the "wooden walls" of the fleet; and the whole naval force of Greece was gathered together at Salamis under Eurybiades. Of the 378 ships, beside penteconters, comprising the fleet, the Athenians furnished 180. It was in consequence of the threat of Themistocles that the Athenian contingent would sail away to Siris in Italy, that it was determined to give battle; and when a fresh council had resolved to sail to the Peloponnesus, he frustrated their plan by sending a slave to the Persian commander with a message that the Greeks were meditating a flight, and could easily be cut off. The Persian fleet was consequently moved down in the night so as to enclose the Greeks, and there was no choice left for the latter but to fight. (See GREECE, vol. viii. p. 443.) After the great victory there gained, Themistocles and the Athenians were desirous of pushing on to the Hellespont and destroying the bridge of boats in order to prevent the retreat of Xerxes; but to this the other confederates refused to agree, and the plan was abandoned. Themistocles, however, according to the testimony of Herodotus, privately sent word to the king that he had restrained the Greeks from pursuing his ships and breaking up his bridges over the Hellespont; and this he did in order to induce Xerxes to return, and that he might have a safe retreat in case any mischance should in the future befall him at Athens. He now employed his fleet in levying contributions from the Greek islands which had adhered to the Persians, and by this means gained considerable money for himself, without the knowledge of the other generals. After the division of the booty gained at Salamis, the Greeks sailed to the isthmus, where he was deprived of the first prize for skill and wisdom by each of the commanders voting for himself, but had a large majority of votes for the second prize. The envy of the leaders prevented any decision being made, but Themistocles was regarded as the wisest man in Greece, and the whole country was filled with his fame. He went to Sparta, and was there received with unprecedented honors; and though the Lacedæmonians gave to Eurybiades the crown of valor, they gave to Themistocles the crown of wisdom. When the Athenians returned to rebuild their ruined city, and to reconstruct their fortifications on an enlarged scale, Sparta from jealousy, but under a friendly guise, opposed and might have thwarted the project of refortifying; but Themistocles was sent there as ambassador, and contrived to deceive the Spartans until the walls were far enough advanced to be in a state of defence. Athens was now secure against external enemies, and Themistocles was more than ever desirous of making her a great maritime power. The work on the Piræus was resumed on a far grander scale, and the plan of the fortifications was such as to render them impregnable. To this costly and difficult work he encouraged the people by telling them that the Piræus was of more value to them than Athens itself,

and that in case their city was taken they might retire behind these walls and on the sea defend themselves against the maritime power of the world. He also persuaded the Athenians to build every year 20 new triremes. The story told by Plutarch of his project for burning all the Grecian ships except the Athenian, so that no city but Athens might have a naval force, which was defeated by the justice of Aristides, is unquestionably a pure fabrication. After the fortification of the Piræus his political ascendency declined, in consequence of his duplicity, his unprincipled love of money, and especially his acts in regard to the insular allies. His opponents in Athens were headed by Cimon the son of Miltiades, and by Alcmaon. He was tried and acquitted on a charge of treasonable intercourse with the Persians, but about 471 was ostracized and went into exile to Argos. While he was there the treason of Pausanias was discovered, and among his letters were found proofs of the privity of Themistocles. The Lacedæmonians sent to Athens to prefer against him a charge of treason, and joint envoys from Athens and Sparta were despatched to Argos to arrest him. Having notice of their coming he fled, and after twice narrowly escaping capture reached Susa, where he addressed to Artaxerxes, the son of Xerxes, a letter claiming protection on the score of his services to his father after the battle of Salamis, and asking permission to wait a year and then to come before him in person to explain his views. His request was granted, and he himself treated with honor. At the end of a year, having mastered the Persian language, he entered into personal communication with the king; and no Greek, says Thucydides, had ever before attained such a commanding influence and position at the Persian court. He excited Artaxerxes with plans for the subjugation of Greece, and was presented by him with a Persian wife and with large presents. After visiting various parts of Asia, he lived at Magnesia on the Mæander, and received his maintenance from the revenues of that and two neighboring cities. Some of his property at Athens was secretly sent him by his friends, but the bulk of it, amounting to 80 or 100 talents, was confiscated. He is said to have poisoned himself because he knew his promises to the Persian king could not be fulfilled. "Themistocles," says Thucydides, "was the strongest example of the power of natural talent, and in this respect is particularly worthy of admiration; for by his natural understanding, without any education originally to form it, or afterward to strengthen it, he had the best judgment in actual circumstances, and he formed his judgment with the least deliberation; and as to future events, he made in general the best conjectures; whatever he took in hand, he was also able to expound; and on matters where he had no experience, he was not unable to form a competent judgment; and both of the better and the worse, while it

was still in uncertainty, he had a most excellent foresight; and to express all in brief, by the force of his natural capacity and the quickness of his determination, he was the most efficient of all men in promptly deciding what was to be done." His life was written by Nepos and by Plutarch.

