir nod die Huincn bei Simbaby (1896) ; and von .Afrika," in Andree, Handbuch der Geogra phic (1899).
LE'O (Lat., lion). The fifth sign of the zodiac (q.v.).
LEO. The name of thirteen popes. LEO I., Saint, Pope 440-461, surnamed 'the Great,' one of the most eminent of the Latin fathers. He was born in Tuscany. By Pope Celestine I. (422-432) lie was made one of the seven Roman deacons. His influence is attested by Cassian's dedication to him of his De Inearnatione Contra Nestorian (430), and Cyril of Alexandria appealed to his aid against Bishop Juvenal of Jerusalem. who de sired to be made a patriarch (431). Pope Sixtus III. (432-444) sent him on a civil embassy to Gaul, while absent on which he was elected Pope. Leo's letters, addressed to all parts of the Church, exhibit prodigious activity and zeal, and are used by Catholic controversialists as an evi dence of the extent of the jurisdiction of the Roman See. In a council held at Rome in 449,
he set aside the proceedings of the so-called Bobber Synod of Ephesus, which had been held that year and had pronounced in favor of Entyches (q.v.), summoned a new council at Chalcedon, in which his legates presided, and in which Leo's celebrated 'dogmatical letter' was accepted 'as the voice of Peter,' and adopted as the authentic exposition of the orthodox doctrine on the person of Christ. The history of Leo's in terposition with Attila (452) in defense of the Roman city and people will he found in the article ATTILA ; and his subsequent similar inter position with Genscrie (455). if less dramatic in the incidents with which history or legend has invested it, was at least so far successful as to save the lives of the citizens, and the public and private buildings of the city of Rome. He for mulated clrarly the monarchical idea of the Papacy, which be conceived to lie built upon Peter and the divinely constituted bead of the Chris tian world. Accordingly he acted consistently in the (diameter of universal bishop. He regulated affairs in Africa no less than in Gaul and Spain. When he found that the Council of Clmleedon (451) had put Constantinople above all other apostolic patriarchates, he required the Em peror to cancel the offensive 25th canon, and as the Emperor declared that its confirmation de pended upon the Pope, Leo asserted that the Greeks had given it up. Leo endeavored to ex tirpate heresy (Manielleism, Priscillianism), but rather unsuccessfully. Ile died in Rome, Novem ber 10. 461. His sermons and letters, of great interest and value, are in Migne, Patrologia Latina, ]iv.-]vi.. and a partial English translation in Nicene and Post-Nicene Fathers, 2d series, xii. Consult: Gore. Leo the Great (London, 1880) ; Arendt, Leo der Grosse und seine Zcit (Mainz, 1835) ; Perthe], Pepsi Leos I. Leben und Lehren (Jena, 1843) ; Langen, Gesebiehte der romiseken Kirche eon Len I. Lis :Vicoions I. (Bonn, l885).