peninsula against the attacks of the | Moors. The people opposed the usurp er, Miguel, in 1828, who executed many of them; but they supported Pedro of Brazil, and withstood the besiegers thirteen months. Population, 105,838. Opossum, the only American animal belonging to the curious family of OPOSSUMS. marsupials, but the pouch in which the young are carried is wanting in most varieties. There are twenty-three different species, varying in size from that of a cat to a mouse, and found in the United States and south to the Argentine Republic. They are all flesh eaters, one kind living on crabs. Those who do not carry their young in pouches as the other marsupials, carry them on their backs, their tails twined around their mother's. They are very destructive in robbing poultry yards, showing great cunning in getting their prey, as they also do in feigning death when attacked, which gives rise to the ex pression "playing 'possum." 'Possum hunting is a favorite sport in the south, especially with the negroes. They hide in the trees and are either shaken down or shot while hanging by their long tail, or sometimes the tree is cut down. Optics. See LIGHT. Oracle, the name given in ancient times to a revelation given by some god in answer to questions, and also to the place where the revelations were given. The revelations were usually made by the mouths of priests or priestesses, and sometimes by other signs. At Dodona, the oracle answered by the motion of leaves, or the murmuring of the waters of a fountain, and the oracle of Ammon responded by the shaking of the statue of the god. The Egyptian temples were nearly all oracles, and there were oracles among the Babylonians and Phoenicians. The most famous oracle of the Greeks was the one at Delphi. The inquirers of ORANG fered sacrifices, walked around the oracle with laurel crowns on their heads, and inscribed their questions on leaden tablets, many of which have been discovered. The answer was accepted as final and having authority, and usually was just and reasonable. Other oracles were at Ismenus, Delos and Olympia. See Greek Oracles, by F. W. H. Myers; Religious Antiquities, by Schomanns (trans.). Oran (o-ran'), a city in Algeria, is on the Gulf of Oran, 260 miles southwest of Algiers. The harbor is protected by moles built in 1880. The city is at the foot of a hill, and defended by forts, and has two citadels. There is a Roman Catholic cathedral, a Mohammedan mosque, a military hospital, a college and a seminary. The principal exports are alfa, iron ore and grain. The city was founded by the Moors and in the 15th century was very prosperous, celebrated for its cloth and arms and fine public buildings. In 1509 the Spaniards, after taking it, made a penal settlement of it. Captured by the Turks in 1708 it was retaken by the Spaniards in 1732, who abandoned it in 1790, after it was almost destroyed by an earthquake. The French took possession of it in 1831. Population, 67,681. Orang or Orang-Outang (6-rang'-oo-tung') is an ape, found only in ORANGE 908 ORANGE RIVER but not more so than the chimpanzee | as ornaments for brides in a great or gorilla does in other respects. His color differs from other apes, being a reddish-brown, matching the color of the people in the countries where he is found, as the gorilla and chimpanzee do their black neighbors. He builds a nest in the trees, something like a hut, and goes from tree to tree with considerable swiftness, but is awkward on the ground. He is very strong but not fierce, and is easily tamed. Orange, the name of a tree, growing in warm regions, the fruit of which is in very common use. There are several varieties, though they are usually considered to belong to one species. It has been cultivated in India from very ORANGE. early days, and from thence has spread into Western Asia, Europe and America. It was probably brought to Europe by the Moors. It is a medium-sized evergreen tree, with thick, smooth leaves, and very fragrant white waxlike flowers. The fruit is round, yellow, with a thick rind and juicy pulp, divided into sections. The tree is cultivated in all parts of the world where the climate is suitable. In the United States it is grown largely in Florida, California and Louisiana. The Lisbon orange, China orange, blood or Maltese orange, remarkable for its red pulp; the egg orange, shaped like an egg; Mandarin orange, and the seedless Majorca orange are some of the different varieties. The bitter orange has a bitter juice, and is used in medicine and for flavoring food. The flowers are used many countries, and dried, with the dried leaves, furnish an oil which is much used in perfumery. They are packed in barrels with salt, and exported from the south of Europe. The fruit of the orange bears transportation better than most fruits, and is a very important article of commerce. They are gathered before they are quite ripe, and wrapped separately in paper, and packed in boxes or chests. The boxes hold about 250 oranges. The small green oranges