THENARD, LOUIS JACQUES, baron, a French chemist, born at La Louptière, Aube, May 4, 1777, died in Paris, June 21, 1857. The son of a poor farmer, he early repaired to Paris, and applied himself to chemistry under Fourcroy with such success as to be appointed, when scarcely 20 years old, assistant professor of that science in the polytechnic school, and afterward became professor there, at the college of France, and at the Sorbonne. He succeeded Fourcroy as member of the academy of sciences in 1810, and subsequently became a member of nearly all the learned societies of Europe. His clearness of exposition and elegance of style, enhanced by scientific fervor, made his lectures very popular. (See CHEMISTRY, vol. v. p. 41.) Charles X. on his accession to the throne made him a baron, and in 1827 he was elected to the chamber of deputies. Under Louis Philippe he became a member of the council of public instruction, was created a peer in 1833, grand officer of the legion of honor in 1842, and soon afterward chancellor of the university. He was for many years president of the society for the encouragement of national industry; and near the close of his life he founded a "Society for the Succor of Friends of Science," for the benefit of inventors impoverished by useful researches, and. contributed 20,000 francs to its funds. 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 European languages. He was a constant contributor to the Annales de chimie, Annales de physique et de chimie, and the Mémoires of the society of Arcueil and the academy of sciences. THEOBALD, LEWIS, an English author, born in Sittingbourne, Kent, died in Sept. 1774. He was the son of an attorney, and was bred to his father's business, but early abandoned it for literature. His first production was a now forgotten tragedy called " Electra," which appeared in 1714; and in 1717 he contributed to Mist's "Weekly Journal" a number of papers under the title of "The Censor," and by his criticisms provoked attacks from other writers, one of whom was Dennis. He is now remember ed chiefly for having been the original hero of the Dunciad," though in the later editions he was displaced to make way for Cibber. This position he owed to having pointed out the errors in Pope's edition of Shakespeare in 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 the attack upon him in the "Dunciad" he brought out an edition of Shakespeare's works (7 vols. 8vo., London, 1733), which entirely 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 part of which he asserted was composed by Shakespeare. Dr. Farmer maintained that it was the work of Shirley, but modern critics generally agree that there is in it very little either of Shakespeare or Shirley, and very much of Theobald. He was also author of a life of Walter Raleigh, and at the time of his death was engaged upon an edition of Beaumont and Fletcher.

THEOCRITUS, a Greek pastoral poet, a native of 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. Nothing else is known of his life. 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, although some are doubtless spurious. Beside these, 5 lines from a poem called "Berenice," and 22 epigrams in the Greek anthology, are ascribed to his pen. Theocritus has had several imitators, of whom the greatest was Virgil, numerous commentators, and innumerable editors. The first edition was published without name of place or date, but probably at Milan_about 1493; the latest is that of J. Meineke (Berlin, 1856). The "Idyls" have been several times translated into English.

THEODOLITE (Gr. Jew, see, dŋλos, manifest, and trus, circumference), an instrument used in surveying for measuring angles, both horizontal and vertical. When this instrument was invented is uncertain, but an act of the general court of Massachusetts of 1735 gives to Roland Houghton, a merchant of Boston, exclusive privileges for 7 years, for making and selling an instrument for surveying land of his invention called the new theodolite, by which, as declared in the act, "land could be surveyed with greater ease and despatch than by any surveying instrument heretofore projected or made within this province." It came into use soon after, and took the place in important surveys of the quadrant and repeating circle. It consists of a circular plate of metal so attached upon the head of a tripod or other support as to be readily brought to a horizontal position by thumb screws, according to the indications of the attached levels. Its outer circumference is divided into degrees and parts of degrees. A vertical axis passing through its centre supports a second plate nearly touching the lower one, and easily moved in either direction upon its axis. On opposite sides of the upper disk a portion of the

