diff options
Diffstat (limited to '34878.txt')
| -rw-r--r-- | 34878.txt | 18235 |
1 files changed, 18235 insertions, 0 deletions
diff --git a/34878.txt b/34878.txt new file mode 100644 index 0000000..60486fb --- /dev/null +++ b/34878.txt @@ -0,0 +1,18235 @@ +The Project Gutenberg EBook of Encyclopaedia Britannica, 11th Edition, +Volume 8, Slice 9, by Various + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 9 + "Dyer" to "Echidna" + +Author: Various + +Release Date: January 8, 2011 [EBook #34878] + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK ENCYCLOPAEDIA BRITANNICA *** + + + + +Produced by Marius Masi, Don Kretz and the Online +Distributed Proofreading Team at http://www.pgdp.net + + + + + + + + + +Transcriber's notes: + +(1) Numbers following letters (without space) like C2 were originally + printed in subscript. Letter subscripts are preceded by an + underscore, like C_n. + +(2) Characters following a carat (^) were printed in superscript. + +(3) Side-notes were relocated to function as titles of their respective + paragraphs. + +(4) Macrons and breves above letters and dots below letters were not + inserted. + +(5) dP stands for the partial-derivative symbol, or curled 'd'. + +(6) [oo] stands for the infinity symbol, and [int] for the integral + symbol. + +(7) Letters followed with a grave accent "`" have originally dots above. + +(8) The following typographical errors have been corrected: + + ARTICLE DYER, JOHN: "His poems were collected by Dodsley in 1770, + and by Mr Edward Thomas in 1903 for the Welsh Library, vol. iv." + 'poems' amended from 'peoms'. + + ARTICLE EAR: "The membranous semicircular canals are very much + smaller in section than the bony; in the ampulla of each is a + ridge..." 'the' amended from 'tbe'. + + ARTICLE EARTH, FIGURE OF THE: "O. Callandreau, 'Memoire sur la + theorie de la figure des planetes,' Ann. obs. de Paris (1889);..." + 'Callandreau' amended from 'Callendreau'. + + ARTICLE EATON, THEOPHILUS: "In October 1639 a form of government + was adopted, based on the Mosaic Law, and Eaton was elected + governor..." 'Mosaic' amended from 'Mosiac'. + + ARTICLE ECCLESIASTES: "A particular instance is mentioned (ix. + 13-15) of a beleaguered city saved by a wise man; but the man + happened to be poor, and no one remembered him." 'beleaguered' + amended from 'beleagured'. + + ARTICLE ECCLESIASTES: "Such assertions as those of ii. 26 (God + gives joy to him who pleases him, and makes the sinner toil to lay + up for the latter),..." 'and' amended from 'amd'. + + ARTICLE ECCLESIASTES: "This disagreement comes largely from the + attempts made to find definitely expressed Greek philosophical + dogmas in the book; such formulas it has not, but the general air + of Greek reflection seems unmistakable. The scepticism of Koheleth + differs from that of Job in quality and scope..." 'the' originally + repeated twice. + + ARTICLE ECCLESIASTICAL JURISDICTION: "In the first case, they may + be punished by the ordinary of the place, acting as delegate of the + pope without special appointment (Conc. Trid. Sess. vi. c. 3)." + 'special' amended from 'speical'. + + + + + ENCYCLOPAEDIA BRITANNICA + + A DICTIONARY OF ARTS, SCIENCES, LITERATURE + AND GENERAL INFORMATION + + ELEVENTH EDITION + + + VOLUME VIII, SLICE IX + + Dyer to Echidna + + + + +ARTICLES IN THIS SLICE: + + + DYER, SIR EDWARD EAST LIVERPOOL + DYER, JOHN EAST LONDON + DYER, THOMAS HENRY EASTON + DYMOKE EAST ORANGE + DYNAMICS EASTPORT + DYNAMITE EAST PROVIDENCE + DYNAMO EAST PRUSSIA + DYNAMOMETER EASTWICK, EDWARD BACKHOUSE + DYNASTY EATON, DORMAN BRIDGMAN + DYSART EATON, MARGARET O'NEILL + DYSENTERY EATON, THEOPHILUS + DYSPEPSIA EATON, WILLIAM + DYSTELEOLOGY EATON, WYATT + DZUNGARIA EAU CLAIRE + E EAU DE COLOGNE + EA EAUX-BONNES + EABANI EAVES + EACHARD, JOHN EAVESDRIP + EADBALD EBBW VALE + EADIE, JOHN EBEL, HERMANN WILHELM + EADMER EBEL, JOHANN GOTTFRIED + EADS, JAMES BUCHANAN EBER, PAUL + EAGLE EBERBACH (town of Germany) + EAGLEHAWK EBERBACH (monastery of Germany) + EAGRE EBERHARD + EAKINS, THOMAS EBERHARD, CHRISTIAN AUGUST GOTTLOB + EALING EBERHARD, JOHANN AUGUSTUS + EAR EBERLIN, JOHANN ERNST + EARL EBERS, GEORG MORITZ + EARLE, JOHN EBERSWALDE + EARLE, RALPH EBERT, FRIEDRICH ADOLF + EARL MARSHAL EBINGEN + EARLOM, RICHARD EBIONITES + EARLSTON EBNER-ESCHENBACH, MARIE + EARLY, JUBAL ANDERSON EBOLI + EARLY ENGLISH PERIOD EBONY + EARN EBRARD, JOHANNES HEINRICH AUGUST + EARNEST EBRO + EAR-RING EBROIN + EARTH EBURACUM + EARTH, FIGURE OF THE ECA DE QUEIROZ, JOSE MARIA + EARTH CURRENTS ECARTE + EARTH-NUT ECBATANA + EARTH PILLAR ECCARD, JOHANN + EARTHQUAKE ECCELINO DA ROMANO + EARTH-STAR ECCENTRIC + EARTHWORM ECCHELLENSIS, ABRAHAM + EARWIG ECCLES + EASEMENT ECCLESFIELD + EAST, ALFRED ECCLESHALL + EAST ANGLIA ECCLESIA + EASTBOURNE ECCLESIASTES + EAST CHICAGO ECCLESIASTICAL COMMISSIONERS + EASTER ECCLESIASTICAL JURISDICTION + EASTER ISLAND ECCLESIASTICAL LAW + EASTERN BENGAL AND ASSAM ECCLESIASTICUS + EASTERN QUESTION, THE ECGBERT (king of the West Saxons) + EAST GRINSTEAD ECGBERT (archbishop of York) + EAST HAM ECGFRITH + EASTHAMPTON ECGONINE + EAST HAMPTON ECHEGARAY Y EIZAGUIRRE, JOSE + EAST INDIA COMPANY ECHELON + EAST INDIES ECHIDNA + EASTLAKE, SIR CHARLES LOCK + + + + +DYER, SIR EDWARD (d. 1607), English courtier and poet, son of Sir Thomas +Dyer, Kt., was born at Sharpham Park, Somersetshire. He was educated, +according to Anthony a Wood, either at Balliol College or at Broadgates +Hall, Oxford. He left the university without taking a degree, and after +some time spent abroad appeared at Queen Elizabeth's court. His first +patron was the earl of Leicester, who seems to have thought of putting +him forward as a rival to Sir Christopher Hatton in the queen's favour. +He is mentioned by Gabriel Harvey with Sidney as one of the ornaments of +the court. Sidney in his will desired that his books should be divided +between Fulke Greville (Lord Brooke) and Dyer. He was employed by +Elizabeth on a mission (1584) to the Low Countries, and in 1589 was sent +to Denmark. In a commission to inquire into manors unjustly alienated +from the crown in the west country he did not altogether please the +queen, but he received a grant of some forfeited lands in Somerset in +1588. He was knighted and made chancellor of the order of the Garter in +1596. William Oldys says of him that he "would not stoop to fawn," and +some of his verses seem to show that the exigencies of life at court +oppressed him. He was buried at St Saviour's, Southwark, on the 11th of +May 1607. Wood says that many esteemed him to be a Rosicrucian, and that +he was a firm believer in alchemy. He had a great reputation as a poet +among his contemporaries, but very little of his work has survived. +Puttenham in the _Arte of English Poesie_ speaks of "Maister Edward +Dyar, for Elegie most sweete, solempne, and of high conceit." One of the +poems universally accepted as his is "My Mynde to me a kingdome is." +Among the poems in _England's Helicon_ (1600), signed S.E.D., and +included in Dr A.B. Grosart's collection of Dyer's works (_Miscellanies +of the Fuller Worthies Library_, vol. iv., 1876) is the charming +pastoral "My Phillis hath the morninge sunne," but this comes from the +_Phillis_ of Thomas Lodge. Grosart also prints a prose tract entitled +_The Prayse of Nothing_ (1585). The _Sixe Idillia_ from Theocritus, +reckoned by J.P. Collier among Dyer's works, were dedicated to, not +written by, him. + + + + +DYER, JOHN (c. 1700-1758), British poet, the son of a solicitor, was +born in 1699 or 1700 at Aberglasney, in Carmarthenshire. He was sent to +Westminster school and was destined for the law, but on his father's +death he began to study painting. He wandered about South Wales, +sketching and occasionally painting portraits. In 1726 his first poem, +_Grongar Hill_, appeared in a miscellany published by Richard Savage, +the poet. It was an irregular ode in the so-called Pindaric style, but +Dyer entirely rewrote it into a loose measure of four cadences, and +printed it separately in 1727. It had an immediate and brilliant +success. _Grongar Hill_, as it now stands, is a short poem of only 150 +lines, describing in language of much freshness and picturesque charm +the view from a hill overlooking the poet's native vale of Towy. A visit +to Italy bore fruit in _The Ruins of Rome_ (1740), a descriptive piece +in about 600 lines of Miltonic blank verse. He was ordained priest in +1741, and held successively the livings of Calthorp in Leicestershire, +Belchford (1751), Coningsby (1752), and Kirby-on-Bane (1756), the last +three being Lincolnshire parishes. He married, in 1741, a Miss Ensor, +said to be descended from the brother of Shakespeare. In 1757 he +published his longest work, the didactic blank-verse epic of _The +Fleece_, in four books, discoursing of the tending of sheep, of the +shearing and preparation of the wool, of weaving, and of trade in +woollen manufactures. The town took no interest in it, and Dodsley +facetiously prophesied that "Mr Dyer would be buried in woollen." He +died at Coningsby of consumption, on the 15th of December 1758. + + His poems were collected by Dodsley in 1770, and by Mr Edward Thomas + in 1903 for the _Welsh Library_, vol. iv. + + + + +DYER, THOMAS HENRY (1804-1888), English historical and antiquarian +writer, was born in London on the 4th of May 1804. He was originally +intended for a business career, and for some time acted as clerk in a +West India house; but finding his services no longer required after the +passing of the Negro Emancipation Act, he decided to devote himself to +literature. In 1850 he published the _Life of Calvin_, a conscientious +and on the whole impartial work, though the character of Calvin is +somewhat harshly drawn, and his influence in the religious world +generally is insufficiently appreciated. Dyer's first historical work +was the _History of Modern Europe_ (1861-1864; 3rd ed. revised and +continued to the end of the 19th century, by A. Hassall, 1901), a +meritorious compilation and storehouse of facts, but not very readable. +The _History of the City of Rome_ (1865) down to the end of the middle +ages was followed by the _History of the Kings of Rome_ (1868), which, +upholding against the German school the general credibility of the +account of early Roman history, given in Livy and other classical +authors, was violently attacked by J.R. Seeley and the _Saturday +Review_, as showing ignorance of the comparative method. More favourable +opinions of the work were expressed by others, but it is generally +agreed that the author's scholarship is defective and that his views are +far too conservative. _Roma Regalis_ (1872) and _A Plea for Livy_ (1873) +were written in reply to his critics. Dyer frequently visited Greece and +Italy, and his topographical works are probably his best; amongst these +mention may be made of _Pompeii, its History, Buildings and Antiquities_ +(1867, new ed. in Bohn's _Illustrated Library_), and _Ancient Athens, +its History, Topography and Remains_ (1873). His last publication was +_On Imitative Art_ (1882). He died at Bath on the 30th of January 1888. + + + + +DYMOKE, the name of an English family holding the office of king's +champion. The functions of the champion were to ride into Westminster +Hall at the coronation banquet, and challenge all comers to impugn the +king's title (see CHAMPION). The earliest record of the ceremony at the +coronation of an English king dates from the accession of Richard II. On +this occasion the champion was Sir John Dymoke (d. 1381), who held the +manor of Scrivelsby, Lincolnshire, in right of his wife Margaret, +granddaughter of Joan Ludlow, who was the daughter and co-heiress of +Philip Marmion, last Baron Marmion. The Marmions claimed descent from +the lords of Fontenay, hereditary champions of the dukes of Normandy, +and held the castle of Tamworth, Leicestershire, and the manor of +Scrivelsby, Lincolnshire. The right to the championship was disputed +with the Dymoke family by Sir Baldwin de Freville, lord of Tamworth, who +was descended from an elder daughter of Philip Marmion. The court of +claims eventually decided in favour of the owners of Scrivelsby on the +ground that Scrivelsby was held in grand serjeanty, that is, that its +tenure was dependent on rendering a special service, in this case the +championship. + +Sir Thomas Dymoke (1428?-1471) joined a Lancastrian rising in 1469, and, +with his brother-in-law Richard, Lord Willoughby and Welles, was +beheaded in 1471 by order of Edward IV. after he had been induced to +leave sanctuary on a promise of personal safety. The estates were +restored to his son Sir Robert Dymoke (d. 1546), champion at the +coronations of Richard III., Henry VII. and Henry VIII., who +distinguished himself at the siege of Tournai and became treasurer of +the kingdom. His descendants acted as champions at successive +coronations. Lewis Dymoke (d. 1820) put in an unsuccessful claim before +the House of Lords for the barony of Marmion. His nephew Henry +(1801-1865) was champion at the coronation of George IV. He was +accompanied on that occasion by the duke of Wellington and Lord Howard +of Effingham. Henry Dymoke was created a baronet; he was succeeded by +his brother John, rector of Scrivelsby (1804-1873), whose son Henry +Lionel died without issue in 1875, when the baronetcy became extinct, +the estate passing to a collateral branch of the family. After the +coronation of George IV. the ceremony was allowed to lapse, but at the +coronation of King Edward VII. H.S. Dymoke bore the standard of England +in Westminster Abbey. + + + + +DYNAMICS (from Gr. [Greek: dynamis], strength), the name of a branch of +the science of Mechanics (q.v.). The term was at one time restricted to +the treatment of motion as affected by force, being thus opposed to +Statics, which investigated equilibrium or conditions of rest. In more +recent times the word has been applied comprehensively to the action of +force on bodies either at rest or in motion, thus including "dynamics" +(now termed kinetics) in the restricted sense and "statics." + +ANALYTICAL DYNAMICS.--The fundamental principles of dynamics, and their +application to special problems, are explained in the articles MECHANICS +and MOTION, LAWS OF, where brief indications are also given of the more +general methods of investigating the properties of a dynamical system, +independently of the accidents of its particular constitution, which +were inaugurated by J.L. Lagrange. These methods, in addition to the +unity and breadth which they have introduced into the treatment of pure +dynamics, have a peculiar interest in relation to modern physical +speculation, which finds itself confronted in various directions with +the problem of explaining on dynamical principles the properties of +systems whose ultimate mechanism can at present only be vaguely +conjectured. In determining the properties of such systems the methods +of analytical geometry and of the infinitesimal calculus (or, more +generally, of mathematical analysis) are necessarily employed; for this +reason the subject has been named Analytical Dynamics. The following +article is devoted to an outline of such portions of general dynamical +theory as seem to be most important from the physical point of view. + + + 1. _General Equations of Impulsive Motion._ + + The systems contemplated by Lagrange are composed of discrete + particles, or of rigid bodies, in finite number, connected (it may be) + in various ways by invariable geometrical relations, the fundamental + postulate being that the position of every particle of the system at + any time can be completely specified by means of the instantaneous + values of a finite number of independent variables q1, q2, ... q_n, + each of which admits of continuous variation over a certain range, so + that if x, y, z be the Cartesian co-ordinates of any one particle, we + have for example + + x = [f](q1, q2, ... q_n), y = &c., z = &c., (1) + + where the functions [f] differ (of course) from particle to particle. + In modern language, the variables q1, q2, ... q_n are _generalized + co-ordinates_ serving to specify the _configuration_ of the system; + their derivatives with respect to the time are denoted by q`1, q`2, + ... q`_n, and are called the _generalized components of velocity_. The + continuous sequence of configurations assumed by the system in any + actual or imagined motion (subject to the given connexions) is called + the _path_. + + + Impulsive motion. + + For the purposes of a connected outline of the whole subject it is + convenient to deviate somewhat from the historical order of + development, and to begin with the consideration of _impulsive_ + motion. Whatever the actual motion of the system at any instant, we + may conceive it to be generated instantaneously from rest by the + application of proper impulses. On this view we have, if x, y, z be + the rectangular co-ordinates of any particle m, + + mx` = X', my` = Y', mz` = Z', (2) + + where X', Y', Z' are the components of the impulse on m. Now let + [delta]x, [delta]y, [delta]z be any infinitesimal variations of x, y, + z which are consistent with the connexions of the system, and let us + form the equation + + [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) = + [Sigma](X'[delta]x + Y'[delta]y + Z'[delta]z), (3) + + where the sign [Sigma] indicates (as throughout this article) a + summation extending over all the particles of the system. To transform + (3) into an equation involving the variations [delta]q1, [delta]q2, + ... of the generalized co-ordinates, we have + + dPx dPx + x` = ---- q`1 + ---- q`2 + ..., &c., &c. (4) + dPq1 dPq2 + + dPx dPx + [delta]x = ---- [delta]q1 + ---- [delta]q2 + ..., &c., &c. (5) + dPq1 dPq2 + + and therefore + + [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) = + (A11q`1 + A12q`2 + ...)[delta]q1 + + (A21q`1 + A22q`2 + ...)[delta]q2 + ..., (6) + + where + _ _ + | / dPx \ squared / dPy \ squared / dPz \ squared | \ + A_rr = [Sigma]m | ( ----- ) + ( ----- ) + ( ----- ) |, | + |_ \dPq_r/ \dPq_r/ \dPq_r/ _| | + _ _ > (7) + | dPx dPx dPy dPy dPz dPz | | + A_rs = [Sigma]m | ----- ----- + ----- ----- + ----- ----- | = A_sr. | + |_dPq_r dPq_s dPq_r dPq_s dPq_r dPq_s _| / + + If we form the expression for the kinetic energy [Tau] of the system, + we find + + 2[Tau] = [Sigma]m(x` squared + y` squared + z` squared) = A11q`1 squared + A22q`2 squared + ... + + 2A12q`1q`2 + ... (8) + + The coefficients A11, A22, ... A12, ... are by an obvious analogy + called the _coefficients of inertia_ of the system; they are in + general functions of the co-ordinates q1, q2, ... . The equation (6) + may now be written + + dP[Tau] dP[Tau] + [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) = ------- [delta]q1 + ------- [delta]q2 + ... (9) + dPq`1 dPq`2 + + This maybe regarded as the cardinal formula in Lagrange's method. For + the right-hand side of (3) we may write + + [Sigma](X'[delta]x + Y'[delta]y + Z'[delta]z) = Q'1[delta]q1 + Q'2[delta]q2 + ... , (10) + + where + + / dPx dPy dPz \ + Q'_r = [Sigma]( X'----- + Y'----- + Z'----- ). (11) + \ dPq_r dPq_r dPq_r/ + + The quantities Q1, Q2, ... are called the _generalized components of + impulse_. Comparing (9) and (10), we have, since the variations + [delta]q1, [delta]q2,... are independent, + + dP[Tau] dP[Tau] + ------- = Q'1, ------- = Q'2, ... (12) + dPq`1 dPq`2 + + These are the general equations of impulsive motion. It is now usual + to write + + dP[Tau] + p_r = ------- (13) + dPq`_r + + The quantities p1, p2, ... represent the effects of the several + component impulses on the system, and are therefore called the + _generalized components of momentum_. In terms of them we have + + [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) = p1[delta]q1 + p2[delta]q2 + ... (14) + + Also, since [Tau] is a homogeneous quadratic function of the + velocities q`1, q`2 ..., + + 2[Tau] = p1q`1 + p2q`2 + ... (15) + + This follows independently from (14), assuming the special variations + [delta]x = x`dt, &c., and therefore [delta]q1 = q`1dt, [delta]q2 = + q`2dt, ... + + + Reciprocal theorems. + + Again, if the values of the velocities and the momenta in any other + motion of the system through the same configuration be distinguished + by accents, we have the identity + + p1q`'1 + p2q`'2 + ... = p'1q`1 + p'2q`2 + ..., (16) + + each side being equal to the symmetrical expression + + A11q`1q''1 + A22q`2q`'2 + ... + A12(q`1q`'2 + q`'1q`2) + ... (17) + + The theorem (16) leads to some important reciprocal relations. Thus, + let us suppose that the momenta p1, p2, ... all vanish with the + exception of p1, and similarly that the momenta p'1, p'2, ... all + vanish except p'2. We have then p1q`'1 = p'2q`2, or + + q`2 : p1 = q`'1 : p'2 (18) + + The interpretation is simplest when the co-ordinates q1, q2 are both + of the same kind, e.g. both lines or both angles. We may then + conveniently put p1 = p'2, and assert that the velocity of the first + type due to an impulse of the second type is equal to the velocity of + the second type due to an equal impulse of the first type. As an + example, suppose we have a chain of straight links hinged each to the + next, extended in a straight line, and free to move. A blow at right + angles to the chain, at any point P, will produce a certain velocity + at any other point Q; the theorem asserts that an equal velocity will + be produced at P by an equal blow at Q. Again, an impulsive couple + acting on any link A will produce a certain angular velocity in any + other link B; an equal couple applied to B will produce an equal + angular velocity in A. Also if an impulse F applied at P produce an + angular velocity [omega] in a link A, a couple Fa applied to A will + produce a linear velocity [omega]a at P. Historically, we may note + that reciprocal relations in dynamics were first recognized by H.L.F. + Helmholtz in the domain of acoustics; their use has been greatly + extended by Lord Rayleigh. + + + Velocities in terms of momenta. + + The equations (13) determine the momenta p1, p2,... as linear + functions of the velocities q`1, q`2,... Solving these, we can + express q`1, q`2 ... as linear functions of p1, p2,... The + resulting equations give us the velocities produced by any given + system of impulses. Further, by substitution in (8), we can express + the kinetic energy as a homogeneous quadratic function of the momenta + p1, p2,... The kinetic energy, _as so expressed_, will be denoted by + [Tau]'; thus + + 2[Tau]' = A'11p1 squared + A'22p2 squared + ... + 2A'12p - p2 + ... (19) + + where A'11, A'22,... A'12,... are certain coefficients depending on + the configuration. They have been called by Maxwell the _coefficients + of mobility_ of the system. When the form (19) is given, the values + of the velocities in terms of the momenta can be expressed in a + remarkable form due to Sir W.R. Hamilton. The formula (15) may be + written + + p1q`1 + p2q`2 + ... = [Tau] + [Tau]', ... (20) + + where [Tau] is supposed expressed as in (8), and [Tau]' as in (19). + Hence if, for the moment, we denote by [delta] a variation affecting + the velocities, and therefore the momenta, but not the configuration, + we have + + p1[delta]q`1 + q`1[delta]p + p2[delta]q`2 + q`2[delta]p2 + ... = [delta][Tau] + [delta][Tau]' + + dP[Tau] dP[Tau] dP[Tau]' dP[Tau]' + = ------- [delta]q`1 + ------- [delta]q`2 + ... + -------- [delta]p1 + -------- [delta]p2 + ... (21) + dPq`1 dPq`2 dPp1 dPp2 + + In virtue of (13) this reduces to + + dP[Tau]' dP[Tau]' + q`1[delta]p1 + q`2[delta]p2 + ... = ------- [delta]p1 + ------- [delta]p2 + ... (22) + dPp1 dPp2 + + Since [delta]p1, [delta]p2, ... may be taken to be independent, we + infer that + + dP[Tau]' dP[Tau]' + q`1 = -------, q`2 = -------, ... (23) + dPp1 dPp2 + + In the very remarkable exposition of the matter given by James Clerk + Maxwell in his _Electricity and Magnetism_, the Hamiltonian + expressions (23) for the velocities in terms of the impulses are + obtained directly from first principles, and the formulae (13) are + then deduced by an inversion of the above argument. + + + Routh's modification. + + An important modification of the above process was introduced by E.J. + Routh and Lord Kelvin and P.G. Tait. Instead of expressing the kinetic + energy in terms of the velocities alone, or in terms of the momenta + alone, we may express it in terms of the velocities corresponding to + some of the co-ordinates, say q1, q2, ... q_m, and of the momenta + corresponding to the remaining co-ordinates, which (for the sake of + distinction) we may denote by [chi], [chi]', [chi]", .... Thus, [Tau] + being expressed as a homogeneous quadratic function of q`1, q`2, ... + q`_m, [chi]`, [chi]`', [chi]`", ..., the momenta corresponding to the + co-ordinates [chi], [chi]', [chi]", ... may be written + + dP[Tau] dP[Tau] dP[Tau] + [kappa] = --------, [kappa]' = ---------, [kappa]" = ------------, ... (24) + dP[chi]` dP[chi]`' dP[.