height of fifty or sixty feet, but the wood is reddish, coarse-grained, and little esteemed. The staves which it furnishes are classed as red oak staves, being fit only to contain flour, molasses, salted provisions, and dry wares.-The barrens, or Black Jack oak (Q. nigra), is remarkable for the shape of the leaves, which are narrow at the base and dilated at the summit, frequently resembling the outline of a pear. It grows in a barren soil, together with the post oak above mentioned, and abounds chiefly in the same districts, viz. southern New Jersey, Delaware, and eastern Maryland and Virginia. It is a small tree, but affords excellent fuel, which is sold at Philadelphia at little less than hickory. The Spanish oak (Q. falcata) is a large tree, inhabiting, generally, all those parts of the Union which are south of the forty-first parallel of latitude, but most abundant in the Atlantic states. The leaves are deeply divided, and the lobes are acute, and terminated by a short bristle, as in all the following American species. It may, in general, be distinguished from allied species by the narrowness of these leaves and their falcate lobes, but they vary much in form, and are sometimes entire, with a three-lobed summit. The wood is reddish and coarse-grained, and furnishes "red oak" staves, of rather superior quality, but not so much so as to produce any difference in the price. The Spanish oak is chiefly valued on account of the bark, which, for tanning, is more highly esteemed than that of most others, and is sold at Philadelphia one fourth dearer. Coarse leather is rendered by it whiter and more supple; and its quality is said to be improved by the addition of a small quantity of hemlock bark, which is imported from Maine for that purpose. The black or quercitron oak (Q. tinctoria) is a large tree, found throughout the U. States south of latitude 43°, and abundant in the Middle States. It is most easily recognised by the yellow stain which it gives to the saliva on being chewed. The wood is reddish and coarse-grained, and is frequently substituted for white oak in building. It furnishes a large proportion of the red oak staves which are exported to the West Indies, and the bark is extensively employed in tanning. From the cellular integument quercitron is obtained -an article extensively employed in dyeing wool, silk, and paper hangings, and which forms an important article of export to Europe. This branch of business is chiefly carried on at Philadelphia.-The scarlet oak (Q. coccinea) is most abundant

in the Middle States, and on the mountains of Carolina and Georgia, but is found as far north as latitude 43°. The leaves are deeply laciniated, and, on the first frosts, change to a bright red color. It is a large tree, but the wood is principally used for staves. The bark is very thick, and is employed in tanning.-The red oak (Q. rubra) is easily known by its large shallow cups. It is a more northern species than any of those above mentioned, being most common in Canada and the northern parts of the U. States. It is, however, not unfrequent in the Middle States, and throughout the whole range of the Alleghanies. It grows to a large size, and the wood is similar to that of the Spanish, black and scarlet oaks, but, if any thing, inferior. The bark is employed in tanning, and the wood chiefly for staves.Among the more interesting of the exotic oaks is the cork oak (Q. suber), which furnishes the cork of commerce. This substance is the outer, thick, fungous cov ering of the bark, and is detached, at intervals of ten or twelve years, for as many as twelve or fifteen times, but, after the fifth or sixth, the quality degenerates. If not removed after a certain period, it splits and falls off, and is replaced by a new growth beneath. In some countries, where cork is abundant, the inhabitants use it for lining or covering their houses, and for a great variety of uses unknown in this country, where it bears an excessive price. When burnt in close vessels, a black pow der is obtained, which is employed in the arts, and is known under the name of Spanish black. The cork oak is a native of the countries about the Mediterranean, and is, besides, cultivated in Spain, Portugal, and the south of France. It is best adapted to a dry, sandy, mountainous soil, and is never found in limestone districts. Its introduction into the U. States has been warmly recommended.-The oak (Q. coccifera) is a tortuous, branching shrub, inhabiting the same countries as the preceding. This species is only worthy of notice from its being fed upon by the coccus ilicis, a little insect resembling in form a red berry, which furnishes a scarlet dye. These berries were formerly an article of considerable commerce, but they are now superseded by the cochineal, which indeed is an insect of the same genus.-The Q. infectoria, likewise a tortuous, branching shrub, is pierced by an insect of a different family, by which means the excrescences called in commerce gallnuts are produced. It grows wild in Syria, Persia, and throughout all Asia Minor.

