Part 30

ERITRE'A, or ERYTHRAE'A (from Gr. _erythros_, red, referring to the Red Sea), the official name of an Italian colonial possession stretching along the African shore of the Red Sea, and between it and Abyssinia, from the Egyptian coast territory to the French territory of Obok, at the Strait of Bab-el-Mandeb. The coast-line is about 670 miles in length, the area of the colony about 45,800 sq. miles. Pop., largely nomadic, about 450,000. The chief town is Massowah.

ER'IVAN, a fortified city in Armenia, formerly the capital of a Russian government of the same name in Transcaucasia, on the Sanga, north of Mount Ararat. It has a citadel, barracks, a cannon foundry, and some manufactures. The Armenian Republic of Erivan was constituted in May, 1918. Pop. 34,000. The former Russian government of Erivan had an area of 10,725 sq. miles, and a pop. of 970,000.

ERLANG'EN, a town of Bavaria, 10 miles N.N.W. of N[:u]rnberg. The Protestant university, founded in 1743, is the chief institution. The industries include cotton spinning and weaving, mirrors, hosiery, gloves, and combs. Pop. 24,874.

ERLAU, or EGER, a town, Hungary, on the Eger, 65 miles E.N.E. of Budapest. It has sundry manufactures; and the red wines of the district, esteemed the best in Hungary, are largely exported. Pop. 28,050.

ERL-KING, the English form of the name given in German and Scandinavian poetical mythology to a personified natural power which devises and works mischief, especially to children. Goethe's celebrated poem _Der Erlk[:o]nig_ (literally 'elf-king') has rendered this malicious spirit universally known.

ER'MINE, the stoat (_Putorius ermineus_), a mammal of the weasel family widely distributed through the northern parts of both hemispheres, with a considerable range to the south. It is not generally known that the ermine and stoat are the same. In winter, in cold countries or severe seasons, the fur changes from a reddish-brown to a yellowish-white, or almost pure white, under which shade the animal is recognised as the ermine. In both states the tip of the tail is black. Its fur is short, soft, and silky, the best skins being brought from Russia, Sweden, and Norway. It is in great request, and was formerly one of the insignia of royalty, and is still used by judges. When used as linings of cloaks the black tuft from the tail is sewed to the skin at irregular distances. Stoats are among the enemies of the poultry-keeper, but by keeping down small rodents they benefit agriculture to a considerable extent.--In heraldry, ermine is one of the furs, represented with its peculiar spots black on a white ground.

ERNE ([.e]rn), the name often given to all the eagles of the genus Haliaetus, but more specifically to the white-tailed sea-eagle.

ERNE, LOUGH, a lake, Ireland, County Fermanagh, consisting of a north or lower, and a south or upper lake (with the town of Enniskillen between), connected by a narrow winding channel, and properly forming only expansions of the River Erne. Its entire length is about 40 miles; average breadth, 6 miles. It contains numerous small islands, and is well stocked with fish.--The River Erne rises in Lough Gowna, in the county of Longford, flows through Loughs Oughter and Erne, and falls into Donegal Bay below Ballyshannon. Length, 72 miles.

ERNEST AUGUSTUS, King of Hanover and Duke of Cumberland, the fifth son of George III, born 1771, died 1851. In 1799 he was created Duke of Cumberland, in England, and became a field-marshal in the British army. On the death of William IV in 1837 he ascended the throne of Hanover, in consequence of the succession to the sovereignty of that country being limited to heirs male. He was succeeded by his son, George V, the last of the Hanoverian kings.

EROS, an asteroid discovered in Aug., 1898. It completes its orbit in 642 days, and has a mean distance from the sun of 135-1/2 million miles, or 6 million less than that of Mars, and was the first to be discovered of the class of minor planets which come within the orbit of Mars. It can approach at times to 13-1/2 million miles from the earth. It is supposed to have a diameter of 20 miles or less.

EROSION THEORY, in geology, the theory, now held by all geologists, that valleys are, in the great majority of cases, due to the wearing influences of subaerial agents, such as rivers and glaciers, as opposed to the theory which regards them as the result of fissures in the earth's crusts produced by strains during its upheaval.