[chi]`" + + These equations, when written out in full, determine [chi]`, [chi]`', + [chi]`", ... as linear functions of q`1, q`2, ... q`_m, [kappa], + [kappa]', [kappa]",... We now consider the function + + R = [Tau] - [kappa][chi]' - [kappa]'[chi]]`' - [kappa]"[chi]]`" - ..., (25) + + supposed expressed, by means of the above relations in terms of q`1, + q`2, ... q`_m, [kappa], [kappa]', [kappa]",... Performing the + operation [delta] on both sides of (25), we have + + dPR dPR dP[Tau] dP[Tau] + ----- [delta]q`1 + ... + --------- [delta][kappa] + ... = ------- [delta]q`1 + ... + -------- [delta][chi]` + ... + dPq`1 dP[kappa] dPq`1 dP[chi]` + + - [kappa]dP[chi]` - [chi]`[delta][kappa] - ... , (26) + + where, for brevity, only one term of each type has been exhibited. + Omitting the terms which cancel in virtue of (24), we have + + dPR dPR dP[Tau] + ----- [delta]q`1 + ... + --------- [delta][kappa] + ... = ------- [delta]q`1 + ... - [chi]`[delta][kappa] - ... (27) + dPq`1 dP[kappa] dPq`1 + + Since the variations [delta]q1, [delta]q2, ... [delta]q_m, + [delta][kappa], [delta][kappa]', [delta][kappa]", ... may be taken to + be independent, we have + + dP[Tau] dPR dP[Tau] dPR + p1 = ------- = -----, p2 = ------- = -----, ... (28) + dPq`1 dPq`1 dPq`2 dPq`2 + + and + + dPR dPR dPR + [chi]` = - ---------, [chi]`' = - ----------, [chi]]`" = - ---------, ... (29) + dP[kappa] dP[kappa]' dP[kappa]" + + An important property of the present transformation is that, when + expressed in terms of the new variables, the kinetic energy is the sum + of two homogeneous quadratic functions, thus + + [Tau] = [@] + K, (30) + + where [@] involves the velocities q`1, q`2, ... q`_m alone, and K the + momenta [kappa], [kappa]', [kappa]", ... alone. For in virtue of (29) + we have, from (25), + + / dPR dPR dPR \ + [Tau] = R - ( [kappa] --------- + [kappa]' ---------- + [kappa]" ----------- + ... ), (31) + \ dP[kappa] dP[kappa]' dP[kappa]" / + + and it is evident that the terms in R which are bilinear in respect of + the two sets of variables q`1, q`2, ... q`_m and [kappa], [kappa]', + [kappa]", ... will disappear from the right-hand side. + + + Maximum and minimum energy. + + It may be noted that the formula (30) gives immediate proof of two + important theorems due to Bertrand and to Lord Kelvin respectively. + Let us suppose, in the first place, that the system is started by + given impulses of certain types, but is otherwise free. J.L.F. + Bertrand's theorem is to the effect that the kinetic energy is + _greater_ than if by impulses of the remaining types the system were + constrained to take any other course. We may suppose the co-ordinates + to be so chosen that the constraint is expressed by the vanishing of + the velocities q`1, q`2, ... q`_m, whilst the given impulses are + [kappa], [kappa]', [kappa]",... Hence the energy in the actual motion + is greater than in the constrained motion by the amount [@]. + + Again, suppose that the system is started with prescribed velocity + components q`1, q`2, ... q`_m, by means of proper impulses of + the corresponding types, but is otherwise free, so that in the motion + actually generated we have [kappa] = 0, [kappa]' = 0, [kappa]" = 0, + ... and therefore K = 0. The kinetic energy is therefore _less_ than + in any other motion consistent with the prescribed velocity-conditions + by the value which K assumes when [kappa], [kappa]', [kappa]", ... + represent the impulses due to the constraints. + + Simple illustrations of these theorems are afforded by the chain of + straight links already employed. Thus if a point of the chain be held + fixed, or if one or more of the joints be made rigid, the energy + generated by any given impulses is less than if the chain had + possessed its former freedom. + + + 2. _Continuous Motion of a System._ + + Lagrange's equations. + + We may proceed to the continuous motion of a system. The equations of + motion of any particle of the system are of the form + + mx" = X, my" = Y, mz" = Z (1) + + Now let x + [delta]x, y + [delta]y, z + [delta]z be the co-ordinates + of m in any arbitrary motion of the system differing infinitely little + from the actual motion, and let us form the equation + + [Sigma]m(x"[delta]x + y"[delta]y + z"[delta]z) = + [Sigma](X[delta]x + Y[delta]y + Z[delta]z) (2) + + Lagrange's investigation consists in the transformation of (2) into an + equation involving the independent variations [delta]q1, [delta]q2, + ... [delta]q_n. + + It is important to notice that the symbols [delta] and d/dt are + commutative, since + + d dx d + [delta]x` = --(x + [delta]x) - -- = --[delta]x, &c. (3) + dt dt dt + + Hence + + d + [Sigma]m(x"[delta]x + y"[delta]y + z"[delta]z) = -- [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) + dt + - [Sigma]m(x`[delta]x` + y`[delta]y` + z`[delta]z`) + + d + = --(p1[delta]q1 + p2[delta]q2 + ...) - [delta][Tau], (4) + dt + + by Sec. 1 (14). The last member may be written + + p`1[delta]q1 + p1[delta]q`1 + p`2[delta]q2 + p2[delta]q`2 + ... + + dP[Tau] dP[Tau] dP[Tau] dP[Tau] + - ------- [delta]q`1 - ------- [delta]q1 - ------- [delta]q`2 - ------- [delta]q2 - ... (5) + dPq`1 dPq1 dPq`2 dPq2 + + Hence, omitting the terms which cancel in virtue of Sec. 1 (13), we find + + / dP[Tau]\ / dP[Tau]\ + [Sigma]m(x"[delta]x + y"[delta]y + z"[delta]z) = (p`1 - ------- ) [delta]q1 + (p`2 - ------- ) [delta]q2 + ... (6) + \ dPq1 / \ dPq2 / + + For the right-hand side of (2) we have + + [Sigma](X[delta]x + Y[delta]y + Z[delta]z) = Q1[delta]q1 + Q2[delta]q2 + ..., (7) + + / dPx dPy dPz \ + where Q_r = [Sigma]( X ----- + Y ----- + Z ----- ) (8) + \ dPq_r dPq_r dPq_r/ + + The quantities Q1, Q2, ... are called the _generalized components of + force_ acting on the system. + + Comparing (6) and (7) we find + + dP[Tau] dP[Tau] + p`1 - ------- = Q1, p`2 - ------- = Q2, ..., (9) + dPq`1 dPq`2 + + or, restoring the values of p1, p2, ..., + + d /dP[Tau]\ dP[Tau] d /dP[Tau]\ dP[Tau] + -- ( ------- ) - ------- = Q1, -- ( ------- ) - ------- = Q2, ... (10) + dt \ dPq`1 / dPq1 dt \ dPq`2 / dPq2 + + These are Lagrange's general equations of motion. Their number is of + course equal to that of the co-ordinates q1, q2, ... to be determined. + + Analytically, the above proof is that given by Lagrange, but the + terminology employed is of much more recent date, having been first + introduced by Lord Kelvin and P.G. Tait; it has greatly promoted the + physical application of the subject. Another proof of the equations + (10), by direct transformation of co-ordinates, has been given by + Hamilton and independently by other writers (see MECHANICS), but the + variational method of Lagrange is that which stands in closest + relation to the subsequent developments of the subject. The chapter of + Maxwell, already referred to, is a most instructive commentary on the + subject from the physical point of view, although the proof there + attempted of the equations (10) is fallacious. + + In a "conservative system" the work which would have to be done by + extraneous forces to bring the system from rest in some standard + configuration to rest in the configuration (q1, q2, ... q_n) is + independent of the path, and may therefore be regarded as a definite + function of q1, q2, ... q_n. Denoting this function (the _potential + energy_) by V, we have, if there be no extraneous force on the system, + + [Sigma](X[delta]x + Y[delta]y + Z[delta]z) = - [delta]V, (11) + + and therefore + + dPV dPV + Q1 = - ----, Q2 = - ----, .... (12) + dPq1 dPq2 + + Hence the typical Lagrange's equation may be now written in the form + + d /dP[Tau]\ dP[Tau] dPV + -- ( ------- ) - ------- = - -----, (13) + dt \dPq`_r / dPq_r dPq_r + + or, again, + + dP + p`_r = - ----- (V - [Tau]) (14) + dPq_r + + It has been proposed by Helmholtz to give the name _kinetic potential_ + to the combination V - [Tau]. + + As shown under MECHANICS, Sec. 22, we derive from (10) + + d[Tau] + ------ = Q1q`1 + Q2q`2 + ..., (15) + dt + + and therefore in the case of a conservative system free from + extraneous force, + + d + --([Tau] + V) = 0 or [Tau] + V = const., (16) + dt + + which is the equation of energy. For examples of the application of + the formula (13) see MECHANICS, Sec. 22. + + + 3. _Constrained Systems._ + + Case of varying relations. + + It has so far been assumed that the geometrical relations, if any, + which exist between the various parts of the system are of the type Sec. + 1 (1), and so do not contain t explicitly. The extension of Lagrange's + equations to the case of "varying relations" of the type + + x = f(t, q1, q2,...q_n), y = &c., z = &c., (1) + + was made by J.M.L. Vieille. We now have + + dPx dPx dPx + x` = --- + ---- q`1 + ---- q`2 + ..., &c., &c., (2) + dPt dPq1 dPq2 + + dPx dPx + dPx = ---- [delta]q1 + ---- [delta]q2 + ..., &c., &c., (3) + dPq1 dPq2 + + so that the expression Sec. 1 (8) for the kinetic energy is to be + replaced by + + 2[Tau] = [alpha]0 + 2[alpha]1q`1 + 2[alpha]2q`2 + ... + A11q`1 squared + A22q`2 squared + ... + A12q`1q`2 + ..., (4) + + where + _ _ \ + | /dPx\ squared /dPy\ squared /dPz\ squared | | + a0 = [Sigma]m |( --- ) + ( --- ) + ( --- ) |, | + |_\dPt/ \dPt/ \dPt/ _| | + _ _ > (5) + | dPx dPx dPy dPy dPz dPz | | + a_r = [Sigma]m | --- ----- + --- ----- + --- ----- |, | + |_dPt dPq_r dPt dPq_r dPt dPq_r_| | + / + + and the forms of A_rr, A_rs are as given by Sec. 1 (7). It is to be + remembered that the coefficients [alpha]0, [alpha]1, [alpha]2, ... + A11, A22, ... A12 ... will in general involve t explicitly as well as + implicitly through the co-ordinates q1, q2,... Again, we find + + [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) = + + ([alpha]1 + A11q`1 + A12q`2 + ...)[delta]q1 + + ([alpha]2 + A21q`1 + A22q`2 + ...)dPq2 + ... + + dP[Tau] dP[Tau] + = ------- [delta]q1 + ------- [delta]q2 + ... + dPq`1 dPq`2 + + = p1[delta]q1 + p2[delta]q2 + ..., (6) + + where p_r is defined as in Sec. 1 (13). The derivation of Lagrange's + equations then follows exactly as before. It is to be noted that the + equation Sec. 2 (15) does not as a rule now hold. The proof involved the + assumption that [Tau] is a homogeneous quadratic function of the + velocities q`1, q`2.... + + It has been pointed out by R.B. Hayward that Vieille's case can be + brought under Lagrange's by introducing a new co-ordinate ([chi]) in + place of t, so far as it appears explicitly in the relations (1). We + have then + + 2[Tau] = [alpha]0[chi]` squared + 2([alpha]1q`1 + [alpha]2q`2 + ...)[chi]` + + A11q`1 squared + A22q`2 squared + ... + 2A12q`1q`2 + .... (7) + + The equations of motion will be as in Sec. 2 (10), with the additional + equation + + d dP[Tau] dP[Tau] + -- -------- - ------- = X, (8) + dt dP[chi]` dP[chi] + + where X is the force corresponding to the co-ordinate [chi]. We may + suppose X to be adjusted so as to make [chi]" = 0, and in the + remaining equations nothing is altered if we write t for [chi] before, + instead of after, the differentiations. The reason why the equation Sec. + 2 (15) no longer holds is that we should require to add a term X[chi]` + on the right-hand side; this represents the rate at which work is + being done by the constraining forces required to keep [chi]` + constant. + + As an example, let x, y, z be the co-ordinates of a particle relative + to axes fixed in a solid which is free to rotate about the axis of z. + If [phi] be the angular co-ordinate of the solid, we find without + difficulty + + 2[Tau] = m(x` squared + y` squared +z` squared) + 2[phi]`m(xy` - yx`) + {I + m(x squared + y squared)}[phi]` squared, (9) + + where I is the moment of inertia of the solid. The equations of + motion, viz. + + d dP[Tau] dP[Tau] d dP[Tau] dP[Tau] d dP[Tau] dP[Tau] + -- ------ - ------ = X, -- ------- - ------- = Y, -- ------- - ------- = Z, (10) + dt dPx` dPx dt dPy` dPy dt dPz` dPz + + d dP[Tau] dP[Tau] + and -- -------- - ------- = [Phi], (11) + dt dP[phi]` dP[phi] + + become + + m(x" - 2[phi]`y` - x[phi]` squared - y[phi]") = X, m(y" + 2[phi]`x` - y[phi]` squared + x[phi]`) = Y, mz" = Z, (12) + _ _ + d | / \ | + and -- |(I + m(x squared + y squared)) [phi]` + m(xy` - yx`)| = [Phi]. (13) + dt |_\ / _| + + If we suppose [Phi] adjusted so as to maintain [phi]" = 0, or (again) + if we suppose the moment of inertia I to be infinitely great, we + obtain the familiar equations of motion relative to moving axes, viz. + + m(x" - 2[omega]y` - [omega] squaredx) = X, m(y" + 2[omega]x` - [omega] squaredy) = Y, mz" = Z, (14) + + where [omega] has been written for [phi]. These are the equations + which we should have obtained by applying Lagrange's rule at once to + the formula + + 2[Tau] = m(x` squared + y` squared + z` squared) + 2m[omega](xy` - yx`) + m[omega] squared(x squared + y squared), (15) + + which gives the kinetic energy of the particle referred to axes + rotating with the constant angular velocity [omega]. (See MECHANICS, Sec. + 13.) + + More generally, let us suppose that we have a certain group of + co-ordinates [chi], [chi]', [chi]", ... whose absolute values do not + affect the expression for the kinetic energy, and that by suitable + forces of the corresponding types the velocity-components [chi]`, + [chi]`', [chi]`", ... are maintained constant. The remaining + co-ordinates being denoted by q1, q2, ... q_n, we may write + + 2[Tau] = [@] + [Tau]0 + 2([alpha]1q`1 + [alpha]2q`2 + ...)[chi]` + + 2([alpha]'1q`1 + [alpha]'2q`2 + ...)[chi]`' + ..., (16) + + where [@] is a homogeneous quadratic function of the velocities q`1, + q`2, ... q`_n of the type Sec.1 (8), whilst [Tau]0 is a homogeneous + quadratic function of the velocities [chi]`,[chi]`', [chi]`", ... + alone. The remaining terms, which are bilinear in respect of the two + sets of velocities, are indicated more fully. The formulae (10) of Sec. 2 + give n equations of the type + + d /dP[@]\ /dP[@]\ dP[Tau]0 + --( ----- ) - ( ----- ) + (r, 1)q`1 + (r, 2)q`2 + ... - -------- = Q_r (17) + dt \dPq_r/ \dPq_r/ dPq_r + + where + + /dPa_r dPa_s\ /dPa'_r dPa'_s\ + (r, s) = ( ----- - ----- )[chi]` + ( ------ - ------ )[chi]`' + .... (18) + \dPq_s dPq_r/ \dPq_s dPq_r/ + + These quantities (r, s) are subject to the relations + + (r, s) = -(s, r), (r, r) = 0 (19) + + The remaining dynamical equations, equal in number to the co-ordinates + [chi], [chi]', [chi]", ..., yield expressions for the forces which + must be applied in order to maintain the velocities [chi]`, [chi]`', + [chi]`", ... constant; they need not be written down. If we follow the + method by which the equation of energy was established in Sec. 2, the + equations (17) lead, on taking account of the relations (19), to + + d + --([@] - [Tau]0) = Q1q`1 + Q2q`2 + ... + Q_nq`_n, (20) + dt + + or, in case the forces Q_r depend only on the co-ordinates q1, q2, ... + q_n and are conservative, + + [@] + V - [Tau]0 = const. (21) + + The conditions that the equations (17) should be satisfied by zero + values of the velocities q`1, q`2, ... q`_n are + + dP[Tau]0 + Q_r = - --------, (22) + dPq_r + + or in the case of conservative forces + + dP + ------ (V - [Tau]0) = 0, (23) + dPq_r + + i.e. the value of V - [Tau]0 must be _stationary_. + + + Rotating axes. + + We may apply this to the case of a system whose configuration relative + to axes rotating with constant angular velocity ([omega]) is defined + by means of the n co-ordinates q1, q2, ... q_n. This is important on + account of its bearing on the kinetic theory of the tides. Since the + Cartesian co-ordinates x, y, z of any particle m of the system + relative to the moving axes are functions of q1, q2, ... q_n, of the + form Sec. 1 (1), we have, by (15) + + 2[@] = [Sigma]m(x` squared + y` squared + z` squared), 2[Tau]0 = [omega] squared[Sigma]m(x squared + y squared), (24) + + / dPy dPx \ + a_r= [Sigma]m( x----- - y----- ), (25) + \ dPq_r dPq_r/ + + whence + + dP(x, y) + (r, s) = 2[omega].[Sigma]m ------------. (26) + dP(q_s, q_r) + + The conditions of relative equilibrium are given by (23). + + It will be noticed that this expression V - [Tau]0, which is to be + stationary, differs from the true potential energy by a term which + represents the potential energy of the system in relation to + fictitious "centrifugal forces." The question of stability of relative + equilibrium will be noticed later (Sec. 6). + + It should be observed that the remarkable formula (20) may in the + present case be obtained directly as follows. From (15) and (14) we + find + + d[Tau] d + ------ = --([@] + [Tau]0) + [omega].[Sigma]m(xy" - yx") + dt dt + + d + = --([@] - [Tau]0) + [omega].