chemistry in Paris under Vauquelin and Four- | croy, in 1798 became a teacher of that science in the polytechnic school, in 1804 professor in the collège de France and the Sorbonne as successor of Vauquelin, and in 1810 also in the polytechnic school. In the latter year he was elected a member of the academy in place of Fourcroy. Charles X. on his accession to the throne made him a baron, and under Louis Philippe he was created a peer in 1832, and in 1838 director of the collége de France. He was president of the society for the encouragement of national industry, and founded a society for the benefit of inventors impoverished by useful researches. His most popular work, Traité élémentaire de chimie théorique et pratique (4 vols. 8vo, 1813-'16; 7th ed., 5 vols., 1836), has been translated into several languages.

THEODOLITE, a surveying instrument for measuring vertical and horizontal angles and taking levels, combining the uses of the ordinary transit, the quadrant, and the level. In the American form of the instrument, the telescope turns over and the vertical angles are read on a graduated circle. In the English form the vertical angles are read on a semicircle beneath the telescope and level; the telescope cannot therefore turn over, but is reversible. The American form is preferable by reason of the greater facility and precision of the adjustments. In common with all such kinds of instruments, it is made of brass. The principal parts are the vertical circle A and the horizontal circle F, which rests upon the plate H. A magnetic needle also rests upon the horizontal plate, which may be used when desired for ascertaining the earth's meridian or the deviation of a line from it. The telescope,

THEOBALD, Lewis, an English author, born at Sittingbourne, Kent, died in September, 1744. He was an attorney, but did not practise. His tragedy "Electra" appeared in 1714; and in 1717 he contributed to Mist's "Weekly Journal" papers under the title of "The Censor," which provoked attacks from other writers, one of whom was Dennis. He published a pamphlet entitled "Shakespeare Restored, or a Specimen of the many Errors as well committed as unamended by Mr. Pope in his Edition of this Poet, designed not only to correct the said Edition, but to restore the true Reading of Shakespeare in all the Editions ever yet published" (4to, London, 1726). For this Pope made him the hero of the "Dunciad." (See POPE, ALEXANDER, Vol. xiii., p. 709.) Theobald then brought out an edition of Shakespeare's works (7 vols. 8vo, 1733), which destroyed the reputation of Pope's edition. Theobald wrote or translated 20 plays, now all forgotten, and also brought on the stage a play entitled "The Double Falsehood, or the Distrest Lovers," the greater T part of which he asserted was composed by Shakespeare. He also published a life of Sir Walter Raleigh.

THEOCRITUS, a Greek poet, born in Syracuse, who flourished about 270 B. C. He went to Alexandria, and secured the favor of Ptolemy Philadelphus, but returned to Syracuse during the reign of Hiero II. He wrote in a mixed dialect in which the Doric predominated, and was the creator of pastoral poetry as a department of literature. There are extant 30 poems, called by the general name of "Idyls," which are attributed to him, and 22 epigrams. He had several imitators, of whom the greatest was Virgil. The first edition, containing only 18 idyls, appeared at Milan probably in 1493, and the Aldine edition in 1495. Among the more important subsequent editions are those of Reiske (2 vols., Leipsic, 1765-'6), Warton (Oxford, 1770), and Paley (Cambridge, 1863). The principal English translations of the poems are those of Creech (London, 1681), Fawkes (1767), Polwhele (1786), Chapman (1836), and Calverly (1869).

Theodolite.

B, revolves on a horizontal axis, also the axis of the vertical circle, and which rests upon the supports SS. Beneath the telescope and attached to it by adjusting screws is the long spirit level L, with a scale attached for marking the position of the air bubble. The small spirit levels D and E serve to level the horizontal circle. The vertical axis of the instrument

it to its allegiance. At the head of a small body of men, he advanced into the heart of an unknown and hostile country, driving his enemy before him, until at last the usurper fled to Igmazen, king of the Isaflenses. The latter being threatened with destruction for harboring him, Firmus strangled himself. Theodosius recovered Africa, but for some unassigned reason, probably because his name and services were too great for a subject, he was put to death. From him descended a line of Roman emperors.

by his own troops and put to death. Theodosius entered Rome in triumph, June 13, 389. The people of Thessalonica having for a slight cause murdered Botheric and the other principal officers of the little garrison, the emperor sent thither an army of barbarians, who, when the inhabitants were assembled by invitation at the circus, massacred them to the number of many thousands. For this St. Ambrose forbade him to enter a church in Milan until he had done public penance. He remained in Italy three years.