that fall from the trees are dried and used in making Curaços, a drink, and also yield an oil. The orange rind dried is used in medicine and cooking, and candied is used in confectionery, and it is also used in Italy in the preparation of a drink called orange rosoglio. The trees are very fruitful, bearing from 3,000 to 10,000 oranges in a year, and a single acre will produce ten tons of oranges. They often live from 100 to 150 years. A grove of young orange trees is not really valuable until the seventh year after planting. The wood of the orange is used in fine cabinet work, being smooth and fine grained. See Handbook of Orange Culture, by Moore. Orange, a city of New Jersey, 12 miles west of New York. The name includes also parts of the townships of East Orange, West Orange and South Orange, which are all suburbs of New York, often called the Oranges. The region around the city is laid out in beautiful parks, with elegant homes, rising above each other, ending in a broad crest on the top of Orange mountain, 650 feet high. Llewellyn Park of 50 acres is on the eastern slope of the mountain. The city has manufactures of hats and shoes, and in the northern part the beautiful Rosedale cemetery of fifty acres. At South Orange is a Ro man Catholic College, and theological seminary. Population (of the city), 18,844. Orange, the largest river in South Africa, flowing west into the Atlantic ocean. It is 1,000 miles long but is navigable only in the rainy season, and its mouth is obstructed by a bar. Orange River Free State, a republic of South Africa, lying between the Vaal and Orange rivers. It is a plain rising from 3,000 to 5,000 feet above the sea, sloping down to the rivers on its borders, and dotted with single hills called "kopjies." It covers 41,500 square miles. It was originally inhabited by African tribes, but in 1836 | was taken possession of by the Dutch Boers (colonists) of Cape Colony. From 1845 to 1848 the country was governed by a resident governor sent from the Cape; it was then annexed to the British crown as the Orange River sovereignty, but in 1854 it was given up to the Dutch colonists and formed into an independent state. The country affords very fine pasture, and the principal industry is raising merino sheep, cattle, horses, goats and ostriches. Coal is mined and diamonds are found, though the mineral wealth has not been developed. See South Africa, by Trollope; History of Boers in Southern Africa, by Theal. Oratorio, a sacred story set to music, and accompanied as in the opera, with a chorus and orchestra or band of musical instruments, but without the use of scenery or costumes or acting. Its name is derived from the oratory of the Church of Santa Maria Maggiore near Rome, where from 1571 to 1594, musical performances of this class were first arranged. The oratorio was produced in Rome in 1600, the same year in which the first opera was given in Florence. The first development of the oratorio had the Passion of Christ for its subject, and the greatest passion music is the "St. Matthew," written for service on Good Friday, by Sebastian Bach, in 1729. The next form was the "epic," used by Handel in fifteen grand oratorios, the greatest of which are Israel in Egypt and the Messiah, and by Haydn in his Creation, and Mendelssohn in Elijah. The modern oratorio uses more of the dramatic element, and inclines to the form of a cantata, of which Liszt's St. Elizabeth and Schumann's Paradise and the Peri are fine examples. See Standard Oratorios, by Upton. Orcagna (or-kän-yä ), ANDREA DI CIONE, an Italian painter, sculptor, architect and poet. He was nicknamed Arcagnuolo (archangel), of which Orcagna is a corruption. He was born about 1316, in Florence, his father being a sculptor and worker in silver and his elder brother a painter. He was appointed architect of the Church of San Michel in Florence, in 1335, and his greatest work is the marble tabernacle of this church, which is considered one of the most beautiful art creations of Italy. He was also chief architect of the cathedral at Orvieto. The frescoes of the Last Judgment and Christ and the Virgin, in the Church of Santa Marie at ORCHIDS Florence, still survive as examples of his painting. His work was studied by succeeding painters, especially Michael Angelo and Raphael. He died either in 1368, 1376, or 1389. See Painting in Italy, by Crowe and Cavalcaselle. Orchardson, WILLIAM QUILLER, a Scotch painter, was born in 1835, in Edinburgh, where he studied art. He is considered to belong to the first rank of genre painters, that is the class of paintings whose subjects are taken from everyday life. His pictures are very popular and exquisitely finished. Among the best known are The Challenge, The Bill of Sale, Hard Hit, After, The Salon of Madame Recamier and Her Mother's Voice. Orchids (or'-kids), a class of plants, popularly known as air plants, because in warm countries they fasten themselves to trees or rocks, their roots not having any connection with the soil, and