[Sigma](xY - yX). (27) + dt + + This must be equal to the rate at which the forces acting on the + system do work, viz. to + + [omega][Sigma](xY - yX) + Q1q`1 + Q2q`2 + ... + Q_nq`_n, + + where the first term represents the work done in virtue of the + rotation. + + + Constrained systems. + + We have still to notice the modifications which Lagrange's equations + undergo when the co-ordinates q1, q2, ... q_n are not all + independently variable. In the first place, we may suppose them + connected by a number m ( < n) of relations of the type + + A(t, q1, q2, ... q_n) = 0, B(t, q1, q2, ... q_n) = 0, &c. (28) + + These may be interpreted as introducing partial constraints into a + previously free system. The variations [delta]q1, [delta]q2, ... + [delta]q_n in the expressions (6) and (7) of Sec. 2 which are to be + equated are no longer independent, but are subject to the relations + + dPA dPA dPB dPB + ---- [delta]q1 + ---- [delta]q2 + ... = 0, ---- [delta]q1 + ---- [delta]q2 + ... = 0, &c. (29) + dPq1 dPq2 dPq1 dPq2 + + Introducing indeterminate multipliers [lambda], mu, ..., one for each + of these equations, we obtain in the usual manner n equations of the + type + + d dP[Tau] dP[Tau] dPA dPB + -- ------- - ------- = Q_r + [lambda] ----- + mu ----- + ..., (30) + dt dPq`_r dPq_r dPq_r dPq_r + + in place of Sec. 2 (10). These equations, together with (28), serve to + determine the n co-ordinates q1, q2, ... q_n and the m multipliers + [lambda], mu, .... + + When t does not occur explicitly in the relations (28) the system is + said to be _holonomic_. The term connotes the existence of integral + (as opposed to differential) relations between the co-ordinates, + independent of the time. + + Again, it may happen that although there are no prescribed relations + between the co-ordinates q1, q2, ... q_n, yet from the circumstances + of the problem certain geometrical conditions are imposed on their + _variations_, thus + + A1[delta]q1 + A2[delta]q2 + ... = 0, B1[delta]q1 + B2[delta]q2 + ... = 0, &c., (31) + + where the coefficients are functions of q1, q2, ... q_n and (possibly) + of t. It is assumed that these equations are not integrable as regards + the variables q1, q2, ... q_n; otherwise, we fall back on the previous + conditions. Cases of the present type arise, for instance, in ordinary + dynamics when we have a solid rolling on a (fixed or moving) surface. + The six co-ordinates which serve to specify the position of the solid + at any instant are not subject to any necessary relation, but the + conditions to be satisfied at the point of contact impose three + conditions of the form (31). The general equations of motion are + obtained, as before, by the method of indeterminate multipliers, thus + + d dP[Tau] dP[Tau] + -- ------- - ------- = Q_r + [lambda]A_r + muB_r + ... (32) + dt dPq`_r dPq_r + + The co-ordinates q1, q2, ... q_n, and the indeterminate multipliers + [lambda], mu, ..., are determined by these equations and by the + velocity-conditions corresponding to (31). When t does not appear + explicitly in the coefficients, these velocity-conditions take the + forms + + A1q`1 + A2q`2 + ... = 0, B1q`1 + B2q`2 + ... = 0, &c. (33) + + Systems of this kind, where the relations (31) are not integrable, are + called _non-holonomic_. + + + 4. _Hamiltonian Equations of Motion._ + + In the Hamiltonian form of the equations of motion of a conservative + system with unvarying relations, the kinetic energy is supposed + expressed in terms of the _momenta_ p1, p2, ... and the co-ordinates + q1, q2, ..., as in Sec. 1 (19). Since the symbol [delta] now denotes a + variation extending to the co-ordinates as well as to the momenta, we + must add to the last member of Sec. 1 (21) terms of the types + + dP[Tau] dP[Tau]' + ------- [delta]q1 + -------- [delta]q1 + ... (1) + dPq1 dPq1 + + Since the variations [delta]p1, [delta]p2, ... [delta]q1, [delta]q2, + ... may be taken to be independent, we infer the equations Sec. 1 (23) as + before, together with + + dP[Tau] dP[Tau]' dP[Tau] dP[Tau]' + ------ = - --------, ------- = - --------, ..., (2) + dPq1 dPq1 dPq2 dPq2 + + Hence the Lagrangian equations Sec. 2 (14) transform into + + dP dP + p`1 = - ----([Tau]' + V), p`2 = ---- ([Tau]' + V), ... (3) + dPq1 dPq2 + + If we write + + H = [Tau]' + V, (4) + + so that H denotes the _total energy_ of the system, supposed expressed + in terms of the new variables, we get + + dPH dPH + p`1 = - ----, p`2 = - ----, ... (5) + dPq1 dPq2 + + If to these we join the equations + + dPH dPH + q`1 = ----, q`2 = ----, ..., (6) + dPp1 dPp2 + + + which follow at once from Sec. 1 (23), since V does not involve p1, p2, + ..., we obtain a complete system of differential equations _of the + first order_ for the determination of the motion. + + The equation of energy is verified immediately by (5) and (6), since + these make + + dH dPH dPH dPH dPH + -- = ---- p`1 + ---- p`2 + ... + ---- q`1 + ---- q`2 + ... = 0. (7) + dt dPp1 dPp2 dPq1 dPq2 + + The Hamiltonian transformation is extended to the case of varying + relations as follows. Instead of (4) we write + + H = p1q`1 + p2q`2 + ... - [Tau] + V, (8) + + and imagine H to be expressed in terms of the momenta p1, p2, ..., the + co-ordinates q1, q2, ..., and the time. The internal forces of the + system are assumed to be conservative, with the potential energy V. + Performing the variation [delta] on both sides, we find + + dP[Tau] dPV + [delta]H = q`1[delta]p1 + ... - ------- [delta]q1 + ---- [delta]q + ..., (9) + dPq1 dPq1 + + terms which cancel in virtue of the definition of p1, p2, ... being + omitted. Since [delta]p1, [delta]p2, ..., [delta]q1, [delta]q2, ... + may be taken to be independent, we infer + + dPH dPH + q`1 = ----, q`2 = ----, ..., (10) + dPp1 dPp2 + + and + + dP dPH dP dPH + ---- ([Tau] - V) = - ----, ----([Tau] - V) = - ----, .... (11) + dPq1 dPq1 dPq2 dPq2 + + It follows from (11) that + + dPH dPH + p`1 = - ----, p`2 = - ----, .... (12) + dPq1 dPq2 + + The equations (10) and (12) have the same form as above, but H is no + longer equal to the energy of the system. + + + 5. _Cyclic Systems._ + + A _cyclic_ or _gyrostatic_ system is characterized by the following + properties. In the first place, the kinetic energy is not affected if + we alter the absolute values of certain of the co-ordinates, which we + will denote by [chi], [chi]', [chi]", ..., provided the remaining + co-ordinates q1, q2, ... q_m and the velocities, including of course + the velocities [.[chi]], [.[chi]]', [.[chi]]", ..., are unaltered. + Secondly, there are no forces acting on the system of the types [chi], + [chi]', [chi]", .... This case arises, for example, when the system + includes gyrostats which are free to rotate about their axes, the + co-ordinates [chi], [chi]', [chi]", ... then being the angular + co-ordinates of the gyrostats relatively to their frames. Again, in + theoretical hydrodynamics we have the problem of moving solids in a + frictionless liquid; the ignored co-ordinates [chi], [chi]', [chi]", + ... then refer to the fluid, and are infinite in number. The same + question presents itself in various physical speculations where + certain phenomena are ascribed to the existence of _latent motions_ in + the ultimate constituents of matter. The general theory of such + systems has been treated by E.J. Routh, Lord Kelvin, and H.L.F. + Helmholtz. + + + Routh's equations. + + If we suppose the kinetic energy [Tau] to be expressed, as in + Lagrange's method, in terms of the co-ordinates and the velocities, + the equations of motion corresponding to [chi], [chi]', [chi]'', ... + reduce, in virtue of the above hypotheses, to the forms + + d dP[Tau] d dP[Tau] d dP[Tau] + -- --------- = 0, -- --------- = 0, -- --------- = 0, ..., (1) + dt dP[chi]` dt dP[chi]`' dt dP[chi]`" + + whence + + dP[Tau] dP[Tau] dP[Tau] + -------- = [kappa], --------- = [kappa]', --------- = [kappa]", ..., (2) + dP[chi]` dP[chi]`' dP[chi]`" + + where [kappa], [kappa]', [kappa]", ... are the constant momenta + corresponding to the cyclic co-ordinates [chi], [chi]', [chi]", .... + These equations are linear in [.[chi]], [.[chi]]', [.[chi]]", ...; + solving them with respect to these quantities and substituting in the + remaining Lagrangian equations, we obtain m differential equations to + determine the remaining co-ordinates q1, q2, ... q_m. The object of + the present investigation is to ascertain the general form of the + resulting equations. The retained co-ordinates q1, q2, ... q_m may be + called (for distinction) the _palpable_ co-ordinates of the system; in + many practical questions they are the only co-ordinates directly in + evidence. + + If, as in Sec. 1 (25), we write + + R = [Tau] - [kappa][chi]` - [kappa]'[chi]`' - [kappa]"[chi]`" - ..., (3) + + and imagine R to be expressed by means of (2) as a quadratic function + of q`1, q`2, ... q`_m, [kappa], [kappa]', [kappa]", ... with + coefficients which are in general functions of the co-ordinates q1, + q2, ... q_m, then, performing the operation [delta] on both sides, we + find + + dPR dPR dPR dP[Tau] dP[Tau] + -----[delta]q`1 + ... + ---------[delta][kappa] + ... + ----[delta]q1 + ... = -------[delta]q`1 + ... + -------[delta]q1 + ... + dPq`1 dP[kappa] dPq1 dPq`1 dPq1 + + dP[Tau] dP[Tau] + + --------[delta][chi]` + ... + --------[delta]q1 + ... - [kappa][delta][chi]` - [chi]`[delta][kappa] - .... (4) + dP[chi]` dP[chi]1 + + Omitting the terms which cancel by (2), we find + + dP[Tau] dPR dP[Tau] dPR + ------- = -----, ------- = -----, ..., (5) + dPq`1 dPq`1 dPq`2 dPq`2 + + dP[Tau] dPR dP[Tau] dPR + ------- = ----, ------- = ----, ..., (6) + dPq1 dPq1 dPq2 dPq2 + + dPR dPR dPR + [chi]` = - ---------, [chi]`' = - ----------, [chi]`" = - ----------, ... (7) + dP[kappa] dP[kappa]' dP[kappa]" + + Substituting in Sec. 2 (10), we have + + d dPR dPR d dPR dPR + -- ----- - ----- = Q1, -- ----- - ---- = Q2, ... (8) + dt dPq`1 dPq1 dt dPq`2 dPq2 + + These are Routh's forms of the modified Lagrangian equations. + Equivalent forms were obtained independently by Helmholtz at a later + date. + + + Kelvin's equations. + + The function R is made up of three parts, thus + + R = R(2,0) + R(1,1) + R(0,2), ... (9) + + where R(2,0) is a homogeneous quadratic function of q`1, q`2, ... + q`_m, R(0,2) is a homogeneous quadratic function of [kappa], [kappa]', + [kappa]", ..., whilst R(1,1) consists of products of the velocities + q`1, q`2, ... q`_m into the momenta [kappa], [kappa]', [kappa]".... + Hence from (3) and (7) we have + + / dPR dPR dPR \ + [Tau] = R - ( [kappa] --------- + [kappa]'---------- + [kappa]" ---------- + ...) + \ dP[kappa] dP[kappa]' dP[kappa]" / + + = R(2,0) - R(0,2). (10) + + If, as in Sec. 1 (30), we write this in the form + + [Tau] = [@] + [Kappa], (11) + + then (3) may be written + + R = [@] - [Kappa] + ss1q`1 + ss2q`2 + ..., (12) + + where ss1, ss2, ... are linear functions of [kappa], [kappa]', [kappa]", + ..., say + + ss_r = [alpha]_r[kappa] + [alpha]'_r[kappa]' + [alpha]"_r[kappa]" + ..., (13) + + the coefficients [alpha]_r, [alpha]'_r, [alpha]"_r, ... being in + general functions of the co-ordinates q1, q2, ... q_m. Evidently ss_r + denotes that part of the momentum-component dPR/dPq`_r which is due to + the cyclic motions. Now + + d dPR d / dP[@] \ d dP[@] dPss_r dPss_r + -- ------ = -- ( ------ + ss_r) = -- ------ + -----q`1 + -----q`2 + ..., (14) + dt dPq`_r dt \dPq`_r / dt dPq`_r dPq1 dPq2 + + dPR dP[@] dP[Kappa] dPss1 dPss2 + ----- = ----- - --------- + -----q`1 + -----q`2 + .... (15) + dPq_r dPq_r dPq_r dPq_r dPq_r + + Hence, substituting in (8), we obtain the typical equation of motion + of a gyrostatic system in the form + + d dP[@] dP[@] dP[Kappa] + -- ------ - ----- + (r, 1)q`1 + (r, 2)q`2 + ... + (r, s)q`_s + ... + --------- = Q_r, (16) + dt dPq`_r dPq_r dPq_r + + where + + dPss_r dPss_s + (r, s) = ----- - -----. (17) + dPq_s dPq_r + + This form is due to Lord Kelvin. When q1, q2, ... q_m have been + determined, as functions of the time, the velocities corresponding to + the cyclic co-ordinates can be found, if required, from the relations + (7), which may be written + + dP[Kappa] \ + [Chi]` = --------- - [alpha]1q`1 - [alpha]2q`2 - ..., | + dP[kappa] | + | + dP[Kappa] > (18) + [Chi]`' = ---------- - [alpha]'1q`1 - [alpha]'2q`2 - ..., | + dP[kappa]' | + | + &c., &c. / + + It is to be particularly noticed that + + (r, r) = 0, (r, s) = -(s, r). (19) + + Hence, if in (16) we put r = 1, 2, 3, ... m, and multiply by q`1, + q`2, ... q`_m respectively, and add, we find + + d + --([@] + [Kappa]) = Q1q`1 + Q2q`2 + ..., (20) + dt + + or, in the case of a conservative system + + [@] + V + [Kappa] = const., (21) + + which is the equation of energy. + + The equation (16) includes Sec. 3 (17) as a particular case, the + eliminated co-ordinate being the angular co-ordinate of a rotating + solid having an infinite moment of inertia. + + In the particular case where the cyclic momenta [kappa], [kappa]', + [kappa]", ... are all zero, (16) reduces to + + d dP[@] dP[@] + -- ------ - ----- = Q_r. (22) + dt dPq`_r dPq_r + + The form is the same as in Sec. 2, and the system now behaves, as regards + the co-ordinates q1, q2, ... q_m, exactly like the acyclic type there + contemplated. These co-ordinates do not, however, now fix the position + of every particle of the system. For example, if by suitable forces + the system be brought back to its initial configuration (so far as + this is defined by q1, q2, ..., q_m), after performing any evolutions, + the ignored co-ordinates [chi], [chi]', [chi]", ... will not in + general return to their original values. + + If in Lagrange's equations Sec. 2 (10) we reverse the sign of the + time-element dt, the equations are unaltered. The motion is therefore + reversible; that is to say, if as the system is passing through any + configuration its velocities q`1, q`2, ..., q`_m be all + reversed, it will (if the forces be the same in the same + configuration) retrace its former path. But it is important to observe + that the statement does not in general hold of a gyrostatic system; + the terms of (16), which are linear in q`1, q`2, ..., q`_m, + change sign with dt, whilst the others do not. Hence the motion of a + gyrostatic system is not reversible, unless indeed we reverse the + cyclic motions as well as the velocities q`1, q`2, ..., q`_m. + For instance, the precessional motion of a top cannot be reversed + unless we reverse the spin. + + + Kinetostatics. + + The _conditions of equilibrium_ of a system with latent cyclic motions + are obtained by putting q`1 = 0, q`2 = 0, ... q`_m = 0 in (16); viz. + they are + + dP[Kappa] dP[Kappa] + Q1 = ---------, Q2 = ---------, ... (23) + dPq1 dPq2 + + These may of course be obtained independently. Thus if the system be + guided from (apparent) rest in the configuration (q1, q2, ... q_m) to + rest in the configuration q1 + [delta]q1, q2 + [delta]q2, ..., q_m + + [delta]q_m, the work done by the forces must be equal to the increment + of the kinetic energy. Hence + + Q1[delta]q1 + Q2[delta]q2 + ... = [delta][Kappa], (24) + + which is equivalent to (23). The conditions are the same as for the + equilibrium of a system without latent motion, but endowed with + potential energy [Kappa]. This is important from a physical point of + view, as showing how energy which is apparently potential may in its + ultimate essence be kinetic. + + By means of the formulae (18), which now reduce to + + dP[Kappa] dP[Kappa] dP[Kappa] + [chi]` = ---------, [chi]`' = ----------, [chi]`" = ---------- ..., (25) + dP[kappa] dP[kappa]' dP[kappa]" + + [Kappa] may also be expressed as a homogeneous quadratic function of + the cyclic velocities [.[chi]], [.[chi]]', [.[chi]]", ... Denoting it + in this form by [Tau]0, we have + + [delta]([Tau]0 + [Kappa] = 2[delta][Kappa] = [delta]([kappa] [chi]` + [kappa]'[chi]`' + [kappa]"[chi]`" + ...). (26) + + Performing the variations, and omitting the terms which cancel by (2) + and (25), we find + + dP[Tau]0 dP[Kappa] dP[Tau]0 dP[Kappa] + -------- = - ---------, -------- = - ---------, ..., (27) + dPq1 dPq1 dPq2 dPq2 + + so that the formulae (23) become + + dP[Tau]0 dP[Tau]0 + Q1 = - --------, Q2 = - --------, ... (28) + dPq1 dPq2 + + A simple example is furnished by the top (MECHANICS, Sec. 22). The cyclic + co-ordinates being [psi], [phi], we find + + ( mu - [nu] cos [theta]) squared [nu] squared + 2[@] = A[theta]` squared, 2[Kappa] = ----------------------- + -----, + A sin squared [theta] C + + 2[Tau]0 = A sin squared[theta][psi]` squared + C([phi]` + [psi] cos [theta]) squared, (29) + + whence we may verify that dP[Tau]0/dP[theta] = - dP[Kappa]/dP[theta] + in accordance with (27). And the condition of equilibrium + + dP[Kappa] dPV + --------- = - --------- (30) + dP[theta] dP[theta] + + gives the condition of steady precession. + + + 6. _Stability of Steady Motion._ + + The small oscillations of a conservative system about a configuration + of equilibrium, and the criterion of stability, are discussed in + MECHANICS, Sec. 23. The question of the stability of given types of + motion is more difficult, owing to the want of a sufficiently general, + and at the same time precise, definition of what we mean by + "stability." A number of definitions which have been propounded by + different writers are examined by F. Klein and A. Sommerfeld in their + work _Ueber die Theorie des Kreisels_ (1897-1903). Rejecting previous + definitions, they base their criterion of stability on the character + of the changes produced in the _path_ of the system by small arbitrary + disturbing impulses. If the undisturbed path be the _limiting form_ of + the disturbed path when the impulses are indefinitely diminished, it + is said to be stable, but not otherwise. For instance, the vertical + fall of a particle under gravity is reckoned as stable, although for a + _given_ impulsive disturbance, however small, the deviation of the + particle's position at any time t from the position which it would + have occupied in the original motion increases indefinitely with t. + Even this criterion, as the writers quoted themselves recognize, is + not free from ambiguity unless the phrase "limiting form," as applied + to a path, be strictly defined. It appears, moreover, that a + definition which is analytically precise may not in all cases be easy + to reconcile with geometrical prepossessions. Thus a particle moving + in a circle about a centre of force varying inversely as the cube of + the distance will if slightly disturbed either fall into the centre, + or recede to infinity, after describing in either case a spiral with + an infinite number of convolutions. Each of these spirals has, + analytically, the circle as its limiting form, although the motion in + the circle is most naturally described as unstable. + + A special form of the problem, of great interest, presents itself in + the steady motion of a gyrostatic system, when the non-eliminated + co-ordinates q1, q2, ... q_m all vanish (see Sec. 5). This has been + discussed by Routh, Lord Kelvin and Tait, and Poincare. These writers + treat the question, by an extension of Lagrange's method, as a problem + of small oscillations. Whether we adopt the notion of stability which + this implies, or take up the position of Klein and Sommerfeld, there + is no difficulty in showing that stability is ensured if V + [Kappa] + be a minimum as regards variations of q1, q2, ... q_m. The proof is + the same as that of Dirichlet for the case of statical stability. + + We can illustrate this condition from the case of the top, where, in + our previous notation, + + ( mu - [nu]cos [theta]) squared [nu] squared + V + [Kappa] = Mgh cos[theta] + ---------------------- + -----. (1) + 2A sin squared [theta] 2C + + To examine whether the steady motion with the centre of gravity + vertically above the pivot is stable, we must put mu = [nu]. We then + find without difficulty that V + [Kappa] is a minimum provided [nu] squared + [>=] 4AMgh. The method of small oscillations gave us the condition + [nu] squared > 4AMgh, and indicated instability in the cases [nu] squared [=<] + 4AMgh. The present criterion can also be applied to show that the + steady precessional motions in which the axis has a constant + inclination to the vertical are stable. + + The question remains, as before, whether it is _essential_ for + stability that V + [Kappa] should be a minimum. It appears that from + the point of view of the theory of small oscillations it is not + essential, and that there may even be stability when V + [Kappa] is a + maximum. The precise conditions, which are of a somewhat elaborate + character, have been formulated by Routh. An important distinction + has, however, been established by Thomson and Tait, and by Poincare, + between what we may call _ordinary_ or _temporary_ stability (which is + stability in the above sense) and _permanent_ or _secular_ stability, + which means stability when regard is had to possible dissipative + forces called into play whenever the co-ordinates q1, q2, ... q_m + vary. Since the total energy of the system at any instant is given (in + the notation of Sec. 5) by an expression of the form [@] + V + + [Kappa], where [@] cannot be negative, the argument of Thomson + and Tait, given under MECHANICS, Sec. 23, for the statical question, + shows that it is a necessary as well as a sufficient condition for + secular stability that V + [Kappa] should be a minimum. When a system + is "ordinarily" stable, but "secularly" unstable, the operation of the + frictional forces is to induce a gradual increase in the amplitude of + the free vibrations which are called into play by accidental + disturbances. + + There is a similar theory in relation to the constrained systems + considered in Sec. 3 above. The equation (21) there given leads to the + conclusion that for secular stability of any type of motion in which + the velocities q`1, q`2, ... q`_n are zero it is necessary and + sufficient that the function V - [Tau]0 should be a minimum. + + The simplest possible example of this is the case of a particle at the + lowest point of a smooth spherical bowl which rotates with constant + angular velocity ([omega]) about the vertical diameter. This position + obviously possesses "ordinary" stability. If a be the radius of the + bowl, and [theta] denote angular distance from the lowest point, we + have + + V - [Tau]0 = mga(1 - cos [theta]) - 1/2m[omega] squareda squared sin squared [theta]; (2) + + this is a minimum for [theta] = 0 only so long as [omega] squared < g/a. For + greater values of [omega] the only position of "permanent" stability + is that in which the particle rotates with the bowl at an angular + distance cos^(-1) (g/[omega] squareda) from the lowest point. To examine the + motion in the neighbourhood of the lowest point, when frictional + forces are taken into account, we may take fixed ones, in a horizontal + plane, through the lowest point. Assuming that the friction varies as + the relative velocity, we have + + x" = -p squaredx - k(x` + [omega]y), \ (3) + y" = -p squaredy - k(y` - [omega]x), / + + where p squared = g/a. These combine into + + z" + kz` + (p squared - ik[omega])z = 0, (4) + + where z = x + iy, i = [root]-1. Assuming z = Ce^([lambda]t), we find + + [lambda] = -1/2k(1 [-+] [omega]/p) +- ip, (5) + + if the square of k be neglected. The complete solution is then + + x + iy = C1e^(-ss1t)e^(ipt) + C2e^(-ss2t)e^(-ipt), (6) + + where ss1 = 1/2k(1 - [omega]/p), ss2 = 1/2k(1 + [omega]/p). (7) + + This represents two superposed circular vibrations, in opposite + directions, of period 2[pi]/p. If [omega] < p, the amplitude of each + of these diminishes asymptotically to zero, and the position x = 0, y + = 0 is permanently stable. But if [omega] > p the amplitude of that + circular vibration which agrees in sense with the rotation [omega] + will continually increase, and the particle will work its way in an + ever-widening spiral path towards the eccentric position of secular + stability. If the bowl be not spherical but ellipsoidal, the vertical + diameter being a principal axis, it may easily be shown that the + lowest position is permanently stable only so long as the period of + the rotation is longer than that of the slower of the two normal + modes in the absence of rotation (see MECHANICS, Sec. 13). + + + 7. _Principle of Least Action._ + + Stationary Action. + + The preceding theories give us