EROT'IC (from the Gr. _er[=o]s_, love), relating to love.--_Erotic poetry_, amatory poetry.--The name of _erotic_ writers has been applied, in Greek literature, particularly to a class of romance writers, and to the writers of the _Milesian Tales_.

ERRAT'ICS, OR ERRATIC BLOCKS, in geology, boulders or large masses of angular rock which have been transported to a distance from their original positions by the action of ice during a glacial period. Thus on the slopes of the Jura Mountains immense blocks of granite are found which have travelled 60 miles from their original situation. Similarly, masses of Scottish and Lake-district granites and of Welsh rocks (some of which weigh several tons) occur not uncommonly in the surface soil of the Midland counties of England.

ERROMAN'GO, OR ERROMAN'GA, one of the more important of the New Hebrides Islands, with an area of about 400 sq. miles, hilly and not very fertile, but with spots well cultivated. Several missionaries have been murdered by the natives--including the missionary John Williams--but perhaps half of the 2500 natives are now Christians.

ERRORS OF OBSERVATION. In scientific measurements, objects and instruments alike are so constituted that numerical results can only be approximate. We have to find the value of some quantity, not exactly, but to so many significant figures. Even so, when a number of measurements are made of the same quantity, it regularly happens that different values are obtained, the difference between a value as obtained and the true value being called an _error of observation_. It remains to combine the various measurements in such a way as to obtain the best result which they are capable of yielding.

The usual method is to take the arithmetic mean of the values obtained as the correct value. It is also customary in careful work to state the average deviation of the observed values from the mean. For example, various experimenters found the following numbers for the charge on an electron: 4.67, 4.77, 4.65, 4.79, 4.69. Here the _mean_ is 4.71, and the average _deviation_ from the mean, taken without regard to algebraic sign, is .05. The final result is stated as 4.71 +/- .05. The ambiguous term +/- .05 is sometimes called the probable error. The smaller the probable error, the more reliable is the mean result.

A case of much practical importance occurs when the results obtained by two distinct methods differ by greater amounts than can be accounted for by the uncertainty of either result. In this case there must be a _constant error_ present in at least one of the sets of measurements. Recognition of a constant error has occasionally led to an important discovery; for instance, the hint which led to the detection of argon in the atmosphere came from the observed discrepancy in the densities of atmospheric nitrogen and nitrogen from ammonia.

In many measurements what is sought is not the value of a single quantity, but the relation between the values of two variable quantities. In such cases graphical methods are of great service. Corresponding values of the two variables are found and plotted; and a smooth curve, or it may be a straight line, is drawn to lie as evenly as possible among the plotted points. Where great accuracy is wanted, analytical methods are also available. See _Squares, Method of Least; Probability_.

ERSCH (ersh), John Samuel, German bibliographer, born 1766, died 1828. He was principal librarian and professor of geography and statistics at Halle. Among his publications are: a _Dictionary of French Writers_; a _Manual of German Literature_; and, in connection with Gruber, the _Universal Encyclopaedia of Arts and Sciences_.

ERS'KINE, Ebenezer, the founder of the Secession Church in Scotland, born 1680, died 1754. He studied at Edinburgh, and was ordained minister of Portmoak, in Fife, in 1703, in which situation he continued for twenty-eight years, when he removed to Stirling. His attitude towards patronage and other abuses in the Church led to his being deposed, when, in conjunction with his brother and others, he founded the Secession Church. Erskine was the leader of the Burghers (q.v.). He is the author of several volumes of sermons.

ERSKINE, The Hon. Henry, Scottish barrister, was the third son of Henry David, tenth Earl of Buchan: born at Edinburgh 1746, died 1817. After studying at the Universities of St. Andrews, Edinburgh, and Glasgow, he adopted the legal profession, and in 1768 was called to the Bar. He twice held the office of Lord-Advocate, was for long the leader of the Scottish Bar, and held a high reputation as a wit.

ERSKINE, John, of Carnock, afterwards of Cardross, Scottish jurist, born 1695, died 1768. He was called to the Scottish Bar in 1719, and was author of _Principles of the Law of Scotland_, and the _Institutes of the Law of Scotland_, both works of authority.

