THALER (Dan. and Swed. daler), a coin and money of account of Germany, Austria, Holland, Belgium, Denmark, Sweden, and Norway. Silver coins of an ounce weight were struck in the early part of the 16th century at Joachimsthal, a town in Bohemia, whence the name. (See DOLLAR.) Other countries after a time began to coin thalers, but not always of the same value, and hence originated the Laubthaler or leaf dollar, the Philippsthaler, the Swedish copper dollar, &c. In most of the countries of Europe the royal or imperial mints coined thalers, hence called rigsdaler, riksdaler, or Reichsthaler, that is, dollar of the realm. These varied in value according to the amount of alloy. (See COINS.) As money of account there is still greater diversity of values, owing to the depreciation of the issues of the national banks or treasuries. In Sweden the rigsdaler riksmynt, now the authorized money of account, is about 27 cts. In Denmark the rigsbank daler is about 54 cts. In Germany generally the thaler of account is reckoned at 69 to 73 cts. American currency.

THALES, a Greek philosopher, and one of the seven wise men, born in Miletus, Ionia, about 636 B. C., died probably about 546. He took an active part in the political affairs of his native country. He visited Crete and Egypt, and acquired in the latter country an acquaintance with geometry. Various physical discoveries are attributed to him. He measured the height of the Egyptian pyramids by observation of the time at which a shadow equalled in length the height of the object; and he is said to have computed the sun's orbit, to have fixed the length of the year at 365 days, and to have been the first among the Greeks to predict eclipses, though very vaguely. Aristotle calls him the originator of the Ionic natural philosophy, and hence, indirectly, of Greek philosophy in general. He taught that all things are instinct with life, and originate from water. The writings attributed to him were declared spurious in antiquity, and his sayings recorded by Aristotle and Diogenes Laërtius are probably conjectural.

THALIA, in Greek mythology, the muse of comedy and idyllic poetry. She is generally represented with a mask in one hand and a shepherd's staff or a wreath of ivy in the other. THALLIUM (Gr. 0a2265, a green bough), one of the three metals forming the class of triads, the others being iridium and gold. It was discovered by Crookes of London in 1861, in the seleniferous residue from the manufacture of sulphuric acid from iron pyrites. Its discovery resulted from the observation by Mr. Crookes

ized portion of the residue. It is widely diffused as a constituent of iron and copper pyrites, but forms only about the 4,000th part of the mass. It also exists in the lepidolite of Moravia, in mica from Zinnwald in Bohemia, in the mother liquors of the salt works at Nauheim, and in the mineral crookesite from Skrikerum in Norway. It is most economically prepared from the flue dust of pyrites burners. This dust is stirred with boiling water in wooden tubs, and the decanted or syphoned liquor treated with an excess of strong hydrochloric acid, by which impure monochloride of thallium is precipitated. This impure chloride is then treated with hot oil of vitriol, and contaminations of other metals are separated by sulphuretted hydrogen. A pure sulphate is obtained, from which the metal may be separated by electrolysis or the action of zinc. Thallium resembles cadmium in color, but approaches lead in specific gravity, having a density of 11.8 to 11'91, according to its metallurgic treatment. The symbol of thallium is Tl; its atomic weight, according to recent extended researches by its discoverer, is 203 642. (See "Chemical News," London, 1874.) It has a highly crystalline structure, and crackles like tin when bent, but is easily hammered into leaves. It melts at 561° F. A polished piece of the metal tarnishes rapidly when exposed to the air, but the action continues only a short time, as the thin film of oxide protects it from further oxidation. The metal and its compounds impart an intense green color to colorless flames, which when viewed by the spectroscope is found to be monochromatic, appearing as a sharply defined green band. It forms numerous compounds, including three oxides, the most important being thallous oxide, TlO; this dissolves readily in water, producing a caustic alkaline solution which absorbs carbonic acid from the air. The sulphate forms with aluminic sulphate an octahedral alum. The salts of thallium are poisonous. The metal has been used to render glass highly refractive.

THAMES, a river of Connecticut, formed by the junction of the Quinebaug (with its branch the Shetucket) and Yantic rivers at the city of Norwich, and flowing thence S. about 15 m. to Long Island sound, which it enters below New London. It is wide and beautiful, navigable for large vessels to Norwich, and has an excellent harbor at its mouth. The streams which form it possess numerous valuable mill sites, and the large amount of manufactured goods from the factories on their banks make the Thames an important avenue of commerce.