statements applicable to the system at + any one instant of its motion. We now come to a series of theorems + relating to the whole motion of the system between any two + configurations through which it passes, viz. we consider the actual + motion and compare it with other imaginable motions, differing + infinitely little from it, between the same two configurations. We use + the symbol [delta] to denote the transition from the actual to any one + of the hypothetical motions. + + The best-known theorem of this class is that of _Least Action_, + originated by P.L.M. de Maupertuis, but first put in a definite form + by Lagrange. The "action" of a single particle in passing from one + position to another is the space-integral of the momentum, or the + time-integral of the _vis viva_. The action of a dynamical system is + the sum of the actions of its constituent particles, and is + accordingly given by the formula + _ _ _ + / / / + A = [Sigma] | mvds = [Sigma] | mv squareddt = 2 | [Tau]dt. (1) + _/ _/ _/ + + The theorem referred to asserts that the free motion of a conservative + system between any two given configurations is characterized by the + property + + [delta]A = 0, (2) + + provided the total energy have the same constant value in the varied + motion as in the actual motion. + + If t, t' be the times of passing through the initial and final + configurations respectively, we have + _ + / t' + [delta]A = [delta] | [Sigma]m(x` squared + y` squared + z` squared)dt + _/t + _ + / t' + = 2 | [delta][Tau]dt + 2[Tau]'[delta]t' + 2[Tau][delta]t, (3) + _/t + + since the upper and lower limits of the integral must both be regarded + as variable. This may be written + _ _ + / t' / t' + [delta]A = | [delta][Tau]dt + | [Sigma]m(x`[delta]x` + y`[delta]y` + z`[delta]z`)dt + 2[Tau]'[delta]t' - 2[Tau][delta]t + _/t _/t + _ _ _ + / t' | | t' + = | [delta][Tau]dt + | [Sigma]m (x`[delta]x + y`[delta]y + z`[delta]z | + _/t |_ _| t + _ + / t' + - | [Sigma]m(x"[delta]x + y"[delta]y + z"[delta]z)dt + 2[Tau]'[delta]t' - 2[Tau][delta]t. (4) + _/t + + Now, by d'Alembert's principle, + + [Sigma]m( x"[delta]x + y"[delta]y + z"[delta]z ) = -[delta]V, (5) + + and by hypothesis we have + + [delta]([Tau] + V) = 0. (6) + + The formula therefore reduces to + _ _ + | |t' + [delta]A = | [Sigma]m (x`[delta]x + y`[delta]y + z`[delta]z) | + 2[Tau]'[delta]t' - 2[Tau][delta]t. (7) + |_ _|t + + Since the terminal configurations are unaltered, we must have at the + lower limit + + [delta]x + x`[delta]t = 0, [delta]y + y`[delta]t = 0, [delta]z + z`[delta]t = 0, (8) + + with similar relations at the upper limit. These reduce (7) to the + form (2). + + The equation (2), it is to be noticed, merely expresses that the + variation of A vanishes _to the first order_; the phrase _stationary + action_ has therefore been suggested as indicating more accurately + what has been proved. The action in the free path between two given + configurations is in fact not invariably a minimum, and even when a + minimum it need not be the _least possible_ subject to the given + conditions. Simple illustrations are furnished by the case of a single + particle. A particle moving on a smooth surface, and free from + extraneous force, will have its velocity constant; hence the theorem + in this case resolves itself into + _ + / + [delta] | ds = 0, (9) + _/ + + i.e. the path must be a geodesic line. Now a geodesic is not + necessarily the _shortest_ path between two given points on it; for + example, on the sphere a great-circle arc ceases to be the shortest + path between its extremities when it exceeds 180 deg.. More generally, + taking any surface, let a point P, starting from O, move along a + geodesic; this geodesic will be a minimum path from O to P until P + passes through a point O' (if such exist), which is the intersection + with a consecutive geodesic through O. After this point the minimum + property ceases. On an anticlastic surface two geodesics cannot + intersect more than once, and each geodesic is therefore a minimum + path between any two of its points. These illustrations are due to + K.G.J. Jacobi, who has also formulated the general criterion, + applicable to all dynamical systems, as follows:--Let O and P denote + any two configurations on a natural path of the system. If this be the + sole free path from O to P with the prescribed amount of energy, the + action from O to P is a minimum. But if there be several distinct + paths, let P vary from coincidence with O along the first-named path; + the action will then cease to be a minimum when a configuration O' is + reached such that two of the possible paths from O to O' coincide. For + instance, if O and P be positions on the parabolic path of a + projectile under gravity, there will be a second path (with the same + energy and therefore the same velocity of projection from O), these + two paths coinciding when P is at the other extremity (O', say) of the + focal chord through O. The action from O to P will therefore be a + minimum for all positions of P short of O'. Two configurations such as + O and O' in the general statement are called conjugate _kinetic foci_. + Cf. VARIATIONS, CALCULUS OF. + + Before leaving this topic the connexion of the principle of stationary + action with a well-known theorem of optics may be noticed. For the + motion of a particle in a conservative field of force the principle + takes the form + _ + / + [delta] | vds = 0. (10) + _/ + + On the corpuscular theory of light v is proportional to the refractive + index mu of the medium, whence + _ + / + [delta] | muds = 0. (11) + _/ + + + Hamiltonian principle. + + In the formula (2) the energy in the hypothetical motion is + prescribed, whilst the time of transit from the initial to the final + configuration is variable. In another and generally more convenient + theorem, due to Hamilton, the time of transit is prescribed to be the + same as in the actual motion, whilst the energy may be different and + need not (indeed) be constant. Under these conditions we have + _ + /t' + [delta] | ([Tau] - V)dt = 0, (12) + _/t + + where t, t' are the prescribed times of passing through the given + initial and final configurations. The proof of (12) is simple; we have + _ _ _ + /t' /t' /t' + [delta] | ([Tau] - V)dt = | ([delta][Tau] - [delta]V)dt = | {[Sigma]m(x`[delta]x` + y`[delta]y` + z`[delta]z`) - [delta]V}dt + _/t _/t _/t + _ _ + | |t' + = | [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z) | + |_ _|t + _ + /t' + - | {[Sigma]m(x"[delta]x + y"[delta]y + z"[delta]z) + [delta]V}dt (13) + _/t + + The integrated terms vanish at both limits, since by hypothesis the + configurations at these instants are fixed; and the terms under the + integral sign vanish by d'Alembert's principle. + + The fact that in (12) the variation does not affect the time of + transit renders the formula easy of application in any system of + co-ordinates. Thus, to deduce Lagrange's equations, we have + + _ _ + /t' /t'/dP[Tau] dP[Tau] dPV \ + | ([delta][Tau]-[delta]V)dt = | ( -------[delta]q`1 + -------[delta]q1 + ... - ----[delta]q1 - ...)dt + _/t _/t \ dPq`1 dPq1 dPq1 / + _ _ + | |t' + = | p1[delta]q1 + p2[delta]q2 + ... | + |_ _|t + + _ _ _ + /t'| / dP[Tau] dPV \ / dP[Tau] dPV\ | + - | | (p`1 - ------- + ---- )[delta]q1 + (p`2 - ------- + -----)[delta]q2 + ...|dt. (14) + _/t |_ \ dPq1 dPq1/ \ dPq2 dPq2/ _| + + The integrated terms vanish at both limits; and in order that the + remainder of the right-hand member may vanish it is necessary that the + coefficients of [delta]q1, [delta]q2, ... under the integral sign + should vanish for all values of t, since the variations in question + are independent, and subject only to the condition of vanishing at the + limits of integration. We are thus led to Lagrange's equation of + motion for a conservative system. It appears that the formula (12) is + a convenient as well as a compact embodiment of the whole of ordinary + dynamics. + + + Extension to cyclic systems. + + The modification of the Hamiltonian principle appropriate to the case + of cyclic systems has been given by J. Larmor. If we write, as in Sec. 1 + (25), + + R = T - [kappa][chi]` - [kappa]'[chi]`' - [kappa]''[chi]`" - ..., (15) + + we shall have + _ + /t' + [delta] | (R - V)dt = 0, (16) + _/t + + provided that the variation does not affect the cyclic momenta + [kappa], [kappa]', [kappa]", ..., and that the configurations at times + t and t' are unaltered, so far as they depend on the palpable + co-ordinates q1, q2, ... q_m. The initial and final values of the + ignored co-ordinates will in general be affected. + + To prove (16) we have, on the above understandings, + _ _ + /t' /t' + [delta] | (R - V)dt = | ([delta][Tau] - [kappa][delta][chi]` - ... -[delta]V)dt + _/t _/t + _ + /t' /dP[Tau] dP[Tau] \ + = | ( -------[delta]q`1 + ... + -------[delta]q1 + ... - [delta]V )dt, (17) + _/t \ dPq`1 dPq1 / + + where terms have been cancelled in virtue of Sec. 5 (2). The last member + of (17) represents a variation of the integral + _ + /t' + | ([Tau] - V)dt + _/t + + on the supposition that [delta]X = 0, [delta]X' = 0, [delta]X" = 0, + ... throughout, whilst [delta]q1, [delta]q2, [delta]q_m vanish at + times t and t'; i.e. it is a variation in which the initial and final + configurations are absolutely unaltered. It therefore vanishes as a + consequence of the Hamiltonian principle in its original form. + + Larmor has also given the corresponding form of the principle of least + action. He shows that if we write + _ + / + A = |(2[Tau] - [kappa][chi]` - [kappa]'[chi]`' - [kappa]"[chi]`" - ...)dt, (18) + _/ + + then + + [delta]A = 0, (19) + + provided the varied motion takes place with the same constant value of + the energy, and with the same constant cyclic momenta, between the + same two configurations, these being regarded as defined by the + palpable co-ordinates alone. + + + Sec. 8. _Hamilton's Principal and Characteristic Functions._ + + Principal function. + + In the investigations next to be described a more extended meaning is + given to the symbol [delta]. We will, in the first instance, denote by + it an infinitesimal variation of the most general kind, affecting not + merely the values of the co-ordinates at any instant, but also the + initial and final configurations and the times of passing through + them. If we put + _ + /t' + S = | (T - V)dt, (1) + _/t + + we have, then, + _ + /t' + [delta]S = (T' - V')[delta]t' - (T - V)[delta]t + | ([delta]T - [delta]V)dt + _/t + _ _ + | |t' + = (T' - V')[delta]t' - (T - V)[delta]t + |[Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z)| (2) + |_ _|t + + Let us now denote by x' + [delta]x', y' + [delta]y', z' + [delta]z', + the final co-ordinates (i.e. at time t' + [delta]t') of a particle m. + In the terms in (2) which relate to the upper limit we must therefore + write [delta]x' - x`'[delta]t', [delta]y' - y`'[delta]t', + [delta]z' - z`'[delta]t' for [delta]x, [delta]y, [delta]z. With a + similar modification at the lower limit, we obtain + + [delta]S = - H[delta][tau] + [Sigma]m(x`'[delta]x' + y`'[delta]y' + z`'[delta]z') + - [Sigma]m(x`[delta]x + y`[delta]y + z`[delta]z), (3) + + where H(= T + V) is the constant value of the energy in the free + motion of the system, and [tau](= t' - t) is the time of transit. In + generalized co-ordinates this takes the form + + [delta]S = - H[delta][tau] + p'1[delta]q'1 + p'2[delta]q'2 + ... + - p1[delta]q1 - p2[delta]q2 - .... (4) + + Now if we select any two arbitrary configurations as initial and + final, it is evident that we can in general (by suitable initial + velocities or impulses) start the system so that it will of itself + pass from the first to the second in any prescribed time [tau]. On + this view of the matter, S will be a function of the initial and final + co-ordinates (q1, q2, ... and q'1, q'2, ...) and the time [tau], as + independent variables. And we obtain at once from (4) + + dPS dPS \ + p'1 = -----, p'2 = -----, ..., | + dPq'1 dPq'2 | + > (5) + dPS dPS | + p1 = - ----, p2 = - ----, ..., | + dPq1 dPq2 / + + dPS + and H = - -------. (6) + dP[tau] + + S is called by Hamilton the _principal function_; if its general form + for any system can be found, the preceding equations suffice to + determine the motion resulting from any given conditions. If we + substitute the values of p1, p2, ... and H from (5) and (6) in the + expression for the kinetic energy in the form [Tau]' (see Sec. 1), the + equation + + T¹ + V = H (7) + + becomes a partial differential equation to be satisfied by S. It has + been shown by Jacobi that the dynamical problem resolves itself into + obtaining a "complete" solution of this equation, involving n + 1 + arbitrary constants. This aspect of the subject, as a problem in + partial differential equations, has received great attention at the + hands of mathematicians, but must be passed over here. + + + Characteristic function. + + There is a similar theory for the function + _ + / + A = 2 | Tdt = S + H[tau] (8) + _/ + + It follows from (4) that + + [delta]A = [tau][delta]H + p'1[delta]q'1 + p'2[delta]q'2 + ... + - p1[delta]q1 - p2[delta]q2 - .... (9) + + This formula (it may be remarked) contains the principle of "least + action" as a particular case. Selecting, as before, any two arbitrary + configurations, it is in general possible to start the system from one + of these, with a prescribed value of the total energy H, so that it + shall pass through the other. Hence, regarding A as a function of the + initial and final co-ordinates and the energy, we find + + dPA dPA \ + p'1 = -----, p'2 = -----, ..., | + dPq'1 dPq'2 | + > (10) + dPA dPA | + p1 = - ----, p2 = - ----, ..., | + dPq1 dPq2 / + + dPA + and [tau] = --- (11) + dPH + + A is called by Hamilton the _characteristic function_; it represents, + of course, the "action" of the system in the free motion (with + prescribed energy) between the two configurations. Like S, it + satisfies a partial differential equation, obtained by substitution + from (10) in (7). + + The preceding theorems are easily adapted to the case of cyclic + systems. We have only to write + _ _ + /t' /t' + S = | (R - V)dt= | (T - [kappa][chi]` - [kappa]'[chi]`' - ... - V)dt (12) + _/t _/t + + in place of (1), and + _ + / + A = | (2T - [kappa][chi]` - [kappa]'[chi]`' - ...)dt, (3) + _/ + + in place of (8); cf. Sec. 7 ad fin. It is understood, of course, that in + (12) S is regarded as a function of the initial and final values of + the palpable co-ordinates q1, q2, ... q_m, and of the time of transit + [tau], the cyclic momenta being invariable. Similarly in (13), A is + regarded as a function of the initial and final values of q1, q2, ... + q_m, and of the total energy H, with the cyclic momenta invariable. It + will be found that the forms of (4) and (9) will be conserved, + provided the variations [delta]q1, [delta]q2, ... be understood to + refer to the palpable co-ordinates alone. It follows that the + equations (5), (6) and (10), (11) will still hold under the new + meanings of the symbols. + + + 9. _Reciprocal Properties of Direct and Reversed Motions._ + + Lagrange's formula. + + We may employ Hamilton's principal function to prove a very remarkable + formula connecting any _two_ slightly disturbed natural motions of the + system. If we use the symbols [delta] and [Delta] to denote the + corresponding variations, the theorem is + + d + --[Sigma]([delta]p_r.[Delta]q_r - [Delta]p_r.[delta]q_r) = 0; (1) + dt + + or integrating from t to t', + + [Sigma]([delta]p'_r.[Delta]q'_r - [Delta]q'_r.[delta]q'_r) = [Sigma]([delta]p_r.[Delta]q_r - [Delta]p_r.[delta]q_r). (2) + + If for shortness we write + + dP squaredS dP squaredS + (r,s) = ----------, (r,s') = -----------, (3) + dPq_rdPq_s dPq_rdPq'_s + + we have + + dPp_r = - [Sigma]_s(r,s)[delta]q_s - [Sigma]_s(r,s')[delta]q'_s (4) + + with a similar expression for [Delta]p_r. Hence the right-hand side of + (2) becomes + + - [Sigma]_r{[Sigma]_s(r,s)[delta]q_s + [Sigma]_s(r,s')[delta]q'_s}[Delta]q_r + + [Sigma]_r{[Sigma]_s(r,s)[Delta]q_s + [Sigma]_s(r,s')[Delta]q'_s}[delta]q_r + = [Sigma]_r[Sigma]_s(r,s'){[delta]q_r.[Delta]q'_s - [Delta]q_r.[delta]q'_s}. (5) + + The same value is obtained in like manner for the expression on the + left hand of (2); hence the theorem, which, in the form (1), is due to + Lagrange, and was employed by him as the basis of his method of + treating the dynamical theory of _Variation of Arbitrary Constants_. + + + Helmholtz's reciprocal theorems. + + The formula (2) leads at once to some remarkable reciprocal relations + which were first expressed, in their complete form, by Helmholtz. + Consider any natural motion of a conservative system between two + configurations O and O' through which it passes at times t and t' + respectively, and let t' - t = [tau]. As the system is passing through + O let a small impulse [delta]p_r be given to it, and let the + consequent alteration in the co-ordinate q_s after the time [tau] be + [delta]q'_s. Next consider the _reversed_ motion of the system, in + which it would, if undisturbed, pass from O' to O in the same time + [tau]. Let a small impulse [delta]p'_s be applied as the system is + passing through O', and let the consequent change in the co-ordinate + q_r after a time [tau] be [delta]q_r. Helmholtz's first theorem is to + the effect that + + [delta]q_r : [delta]p'_s = [delta]q'_s : [delta]p_r. (6) + + To prove this, suppose, in (2), that all the [delta]q vanish, and + likewise all the [delta]p with the exception of [delta]p_r. Further, + suppose all the [Delta]q' to vanish, and likewise all the [Delta]p' + except [Delta]p'_s, the formula then gives + + [delta]p_r.[Delta]q_r = - [Delta]p'_s.[delta]q'_s, (7) + + which is equivalent to Helmholtz's result, since we may suppose the + symbol [Delta] to refer to the reversed motion, provided we change + the signs of the [Delta]p. In the most general motion of a top + (MECHANICS, Sec. 22), suppose that a small impulsive couple about the + vertical produces after a time [tau] a change [delta][theta] in the + inclination of the axis, the theorem asserts that in the reversed + motion an equal impulsive couple in the plane of [theta] will produce + after a time [tau] a change [delta][psi], in the azimuth of the axis, + which is equal to [delta][theta]. It is understood, of course, that + the couples have no components (in the generalized sense) except of + the types indicated; for instance, they may consist in each case of a + force applied to the top at a point of the axis, and of the + accompanying reaction at the pivot. Again, in the corpuscular theory + of light let O, O' be any two points on the axis of a symmetrical + optical combination, and let V, V' be the corresponding velocities of + light. At O let a small impulse be applied perpendicular to the axis + so as to produce an angular deflection [delta][theta], and let ss' + be the corresponding lateral deviation at O'. In like manner in the + reversed motion, let a small deflection [delta][theta]' at O' produce + a lateral deviation ss at O. The theorem (6) asserts that + + ss ss' + ----------------- = ---------------, (8) + V'[delta][theta]' V[delta][theta] + + or, in optical language, the "apparent distance" of O from O' is to + that of O' from O in the ratio of the refractive indices at O' and O + respectively. + + + Helmholtz's second reciprocal theorem. + + In the second reciprocal theorem of Helmholtz the configuration O is + slightly varied by a change [delta]q_r in one of the co-ordinates, the + momenta being all unaltered, and [delta]q'_s is the consequent + variation in one of the momenta after time [tau]. Similarly in the + reversed motion a change [delta]p'_s produces after time [tau] a + change of momentum [delta]p_r. The theorem asserts that + + [delta]p'_s : [delta]q_r = [delta]p_r : [delta]q'_s (9) + + This follows at once from (2) if we imagine all the [delta]p to + vanish, and likewise all the [delta]q save [delta]q_r, and if + (further) we imagine all the [Delta]p' to vanish, and all the + [Delta]q' save [Delta]q'_s. Reverting to the optical illustration, if + F, F', be principal foci, we can infer that the convergence at F' of a + parallel beam from F is to the convergence at F of a parallel beam + from F' in the inverse ratio of the refractive indices at F' and F. + This is equivalent to Gauss's relation between the two principal focal + lengths of an optical instrument. It may be obtained otherwise as a + particular case of (8). + + We have by no means exhausted the inferences to be drawn from + Lagrange's formula. It may be noted that (6) includes as particular + cases various important reciprocal relations in optics and acoustics + formulated by R.J.E. Clausius, Helmholtz, Thomson (Lord Kelvin) and + Tait, and Lord Rayleigh. In applying the theorem care must be taken + that in the reversed motion the reversal is complete, and extends to + every velocity in the system; in particular, in a cyclic system the + cyclic motions must be imagined to be reversed with the rest. + Conspicuous instances of the failure of the theorem through incomplete + reversal are afforded by the propagation of sound in a wind and the + propagation of light in a magnetic medium. + + It may be worth while to point out, however, that there is no such + limitation to the use of Lagrange's formula (1). In applying it to + cyclic systems, it is convenient to introduce conditions already laid + down, viz. that the co-ordinates q_r are the palpable co-ordinates and + that the cyclic momenta are invariable. Special inference can then be + drawn as before, but the interpretation cannot be expressed so neatly + owing to the non-reversibility of the motion. + + AUTHORITIES.--The most important and most accessible early authorities + are J.L. Lagrange, _Mecanique analytique_ (1st ed. Paris, 1788, 2nd + ed. Paris, 1811; reprinted in _Oeuvres_, vols. xi., xii., Paris, + 1888-89); Hamilton, "On a General Method in Dynamics," _Phil. Trans._ + 1834 and 1835; C.G.J. Jacobi, _Vorlesungen ueber Dynamik_ (Berlin, + 1866, reprinted in _Werke_, Supp.