ERSKINE, Ralph, brother of Ebenezer Erskine, born 1685, died 1752. He was ordained to the parish of Dunfermline in 1711, and in 1737 joined his brother, who had seceded from the Established Church. His _Gospel Sonnets_ and other religious works were once very popular.

ERSKINE, Thomas, Lord Erskine, Scottish lawyer, the youngest son of the tenth Earl of Buchan, was born in 1750, and died in 1823. He was educated partly at the High School of Edinburgh, and partly at the University of St. Andrews. After serving four years in the navy and seven in the army, he commenced the study of law, and in 1778 both took his degree at Cambridge and was called to the Bar. His success was immediate. In May, 1783, he took silk, and the same year was elected member of Parliament for Portsmouth, a seat he held (except from 1784-90, when he had no seat) till 1806, when he was raised to the peerage. The rights of juries he firmly maintained on all occasions, but particularly in the celebrated trial of the Dean of St. Asaph for libel. In 1789 he defended Stockdale, a bookseller, for publishing what was charged as a libellous pamphlet in favour of Warren Hastings. In 1792, being employed to defend Thomas Paine, when prosecuted for the second part of his work _The Rights of Man_, he declared that, waiving all personal convictions, he deemed it right, as an English advocate, to obey the call: by the maintenance of which principle he lost his office of Attorney-General to the Prince of Wales. In the trials of Hardy, Tooke, and others for high treason in 1794, which lasted for several weeks, the ability displayed by Erskine was acknowledged by all parties. He was a warm partisan of Fox, and a strenuous opposer of the war with France. In 1802 the Prince of Wales not only restored him to his office of Attorney-General, but made him Keeper of Seals for the Duchy of Cornwall. On the death of Pitt, in 1806, Erskine was created a peer, and raised to the dignity of Lord Chancellor. During his short tenure of office the Bill for the abolition of slavery was passed. After he retired with the usual pension, he took little part in politics.

ERUPTIVE ROCKS, in geology, those which, as lavas, have broken through other rocks while in a molten state, and become eruptive at the surface.

ERVUM. See _Lentil_.

ERYNGIUM, a genus of plants belonging to the nat. ord. Umbelliferae. There are upwards of 100 species found in temperate and sub-tropical climates, but chiefly in South America. _E. marit[)i]mum_, also called sea-holly, is the only truly native British species. It frequents sandy shores, and is distinguished by its rigid, spiny, glaucous, veined leaves, and its dense heads of blue flowers. The roots are sometimes candied, and are reputed to be stimulating and restorative, as well as to have aphrodisiac properties. It is mentioned by Shakespeare, _Merry Wives_, v. 5, 23, as an aphrodisiac.

ERYSIP'ELAS, ROSE, or ST. ANTHONY'S FIRE, is a contagious disease of the skin due to infection by a germ, the Streptococcus, and accompanied by severe general disturbance. Cold, damp weather favours its appearance. It rarely affects those under fifteen years, and is commoner in women than men. The disease is characterized by sudden onset, with shivering, headache, vomiting, and occasionally sore throat, followed by the appearance of the typical erysipelatous flush on the skin of the affected part, most usually the face. This part becomes deep red, and is much swollen, with a glossy, tender surface. It is definitely raised, and has a spreading edge merging into the normal parts around. In extreme cases there is marked disfigurement. Local treatment to allay pain and prevent spreading is by the application of lotions and ointments, and general treatment in the form of stimulating foods is given to maintain strength. Serum treatment has been used, but so far there have been very conflicting results. The disease is not so common nor so fatal as previously.

ERYSIPHA'LES, an important family of ascomycetous Fungi, distinguished by the presence of typical sexual organs and closed ascus-fruits (_cleistocarps_) which bear characteristic appendages concerned with dispersal; also by the fact that each segment of the septate mycelium contains a single nucleus. They are all parasites, appearing on leaves, stems, or fruits as white patches of mycelium ('mildew'). During summer innumerable conidia are produced, which spread the disease rapidly; in autumn the black ascus-fruits develop and carry the fungus through the winter. Erysiphales are responsible for many important plant-diseases, e.g. the mildew of hops (_Sphaerotheca Castagnei_), vine (_Uncinula spiralis_), wheat (_Erysiphe communis_), and the American gooseberry mildew (_Sphaerotheca Mors-uvae_), a 'notifiable' disease in Britain.