edge is chamfered away, and upon the bevelled surface, forming a continuous slope with that of the edge of the lower plate, are marked the divisions of the vernier scale by which the degrees may be read off to minutes. Very large theodolites have 3 verniers 120° apart, the average readings of which reduce the liability of error. The upper plate carries upright standards firmly fixed to it, upon which is supported a telescope directed across its horizontal axis, so that it may be turned up and down in a vertical plane. A graduated arc of which this axis is the centre passes below the telescope between the standards, and serves to measure the degree of elevation or depression of the telescope. A long spirit level attached to the telescope itself affords a further check upon the accuracy of the levelling when the telescope is taken out of the Y's that support it and reversed. The vernier for the vertical arc is attached to the compass box, which occupies a position directly over the centre of the upper plate. The instrument is furnished with screws by which the plates are clamped, and also tangent screws for giving slight motions in a horizontal or vertical direction. When the telescope is directed to any object, the readings of the verniers are taken; the lower plate is then clamped, and the telescope is turned with the upper plate to any other object, and the horizontal angle between the two is thus directly obtained, the telescope being elevated or depressed as may be necessary. The difference of elevation may at the same time be noticed upon the vertical arc if desired, or the angle which either point makes from the horizontal line. The instrument may thus be used for levelling or for determining heights by triangulation. The theodolite differs from the transit in the limited range of the telescope of the former upon its horizontal axis, while the transit can be turned completely over so as to sight in either direction. The latter is a much more convenient and exact method of prolonging a straight line than by turning the telescope of the theodolite half round or reversing it in its Y's. The transit is very generally used in the United States, especially by railroad surveyors, instead of a theodolite; and to distinguish it from the astronomical transit instrument it is sometimes called engineer's transit, or railroad transit. It is sometimes furnished with a vertical circle for measuring vertical angles, and may then be called a transit theodolite. Theodolites of large size have been employed upon important trigonometrical surveys. Ramsden's great theodolite, completed in 1787 and used upon the surveys for connecting the observatories of Greenwich and Paris, had a circle of 3 feet diameter; other instruments of the same size have been used by the British government in England, Ireland, and India. The principal theodolites used upon the United States coast survey are very perfect instruments constructed by Gambey of Paris, the largest with a circle of 30 inches diameter and others of 10 inches.

(See COAST SURVEY, vol. v. p. 396.) Theodolites in ordinary use have circles 5 inches in diameter.-For full descriptions of the construction and use of theodolites, see Heather's "Treatise on Mathematical Instruments," in Weale's "Rudimentary Series," and "Gillespie's Treatise on Land Surveying" (New York). The report of the superintendent of the coast survey for the year 1856 contains full instructions, by assistant J. E. Hilgard, in the method of testing a repeating theodolite.

THEODORA. See JUSTINIAN.

THEODORET (THEODORETUS), a father of the Greek church, and one of the chief representatives of the theological school of Antioch, born at Antioch in 386 or 393, died in 457 or 458. He was the scion of a noble family, went after the death of his parents into a cloister, became in 420 bishop of Cyrrhus on the Euphrates in Syria, and reunited many members of the sects with the Catholic church. He declared against the Nestorians, and at the council of Chalcedon, in 451, subscribed the condemnatory decree against Nestorius. He was one of the best exegetical writers of the ancient school (see Richter, De Theodoreto Epistolarum Paulinarum Interprete, Leipsic, 1822), and beside wrote homilies, of which those on Divine Providence are especially valuable; a history of the Christian church from 324 to 429; an epitome of heretical fables, the lives of 30 hermits, and 180 letters. Collective editions of his works have been edited by Sirmond (4 vols., Paris, 1642), and by J. L. Schulze and Nösselt (10 vols., Halle, 1769-'74). A translation of his " Ecclesiastical History" was published in Bohn's "Ecclesiastical Library" (London, 1854).

THEODORIC (Ger. Dietrich), surnamed THE GREAT, king of the Ostrogoths, born in Pannonia in 455, died in 526. The son of Theodemir, one of the chiefs of the Ostrogoths settled on the banks of the Danube, he was when 8 years old sent as a hostage to the court of Constantinople, where he was carefully educated in all martial arts and exercises, but utterly neglected literary culture. He was restored to his father at the age of 18, and, after greatly distinguishing himself in war, succeeded him as sole king of the Ostrogoths in 475. The southern part of Pannonia and Dacia had previously been ceded to them by the emperor Zeno the Isaurian, of whom Theodoric was for some years a faithful ally; but the emperor breaking his promises, war broke out between them, and Theodoric ravaged the Byzantine territories till Zeno in 483 appeased him by conferring upon him large gifts and many honors, even naming him consul in 484. The war was however renewed in 487, and Theodoric marched upon Constantinople; and to get rid of him Zeno proposed to him the invasion of Italy, then ruled by the usurper Odoacer. He consequently in 488 marched toward the peninsula at the head of his whole people, amounting to about 200,000, with a large num