derive their nourishment from the air. In temperate regions they are herbs or shrubs growing in the ground. The flowers are very curious, one of the six petals, called the lip, assuming a great variety of shapes. They have, many of them, a curious resemblance to insects, as the butterfly orchid and the spider orchid, and there is one resembling a dove, and another the mouth of a cuttlefish. The colors are brilliant and the flowers are very fragrant. Found in almost all parts of the world, the family is very numerous, with about 334 classes, and 5,000 species. They are found wild in marshes and meadows in temperate regions, growing in the earth. In the forests of South America and Mexico, and in the West Indies, they are very abundant, growing on trees and stones and crags. The cultivation of orchids in Great Britain and America is becoming a favorite pursuit with flower lovers, though the prices obtained for the rarer kinds put them out of the reach of any but the wealthy. They are nearly all ornamental, the vanilla being almost the only exception. See Orchids, Their Culture and Management, by Watson. Ord, EDWARD OTHO CRESAP, an American general, was born in Cumberland, Maryland, Oct. 18, 1818. He served in the Seminole war in Florida, and on the frontiers, until the beginning of the civil war, when he became brigadier-general of volunteers, and was given a command of Pennsylvania reserves. In May, 1862, as major-general of volunteers, he was given a command in the department of the Mississippi, and took part in the battle of Iuka and the capture of Vicksburg. In 1865 he was in command of the army of the James, and the department of Virginia, and was in the battles that ended the war. After the war he became a brigadier-general in the regular army, had command of various departments, and retired in 1881 with the rank of majorgeneral. He died at Havanna, Cuba, July 22, 1883. Oregon, one of the Pacific states of the Union, and the twentieth admitted. It is divided into two unequal parts by the Cascade mountains, which are about 130 miles from the coast, while the coast-range is within 25 miles of the Pacific shore. The Cascade range rises 6,000 or 8,000 feet with high peaks, among them Mt. Hood (11,225), Mt. Jefferson (10,200), Mt. Pitt (11,000); all being extinct volcanoes. On the east are the Blue mountains and Powder river mountains, from 8,000 to 10,000 feet high. The state is 360 miles broad and 270 miles long, and is twice as large as England. There are 330 miles of coast, with a narrow strip of land and several fertile valleys. The part of the state west of the Cascade range is the most valuable, two-thirds of it being occupied by the Willamette valley, which is rich in farms and villages, where the crops never fail, and where half of the population and the wealth of the state are found. The eastern part of the state is very varied, having pasture lands and grazing grounds in the north, and in the south the Great Basin, an arid region larger than France, requiring OREGON irrigation to make it productive. Great beds of lava, plains covered with sage brush, rivers sinking away into shallow lakes or marshes and brackish lakes in which fish cannot live are the features of this region, which is crossed by the Stein mountains. Crater lake in the southwest of Oregon is one of the deepest fresh-water lakes in the world, and is formed by the snows filling an extinct crater. In the center rises Wizard island, 845 feet high, with an extinct crater at the top. A large area, including this lake, has been set aside as the Oregon National Park. Other lakes are the Upper and Lower Klamath lakes, Lake Harney and Lake Wallowa, 6,000 feet high, on the Blue mountains. The Columbia river is 1,200 miles long, one-fourth of it forming the northern boundary of Oregon. It is six miles wide at the mouth, and has a fall of 850 feet near the Cascade mountains, where the government is building a canal 3,000 feet long. The Willamette, 200 miles long, the Umpqua and the Rogue, Des Chutes, Umatilla, with the Snake river, on the eastern boundary, are other rivers of Oregon. The climate of the western part of Oregon is mild with an excessive rainfall. The climate is affected by the southwestern trade winds, the ocean currents from Japan, and the protection of the Cascade range, making it much warmer than regions in the same latitudes on the Atlantic coast. Eastern Oregon has very little rain, and is colder, though the Rocky mountains protect it from blizzards. Oregon has coal fields, iron ore, in veins from six feet to 15 feet thick, and mines of gold, silver, manganese and quicksilver. As an agricultural state, its largest crop is wheat, while oats, flax, rye, barley and buckwheat give large crops. The hop gardens employ large numbers of Chinese, and the prune orchards are among the best in America, while its apples and cherries are noted. Stock raising is an important industry, as cattle and sheep can be kept outdoors all winter. The Oregon pine and the red fir, making