ERYTHE'MA is redness of the skin, and in this sense is applied to a number of general conditions which bring about redness of the skin, e.g. abscess, oedema, scarlet fever, &c. Of late, in medicine, its use has been more restricted, and refers only to an inflammation of part of the skin. This disease is characterized by redness and tenderness, and may become sufficiently severe to lead to the production of bullae in the centre of the affected part. Dermatologists recognize various types of erythema.

ERYTHRAE'AN SEA, in ancient geography, a name given to what is now called the Indian Ocean, but including the Persian and Arabian Gulfs. The name was eventually restricted to the Arabian Gulf.

ERYTHRI'NA. See _Coral Tree_.

ERYTHRO'NIUM. See _Dog's Tooth Violet_.

ERYTHROPHLOE'UM, a genus of tropical trees, nat. ord. Leguminosae, containing three species, two found in Africa and the third in Australia. The _E. guineense_ of Guinea has a poisonous juice, which is used by the natives as a test of innocence and guilt, hence the name 'ordeal tree'.

ERYX, an ancient city and a mountain in the west of Sicily, about 2 miles from the sea-coast. The mountain, now Monte San Giuliano, rises direct from the plain to a height of 2184 feet. On the summit anciently stood a celebrated temple of Venus. All traces of the ancient town of Eryx have now disappeared, and its site is occupied by the modern town of San Giuliano.

ERZBERGER, Matthias, German politician, born at Buttenhausen in 1875. Educated at Freiburg, where he studied political economy, he took an interest in 1897 in the Christian Socialist movement, and entered the Reichstag as a member of the Centre or Catholic party. He became prominent in 1917, when he accused the German Government of misrepresenting the military situation, and urged for a statement of Germany's peace aims. Secretary of State in 1918, he became Minister of Finance in 1919 in Bauer's Cabinet, but was compelled to resign in 1920. He was murdered on 26th Aug., 1921, by two young men of the militarist party.

ERZERUM, ERZEROUM, or ERZEROOM (er'ze-r[:o]m), a city of Armenia, formerly the capital of a Turkish vilayet with an area of 27,000 sq. miles, and a pop. of 582,745. The town is about 6000 feet above sea-level, and forms an important strategical centre. It is irregularly built, its narrow dirty streets, flanked by mean houses, being crowded together in the small space enclosed by its lofty walls. The Moslem element prevails largely over the Christian, although it is the metropolis of the Armenian Church in union with Rome. In addition to important manufactures, especially in copper and iron, it carries on an extensive trade, and is a chief halting-place for Persian pilgrims on their way to Mecca. The town was captured by the Russians in Feb., 1916, and recaptured by the Turks in March, 1918. Pop. (before the European War), about 80,000.

ERZGEBIRGE (erts'ge-bir-ge; 'Ore Mountains'), a chain of European mountains forming a natural boundary between Saxony and Bohemia, nearly 120 miles in length and 25 miles broad. The highest summits, which are on the side of Saxony, rise to 3800 or 3900 feet. The mountains are rich in silver, iron, copper, lead, cobalt, and arsenic.

ESARHAD'DON (Assyr. _Asur-akhi-iddina_, Asur has given a brother), the son of Sennacherib, and one of the most powerful of all the Assyrian monarchs. He extended the empire on all sides, and is the only Assyrian monarch who actually reigned at Babylon. He died about 667 B.C.

E'SAU, the eldest son of Isaac, and twin-brother of Jacob. His name (which signifies rough, hairy) was due to his singular appearance at birth, being "red, and all over like an hairy garment". The story of his losing the paternal blessing through the craft of Rebekah and Jacob, with other facts, is told in _Genesis_, xxvii. He was the progenitor of the Edomites.

ESBJERG, a Danish seaport in South-West Jutland, opposite the Island of Fan[:o]. Pop. 18,000.