THAMES, a river of Ontario, Canada, flowing through a fertile country in the peninsula formed by Lakes Huron and Erie, and after a S. W. course of about 160 m. discharging into Lake St. Clair. It is navigable for small vessels from its mouth to Chatham, 18 m. city of London is the most important place on its banks.-At the Moravian settlement on this

The

THAMES, or Isis (anc. Tamesis or Tamesa), the largest and most important river of England. Its source, called Thames Head, is in the Cotswold hills, about 3 m. S. W. of Cirencester, 376 ft. above the sea level. In the first 30 m. of its course it receives the Churnet, the Coln, and the Lech, and below Lechlade becomes navigable for barges; from Lechlade its course is first E. and then N. N. E. and S. S. E. to Oxford, through a level country, the river receiving on its way the Windrush and the Cherwell. Flowing generally S. S. E. from Oxford to Reading, it receives the Thame and the Kennet; thence making a considerable circuit to the north by Henley, Great Marlow, and Maidenhead, it turns eastward to Windsor, then makes a detour southeastward by Staines and Chertsey to Kingston, where it turns N., and, passing Richmond, reaches Brentford, whence its course is nearly due E. to its mouth. From Brentford it passes by Putney, Hammersmith, and Chelsea to London, receiving in its course the Loddon, Colne, Mole, Cran, Brent, and Wandle, all small streams. From London to its mouth, nearly 60 m., the Thames is navigable for vessels of 700 or 800 tons, and for vessels of any burden to Deptford, 3 m. S. E. of London bridge. It is about 300 yards wide at London bridge; at Woolwich, 9 m. below, 500 yards; at Coalhouse point, 20 m. further down, 1,300 yards; at the Nore, 6 m.; and at its mouth, 18 m. Below London it receives the Ravensbourne, Roding, Darent, and Medway. Its tide is perceptible as far as Teddington, 72 m. above its mouth. The Thames and Severn canal connects it with the Severn; the Oxford canal with the grand canal system of the central counties; the Wilts and Berks and the Kennet and Avon canals with the Avon and the Severn; the Wey and Arun and the Basingstoke canals with the Sussex coast; the Grand Junction, the Regent's, and the Paddington canals connect the Brent with the Oxford canal, and encircle the N. and E. sides of the metropolis. The whole course of the Thames is about 220 m. Its commerce is surpassed probably by that of no river in the world. Its docks are described in the article Dock. It is crossed at and above London by numerous bridges, and several tunnels pass under it. For a description of the bridges, the tunnels, and the new Thames embankments, see LONDON, vol. x., pp. 592 and 617.

THAN, Móricz, a Hungarian painter, born at Old Becse in 1828. After studying law at Pesth, he devoted himself to painting at the

THANET, Isle of, an island of England, on the N. coast of Kent, separated from the mainland by branches of the river Stour called the Stourwantsome, the Mele-stream, and the Nethergong-wantsoine; length 10 m., breadth 5 m.; area, about 40 sq. m.; pop. in 1871, 30,134. The most important towns are the watering places Ramsgate, Margate, and Broadstairs. The N. E. point of the island is called the North Foreland, and has a lighthouse. The surface, elevated and nearly level, is cultivated with great care. In the time of the Romans the channel on the N. W. side, now almost closed, was from 1 to 4 m. wide, and was used as the main passage for vessels going toward London; and it continued to be navigable for vessels of considerable size till the time of the Norman conquest. The island was then nearly circular, but it is now an irregular oval. The washing away is still going on, and the average annual loss is estimated at 2 ft. on the N. side, and 3 ft. on the S. side between Ramsgate and Pegwell bay.

THANKSGIVING DAY, an annual religious festival, observed in the United States, and particularly in New England, suggested by the Hebrew feast of tabernacles, or "feast of ingathering at the end of the year." The occasional observance of a day of thanksgiving, formally recommended by the civil authorities, was not unusual in Europe, and such a day was observed in Leyden, Holland, Oct. 3, 1575, the first anniversary of the deliverance of that city from siege. In 1608 the Pilgrim church, exiled from England, went to Holland, and remained there till 1620, when it sent off the Mayflower colony to New England. After the first harvest of the colonists at Plymouth in 1621, Gov. Bradford sent four men out fowling, that they "might after a more special manner rejoice together." In July, 1623, a day of fasting and prayer was appointed on account of drought. Rain came abundantly while they were praying, and the governor appointed a day of thanksgiving, which was observed with religious services. The Charlestown records show a similar change of fast day into thanksgiving in 1631 on account of the arrival of supplies from Ireland. In June, 1632, Gov. Winthrop, of the Massachusetts Bay colony, recommended a day of thanksgiving on account of action of the British privy council favorable to the colonies, and invited the governor of Plymouth colony to unite with him. There is record of the official appointment of days of thanksgiving in Massachusetts Bay in 1633, 1634, 1637, 1638, and