Kermes

1

The common European oak (Q. robur) is a tree of the first consequence, on account of the qualities of its wood. The leaves resemble, in form, those of our white oak. It attains the height of from 60 to 100 feet, with a trunk 6 to 12, or more, in circumference. The wood is superior, in solidity and durability, to any other in Europe, and is employed for a vast variety of purposes, and, above all, for ship-building; indeed, it is the chief reliance of the European navies, Before the introduction of mahogany, it was very generally used for furniture, and, besides, furnishes the best fuel. Except in the north of Russia, the bark is exclusively employed, throughout Europe, for tanning; and that from the small branches is preferred, because the epidermis is thinner, and the cellular integument, which contains the tannin, is more abundant. In ancient times, the acorns formed an important article of nutriment to some of the northern nations, and, among others, to the former inhabitants of Great Britain. As the timber is superior to that of any American species (the live oak excepted), and the tree, moreover, flourishes in a northern climate, its introduction into our forests cannot be too strongly recommended.

OAKUM; the substance into which old ropes are reduced when they are untwisted, loosened, and drawn asunder. It is principally used in calking the seams, tree-nails and bends of a ship, for stopping or preventing leaks.

OAR; a long piece of timber, flat at one end, and round or square at the other, used to make a vessel advance upon the water. The flat part, which is dipped into the water, is called the blade, and that which is within the board is termed the loom, whose extremity, being small enough to be grasped by the rowers, is called the handle. To push the boat or vessel forwards by means of this instrument, the rowers turn their backs forwards, and, dipping the blade of the oar in the water, pull the handle forward, so that the blade, at the same time, may move aft in the water. But since the blade cannot be so moved without striking the water, this impulsion is the same as if the water were to strike the blade from the stern towards the head: the vessel is therefore necessarily moved according to the direction. Hence it follows, that she will advance with the - greater rapidity, by as much as the oar strikes the water more forcibly; consequently, an oar acts upon the side of a boat or vessel like a lever of the second class, whose fulcrum is the station upon

which the oar rests on the boat's gunwale.

OASIS (Coptic, an inhabited place); a fertile spot, situated in the midst of the uninhabitable deserts of northern Africa: the name is also applied to a cluster of verdant spots. They serve as stoppingplaces for the caravans, and often contain villages. In the desert of Sahara there are thirty-two of these regions, which contain fountains, and date and palm trees: twenty of them are inhabited. Those of the Libyan desert are the following:-the Great Oäsis, of which the principal town is El Kargeh; it consists of a number of insulated spots, extending, for about a hundred miles, in a line parallel with the Nile; it is the first stage of the Darfour caravan, and it contains interesting ruins :

the Little Oäsis, or that of El Wah, or El Kassar, of which the best account has been given by Belzoni; the Northern Oäsis, or that of Siwah (29° 12′ N.; lon. 26° 6′ E.), inhabited by a population of about 8000 souls, and supposed by some to contain the ruins of the temple of Jupiter Ammon:the Western Oasis (lat. 20° N.), first visited by Edmondstone, in 1819, is composed of 12 villages.-See his Journey to the Oases of Upper Egypt (London, 1823); see, also, the Travels of Browne,Henniker, and Caillaud.

OAT (avena). The species most commonly cultivated is the A. sativa, a grass, bearing a few large flowers, which are disposed in a loose panicle, frequently inclined in one direction. The calyx consists of two valves, enclosing several florets, bearing on their outer valves a twisted awn. The seed is oblong and pointed at each extremity. Another species, the naked oat (A. nuda), differing only in not having the seed adherent to the floral valves, and perhaps only a variety, is also frequently cultivated. The native country of these two species, like that of our other cultivated grains, is entirely unknown. They succeed only in cold and moist climates, and the seed is employed indifferently for the same purposes. The meal is nutritious, and, in some countries, forms an important article of food; but the bread made of it is rather indifferent in quality, and somewhat bitter. Beer is made from this grain in Britain and Poland; and it is, besides, distilled to procure ardent spirits. Oats are the best food for horses, and for this purpose are principally cultivated. They are also recommended as a good winter fodder for sheep, a handful to be given daily.