-Bd., Berlin, 1884). An account of + the extensive literature on the differential equations of dynamics and + on the theory of variation of parameters is given by A. Cayley, + "Report on Theoretical Dynamics," _Brit. Assn. Rep._ (1857), + _Mathematical Papers_, vol. iii. (Cambridge, 1890). For the modern + developments reference may be made to Thomson and Tait, _Natural + Philosophy_ (1st ed. Oxford, 1867, 2nd ed. Cambridge, 1879); Lord + Rayleigh, _Theory of Sound_, vol. i. (1st ed. London, 1877; 2nd ed. + London, 1894); E.J. Routh, _Stability of Motion_ (London, 1877), and + _Rigid Dynamics_ (4th ed. London, 1884); H. Helmholtz, "Ueber die + physikalische Bedeutung des Prinzips der kleinsten Action," _Crelle_, + vol. c., 1886, reprinted (with other cognate papers) in _Wiss. Abh._ + vol. iii. (Leipzig, 1895); J. Larmor, "On Least Action," _Proc. Lond. + Math. Soc._ vol. xv. (1884); E.T. Whittaker, _Analytical Dynamics_ + (Cambridge, 1904). As to the question of stability, reference may be + made to H. Poincare, "Sur l'equilibre d'une masse fluide animee d'un + mouvement de rotation" _Acta math._ vol. vii. (1885); F. Klein and A. + Sommerfeld, _Theorie des Kreisels_, pts. 1, 2 (Leipzig, 1897-1898); A. + Lioupanoff and J. Hadamard, _Liouville_, 5me serie, vol. iii. (1897); + T.J.I. Bromwich, Proc. Lond. Math. Soc. vol. xxxiii. (1901). A + remarkable interpretation of various dynamical principles is given by + H. Hertz in his posthumous work _Die Prinzipien der Mechanik_ + (Leipzig, 1894), of which an English translation appeared in 1900. + (H. Lb.) + + + + +DYNAMITE (Gr. [Greek: dynamis], power), the name given to several +explosive preparations containing nitroglycerin (q.v.) which are almost +exclusively used for blasting purposes. The first practical application +of nitroglycerin in this way was made by A. Nobel in 1863. He soaked +gunpowder with the liquid and fired the gunpowder by an ordinary fuse. +Later he found that nitroglycerin could be detonated by the explosion of +several materials such as fulminate of mercury, the use of which as a +detonator he patented in 1867. In 1866-1867 he experimented with +charcoal and other substances, and found the infusorial earth known as +kieselguhr, which consists mainly of silica (nearly 95%), eminently +adapted to the purpose, as it was inert, non-combustible, and after a +little heating and preparation very porous, retaining a large amount of +nitroglycerin as water is held in a sponge, without very serious +exudation on standing. This kieselguhr dynamite is generally made by +incorporating three parts of nitroglycerin with one part of the dry +earth, the paste being then formed into cylindrical cartridges. This +work is done by hand. Generally a small percentage of the kieselguhr is +replaced by a mixture containing sodium and ammonium carbonates, talc +and ochre. This product is known as dynamite No. 1. Disabilities +attaching to kieselguhr dynamite are that when placed in water the +nitroglycerin is liable to be exuded or displaced, also that, like +nitroglycerin itself, it freezes fairly easily and thawing the frozen +cartridges is a dangerous operation. Other substances, e.g. kaolin, +tripoli, magnesia alba (magnesium carbonate), alumina, sugar, charcoal, +some powdered salts and mixtures of sawdust and salts, have been shown +to be absorbents more or less adapted to the purpose of making a +dynamite. Charcoal from cork is said to absorb about 90% of its weight +of nitroglycerin. With the idea of obtaining greater safety, mixtures +have been made of nitroglycerin with wood fibre, charcoal and metallic +nitrates. Lithofracteur, for instance, consists of 50% nitroglycerin and +a mixture of prepared sawdust, kieselguhr and barium nitrate. Carbonite +contains 25% of nitroglycerin, the remainder being a mixture of +wood-meal and alkali nitrates, with about 1% of sulphur. Dualin, atlas +dynamite and potentite are other modifications. + +A convenient form in which nitroglycerin can be made up for blasting +purposes, especially in wet ground, is the gelatinous material obtained +by the action of nitroglycerin, either alone or with the help of +solvents, on low-grade or soluble gun-cottons. It is known as blasting +gelatin, and was first made by Nobel by incorporating 6 or 7% of low +nitrated cellulose (collodion cotton or soluble gun-cotton) with +slightly warmed nitroglycerin. The result is a transparent plastic +material, of specific gravity 1.5 to 1.6, which may be kept under water +for a long time without appreciable change. It is less sensitive to +detonation than ordinary dynamite, and although its explosion is +slightly slower it is more powerful than dynamite and much superior to +the liquid nitroglycerin. Blasting gelatin also freezes and is sensitive +to percussion in this state. Camphor and other substances have been +added to blasting gelatin to render it more solid and less sensitive. +Some modifications of blasting gelatin, e.g. gelignite, contain +wood-meal and such oxygen-containing salts as potassium nitrate. +Experience has conclusively shown that dynamites are more satisfactory, +quicker, and more intense in action than liquid nitroglycerin. + +To prevent nitroglycerin and some of the forms of dynamite from freezing +it has been proposed to add to them small quantities of either +monochlor-dinitroglycerin or of a nitrated poly-glycerin. The former is +obtained by first acting upon glycerin with hydrogen chloride to produce +_u-_chlorhydrin or chlor-propylene glycol, C3H7O2Cl, which is then +nitrated as in the case of glycerin. The latter is obtained by heating +glycerin for six or seven hours to about 300 deg. C., whereby water is split +off in such manner that a diglycerin C6H14O5, for the most part, +results. This on nitration in the usual manner gives a product +C6H{10}N4O{13}, which burns and explodes in a similar manner to ordinary +nitroglycerin, but is less sensitive and does not so easily freeze. The +mono- and di-nitrates of glycerin have also been proposed as additions +to ordinary nitroglycerin (q.v.) for the same purpose. (W. R. E. H.) + + + + +DYNAMO (a shortened form of "dynamo-electric machine," from Gr. [Greek: +dynamis], power), a machine for converting mechanical into electrical +energy. + +The dynamo ranks with the telegraph and telephone as one of the three +striking applications of electrical and magnetic science to which the +material progress that marked the second half of the 19th century was in +no small measure due. Since the discovery of the principle of the dynamo +by Faraday in 1831 the simple model which he first constructed has been +gradually developed into the machines of 5000 horse-power or more which +are now built to meet the needs of large cities for electric lighting +and power, while at the same time the numbers of dynamos in use have +increased almost beyond estimate. Yet such was the insight of Faraday +into the fundamental nature of the dynamo that the theory of its action +which he laid down has remained essentially unchanged. His experiments +on the current which was set up in a coil of wire during its movement +across the poles of a magnet led naturally to the explanation of induced +electromotive force as caused by the linking or unlinking of magnetic +lines of flux with an electric circuit. For the more definite case of +the dynamo, however, we may, with Faraday, make the transition from +line-linkage to the equivalent conception of "line-cutting" as the +source of E.M.F.--in other words, to the idea of electric conductors +"cutting" or intersecting[1] the lines of flux in virtue of relative +motion of the magnetic field and electric circuit. On the 28th of +October 1831 Faraday mounted a copper disk so that it could be rotated +edgewise between the poles of a permanent horse-shoe magnet. When so +rotated, it cut the lines of flux which passed transversely through its +lower half, and by means of two rubbing contacts, one on its periphery +and the other on its spindle, the circuit was closed through a +galvanometer, which indicated the passage of a continuous current so +long as the disk was rotated (fig. 1). Thus by the invention of the +first dynamo Faraday proved his idea that the E.M.F. induced through the +interaction of a magnetic field and an electric circuit was due to the +passage of a portion of the electric circuit _across_ the lines of flux, +or vice versa, and so could be maintained if the cutting of the lines +were made continuous.[2] In comparison with Faraday's results, the +subsequent advance is to be regarded as a progressive perfecting of the +mechanical and electro-magnetic design, partly from the theoretical and +partly from the practical side, rather than as modifying or adding to +the idea which was originally present in his mind, and of which he +already saw the possibilities. + +[Illustration: FIG. 1.] + +A dynamo, then, is a machine in which, by means of continuous relative +motion, an electrical conductor or system of conductors forming part of +a circuit is caused to cut the lines of a magnetic field or fields; the +cutting of the magnetic flux induces an electromotive force in the +conductors, and when the circuit is closed a current flows, whereby +mechanical energy is converted into electrical energy. + + Little practical use could be made of electrical energy so long as its + only known sources were frictional machines and voltaic batteries. The + cost of the materials for producing electrical currents on a large + scale by chemical action was prohibitive, while the frictional machine + only yielded very small currents at extremely high potentials. In the + dynamo, on the other hand, electrical energy in a convenient form + could be cheaply and easily obtained by mechanical means, and with its + invention the application of electricity to a wide range of commercial + purposes became economically possible. As a converter of energy from + one form to another it is only surpassed in efficiency by another + electrical appliance, namely, the transformer (see TRANSFORMERS). In + this there is merely conversion of electrical energy at a high + potential into electrical energy at a low potential, or vice versa, + but in the dynamo the mechanical energy which must be applied to + maintain the relative movement of magnetic field and conductor is + absorbed, and reappears in an electrical form. A true transformation + takes place, and the proportion which the rate of delivery of + electrical energy bears to the power absorbed, or in other words the + _efficiency_, is the more remarkable. The useful return or "output" at + the terminals of a large machine may amount to as much as 95% of the + mechanical energy which forms the "input." Since it needs some prime + mover to drive it, the dynamo has not made any direct addition to our + sources of energy, and does not therefore rank with the primary + battery or oil-engine, or even the steam-engine, all of which draw + their energy more immediately from nature. Yet by the aid of the + dynamo the power to be derived from waterfalls can be economically and + conveniently converted into an electrical form and brought to the + neighbouring factory or distant town, to be there reconverted by + motors into mechanical power. Over any but very short distances energy + is most easily transmitted when it is in an electrical form, and + turbine-driven dynamos are very largely and successfully employed for + such transmission. Thus by conducing to the utilization of water-power + which may previously have had but little value owing to its + disadvantageous situation, the dynamo may almost be said to have added + another to our available natural resources. + +The two essential parts of the dynamo, as required by its definition, +may be illustrated by the original disk machine of Faraday. They are (1) +the _iron magnet_, between the poles of which a magnetic field exists, +and (2) the _electrical conductors_, represented by the rotating copper +disk. The sector of the disk cutting the lines of the field forms part +of a closed electric circuit, and has an E.M.F. induced in it, by reason +of which it is no longer simply a conductor, but has become "active." In +its more highly developed form the simple copper disk is elaborated into +a system of many active wires or bars which form the "winding," and +which are so interconnected as to add up their several E.M.F.'s. Since +these active wires are usually mounted on an iron structure, which may +be likened to the keeper or "armature" of a magnet rotating between its +poles, the term "armature" has been extended to cover not only the iron +core, but also the wires on it, and when there is no iron core it is +even applied to the copper conductors themselves. In the dynamo of +Faraday the "armature" was the rotating portion, and such is the case +with modern continuous-current dynamos; in alternators, however, the +magnet, or a portion of it, is more commonly rotated while the armature +is stationary. It is in fact immaterial to the action whether the one or +the other is moved, or both, so long as their relative motion causes the +armature conductors to cut the magnetic flux. As to the ultimate reason +why an E.M.F. should be thereby induced, physical science cannot as yet +yield any surer knowledge than in the days of Faraday.[3] For the +engineer, it suffices to know that the E.M.F. of the dynamo is due to +the cutting of the magnetic flux by the active wires, and, further, is +proportional to the rate at which the lines are cut.[4] + +[Illustration: FIG. 2.] + +The equation of the _electromotive force_ which is required in order to +render this statement quantitative must contain three factors, namely, +the density of the flux in the air-gap through which the armature +conductors move, the active length of these wires, and the speed of +their movement. For given values of the first and third factors and a +single straight wire moved parallel to itself through a uniform field, +the maximum rate of cutting is evidently obtained when the three +directions of the lines of the conductor's length and of the relative +motion are respectively at right angles to each other, as shown by the +three co-ordinate axes of fig. 2. The E.M.F. of the single wire is then + + E = B_gLV x 10^(-8) volts (1) + +where B_g is the density of the flux within the air-gap expressed in +C.G.S. lines per square centimetre, L is the active length of the +conductor within the field in centimetres, and V is the velocity of +movement in centimetres per second. Further, the direction in which the +E.M.F. has the above maximum value is along the length of the conductor, +its "sense" being determined by the direction of the movement[5] in +relation to the direction of the field. + +The second fundamental equation of the dynamo brings to light its +mechanical side, and rests on H.C. Oersted's discovery of the +interaction of a magnetic field and an electric current. If a straight +electric conductor through which a current is passing be so placed in a +magnetic field that its length is not parallel to the direction of the +lines of flux, it is acted on by a force which will move it, if free, in +a definite direction relatively to the magnet; or if the conductor is +fixed and the magnet is free, the latter will itself move in the +opposite direction. Now in the dynamo the active wires are placed so +that their length is at right angles to the field; hence when they are +rotated and an electric current begins to flow under the E.M.F. which +they induce, a mutual force at once arises between the copper conductors +and the magnet, and the direction of this force must by Lenz's law be +opposed to the direction of the movement. Thus as soon as the disk of +fig. 1 is rotated and its circuit is closed, it experiences a mechanical +pull or drag which must be overcome by the force applied to turn the +disk. While the magnet must be firmly held so as to remain stationary, +the armature must be of such mechanical construction that its wires can +be forcibly driven through the magnetic field against the mutual pull. +This law of electrodynamic action may be quantitatively stated in an +_equation of mechanical force_, analogous to the equation (I.) of +electromotive force, which states the law of electromagnetic induction. +If a conductor of length L cm., carrying a current C amperes, is +immersed in a field of uniform density B_g, and the length of the +conductor is at right angles to the direction of the lines, it is acted +on by a force + + F = B_gLC x 10^(-1) dynes, (2) + +and the direction of this force is at right angles to the conductor and +to the field. The rate at which electrical energy is developed, when +this force is overcome by moving the conductor as a dynamo through the +field, is EC = B_gLVC x 10^(-8) watts, whence the equality of the +mechanical power absorbed and the electrical power developed (as +required by the law of the conservation of energy) is easily +established. The whole of this power is not, however, available at the +terminals of the machine; if R_a be the resistance of the armature in +ohms, the passage of the current C_a through the armature conductors +causes a drop of pressure of C_aR_a volts, and a corresponding loss of +energy in the armature at the rate of C_a squaredR_a watts. As the resistance +of the external circuit R_e is lowered, the current C = E_a/(R_e + R_a) +is increased. The increase of the current is, however, accompanied by a +progressive increase in the loss of energy over the armature, and as +this is expended in heating the armature conductors, their temperature +may rise so much as to destroy the insulating materials with which they +are covered. Hence the temperature which the machine may be permitted to +attain in its working is of great importance in determining its output, +the current which forms one factor therein being primarily limited by +the heating which it produces in the armature winding. The lower the +resistance of the armature, the less the rise of its temperature for a +given current flowing through it; and the reason for the almost +universal adoption of copper as the material for the armature conductors +is now seen to lie in its high conductivity.[6] + +Since the voltage of the dynamo is the second factor to which its output +is proportional, the conditions which render the induced E.M.F. a +maximum must evidently be reproduced as far as possible in practice, if +the best use is to be made of a given mass of iron and copper. The first +problem, therefore, in the construction of the dynamo is the disposition +of the wires and field in such a manner that the three directions of +field, length of active conductors, and movement are at right angles to +one another, and so that the relative motion is continuous. +Reciprocating motion, such as would be obtained by direct attachment of +the conductors to the piston of a steam-engine, has been successfully +employed only in the special case of an "oscillator,"[7] producing a +small current very rapidly changing in direction. Rotary motion is +therefore universally adopted, and with this two distinct cases arise. +Either (A) the active length of the wire is parallel to the axis of +rotation, or (B) it is at right angles to it. + +[Illustration: FIG. 3.] + +(A) If a conductor is rotated in the gap between the poles of a +horse-shoe magnet, and these poles have plane parallel faces opposing +one another as in fig. 3, not only is the density of the flux in the +interpolar gap small, but the direction of movement is not always at +right angles to the direction of the lines, which for the most part pass +straight across from one opposing face to the other. When the conductor +is midway between the poles (i.e. either at its highest or lowest +point), it is at this instant sliding along the lines and does not cut +them, so that its E.M.F. is zero. Taking this position as the +starting-point, as the conductor moves round, its rate of line-cutting +increases to a maximum when it has moved through a right angle and is +opposite to the centre of a pole-face (as in fig. 3), from which point +onward the rate decreases to zero when it has moved through 180 deg.. Each +time the conductor crosses a line drawn symmetrically through the gap +between the poles and at right angles to the axis of rotation, the +E.M.F. along its length is reversed in direction, since the motion +relatively to the direction of the field is reversed. If the ends of the +active conductor are electrically connected to two collecting rings +fixed upon, but insulated from, the shaft, two stationary brushes bb can +be pressed on the rings so as to make a sliding contact. An external +circuit can then be connected to the brushes, which will form the +"terminals" of the machine, the periodically reversed or alternating +E.M.F. induced in the active conductor will cause an alternating current +to flow through conductor and external circuit, and the simplest form of +"alternator" is obtained. If the field cut by the straight conductor is +of uniform density, and all the lines pass straight across from one +pole-face to the other (both of which assumptions are approximately +correct), a curve connecting the instantaneous values of the E.M.F. as +ordinates with time or degrees of angular movement as abscissae (as +shown at the foot of fig. 3), will, if the speed of rotation be uniform, +be a sine curve. If, however, the conductor is mounted on an iron +cylinder (fig. 4),[8] a sufficient margin being allowed for mechanical +clearance between it and the poles, not only will the reluctance of the +magnetic circuit be reduced and the total flux and its density in the +air-gap B_g be thereby increased, but the path of the lines will become +nearly radial, except at the "fringe" near the edges of the pole-tips; +hence the relative directions of