ESCALLONIA, a genus of saxifragaceous shrubs and trees, natives chiefly of the Andes. _E. rubra_ is a handsome evergreen shrub, with shiny, resinous, aromatic leaves, and fine pink flowers; it is hardy in many parts of Britain, and makes an excellent hedge, especially near the sea, where it bears the salt-laden winds without damage.

ESCAPE'MENT, the general contrivance in a timepiece by which the pressure of the wheels (which move always in one direction) and the vibratory motion of the pendulum or balance-wheel are accommodated the one to the other. By this contrivance the wheelwork is made to communicate an impulse to the regulating power (which in a clock is the pendulum and in a watch the balance-wheel), so as to restore to it the small portion of force which it loses in every vibration, in consequence of friction and the resistance of the air. The leading requisite of a good escapement is that the impulse communicated to the pendulum or balance-wheel shall be invariable, notwithstanding any irregularity or foulness in the train of wheels. Various kinds of escapements have been contrived, some of which are shown in the accompanying figure. See _Clock_; _Watch_.

ES'CAR, or ESKER, a geological formation in the superficial drift, generally consisting of a long linear ridge of sand and gravel, sometimes including blocks of considerable size. The materials are derived from the waste of till or boulder-clay, and their arrangement took place probably in water flowing in channels beneath ice-sheets, the escar becoming exposed as the ice finally melted away. In Sweden escars have been formed, season by season, at the mouths of glacier-tunnels as the ice shrank back, the ice-front opening on a lake. See _Kames_.

ESCHAR (es'k[.a]r), a slough or portion of dead or disorganized tissue. The name is commonly applied to the crust or scab occasioned on the skin by burns or caustic applications.

ESCHATOL'OGY (es-ka-; Gr. _eschatos_, last, and _logia_, account), in theology, the 'doctrine respecting the last things', which treats of the millennium, the second advent of Christ, the resurrection, judgment, conflagration of the world, and the final state of the dead.

ESCHEAT (es-ch[=e]t'), in law, a species of reversion arising from default of heirs. Lands, if freehold, escheat to the king or other lord of the manor; if copyhold, to the lord of the manor. By modern legislation there can be no escheat on failure of the whole blood wherever there are persons of the half-blood capable of inheriting.

ESCHENBACH (esh'en-b[.a]_h_), Wolfram von, German mediaeval poet or minnesinger, flourished in the first half of the thirteenth century. The most esteemed of his numerous works are: _The Parzival_ (printed 1477); _The Titurel_, or _The Guardian of the Graal_ (printed 1477); and _The Willehalm_, a poem on the deeds of William of Orange, a contemporary of Charlemagne.

ESCHSCHOLTZIA (esh-sholt'si-a), a small genus of glabrous whitish plants, of the poppy order, natives of California and the neighbouring regions. They have divided leaves, and yellow peduncled flowers. The sepals cohere and fall off as the flower opens in the form of a cap. They are now common in the gardens of Great Britain.

ESCHWEGE (esh'v[=a]-ge), a town of Prussia, province of Hesse-Nassau, on the Werra, 26 miles E.S.E. of Cassel. Pop. 12,540.

ESCHWEILER (esh'v[=i]-l[.e]r), a town of Prussia, in the province of Rheinland, 9 miles E.N.E. of Aix-la-Chapelle, on the Inde. It is the seat of large and varied manufacturing industries, especially in iron, copper, and zinc, and has coal-mines. Pop. 24,718.

ESCOBAR Y MENDOZA (es-ko-b[:a]r' [=e] men-_d_o'-th[.a]), Antonio, a Spanish casuist and Jesuit, born 1589, died 1669. His principal works are: _Summula Casuum Conscientiae_, and several scriptural commentaries. His casuistry was severely criticized by Pascal in his _Lettres Provinciales_, and the extreme laxity of his moral principles was ridiculed by Boileau, Moli[`e]re, and La Fontaine.

ESCROW', a legal writing delivered to a third person to be delivered by him to the person whom it purports to benefit, when some condition is performed. Upon the performance of this condition it becomes an absolute deed, but if the condition be not performed, it remains an _escrow_ or scroll.