OATES, Titus. This infamous character was born about 1619. He was the son

of an Anabaptist preacher, and was educated at Merchant Tailors' school, whence he removed to Cambridge, and afterwards took orders. In 1677, he pretended a conversion to the Roman Catholic religion, and was admitted into the society of Jesuits; but subsequently declared himself a Protestant, and, in conjunction with one doctor Tonge, gave information of a pretended popish plot, for the destruction of the Protestant religion, and falsely accused the Catholic lords Petre, Powis, Bellasis, Arundel of Wardour, and other persons of quality, of being concerned in the conspiracy, several of whom, including lord Stafford, were executed. Such was the credulity of the times, that he was rewarded with a pension of £1200 per annum, and lodged, for safety, at the palace of Whitehall. On the accession of James II, however, he was thrown into prison, and indicted for perjury; and, being convicted, was sentenced to stand in the pillory five times a year during his life, and to be whipped from Aldgate to Newgate, and thence to Tyburn; the last part of which sentence was executed with great severity. At the revolution, the current of popular prejudice again setting in his favor, he was rewarded with a pension of £1000 per annum. In 1698, he sought to be restored to the congregation of Anabaptists, to which he had at first belonged; but in the course of a few months he was excluded, as a hypocrite and disorderly person. He died in 1705. In early life, he had been chaplain on board the fleet, from which he was dismissed for unnatural practices. (See Popish Plot.)

OATH (in Latin, jusjurandum, juramentum); a solemn assertion or promise, with the invocation of God to be a witness of the truth of what we say; hence the end of the English and American judicial oath "So help me God." Such an invocation is of very early origin, it being the most natural and solemn confirmation of the truth of what is said. Some sects consider oaths altogether as a violation of the command of Christ, "Swear not at all;" but this is not the proper place to discuss that point; the reader will find it treated in many works on moral philosophy, for instance, Paley's. Such a solemn invocation, however, should obviously be reserved for important occasions. The custom-house oaths, so numerous in England and the U. States, can hardly fail to diminish the character of sacredness and obligation belonging to such a promise. The obligation of an oath is variously

considered by different religions and sects: some consider oaths binding even if the promise be, in itself, criminal, or has been extorted by extreme fear. The Greeks connected the idea of awful solemnity with an oath. In the middle ages, oaths were enormously abused, and, at the same time, most superstitiously observed. In that period, oaths were often obtained by fraud, and the promiser, nevertheless, considered himself absolutely bound by them. William the Conqueror, when he made his prisoner Harold swear to aid him in ascending the throne of England, "secretly conveyed under the altar, on which Harold agreed to swear, the reliques of some of the most revered martyrs; and, when Harold had taken the oath, he showed him the reliques, and admonished him to observe, religiously, an engagement which had been ratified by so tremendous a sanction."—(Hume, vol. i.) The pope is believed, by the Catholics, to have authority to absolve from the obligation of an oath; and this is a natural consequence of the papal attributes. In the middle ages, this gave him a fearful power.-In civil law, oaths are divided into two classes: 1. oaths by which something is asserted as true (juramentum assertorium), either because we know it from our own observation (juramentum veritatis), or because we consider it true after full investigation, or, at least, have no reason to doubt the fact (juramentum credulitatis seu ignorantia). Most oaths, in the forms of judicial process, are juramenta assertoria; for instance, the oath of a party that he has good cause to ask a delay of trial; also the oath offered by one party to the other, for the settlement of a fact in dispute (juramentum delatum: and the oath of valuation, by which a party asserts that he estimates the damage which he has suffered at such a rate. 2. The second class of oaths are the juramenta promissoria, by which we promise something: such are the oaths of princes to rule constitutionally, or to protect such a sect or interest, &c.; the oath of alleg ance; the oath of office; the oath of witnesses, if they take an oath before testifying. Oaths to perform illegal acts do not bind, nor do they excuse the performance of the act. Perjury is the wilful violation of an oath administered by a lawful authority to a witness in a judicial proceeding. The breach of a promissory oath, whether public or private, is not punishable as perjury.