When Valentinian was strangled in 392 by his general Arbogastes, who had secured for himself all the real power of the government, and now set up as emperor the rhetorician Eugenius, Theodosius undertook again the conquest of the West. After a severe and long uncertain contest he defeated Arbogastes near the passes of the Julian Alps. Theodosius was now master of the whole Roman world. Honorius, his younger son, was called to Milan to receive the sceptre of the West, and here Theodosius died immediately after his arrival. In the eastern empire he was succeeded by his elder son Arcadius.

THEOGNIS, a Greek elegiac poet, who flourished about 540 B. C. He was a citizen of Megara; and as in the contests between the aristocratic and democratic parties he belonged to the former, he shared in their defeat, and went into exile at Thebes. He visited Sicily, Euboea, and Sparta, and survived the Persian war of 490. He is the author of numerous elegies, originally comprising 2,800 verses, of which 1,389 are extant. They discuss oligarchical education and the humanities. The best editions are Welcker's (Frankfort, 1826) and Bergk's in Poeta Lyrici Græci (3d ed., Leipsic, 1866).

THEODOSIUS I., the Great, a Roman emperor, son of the preceding, born in Italica or Cauca, Spain, about A. D. 346, died in Milan, Jan. 17, 395. He learned the art of war under his father, was early given a separate command and appointed duke of Moesia, and in 374 gained a victory over the Sarmatians. After the execution of his father he retired to Spain, where he led a private life until the emperor Gratian summoned him to take the supreine command, declared him Augustus, Jan. 19, 379, and assigned to him the administration of Thrace, Asia, and Egypt, with Dacia and Macedonia. Fixing his headquarters at Thessalonica, Theodosius carried on the war against the Goths during four campaigns (379–382). The Goths, divided by dissensions and jealousies after the death of their leader Fritigern, were again united under Athanaric, who made peace and visited Constantinople, where he died; and the magnificent funeral honors paid him by Theodosius so won over his followers that they enlisted in the Roman army. In 383 Gratian, the emperor of the West, was dethroned and put to death by Maximus, and Theodosius entered into a treaty with the usurper, by which he recognized him as emperor of the countries THEOLOGY (Gr. Oɛóç, God, and 26yos, disnorth of the Alps, Valentinian, the brother of course), the science which treats of God and Gratian, being secured the possession of Italy, divine things. The name theologos was given Africa, and western Illyricum. Theodosius by the Greeks to the authors of theogonies now devoted his attention to the affairs of the (as Orpheus and Hesiod), and to those who church. Fixing his residence at Constantinople, wrote poems (as Empedocles) or philosophical the stronghold of Arianism, he determined to treatises (as Pherecydes) on divine things and do away with that creed, and gave to the arch- the origin of things through the gods. A disbishop Demophilus the alternative of subscri- tinction was early made, as by Varro, between bing to the Nicene creed or instantly resigning."mythical theology," a knowledge of the Demophilus resigned, and Gregory Nazianzen was installed in his place. Six weeks afterward Theodosius commissioned his lieutenant Sapor to expel all the Arian clergy from the churches in his dominions, and gave him a military force sufficient to carry out the decree. In May, 381, he assembled the first council of Constantinople, to confirm and complete the Nicene creed; and during 15 years he issued at least 15 edicts against all heretics, especially against those disbelieving the doctrine of the Trinity. In the mean time Maximus had entered Italy, and dethroned Valentinian II. Theodosius, who had married a sister of Valentinian, marched against Maximus, then encamped at the Pannonian city of Siscia (now Sissek) on the Save, defeated him, and pursued him to Aquileia, where Maximus was given up

myths and legends concerning the deities in the classic poets; "physical theology," the investigations of philosophers on the origin of the world; and "civil theology," a knowledge of public worship. The ecclesiastical writers of the 3d and 4th centuries used the word, but applied it only to doctrinal treatises on the nature of the Godhead, or on the Trinity. Somewhat later the term was used by Theodoret, Maximus, and others, of the aggregate doctrines of the Bible, but its most common signification remained the doctrine of God. Abélard was the first to apply the term to the entire science of the Christian religion, which signification it has since retained. With regard to the sources from which theology derives its contents, it is common to divide it into natural or philosophical theology, which confines itself

is Wimmer's (Leipsic, 1854, and Paris, 1866). His "Characters" were translated into French and prefixed to his own by La Bruyère (1688), and into English, among others, by Francis Howell (London, 1824).

known to have taken place in or near this island are 197 B. C. and A. D. 46, 726, 1573, 1707, and 1866. By that of 197 B. C. the island of Palæa (Old) Cammeni was formed, by that of 46 Mikra (Little) Cammeni, and by that of A. D. 1707 Nea (New) Cammeni. The last was at first composed of white pumice, but subsequently received additions of brown trachytic rock. The eruption did not wholly cease or the island assume its present form till 1712. In the beginning of 1866 stones flew up from the port of Volcano, and a new volcano arose which attained a height of about 100 ft. The eruptions continued until the autumn of 1870, and enormous quantities of lava were thrown surpassing in size those projected in 1707'12. Near Nea Cammeni a regular cone was formed 325 ft. high.