the finest of ship timber, with oak, cedar, hemlock, maple and ash trees, furnish material for its great lumber trade, while its rivers supply the large trade in salmon canning. The State University, founded in 1876, with a large national land grant; the State Agricultural College at Corvallis; Willamette University, with a college of arts, conservatory of music, and a woman's college, with its law and medical colleges at Portland; Pacific University at Forest Grove; the Indian training school near Salem, with 180 boys and girls from thirty different tribes; and many normal schools and academies, with a fine system of free schools, furnish the educational advantages of the state. Oregon was originally the name for all the land between Alaska and California, and was claimed by Spain, Russia, France, Great Britain and the United States. Spain ceded her rights in 1819, and Russia in 1821, and the Louisiana Purchase settled those of France. In 1811 Astoria was founded by John Jacob Astor, and from 1818 to 1846 the United States and Great Britain by treaty occupied the land together. In 1846 the boundary between the state and British America was fixed, and Oregon territory was formed in 1848, and in 1859 a part of it was made into the state of Oregon. Population, 313,767. Orellana (o-rel-yä'-na), FRANCISCO, a Spanish adventurer, was born in Trujello, Spain, about 1500. He went with Pizarro to Peru in 1535, sharing in the conquest of that country. In 1540, Pizarro while exploring the country east of the Andes, sent Orellana with sixty men in a boat down the river Napo after supplies. In three days Orellana reached the Amazon, and finding it difficult to return, sailed down the river to the sea, being the first European to sail on its waters. His journey occupied seven months, reaching the ocean in August, 1541. He reported in Spain that he had passed through a country inhabited only by women, who were warriors, and where gold was used to roof the houses. He obtained a grant of the land along the river, and sailed with four ships and 400 men, but lost his ships and his men, and died of fever after entering the Amazon, about 1550. Orestes (o-res'-teez), a Greek hero, the son of Agamemnon and Clytemnestra. His father was murdered by Clytemnestra and her lover Ægisthus, but Orestes was saved by his sister Electra, and brought up at the court of his uncle in Phocis. His cousin Pylades joined with him in his efforts to avenge his father's death, the pair going secretly to Argos and killing Clytemnestra and Ægisthus. But realizing that he had killed his mother, Orestes became mad, and fled from ORGAN land to land, pursued by the Furies. Learning from Apollo that he could be cured of his madness by bringing the statue of Diana from Tauris in Scythia to Athens, he and Pylades journeyed there but were seized to be sacrificed by the natives. The priestess Iphigenia recognized her brother in Orestes, and with her help they all escaped, carrying the statue with them. Orestes recovered his father's kingdom at Mycenæ, and married Hermione. The story of Orestes is a theme for the tragedies of Euripides, Sophocles and Eschylus. Organ, one of the largest musical instruments. It is a wind instrument having a large number of pipes, which produce the sounds on admission of air, which is carried to them by means of a bellows. It is played by keys and pedals. The most usual form of the organ is that seen in churches, which consists of four and sometimes five parts, each part being almost a separate instrument. These are called the great organ, the swell organ, the pedal organ, the choir organ, and the fifth part, when it exists, is called the solo organ. Each has its own keyboard, but they are brought close together so that one performer can reach them all. The pedal organ is played with the feet, while the other keyboards are reached by the hands. There is also a system of stops, within reach of the performer's hand, which closes or opens the pipes as the keys do. Organ pipes are made of metal and of wood. The ancient organs were worked by water, and were used in the Roman theaters, Nero being one of its earliest patrons. In the reign of Honorius, 400 A. D., no nobleman's house was complete without an organ, and small ones were carried by slaves from house to house. Constantinople was the great home of organ building in the ancient world, and the first organ built in medieval Europe was patterned after one brought by Byzantine ambassadors on a mission to Charlemagne. The use of the bellows in organs dates from the time of the Emperor Julian in the 4th century, though it did not come into general use until the end of the 9th century. The smallest organs ever built were made in the monasteries; they were called regals and could be held on the palm of the hand. The largest organs in England are those of the Royal Albert Hall, Alexandra Palace, Crystal Palace, St. Paul's Cathedral, London; St. George's Hall, Liverpool, and the Leeds town hall. Among the largest in the |