OAXACA; formerly, an intendancy in the viceroyalty of New Spain; at present,

one of the states of the Mexican confederacy, comprising the greater part of the isthmus of Tehuantepec, between the gulf of Mexico and the Pacific ocean. It has the state La Puebla on the west, that of Vera Cruz and that of Tabasco on the east. The climate is healthy, and the soil fertile. The finest fruits, cotton, sugar, indigo and wine, are among the productions. The mulberry tree was formerly extensively cultivated, and silk was produced in large quantities; but the natives, exasperated by the treatment of the Spaniards, extirpated it. Gold and silver abound. The cochineal plant thrives here better than in any other part of Mexico. The capital, of the same name, a handsome city, with 24,000 inhabitants, 65 miles from the Pacific, is situated in a delightful valley. The population of the state is about 600,000.

OBADIAH, OF ABDIAS; one of the twelve minor prophets, who foretells the speedy ruin of the Edomites. The time when he lived is uncertain. Some have supposed him to be the same person as the Obadiah who preserved 100 prophets from the fury of Jezebel; but he probably flourished at a much later period.

OBEAH; a species of witchcraft practised among the negroes, the apprehension of which, operating upon their superstitious fears, is frequently attended with disease and death.

OBELISK (Beλokos, and oßeλos). Obelisks belong to the oldest and most simple monuments of Egyptian architecture, and are high four-sided pillars, diminishing as they ascend, and terminating in a small pyramid. Herodotus speaks of them, and Pliny gives a particular account of them. The latter mentions king Mesphres, or Mestres, of Thebes, as the first builder of obelisks, but does not give the time; nor is this king noticed either by Herodotus or Diodorus. It is probable that these monuments were first built before the time of Moses, at least two centuries before the Trojan war. There are still several obelisks in Egypt: there is one erect, and another fallen, at Alexandria, between the new city and the light-house; one at Matarea, among the ruins of old Heliopolis; one in the territory of Fajum, near ancient Arsinoë; eight or ten among the rains of Thebes; the two finest at Luxor, at the entrance of the temple, &c. These obelisks, exclusively of the pedestals, are mostly from 50 to 100 feet high, and of a red polished granite (sienite); a few of the later ones are of white marble and other kinds of stone. At their base, they com

monly occupy a space of from 4 to 12 feet square, and often more. Some are adorned on all sides, and some on fewer, with hieroglyphics cut in them, sometimes to the depth of two inches, divided into little squares and sections, and filled with paint: sometimes they are striped with various colors. Some are entirely plain, and without hieroglyphics. The foot of the obelisk stands upon a quadrangular base, commonly two or three feet broader than the obelisk, with a socket, in which it rests. They were commonly hewn out of a single stone, in the quarries of Upper Egypt, and brought on canals, fed by the Nile, to the place of their erection. Several learned men have doubted this, and others have sought to prove it; but, according to the accounts of travellers, there are still to be found, in Upper Egypt, old quarries with obelisks already hewn out, or with places whence monuments of this form must evidently have been taken. Of their origin we know. nothing with certainty. Perhaps the first images of the gods, which, at an early period, were nothing but stones of a pyramidal form, gave occasion to them. Thus the ancient image of Venus, at Paphos, was a pyramid of white marble. According to Herodotus, they were first raised in honor of the sun, and meant to represent its rays. This is confirmed by their name and their form. They might also have been raised to perpetuate the memory of certain events, since the hieroglyphics contained the praises of their gods and their kings, or inscriptions relating to their religious notions. It is not probable that they were intended for sundials, because their point did not throw a distinct shadow. They were afterwards, however, used for that purpose, and balls were placed upon the points of some, as was the case with that which Augustus had brought to Rome, and which he placed in the field of Mars, under the direction of the astronomer Manilius, in such a position that it could be used for a dial. It is well known that, among the ancient Egyptians, they made a principal ornament of the open squares and the temples, before the large gates of which two or more were commonly placed. For this purpose, they used only obelisks of considerable height. After the conquest of Egypt by the Persians, no more were erected, and the successors of Lagus adorned Alexandria with the obelisks of the ancient kings. The Roman emperors carried several of them from Egypt to Rome, Arles and Constantinople, most of