THEOPHYLACT (Oeopuháкros), surnamed SIMOCATTA, a Byzantine historian, born of an Egyptian family in Locris in the latter part of the 6th century, died about 629. From 610 till about the close of his life he held various offices at Constantinople. He wrote a history of the reign of the emperor Maurice (582-602), of which a Latin translation, Historia Mauricii Tiberii Imperatoris Libri VIII., was published at Ingolstadt in 1648. Besides 85 letters (Epistola Morales, Rustica et Amatoria, 4to, Cra-out, cow, 1509), he wrote a work on the nature of animals, especially of man ('Aropiai voikai, or Quæstiones Physica, 4to, Leyden, 1596; Leipsic, 1653.) These two works were published together at Paris in 1835.

THEOPHYLACT, a Greek theologian, born in Constantinople probably about the middle of the 11th century, died after 1112. He was instructed by Clement, archbishop of Bulgaria, and became archbishop of Achris or Achrida, a chief city of Bulgaria, between the years 1070 and 1077. He engaged in the controversies of his day, especially those relating to the true character, procedure, and office work of the Holy Ghost, and the question whether or not common bread or only unleavened should be used in the sacrament, opposing the views of the Latin church. He compiled commentaries upon the minor prophets and a large part of the New Testament from the works of Chrysostom, and wrote a treatise on royal education (Пaideía Baσihikh, or Institutio Regia) for the instruction of his pupil Prince Constantine Porphyrogenitus, the son of Michael VII. There exist 75 of his letters, with some homilies and orations and a few small treatises. An edition of all his works in Greek and Latin was issued at Venice (4 vols. fol., 1754-'63).

THERA (now Santorin), an island of the Egean sea, now forming with Amorgos and other islands an eparchy of Greece, in the nomarchy of the Cyclades; length about 9 m. from N. to S., average breadth about 4 m.; pop. about 13,000; of the eparchy, in 1870, 21,907. It was originally circular, but the islet Therasia was torn from it by an earthquake about 237 B. C., and it now resembles a horseshoe. The harbor thus formed is the crater of a volcano, and as no bottom is found, vessels make fast to the abrupt and rocky shores. The soil is volcanic and inclined to dryness, but very fertile. The annual production of wine is about 1,750,000 gallons. Ship building is the only considerable industry. Thera, the capital, had a population in 1870 of 5,143.Though an ancient Lacedæmonian colony, Thera is only of historic importance as having sent a colony to found the city of Cyrene in Africa, 631 B. C. The dates of the eruptions

THERAMENES, a political leader at Athens toward the end of the 5th century B. C., born in Cos. In 411 he became a member of the council of 400; but he deserted it and became one of the leading agents in its overthrow. In 410 he joined the fleet under Thrasybulus, and took part in the battle of Cyzicus; and in 408 he participated in the siege of Chalcedon and the capture of Byzantium, under Alcibiades. He was one of the inferior generals at the battle of Arginusæ in 406; and it was chiefly through his influence that six of the commanders were condemned to death for not saving the drowning crews, although, as they asserted, he had himself been sent with others to perform that office. During the siege of Athens by the Spartan general Lysander, when the city was reduced to great extremity, Theramenes was sent as envoy to the Lacedæmonians. He remained three months with Lysander, who he pretended detained him that length of time without informing him that the ephors only had power to grant peace; and upon his return to the city, which was now suffering under a terrible famine, he was sent back to make peace on any terms. The hard conditions imposed by the Lacedæmonians were assented to (see GREECE, vol. viii., p. 195), and in 404 Theramenes, who during his three months' stay with Lysander had made arrangements with the Athenian oligarchical exiles, was among the most active in subverting the constitution, and became one of the thirty tyrants. He warmly supported the first measures of the government in crushing the democracy and putting to death its prominent leaders; but he afterward opposed the violent measures of Critias and his colleagues. His party daily increased; but Critias, after charging him with being a public enemy, caused him to be dragged off to prison by partisans with concealed daggers whom he had brought into the senate house, and compelled him to drink the hemlock.

THERESA, or Teresa, Saint, a Spanish mystical writer, born in Ávila, March 28, 1515, died at Alba, Oct. 4, 1582. She was called Teresa de Ahumada (her mother's family name) till Au