ber of wagons conveying their most precious effects and their store of provisions. He first met in the Alpine passes and routed an army of Gepida and Sarmatians, then defeated Odoacer himself on the banks of the Sontius (Isonzo), Aug. 28, 489. After two other victories, one near Verona, the other on the banks of the Adda, he shut his opponent within the walls of Ravenna, and after a siege of more than 3 years received his capitulation in 493, apparently consenting to share the kingdom of Italy with him; but Theodoric soon after had his rival assassinated at a solemn banquet, and firmly established his power over the whole peninsula. He distributed one third of the lands to his soldiers in military tenures, but preserved as far as possible the administrative organization of the Roman empire. Under his fostering care Italy became prosperous again; agriculture and industry revived; literature and the fine arts flourished; internal improvements went on, and new monuments were erected. His foreign policy proved equally successful; through well devised alliances, he controlled nearly all the barbarians that had settled in western Europe. He checked the triumphant progress of Clovis after the victory of Vouillé in 507, protected the Visigoths, and secured for himself the possession of Provence. His latter years were embittered by religious troubles; the Arians, to which sect he belonged, being persecuted in the East, he retaliated against the Catholics of Italy; this brought on a conspiracy, in which the philosopher Boëthius, a great favorite with him, and the venerable Symmachus were apparently involved, and in a moment of passion he ordered them to be put to death. Their innocence being afterward demonstrated, remorse preyed upon his mind and hastened his death. He is the Dietrich of Bern of the Nibelungen-Lied.

THEODORUS, king of Abyssinia, born about 1820. He is the son of a petty official in the province of Kuara in West Abyssinia, and his real name is Kassai. In a school at Gondar he learned to read and write, and afterward entered the army of the governor of Dembea, and served in the campaigns against the Turks. The governor recommended Kassai to his master Ras Ali, who gave him his daughter in marriage, and an official station under his mother Waisoro Meunen, to whom the province of Dembea belonged. With her Kassai soon quarrelled, defeated her army, took her prisoner, and released her only on condition of surrendering Dembea. Ras Ali, unable to avenge his mother, made over the province to Buru Goshu, the governor of Gojam, who in 1850 forced Kassai to seek refuge in the mountains of his native Kuara. Here he collected a band of followers, and, in Nov. 1852, unexpectedly reentered Dembea, killed Buru Goshu himself, and defeated his army near Lake Tzana. In 1853 he became involved in a war with his father-in-law, who called in to his aid Ubye, the powerful ruler of Tigré, but was de

feated and obliged to fly to the Gallas. Before attacking Ubye, Kassai formed an alliance with the abuna or primate, Abba Salama, who agreed to come to Gondar on condition that the Roman Catholic priests were expelled. By the defeat of Ras Ali, Kassai had become prince of Amhara, and he summoned Ubye to pay tribute; and on the refusal of that ruler a war ensued, in which the lord of Tigré lost his kingdom and his liberty. Kassai now assumed the title of king of the kings of Ethiopia, and the name of Theodorus, doubtless in reference to the old tradition that a king of the name of Theodorus should arise, who would make Abyssinia great and prosperous, and destroy the two chief Mohammedan cities in Arabia, Mecca and Medina. He now set about the task of civilizing the people. The Coptic was de-. clared the national church, the Catholic priests being driven away, although the Protestant missionaries were suffered to remain. Edicts were issued forbidding the slave trade, polyg amy, the emasculation of enemies, and the mutilation of adult captives. Trade and agriculture have been specially favored, and all custom houses from Gondar to Halai have been abolished. In 1855 he issued an order to the Mohammedans to become Christians within two years or to leave the country; and the Galla tribes whose land he has conquered have assumed the Christian faith. In 1856 he subdued Shoa in southern Abyssinia, but the Mohammedan element, which is strong in that region, is not entirely suppressed. John Bell, an Englishman, is his adjutant and engineer, and an English consul resides at his court. The missionary Krapf, who visited him in 1855, says that at that time he not only conducted all his wars in person, but was also personally the dispenser of justice, was quick in judgment, and friendly to Europeans.