tament; hence its members were popularly known as Cajetans (Gaetani). But the extension and establishment of the order were mainly due to Caraffa, who was archbishop of Chieti (Lat. Theate) when he was received by Gaetano as his associate, and thus gave the . order its official name. It was approved in 1524 by Clement VII., under the designation of "regular clerks," the dress of the members being that of the secular clergy. Caraffa had been elected superior general. Their first residence on Monte Pincio was sacked by the Spaniards May 6, 1527, and Gaetano was subjected to the most cruel tortures to make him give up the riches he was thought to possess. He soon after retired to Venice with his companions, and was chosen superior, and he and they displayed extraordinary charity during the plague and famine of 1528. They were afterward united with the congregation of Somascha, founded about this time in a town of that name near Bergamo by St. Girolamo Emiliano. The two congregations were separated on the elevation of Caraffa to the papal chair, May 23, 1555. In 1547 they had only two establishments, one at Venice and another at Naples. Through the influence of Paul IV. they spread rapidly, and soon possessed four provinces in Italy, one in Germany, one in Spain, two establishments in Poland, one in Portugal, and one in Goa. In France they had only the Parisian residence, which produced several remarkable men. They also founded missions in Tartary, Tiflis, and Circassia. At the beginning of the present century the Theatines did not exist outside of Italy, where they had nine establishments. These were all suppressed in 1870.-There were also two communities of Theatine nuns (one a congregation of hermits), both founded by Ursula Benincasa, the one in 1583, the other in 1610. Neither had ever more than two establishments, and both are now extinct.

THEATRE (Gr. Okarpov, a seeing place, from bɛãσbaι, to view), a building in which plays are represented. The first theatres of the Greeks, who were the founders of the drama in our sense of the word (see DRAMA), were exceedingly rude affairs. Thespis is said to have acted his plays in a wagon, and in the time of Eschylus the performances took place upon temporary wooden scaffolds, one of which having broken down during a representation in which Eschylus and Pratinas were rivals (about 500 B. C.), the Athenians in that year began to build the great theatre of Dionysus (Bacchus), the first permanent stone structure of the kind. It was probably used for dramatic purposes within a few years, though it was not finished until about 340; and in the mean time theatres had been erected in many parts of Greece, Asia Minor, and Sicily. The seats of the spectators, comprising the tarpov proper, rose one above another in arcs of concentric circles, each row forming nearly two thirds of a circumference. The space immediately in front of the spectators, corre

sponding nearly to the modern pit or parquet, was called the orchestra, and was appropriated to the chorus. It was floored with boards, and in the centre of it stood the Ovuéλn or altar of Bacchus, upon a raised platform which was sometimes occupied by the leader of the chorus, the police, the flute player, and the prompter; the last two were placed on the side next the stage, and concealed from the spectators by the altar. The stage was behind the orchestra and above it, and the chorus, whenever they had to take a part in the real action of the drama, ascended to it by steps. The back was closed by a wall called the σký (Lat. scena); the whole space between the scena and the orchestra was known as the proscenium; and the part nearest the audience, where the actors stood when they spoke, was the Zoyɛiov. There was no scenery properly so called, but the scena was architecturally decorated and made to represent as far as possible the locality in which the action was going on. It had an entrance in the centre called the royal door, through which the principal characters made their appearance, and doors on the right and left for the subordinate personages. The plays of Eschylus and Euripides seem to require frequent changes of scene, but probably they were rather hinted at than actually made; they perhaps consisted merely in turning the EpiaкTO (Lat. versuræ) or "wings," which were prism-shaped frames moving on pivots at each side of the proscenium. The whole stage was never concealed from the spectators; there is mention of a curtain, which instead of being drawn up was lowered through a crevice in the stage, but it covered only the background, or according to some authorities the wings. The machines for producing supernatural effects must have been numerous and elaborate, but are now imperfectly understood. They included the "Charonian steps," by which shades ascended from the lower world; the unxavý, by which gods and heroes were represented passing through the air; and the coλoyɛiov, an elevated place above the scena, where the deities appeared in full majesty. Neither the stage, the orchestra, nor the auditorium was roofed, but there were porticoes running around the building, to which the people retreated in case of rain, and awnings were sometimes used to ward off the heat of the sun, for the performances always took place by daylight. The vast size of the ancient theatres, intended as they were to accommodate almost the entire population of a city at each performance, made it impossible for the unaided voice to be heard by the whole audience. Metallic vases were therefore placed under the seats to serve as reflectors of sound, and the actors wore masks with metallic mouthpieces to answer the purpose of speaking trumpets. The spectators were seated according to their rank. A price was charged for admission, at least until the performance was pretty far advanced; but in Athens from the time of Pericles the poorer class and subsequently all the