the movement and of the lines will be +continuously at right angles. The shape of the E.M.F. curve will then be +as shown in fig. 4--flat-topped, with rounded corners rapidly sloping +down to the zero line. + +[Illustration: FIG. 4.] + +But a single wire cannot thus be made to give more than a few volts, and +while dynamos for voltages from 5 to 10 are required for certain +purposes, the voltages in common use range from 100 to 10,000. It is +therefore necessary to connect a number of such wires in series, so as +to form an "armature winding." If several similar conductors are +arranged along the length of the iron core parallel to the first (fig. +5), the E.M.F.'s generated in the conductors which at any moment are +under the same pole are similarly directed, and are opposite to the +directions of the E.M.F.'s in the conductors under the other pole (cf +fig. 5 where the dotted and crossed ends of the wires indicate E.M.F.'s +directed respectively towards and away from the observer). Two distinct +methods of winding thence arise, the similarity of the E.M.F.'s under +the same pole being taken advantage of in the first, and the opposite +E.M.F.'s under N and S poles in the second. + +[Illustration: FIG. 5.] + +[Illustration: FIG. 6.] + +1. The first, or _ring_-winding, was invented by Dr Antonio Pacinotti of +Florence[9] in 1860, and was subsequently and independently reintroduced +in 1870[10] by the Belgian electrician, Zenobe Theophile Gramme, whence +it is also frequently called the "Gramme" winding. By this method the +farther end of conductor 1 (fig. 5) is joined in series to the near end +of conductor 2; this latter lies next to it on the surface of the core +or immediately above it, so that both are simultaneously under the same +pole-piece. For this series connexion to be possible, the armature core +must be a hollow cylinder, supported from the shaft on an open +non-magnetic spider or hub, between the arms of which there is room for +the internal wire completing the loop (fig. 6). The end of one complete +loop or turn embracing one side of the armature core thus forms the +starting-point for another loop, and the process can be continued if +required to form a coil of two or more turns. In the ring armature the +iron core serves the double purpose of conducting the lines across from +one pole to the other, and also of shielding from the magnetic flux the +hollow interior through which the connecting wires pass. Any lines which +leak across the central space are cut by the internal wires, and the +direction of cutting is such that the E.M.F. caused thereby opposes the +E.M.F. due to the active conductors proper on the external surface. If, +however, the section of iron in the core be correctly proportioned, the +number of lines which cross the interior will bear but a small ratio to +those which pass entirely through the iron, and the counter E.M.F. of +the internal wires will become very small; they may then be regarded +simply as connectors for joining the external active wires in series. + +[Illustration: FIG. 7.] + +2. The second or _drum_ method was used in the original "shuttle-wound" +armatures invented by Dr Werner von Siemens in 1856, and is sometimes +called the "Siemens" winding. The farther end of conductor 1 (fig. 5) is +joined by a connecting wire to the farther end of another conductor 2' +situated nearly diametrically opposite on the other side of the core and +under the opposite pole-piece. The near end of the complete loop or turn +is then brought across the end of the core, and can be used as the +starting-point for another loop beginning with conductor 2, which is +situated by the side of the first conductor. The iron core may now be +solid from the surface to the shaft, since no connecting wires are +brought through the centre, and each loop embraces the entire armature +core (fig. 7). By the formation of two loops in the ring armature and of +the single loop in the drum armature, two active wires are placed in +series; the curves of instantaneous E.M.F. are therefore similar in +shape to that of the single wire (fig. 4), but with their ordinates +raised throughout to double their former height, as shown at the foot of +fig. 6. + +Next, if the free ends of either the ring or drum loops, instead of +being connected to two collecting rings, are attached to the two halves +of a split-ring insulated from the shaft (as shown in fig. 7 in +connexion with a drum armature), and the stationary brushes are so set +relatively to the loops that they pass over from the one half of the +split-ring to the other half at the moment when the loops are passing +the centre of the interpolar gap, and so are giving little or no E.M.F., +each brush will always remain either positive or negative. The current +in the external circuit attached to the brushes will then have a +constant direction, although the E.M.F. in the active wires still +remains alternating; the curve of E.M.F. obtained at the brushes is thus +(as in fig. 7) entirely above the zero line. The first dynamo of H. +Pixii,[11] which immediately followed Faraday's discovery, gave an +alternating current, but in 1832[12] the alternator was converted into a +machine giving a _unidirected current_ by the substitution of a +rudimentary "commutator" in place of mercury collecting cups. + +(B) So far the length of the active wires has been parallel to the axis +of rotation, but they may equally well be arranged perpendicularly +thereto. The poles will then have plane faces and the active wires will +be disposed with their length approximately radial to the axis of the +shaft. In order to add their E.M.F.'s in series, two types of winding +may be employed, which are precisely analogous in principle to the ring +and drum windings under arrangement (A). + +3. The _discoidal_ or flat-ring armature is equivalent to a ring of +which the radial depth greatly exceeds the length, with the poles +presented to one side of the ring instead of embracing its cylindrical +surface. A similar set of poles is also presented to the opposite side +of the ring, like poles being opposite to one another, so that in effect +each polar surface is divided into two halves, and the groups of lines +from each side bifurcate and pass circumferentially through the armature +core to issue into the adjacent poles of opposite sign. + +4. In the _disk_ machine, no iron core is necessary for the armature, +the two opposite poles of unlike sign being brought close together, +leaving but a short path for the lines in the air-gap through which the +active wires are rotated. + +If the above elementary dynamos are compared with fig. 1, it will be +found that they all possess a distinctive feature which is not present +in the original disk machine of Faraday. In the four types of machine +above described each active wire in each revolution first cuts the group +of lines forming a field in one direction, and then cuts the same lines +again in the opposite direction relatively to the sense of the lines, so +that along the length of the wire the E.M.F. alternates in direction. +But in the dynamo of fig. 1 the sector of the copper disk which is at +any moment moving through the magnetic field and which forms the single +active element is always cutting the lines in the same manner, so that +the E.M.F. generated along its radial length is continuous and unchanged +in direction. This radical distinction differentiates the two classes of +_heteropolar_ and _homopolar_ dynamos, Faraday's disk machine of fig. 1 +being the type of the latter class. In it the active element may be +arranged either parallel or at right angles to the axis of rotation; +but in both cases, in order to increase the E.M.F. by placing two or +more elements in series, it becomes necessary either (1) to employ some +form of sliding contact by which the current may be collected from the +end of one active element and passed round a connecting wire into the +next element without again cutting the field in the reverse direction, +or (2) to form on the armature a loop of which each side is alternately +active and inactive. The first method limits the possibilities of the +homopolar machine so greatly when large currents and high voltages are +required that it is now only used in rare instances, as e.g. +occasionally in dynamos driven by steam-turbines which have a very high +speed of rotation. The second alternative may be carried into effect +with any of the four methods of armature winding, but is practically +confined to the drum and disk types. In its drum form the field is +divided into two or more projecting poles, all of the same sign, with +intervening neutral spaces of equal width, and the span of the loop in +the direction of rotation is at least equal to the width of a polar +projection, as in fig. 8, where two polar projections are shown. Each +side of the loop then plays a dual part; it first cuts the lines of one +polar projection and generates an E.M.F., and next becomes an inactive +connecting wire, while the action is taken up by the opposite side of +the loop which has previously served as a connector but now cuts the +lines of the next polar projection. The E.M.F. is thus always in the +same direction along the side which is at any moment active, but +alternates round the loop as a whole, and the distinctive peculiarity of +the homopolar machine, so soon as any form of "winding" is introduced +into its armature, is lost. It results that the homopolar principle, +which would prima facie appear specially suitable for the generation of +a unidirectional E.M.F. and continuous current, can seldom be used for +this purpose and is practically confined to alternators. It may +therefore be said that in almost all dynamos, whether they supply an +alternating or a continuous current in the external circuit, the E.M.F. +and current in the armature are alternating. + +[Illustration: FIG. 8.] + +Ring winding was largely employed in early continuous-current dynamos +and also in the alternators of Gramme and H. Wilde, and later of Auguste +de Meritens. Disk winding was also successfully introduced for +alternators, as in the magneto-machines of Nollet (1849) and the +alternators of Wilde (1866) and Siemens (1878), and its use was +continued in the machines of W.M. Mordey and S.Z. Ferranti. But although +the ring, discoidal-ring and disk methods of winding deserve mention +from their historical importance, experience has shown that drum winding +possesses a marked superiority for both electrical and manufacturing +reasons; the three former methods have in fact been practically +discarded in its favour, so that the drum method will hereafter alone be +considered. + +The drum coil, composed of several loops wound side by side, may +therefore be regarded as the constituent active element out of which the +armature winding of the modern dynamo is developed. Its application to +the multipolar machine is easily followed from fig. 9, which illustrates +the heteropolar type of dynamo. The span of the loops, which is nearly +180 deg. or across the diameter of the two-pole machine, is reduced +approximately to 90 deg. in the four-pole or to 60 deg. in the six-pole machine +and so on, the curvature of the coil becoming gradually less as the +number of poles is increased. The passage of a coil through two magnetic +fields of opposite direction yields a complete wave of E.M.F., such as +is shown in fig. 6, and the time in seconds taken to pass through such a +complete cycle is the "period" of the alternating E.M.F. The number of +complete periods through which the E.M.F. of the coil passes per second +is called the "periodicity" or "frequency" of the machine. In the +bipolar machine this is equal to the number of revolutions per second, +and in the multipolar machine it is equal to the number of pairs of +fields through which the coil passes in one second; hence in general the +periodicity is pN/60, where N = the number of revolutions per minute and +p = the number of pairs of poles, and this holds true of the E.M.F. and +current round the coil, even though the E.M.F. and current furnished to +the external circuit may be rendered unidirectional or continuous. The +only difference on this point is that in the continuous-current machine +the poles are usually fewer than in the alternator, and the periodicity +is correspondingly lower. Thus in the former case the number of poles +ranges from 2 to 12 and the usual frequencies from 5 to 20; but with +alternators the frequencies in commercial use range from 25 to 120, and +in large machines driven by slow-speed engines the number of poles may +even be as high as 96. + +[Illustration: FIG. 9. + +I. Smooth. II. Toothed.] + +[Illustration: FIG. 10.] + +The drum coil may be applied either to the external surface of a +rotating armature, the field-magnet being external and stationary (fig. +9), or to the internal surface of a stationary armature (fig. 10), the +field-magnet being internal and rotating. While the former combination +is universally adopted in the continuous-current dynamo, the latter is +more usual in the modern alternator. In either case the iron armature +core must be "laminated"; the passage of the lines of the field across +its surface sets up E.M.F.'s which are in opposite directions under +poles of opposite sign, so that if the core were a solid mass a +current-sheet would flow along its surface opposite to a pole, and +complete its circuit by passing through the deeper layers of metal or by +returning in a sheet under a pole of opposite sign. Such "eddy-currents" +can be practically avoided by dividing the metal core into laminations +at right angles to the length of the active wires which are themselves +arranged to secure the greatest rate of line-cutting and maximum E.M.F. +The production of the eddy-current E.M.F. is not thereby prevented, but +the paths of the eddy-currents are so broken up that the comparatively +high resistance with which they meet reduces their amount very greatly. +The laminae must be lightly insulated from one another, right up to +their edges, so that the E.M.F.'s which still act across their thickness +will not be added up along the length of the core, but will only produce +extremely small currents circulating through the interior of the +separate laminations. Each thin iron plate is either coated with an +insulating varnish or has one of its sides covered with a sheet of very +thin paper; the thickness of the laminae is usually about one-fortieth +of an inch, and if this is not exceeded the rate at which energy is +dissipated by eddy-currents in the core is so far reduced that it does +not seriously impair the efficiency of the machine. + +Lastly, the drum coils may be either attached to the surface of a smooth +armature core (fig. 9, I.), or may be wound through holes formed close +to the periphery of the core, or may be embedded in the slots between +projecting iron teeth (figs. 9 [II.] and 10). Originally employed by +Antonio Pacinotti in connexion with ring winding, the toothed armature +was after some considerable use largely discarded in favour of the +smooth core; it has, however, been reintroduced with a fuller +understanding of the special precautions necessitated in its design, and +it is now so commonly used that it may be said to have superseded the +smooth-surface armature. + + Not only does the toothed armature reduce the length of the air-gap to + the minimum permitted by mechanical and magnetic considerations, and + furnish better mechanical protection to the armature coils, but it + also ensures the positive holding of the active wires against the + mechanical drag which they experience as they pass through the + magnetic field. Further, the active wires in the toothed armature are + relieved of a large proportion of this mechanical drag, which is + transferred to the iron teeth. The lines of the field, after passing + through the air-gap proper, divide between the teeth and the slots in + proportion to their relative permeances. Hence at any moment the + active wires are situated in a weak field, and for a given armature + current the force on them is only proportional to this weak field. + This important result is connected with the fact that when the + armature is giving current the distribution of the lines over the face + of each tooth is distorted, so that they become denser on the + "trailing" side than on the "leading" side;[13] the effect of the + non-uniform distribution acting on all the teeth is to produce a + magnetic drag on the armature core proportional to the current passing + through the wires, so that the total resisting force remains the same + as if the armature had a smooth core. The amount by which the stress + on the active wires is reduced entirely depends upon the degree to + which the teeth are saturated, but, since the relative permeability of + iron even at a flux density of 20,000 lines per sq. cm. is to that of + air approximately as 33:1, the embedded wires are very largely + relieved of the driving stress. An additional gain is that solid bars + of much greater width can be used in the toothed armature than on a + smooth core without appreciable loss from eddy-currents within their + mass. + + A disadvantage of the slotted core is, however, that it usually + necessitates the lamination of the pole-pieces. If the top of the slot + is open, and its width of opening is considerably greater than the + length of the air-gap from the iron of the pole-face to the surface of + the teeth, the lines become unequally distributed not only at the + surface of the teeth, but also at the face of the pole-pieces; and + this massing of the lines into bands causes the density at the + pole-face to be rhythmically varied as the teeth pass under it. No + such variation can take place in a solid mass of metal without the + production of eddy-currents within it; hence if the width of the + slot-opening is equal to or exceeds twice the length of the single + air-gap, lamination of the pole-pieces in the same plane as that of + the armature core becomes advisable. + + If the wires are threaded through holes or tunnels pierced close to + the periphery of the core, the same advantages are gained as with open + slots, and lamination of the pole-pieces is rendered unnecessary. But + on the other hand, the process of winding becomes laborious and + expensive, while the increase in the inductance of the coils owing to + their being surrounded by a closed iron circuit is prejudicial to + sparkless commutation in the continuous-current dynamo and to the + regulation of the voltage of the alternator. A compromise is found in + the half-closed slot, which is not uncommon in alternators, although + the open slot is more usual in continuous-current dynamos. + +With the addition of more turns to the elementary drum loop or of +several complete coils, new questions arise, and in connexion therewith +the two great classes of machines, viz. alternators and +continuous-current dynamos, which have above been treated side by side, +diverge considerably, so that they are best considered separately. The +electromotive-force equation of the alternator will be first deduced, +and subsequently that of the continuous-current machine. + +[Illustration: FIG. 11.] + +Corresponding to the number of pairs of poles in the multipolar +alternator, it is evident that there may also be an equal number of +coils as shown diagrammatically in fig. 11. The additional coils, being +similarly situated in respect to other pairs of poles, will exactly +reproduce the E.M.F. of the original coil in phase and magnitude, so +that when they are connected in series the total E.M.F. will be +proportional to the number of coils in series; or if they are connected +in parallel, while not adding to the E.M.F., they will proportionately +increase the current-carrying capacity of the combination. But within +each coil the addition of more loops will not cause an equal increase in +the total E.M.F., unless the phases of the component E.M.F.'s due to the +several turns are identical, and on this account it becomes necessary to +consider the effect of the width of the coil-side. + +[Illustration: FIG. 12.] + +If the additional loops are wound within the same slots as the original +loop, the winding is "concentrated," and each turn will then add the +same E.M.F. But if the coil-side is divided between two or more slots, +the phase of the E.M.F. yielded by the wires in one slot being different +from that of the wires in another neighbouring slot, the sum of all the +E.M.F.'s will be less than the E.M.F. of one component loop multiplied +by the number of loops or turns in the coil. The percentage reduction in +the E.M.F. will depend upon the number of the slots in a coil-side and +their distance apart, i.e. on the virtual width of the coil-side +expressed as a fraction of the "pole-pitch" or the distance measured +along the pitch-line from the centre of one pole to the centre of a +neighbouring pole of opposite sign (fig. 12). The winding is now to be +regarded as "grouped," since a small number of distinct phases +corresponding to the groups within the two, three or four slots have to +be compounded together. As the number of slots per coil-side is +increased, an approach is gradually made to the case of "uniform +distribution," such as would obtain in a smooth-core armature in which +the turns of the coil are wound closely side by side. Thus in the +six-turn coil of fig. 12 A, which represents the development of a +two-pole armature when the core is cut down to the shaft and opened out +flat, there are in effect six phases compounded together, each of which +differs but little from that of its next neighbour. With numerous wires +lying still closer together a large number of phases are compounded +until the distribution becomes practically uniform; the decrease in the +E.M.F., as compared with that of a single turn