THEODOSIUS, a Roman general, beheaded in Carthage, A. D. 376. During the reign of Valentinian he was sent to the defence of Britain, in 367 crossed the channel at the head of a large army, and in two campaigns freed the country from the barbarians, strengthened the fortifications, and confirmed the Roman power. In 370 he returned, was made master-general of the cavalry, and was stationed on the upper Danube, where he defeated the Alemanni. When in 372 Firmus, a Moor, had made himself master of Mauritania and Numidia, and Count Romanus, the governor of Africa, unable to oppose, had joined him in rebellion, Theodosius was sent to that country to reduce it to its allegiance. Firmus at first attempted to deceive him by an appearance of submission, but all his arts were rendered unavailing by the prudence and perseverance of Theodosius. 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, and his dead body was given up by Igmazen. Theodosius recovered Africa, but on the suspicion that his name and services were too great for a subject, he was put to death. From him descended a line of Roman emperors. THEODOSIUS I., THE GREAT, a Roman emperor, son of the preceding, born in Italica or Cauca, Spain, about A. D. 346, died Jan. 17, 395, He learned the art of war under his father, was early given a separate command and appointed duke of Moesia, and while occupying that station gained in 374 a victory over the Sarmatians. After the execution of his father he retired to Spain, where he led a private life, cultivating and improving his land. In 378 the emperor Valens was killed and the Roman army terribly defeated by the Goths on the plains of Adrianople; and the surviving emperor, Gratian, summoned Theodosius from his retirement to take the supreme command, declared him Augustus, Jan. 19, 379, and assigned to him the administration of Thrace, Asia, and Egypt, with Dacia and Macedonia. Fixing his head-quarters at Thessalonica, Theodosius carried on the war against the Goths during 4 campaigns (379–382), hazarding no general engagement, but reviving the dispirited Roman troops by attacking the enemy in detail. After the death of Fritigern, the Gothic leader, that nation was broken up by dissensions and jealousies; and Modar, a prince of the Amali, was won over to the Roman cause, and surprised and slaughtered a large body of his countrymen. ` The Goths were afterward again united under Athanaric, who made peace and visited Oonstantinople, 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, who sent envoys to Theodosius excusing his conduct and offering him peace or war. Theodosius was not in a condition to accept the latter, and he reluctantly entered into a treaty with the usurper, by which he recognized him as emperor of the countries north of the Alps, Valentinian, the brother of Gratian, being secured the possession of Italy, Africa, and western Illyricum. Theodosius now devoted his attention to the affairs of the church. Although born of Christian parents, he was not baptized until the first year of his reign, when he confessed the orthodox faith. Returning to Constantinople, the stronghold of Arianism, he determined to do away with that creed, and gave to the archbishop Demophilus the alternative of subscribing to the Nicene creed or instantly resigning. Demophilus chose the latter, 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 do minions, 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 dur

ing 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, having collected an army of barbarians, entered and conquered Italy, which Valentinian had deserted on his approach, fleeing to Thessalonica. The disposition of Theodosius to undertake the cause of the fugitive emperor was seconded by the tears of Galla, the beautiful sister of the latter, whose marriage with the emperor of the East was the pledge of civil war. His army and navy were quickly assembled, and at the head of a large body of disciplined men he marched against Maximus, encamped at the Pannonian city of Siscia on the Savus, who was defeated and fled to Aquileia; but the gates of the city had scarcely been shut before Theodosius appeared, and Maximus was given up by his own troops and put to death. The emperor of the East, after restoring peace to the provinces, entered Rome in triumph, June 13, 389. At this time the citizens of Antioch, burdened by the expenses of the war, rose in a fury which discharged itself on the images of the imperial family, which were torn down and dragged through the streets. The disturbance was quickly suppressed; but a sentence of terrible punishment was pronounced against the city by Theodosius, who however was finally induced to suspend its complete execution. The people of Thessalonica having for a slight cause murdered Botheric and the 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 his crime in sending the order for this deed, Theodosius was forced by the undaunted Ambrose, archbishop of Milan, to do public penance. The emperor spent 3 years in Italy, and seated Valentinian on the throne of that country. The latter did not long enjoy his elevation, being strangled in 392 by his general Arbogastes, who had secured for himself all the real power of the government, and who now set up as emperor the rhetorician Eugenius. Theodosius undertook again the conquest of the West. He crossed the Julian Alps, and, after a severe and long uncertain contest, defeated Arbogastes in the open country extending from their foot to the walls of Aquileia. He 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. Theodosius, though naturally of a mild temperament, was much influenced by his passions, and many of the measures of his reign were marked by extreme cruelty. His great panegyrist is the poet Claudian. His reign is especially remarkable for the formal destruction of paganism, and for his efforts in this respect his fame is placed by the ecclesiastical writers of the time on a level with that of Constantine.