multiplied by the number +in series, is then immediately dependent upon the width of the coil-side +relatively to the pole-pitch. + +[Illustration: FIG. 13.] + +If the width of the inner loop of fig. 12 A is less than that of the +pole-face, its two sides will for some portion of each period be moving +under the same pole, and "differential action" results, the net E.M.F. +being only that due to the difference between the E.M.F.'s of the two +sides. The loop of smallest width must therefore exceed the width of +pole-face, if direct differential action is to be avoided. The same +consideration also determines the width of the outer loop; if this be +deducted from twice the pole-pitch, the difference should not be less +than the width of the pole-face, so that, e.g., in a bipolar machine the +outer loop may stand to the S. pole exactly as the inner loop stands to +the N. pole (fig. 13). In other words, the width of the coil-side must +not exceed the width of the interpolar gap between two fields. Evidently +then if the ratio of the pole-width to the pole-pitch approaches unity, +the width of the coil-side must be very small, and vice versa. A +compromise between these conflicting considerations is found if the pole +is made not much more than half the pole-pitch, and the width of the +coil-side is similarly about half the pole-pitch and therefore equal in +width to the pole (fig. 13). A single large coil, such as that of fig. +12 A, can, however, equally well be divided into two halves by taking +the end-connexions of one half of the turns round the opposite side of +the shaft (fig. 12 B), as indeed has already been done in fig. 13. Each +sheaf or band of active wires corresponding to a pole is thereby +unaffected, but the advantages are gained that the axial length of the +end-connexions is halved, and that they have less inductance. Thus if in +fig. 11 there are four turns per coil, fig. 14 is electrically +equivalent to it (save that the coils are here shown divided into two +parallel paths, each carrying half the total current). When the large +coils are divided as above described, it results that there are as many +coils as there are poles, the outer loop of the small coil having a +width equal to the pole-pitch, and the inner a width equal to the +pole-face. + +[Illustration: FIG. 14.] + +Such is the form which the "single-phase alternator" takes, but since +only one-half of the armature core is now covered with winding, an +entirely distinct but similar set of coils may be wound to form a second +armature circuit between the coils of the first circuit. The phase of +this second circuit will differ by 90 deg. or a quarter of a period from +that of the first, and it may either be used to feed an entirely +separate external circuit possibly at a different pressure or, if it be +composed of the same number of turns and therefore gives the same +voltage, it may be interconnected with the first circuit to form a +"quarter-phase alternator," as will be more fully described later. By an +extension of the same process, if the width of each side of a coil is +reduced to one-sixth of the pole-pitch, three armature circuits can be +wound on the same core, and a "three-phase alternator," giving waves of +E.M.F. differing in phase by 120 deg., is obtained. + + The fundamental "electromotive-force equation" of the heteropolar + alternator can now be given a more definite form. Let Z_a be the + number of C. G. S. lines or the total flux, which issuing from any + one pole flows through the armature core, to leave it by another pole + of opposite sign. Since each active wire cuts these lines, first as + they enter the armature core and then as they emerge from it to enter + another pole, the total number of lines cut in one revolution by any + one active wire is 2pZ_a. The time in seconds taken by one revolution + is 60/N. The average E.M.F. induced in each active wire in one + revolution being proportional to the number of lines cut divided by + the time taken to cut them is therefore 2Z_a(pN/60) x 10^(-8) volts. + The active wires which are in series and form one distinct phase may + be divided into as many bands as there are poles; let each such band + contain t active wires, which as before explained may either form one + side of a single large coil or the adjacent sides of two coils when + the large coil is divided into two halves. Since the wires are joined + up into loops, two bands are best considered together, which with + either arrangement yield in effect a single coil of t turns. The + average E.M.F.'s of all the wires in the two bands when added together + will therefore be 4Z_a(pN/60)t x 10^(-8). But unless each band is + concentrated within a single slot, there must be some differential + action as they cross the neutral line between the poles, so that the + last expression is virtually the _gross_ average E.M.F. of the loops + on the assumption that the component E.M.F.'s always act in agreement + round the coil and do not at times partially neutralize one another. + The _net_ average E.M.F. of the coil as a whole, or the arithmetical + mean of all the instantaneous values of a half-wave of the actual + E.M.F. curve, is therefore reduced to an extent depending upon the + amount of differential action and so upon the width of the coil-side + when this is not concentrated. Let k' = the coefficient by which the + gross average E.M.F. must be multiplied to give the net average + E.M.F.; then k' may be called the "width-factor," and will have some + value less than unity when the wires of each band are spread over a + number of slots. The net average E.M.F. of the two bands corresponding + to a pair of poles is thus e_(av) = 4k'Z_a(pN/60)t x 10^(-8). + + The shape of the curve of instantaneous E.M.F. of the coil must + further be taken into account. The "effective" value of an alternating + E.M.F. is equal to the square root of the mean square of its + instantaneous values, since this is the value of the equivalent + unidirectional and unvarying E.M.F., which when applied to a given + resistance develops energy at the same rate as the alternating E.M.F., + when the effect of the latter is averaged over one or any whole number + of periods. Let k" = the ratio of the square root of the mean square + to the average E.M.F. of the coil, i.e. = effective E.M.F./average + E.M.F. Since it depends upon the shape of the E.M.F. curve, k" is also + known as the "form-factor"; thus if the length of gap between + pole-face and armature core and the spacing of the wires were so + graduated as to give a curve of E.M.F. varying after a sine law, the + form-factor would have the particular value of [pi]/2[root]2 = 1.11, + and to this condition practical alternators more or less conform. The + effective E.M.F. of the two bands corresponding to a pair of poles is + thus e_(eff) = 4k'k"Z_a(pN/60)t x 10^(-8). + + In any one phase there are p pairs of bands, and these may be divided + into q parallel paths, where q is one or any whole number of which p + is a multiple. The effective E.M.F. of a complete phase is therefore + pe{eff}/q. Lastly, if m = the number of phases into which the armature + winding is divided, and [tau] = the total number of active wires on + the armature counted all round its periphery, t = [tau]/2pm, and the + effective E.M.F. per phase is E_a = 2k'k"Z_a(pN[tau]/60mq) x 10^(-8). + + The two factors k' and k" may be united into one coefficient, and the + equation then takes its final form + + E_a = 2KZ_a(pN[tau]/60mq) x 10^(-8) volts (1a) + + In the alternator q is most commonly 1, and there is only one circuit + per phase; finally the value of K or the product of the width-factor + and the form-factor usually falls between the limits of 1 and 1.25. + +We have next to consider the effect of the addition of more armature +loops in the case of dynamos which give a unidirectional E.M.F. in +virtue of their split-ring collecting device, i.e. of the type shown in +fig. 7 with drum armature or its equivalent ring form. As before, if the +additional loops are wound in continuation of the first as one coil +connected to a single split-ring, this coil must be more or less +concentrated into a narrow band; since if the width becomes nearly equal +to or exceeds the width of the interpolar gap, the two edges of the +coil-side will just as in the alternator act differentially against one +another during part of each revolution. The drum winding with a single +coil thus gives an armature of the H- or "shuttle" form invented by Dr +Werner von Siemens. Although the E.M.F. of such an arrangement may have +a much higher maximum value than that of the curve of fig. 7 for a +single loop, yet it still periodically varies during each revolution and +so gives a pulsating current, which is for most practical uses +unsuitable. But such pulsation might be largely reduced if, for example, +a second coil were placed at right angles to the original coil and the +two were connected in series; the crests of the wave of E.M.F. of the +second coil will then coincide with the hollows of the first wave, +and although the maximum of the resultant curve of E.M.F. may be no +higher its fluctuations will be greatly decreased. A spacial +displacement of the new coils along the pole-pitch, somewhat as in a +polyphase machine, thus suggests itself, and the process may be carried +still further by increasing the number of equally spaced coils, provided +that they can be connected in series and yet can have their connexion +with the external circuit reversed as they pass the neutral line between +the poles. + +[Illustration: FIG. 15.] + +[Illustration: FIG. 16.] + +Given two coils at right angles and with their split-rings displaced +through a corresponding angle of 90 deg., they may be connected in series by +joining one brush to the opposite brush of the second coil, the external +circuit being applied to the two remaining brushes.[14] The same +arrangement may again be repeated with another pair of coils in parallel +with the first, and we thus obtain fig. 15 with four split-rings, their +connexions to the loops being marked by corresponding numerals; the four +coils will give the same E.M.F. as the two, but they will be jointly +capable of carrying twice the current, owing to their division into two +parallel circuits. Now in place of the four split-rings may be employed +the greatly simplified four-segment structure shown in fig. 16, which +serves precisely the same purpose as the four split-rings but only +requires two instead of eight brushes. The effect of joining brush 2 in +fig. 15 across to brush 3, brush 4 to brush 5, 5 to 6, &c., has +virtually been to connect the end of coil A with the beginning of coil +B, and the end of coil B with the beginning of coil A', and so on, until +they form a continuous closed helix. Each sector of fig. 16 will +therefore replace two halves of a pair of adjacent split-rings, if the +end and beginning of a pair of adjacent coils are connected to it in a +regular order of sequence. The four sectors are insulated from one +another and from the shaft, and the whole structure is known as the +"commutator,"[15] its function being not simply to collect the current +but also to commute its direction in any coil as it passes the +interpolar gap. The principle of the "closed-coil continuous-current +armature" is thus reached, in which there are at least two parallel +circuits from brush to brush, and from which a practically steady +current can be obtained. Each coil is successively short-circuited, as a +brush bridges over the insulation between the two sectors which +terminate it; and the brushes must be so set that the period of +short-circuit takes place when the coil is generating little or no +E.M.F., i.e. when it is moving through the zone between the pole-tips. +The effect of the four coils in reducing the percentage fluctuation of +the E.M.F. is very marked, as shown at the foot of fig. 15 (where the +upper curve is the resultant obtained by adding together the separate +curves of coils A and B), and the levelling process may evidently be +carried still further by the insertion of more coils and more +corresponding sectors in the commutator, until the whole armature is +covered with winding. For example, figs. 17 and 18 show a ring and a +drum armature, each with eight coils and eight commutator sectors; their +resultant curve, on the assumption that a single active wire gives the +flat-topped curve of fig. 4, will be the upper wavy line of E.M.F. +obtained by adding together two of the resultant curves of fig. 15, with +a relative displacement of 45 deg.. The amount of fluctuation for a given +number of commutator sectors depends upon the shape of the curve of +E.M.F. yielded by the separate small sections of the armature winding; +the greater the polar arc, the less the fluctuation. In practice, with a +polar arc equal to about 0.75 of the pitch, any number of sectors over +32 per pair of poles yields an E.M.F. which is sensibly constant +throughout one or any number of revolutions. + +[Illustration: FIG. 17.] + +[Illustration: FIG. 18.] + + The fundamental electro-motive-force equation of the + continuous-current heteropolar machine is easily obtained by analogy + from that of the alternator. The gross average E.W.F. from the two + sides of a drum loop without reference to its direction is as before + 4Z_a(pN/60) x 10^(-8) volts. But for two reasons its net average + E.M.F. may be less; the span of the loop may be less than the + pole-pitch, so that even when the brushes are so set that the position + of short-circuit falls on the line where the field changes its + direction, the two sides of the loop for some little time act against + each other; or, secondly, even if the span of the loop be equal to the + pole-pitch, the brushes may be so set that the reversal of the + direction of its induced E.M.F. does not coincide with reversal of the + current by the passage of the coil under the brushes. The net average + E.M.F. of the loop is therefore proportional to the algebraic sum of + the lines which it cuts in passing from one brush to another, and this + is equal to the net amount of the flux which is included within the + loop when situated in the position of short-circuit under a brush. The + amount of this flux may be expressed as k'Z_a where k' is some + coefficient, less than unity if the span of the coil be less than the + pole-pitch, and also varying with the position of the brushes. The net + average E.M.F. of the loop is therefore + + 4k'Z_a(pN/60) x 10^(-8). + + In practice the number of sections of the armature winding is so large + and their distribution round the armature periphery is so uniform, + that the sum total of the instantaneous E.M.F.'s of the several + sections which are in series becomes at any moment equal to the net + average E.M.F. of one loop multiplied by the number which are in + series. If the winding is divided into q parallel circuits, the number + of loops in series is [tau]/2q, so that the total E.M.F. is E_a = + 2(k'/q)Z_a(pN/60)[tau] x 10^(-8) volts. Thus as compared with the + alternator not only is there no division of the winding into separate + phases, but the form-factor k' disappears, since the effective and + average E.M.F.'s are the same. Further whereas in the alternator q may + = 1, in the continuous-current closed-coil armature there can never be + less than two circuits in parallel from brush to brush, and if more, + their number must always be a multiple of two, so that q can never be + less than two and must always be an even number. Lastly, the factor k' + is usually so closely equal to 1, that the simplified equation may in + practice be adopted, viz. + + E_a = (2/q)(ZpN/60)[tau] x 10^(-8) volts (1b) + + The fundamental equation of the electromotive force of the dynamo in + its fully developed forms (1 a) (and 1 b) may be compared with its + previous simple statement (1.). The three variable terms still find + their equivalents, but are differently expressed, the density B_g + being replaced by the total flux of one field Z_a, the length L of the + single active wire by the total number of such wires [tau], and the + velocity of movement V by the number of revolutions per second. Even + when the speed is fixed, an endless number of changes may be rung by + altering the relative values of the remaining two factors; and in + successful practice these may be varied between fairly wide limits + without detriment to the working or economy of the machine. While it + may be said that the equation of the E.M.F. was implicitly known from + Faraday's time onwards, the difficulty under which designers laboured + in early days was the problem of choosing the correct relation of Z_a + or [tau] for the required output; this, again, was due chiefly to the + difficulty of predetermining the total flux before the machine was + constructed. The general error lay in employing too weak a field and + too many turns on the armature, and credit must here be given to the + American inventors, E. Weston and T.A. Edison, for their early + appreciation of the superiority in practical working of the drum + armature, with comparatively few active wires rotating in a strong + field. + + + The armature core. + +_Continuous-current Dynamos._--On passing to the separate consideration +of alternators and continuous-current dynamos, the chief constructive +features of the latter will first be taken in greater detail. As already +stated in the continuous-current dynamo the armature is usually the +rotating portion, and the necessity of laminating its core has been +generally described. The thin iron stampings employed to build up the +core take the form of circular washers or "disks," which in small +machines are strung directly on the shaft; in larger multipolar +machines, in which the required radial depth of iron is small relatively +to the diameter, a central cast iron hub supports the disks. Since the +driving force is transmitted through the shaft to the disks, they must +in the former case be securely fixed by keys sunk into the shaft; when a +central hub is employed (fig. 19) it is keyed to the shaft, and its +projecting arms engage in notches stamped on the inner circumference of +the disks, or the latter have dovetailed projections fitting into the +arms. The disks are then tightly compressed and clamped between stout +end-plates so as to form a nearly solid iron cylinder of axial length +slightly exceeding the corresponding dimension of the poles. If the +armature is more than 4 ft. in diameter, the disks become too large to +be conveniently handled in one piece, and are therefore made in +segments, which are built up so as to break joint alternately. Prior to +assemblage, the external circumference of each disk is notched in a +stamping machine with the required number of slots to receive the +armature coils, and the longitudinal grooves thereby formed in the +finished core only require to have their sharp edges smoothed off so +that there may be no risk of injury to the insulation of the coils. + +[Illustration: FIG. 19.] + + + Armature winding. + +With open slots either the armature coils may be encased with wrappings +of oiled linen, varnished paper and thin flexible micanite sheeting in +order to insulate them electrically from the iron slots in which they +are afterwards embedded; or the slots may be themselves lined with +moulded troughs of micanite, &c., for the reception of the armature +coils, the latter method being necessary with half-closed slots. +According to the nature of the coils armatures may be divided into the +two classes of coil-wound and bar-wound. In the former class, round +copper wire, double-cotton covered, is employed, and the coils are +either wound by hand directly on to the armature core, or are shaped on +formers prior to being inserted in the armature slots. Hand-winding is +now only employed in very small bipolar machines, the process being +expensive and accompanied by the disadvantage that if one section +requires to be repaired, the whole armature usually has to be dismantled +and re-wound. Former-wound coils are, on the other hand, economical in +labour, perfectly symmetrical and interchangeable, and can be thoroughly +insulated before they are placed in the slots. The shapers employed in +the forming process are very various, but are usually arranged to give +to the finished coil a lozenge shape, the two straight active sides +which fit into the straight slots being joined by V-shaped ends; at each +apex of the coil the wire is given a twist, so that the two sides fall +into different levels, an upper and a lower, corresponding to the two +layers which the coil-sides form on the finished armature. Rectangular +wire of comparatively small section may be similarly treated, and if +only one loop is required per section, wide and thin strip can be bent +into a complete loop, so that the only soldered joints are those at the +commutator end where the loops are interconnected. But finally with +massive rectangular conductors, the transition must be made to +bar-winding, in which each bar is a half-loop, insulated by being taped +after it has been bent to the required shape; the separate bars are +arranged on the armature in two layers, and their ends are soldered +together subsequently to form loops. As a general rule, whether bars or +former-wound coils are employed, the armature is barrel-wound, i.e. the +end-connexions project outwards from the slots with but little change of +level, so that they form a cylindrical mass supported on projections +from the end-plates of the core (fig. 19); but, in certain cases, the +end-connexions are bent downwards at right angles to the shaft, and they +may then consist of separate strips of copper bent to a so-called +butterfly or evolute shape. + +After the coils or loops have been assembled in the slots on the +armature core, and the commutator has been fixed in place on the shaft, +the soldering of the ends of the coils proceeds, by which at once the +union of the end of one coil with the beginning of the next, and also +their connexion to the commutator sectors, is effected, and in this lies +the essential part of armature winding. + +[Illustration: FIG. 20. + +Lap-loops] + + + Lap-winding. + + The development of the modern drum armature, with its numerous coils + connected in orderly sequence into a symmetrical winding, as + contrasted with the earlier Siemens armatures, was initiated by F. von + Hefner Alteneck (1871), and the laws governing the interconnexion of + the coils have now been elaborated into a definite system of winding + formulae. Whatever the number of wires or bars in each side of a coil, + i.e. whether it consist of a single loop or of many turns, the final + connexions of its free ends are not thereby affected, and it may be + mentally replaced by a single loop with two active inducing sides. The + coil-sides in their final position are thus to be regarded as separate + primary elements, even in number, and distributed uniformly round the + armature periphery or divided into small, equally spaced groups by + being located within the slots of a toothed armature. Attention must + then be directed simply to the span of the back connexion between the + elements at the end of the armature further from the commutator, and + to the span of the front connexion by which the last turn of a coil is + finally connected to the first turn of the next in sequence, precisely + as if each coil of many turns were reduced to a single loop. In order + to avoid direct differential action, the span of the back connexion + which fixes the width of the coil must exceed the width of the + pole-face, and should not be far different from the pole-pitch; it is + usually a little less than the pole-pitch. Taking any one element as + No. 1 in fig. 20, where for simplicity a smooth-core bipolar armature + is shown, the number of winding-spaces, each to be occupied by an + element, which must be counted off in order to find the position of + the next element in series, is called the "pitch" of the + end-connexion, front or back, as the case may be. Thus the back pitch + of the winding as marked by the dotted line in fig. 20 is 7, the + second side of the first loop being the element numbered 1 + 7 = 8. In + forming the front end-connexion which completes the loop and joins it + to the next in succession, two possible cases present themselves. By + the first, or "lap-winding," the front end-connexion is brought + backwards, and passing on its way to a junction with a commutator + sector is led to a third element lying within the two sides of the + first loop, i.e. the second loop starts with the element, No. 3, lying + next but one to the starting-point of the first loop. The winding + therefore returns backwards on itself to form each front end, but as a + whole it works continually forwards round the armature, until it + finally "re-enters," after every element has been traversed. The + development of the completed winding on a flat surface shows that it + takes the form of a number of partially overlapping loops, whence its + name originates. The firm-line portion of fig. 21 gives the + development of an armature similar to that of fig. 18 when cut through + at the point marked X and opened out; two of the overlapping loops are + marked thereon in heavy lines. The multipolar lap-wound armature is + obtained by simply repeating the bipolar winding p times, as indicated + by the dotted additions of fig. 21 which convert it from a two-pole to + a four-pole machine. The characteristic feature of the lap-wound + armature is that there are as many parallel paths from brush to brush, + and as many points at which the current must be collected, as there + are poles. As the bipolar closed-coil continuous-current armature has + been shown to consist in reality of two circuits in parallel, each + giving the same E.M.F. and carrying half the total current, so the + multipolar lap-wound drum consists of p pairs of parallel paths, each + giving the same E.M.F. and carrying 1/2p of the total current. Thus in + equation 1.b we have q = 2p, and the special form which the _E.M.F. + equation of the lap-wound armature_ takes is E_[alpha] = Z_a + (N/60)[tau] x 10^(-8) volts. All the brushes which are of the same + sign must be connected together in order to collect the total armature + current. The several brush-sets of the multipolar lap-wound machine + may again be reduced to two by "cross-connexion" of sectors situated + 360 deg./p apart, but this is seldom done, since the commutator must then + be lengthened p times in order to obtain the necessary brush + contact-surface for the collection of the entire current. + + [Illustration: FIG. 21.] + + [Illustration: FIG. 22. + + Wave-loops] + + [Illustration: FIG. 23.] + + + Wave-winding. + + But for many purposes, especially where the voltage is high and the + current small, it is advantageous to add together the inductive effect + of the several poles of the multipolar machine by throwing the E.M.F's + of half the total number of elements into series, the number of + parallel circuits being conversely again reduced to two. This is + effected by the second method of winding the closed-coil continuous + current drum, which is known as "wave-winding." The front pitch is now + in the same direction round the armature as the back pitch (fig. 22), + so that the beginning of the second loop, i.e. element No. 15, lies + outside the first loop. After p loops have been formed and as many + elements have been traversed as there are poles, the distance covered + either falls short of or exceeds a complete tour of the armature by + two winding-spaces, or the width of two elements. A second and third + tour are then made, and so on, until finally the winding again closes + upon itself. When the completed winding is developed as in fig. 23, it + is seen to work continuously forwards round the armature in zigzag + waves, one of which is marked in heavy lines, and the number of + complete tours is equal to the average of the back and front pitches. + Since the number of parallel circuits from brush to brush is q = 2, + the _E.M.F. equation of the wave-wound drum_ is E_a = pZ_a (N/60)[tau] + x 10^(-8) volts. Only two sets of brushes are necessary, but in order + to shorten the length of the commutator, other sets may also be added + at the point of highest and lowest potential up to as many in number + as there are poles. Thus the advantage of the wave-wound armature is + that for a given voltage and number of poles the number of active + wires is only 1/p of that in the lap-wound drum, each being of larger + cross-section in order to carry p times as much current; hence the + ratio of the room occupied by the insulation to the copper area is + less, and the available space is better utilized. A further advantage + is that the two circuits from brush to brush consist of elements + influenced by all the poles, so that if for any reason, such as + eccentricity of the armature within the bore of the pole-pieces, or + want of uniformity in the magnetic qualities of the poles, the flux of + each field is not equal to that of every other, the equality of the + voltage produced by the two halves of the winding is not affected + thereby. + + In appearance the two classes of armatures, lap and wave, may be + distinguished in the barrel type of winding by the slope of the upper + layer of back end-connexions, and that of the front connexions at the + commutator end being parallel to one another in the latter, and + oppositely directed in the former. + +[Illustration: FIG. 24.] + +After completion of the winding, the end-connexions are firmly bound +down by bands of steel or phosphor bronze binding wire, so as to resist +the stress of centrifugal force. In the case of smooth-surface +armatures, such bands are also placed at intervals along the length of +the armature core, but in toothed armatures, although the coils are +often in small machines secured in the slots by similar bands of a +non-magnetic high-resistance wire, the use of hard-wood wedges driven +into notches at the sides of the slots becomes preferable, and in very +large machines indispensable. The external appearance of a typical +armature with lap-winding is shown in fig. 24. + + + The commutator. + +A sound mechanical construction of the commutator is of vital importance +to the good working of the continuous-current dynamo. The narrow, +wedge-shaped sectors of hard-drawn copper, with their insulating strips +of thin mica, are built up into a cylinder, tightly clamped together, +and turned in the lathe; at each end a V-shaped groove is turned, and +into these are fitted rings of micanite of corresponding section (fig. +19); the whole is then slipped over a cast iron sleeve, and at either +end strong rings are forced into the V-shaped grooves under great +pressure and fixed by a number of closely-pitched tightening bolts. In +dynamos driven by steam-turbines in which the peripheral speed of the +commutator is very high, rings of steel are frequently shrunk on the +surface of the commutator at either end and at its centre. But in every +case the copper must be entirely insulated from the supporting body of +metal by the interposition of mica or micanite and the prevention of any +movement of the sectors under frequent and long-continued heating and +cooling calls for the greatest care in both the design and the +manufacture. + + + Forms of field-magnet. + +On passing to the second fundamental part of the dynamo, namely, the +field-magnet, its functions may be briefly recalled as follows:--It has +to supply the magnetic flux; to provide for it an iron path as nearly +closed as possible upon the armature, save for the air-gaps which must +exist between the pole-system and the armature core, the one stationary +and the other rotating; and, lastly, it has to give the lines such +direction and intensity within the air-gaps that they may be cut by the +armature wires to the best advantage. Roughly corresponding to the three +functions above summarized are the three portions which are more or less +differentiated in the complete structure. These are: (1) the magnet +"cores" or "_limbs_," carrying the exciting coils whereby the inert iron +is converted into an electro-magnet; (2) the _yoke_, which joins the +limbs together and conducts the flux between them; and (3) the +_pole-pieces_, which face the armature and transmit the lines from the +limbs through the air-gap to the armature core, or vice versa. + + [Illustration: FIG. 25.] + + Of the countless shapes which the field-magnet may take, it may be + said, without much exaggeration, that almost all have been tried; yet + those which have proved economical and successful, and hence have met + with general adoption, may be classed under a comparatively small + number of types. For bipolar machines the _single horse-shoe_ (fig. + 25), which is the lineal successor of the permanent magnet employed in + the first magneto-electric machines, was formerly very largely used. + It takes two principal forms, according as the pole-pieces and + armature are above or beneath the magnet limbs and yoke. The + "over-type" form is best suited to small belt-driven dynamos, while + the "under-type" is admirably adapted to be directly driven by the + steam-engine, the armature shaft being immediately coupled to the + crank-shaft of the engine. In the latter case the magnet must be + mounted on non-magnetic supports of gun-metal or zinc, so as to hold + it at some distance away from the iron bedplate which carries both + engine and dynamo; otherwise a large proportion of the flux which + passes through the magnet limbs would leak through the bedplate across + from pole to pole without passing through the armature core, and so + would not be cut by the armature wires. + + [Illustration: FIG. 26.] + + Next may be placed the "Manchester" field (fig. 26)--the type of a + divided magnetic circuit in which the flux forming one field or pole + is divided between two magnets. An exciting coil is placed on each + half of the double horse-shoe magnet, the pair being so wound that + consequent poles are formed above and below the armature. Each magnet + thus carries one-half of the total flux, the lines of the two halves + uniting to form a common field where they issue forth into or leave + the air-gaps. The pole-pieces may be lighter than in the single + horse-shoe type, and the field is much more symmetrical, whence it is + well suited to ring armatures of large diameter. Yet these advantages + are greatly discounted by the excessive magnetic leakage, and by the + increased weight of copper in the exciting coils. Even if the greater + percentage which the leakage lines bear to the useful flux is + neglected, and the cross sectional area of each magnet core is but + half that of the equivalent single horse-shoe, the weight of wire in + the double magnet for the same rise of temperature in the coils must + be some 40% more than in the single horse-shoe, and the rate at which + energy is expended in heating the coils will exceed that of the single + horse-shoe in the same proportion. + + Thirdly comes the two-pole _ironclad_ type, so called from the + exciting coil being more or less encased by the iron yoke; this latter + is divided into two halves, which pass on either side of the armature. + Unless the yoke be kept well away from the polar edges and armature, + the leakage across the air into the yoke becomes considerable, + especially if only one exciting coil is used, as in fig. 27 A; it is + better, therefore, to divide the excitation between two coils, as in + fig. 27 B, when the field also becomes symmetrical. + + From this form is easily derived the _multipolar_ type of fig. 28 or + fig. 29, which is by far the most usual for any number of poles from + four upwards; its leakage coefficient is but small, and it is + economical in weight both of iron and copper. + + + Materials of magnets. + + As regards the materials of which magnets are made, generally speaking + there is little difference in the permeability of "wrought iron" or + "mild steel forgings" and good "cast steel"; typical (B, H) curves + connecting the magnetizing force required with different + flux-densities for these materials are given under ELECTROMAGNETISM. + On the other hand there is a marked inferiority in the case of "cast + iron," which for a flux-density of B = 8000 C.G.S. lines per sq. cm. + requires practically the same number of ampere-turns per centimetre + length as steel requires for B = 16,000. Whatever the material, if the + flux-density be pressed to a high value the ampere-turns are very + largely increased owing to its approaching saturation, and this + implies either a large amount of copper in the field coils or an undue + expenditure of electrical energy in their excitation. Hence there is a + limit imposed by practical considerations to the density at which the + magnet should be worked, and this limit may be placed at about B = + 16,000 for wrought iron or steel, and at half this value for cast + iron. For a given flux, therefore, the cast iron magnet must have + twice the sectional area and be twice as heavy, although this + disadvantage is partly compensated by its greater cheapness. If, + however, cast iron be used for the portion of the magnetic circuit + which is covered with the exciting coils, the further disadvantage + must be added that the weight of copper on the field-magnet is much + increased, so that it is usual to employ forgings or cast steel for + the magnet cores on which the coils are wound. If weight is not a + disadvantage, a cast iron yoke may be combined with the wrought iron + or cast steel magnet cores. An absence of joints in the magnetic + circuit is only desirable from the point of view of economy of expense + in machining the component parts during manufacture; when the surfaces + which abut against each other are drawn firmly together by screws, the + want of homogeneity at the joint, which virtually amounts to the + presence of a very thin film of air, produces little or no effect on + the total reluctance by comparison with the very much longer air-gaps + surrounding the armature. In order to reduce the eddy-currents in the + pole-pieces, due to the use of toothed armatures with relatively wide + slots, the poles themselves must be laminated, or must have fixed to + them laminated pole-shoes, built up of thin strips of mild steel + riveted together (as shown in fig. 29). + + [Illustration: FIG. 27.] + + [Illustration: FIG. 28.] + + However it be built up, the mechanical strength of the magnet system + must be carefully considered. Any two surfaces between which there + exists a field of density B_g experience a force tending to draw them + together proportional to the square of the density, and having a value + of B_g squared/(1.735 x 10^6) lb. per sq. in. of surface, over which the + density may be regarded as having the uniform value B_g. Hence, quite + apart from the torque with which the stationary part of the dynamo + tends to turn with the rotating part as soon as current is taken out + of the armature, there exists a force tending to make the pole-pieces + close on the armature as soon as the field is excited. Since both + armature and magnet must be capable of resisting this force, they + require to be rigidly held; although the one or the other must be + capable of rotation, there should otherwise be no possibility of one + part of the magnetic circuit shifting relatively to any other part. An + important conclusion may be drawn from this circumstance. If the + armature be placed exactly concentric within the bore of the poles, + and the two or more magnetic fields be symmetrical about a line + joining their centres, there is no tendency for the armature core to + be drawn in one direction more than in another; but if there is any + difference between the densities of the several fields, it will cause + an unbalanced stress on the armature and its shaft, under which it + will bend, and as this bending is continually reversed relatively to + the fibres of the shaft, they will eventually become weakened and give + way. Especially is this likely to take place in dynamos with short + air-gaps, wherein any difference in the lengths of the air-gaps + produces a much greater percentage difference in the flux-density than + in dynamos with long air-gaps. In toothed armatures with short + air-gaps the shaft must on this account be sufficiently strong to + withstand the stress without appreciable bending. + + + The magnetic circuit. + +Reference has already been made to the importance in dynamo design of +the _predetermination of the flux_ due to a given number of ampere-turns +wound on the field-magnet, or, conversely, of the number of ampere-turns +which must be furnished by the exciting coils in order that a certain +flux corresponding to one field may flow through the armature core from +each pole. An equally important problem is the correct proportioning of +the field-magnet, so that the useful flux Z_a may be obtained with the +greatest economy in materials and exciting energy. The key to the two +problems is to be found in the concept of a magnetic circuit as +originated by H.A. Rowland and R.H.M. Bosanquet;[16] and the full +solution of both may be especially connected with the name of Dr J. +Hopkinson, from his practical application of the concept in his design +of the Edison-Hopkinson machine, and in his paper on "Dynamo-Electric +Machinery."[17] The publication of this paper in 1886 begins the second +era in the history of the dynamo; it at once raised its design from the +level of empirical rules-of-thumb to a science, and is thus worthy to be +ranked as the necessary supplement of the original discoveries of +Faraday. The process of predetermining the necessary ampere-turns is +described in a simple case under ELECTROMAGNETISM. In its extension to +the complete dynamo, it consists merely in the division of the magnetic +circuit into such portions as have the same sectional area and +permeability and carry approximately the same total flux; the difference +of magnetic potential that must exist between the ends of each section +of the magnet in order that the flux may pass through it is then +calculated _seriatim_ for the several portions into which the magnetic +circuit is divided, and the separate items are summed up into one +magnetomotive force that must be furnished by the exciting coils. + +[Illustration: FIG. 29.] + + The chief sections of the magnetic circuit are (1) the air-gaps, (2) + the armature core, and (3) the iron magnet. + + The _air-gap_ of a dynamo with smooth-core armature is partly filled + with copper and partly with the cotton, mica, or other materials used + to insulate the core and wires; all these substances are, however, + sensibly non-magnetic, so that the whole interferric gap between the + iron of the pole-pieces and the iron of the armature may be treated as + an air-space, of which the permeability is constant for all values of + the flux density, and in the C.G.S. system is unity. Hence if l_g and + A_g be the length and area of the single air-gap in cm. and sq. cm., + the reluctance of the double air-gap is 2l_g/A_g, and the difference + of magnetic potential required to pass Z_a lines over this reluctance + is Z_a.2l_g/A_g = B_g.2l_g; or, since one ampere-turn gives 1.257 + C.G.S. units of magnetomotive force, the exciting power in + ampere-turns required over the two air-gaps is X_g = B_g.2l_g/1.257 = + 0.8 B_g.2l_g. In the determination of the area A_g small allowance + must be made for the fringe of lines which extend beyond the actual + polar face. In the toothed armature with open slots, the lines are no + longer uniformly distributed over the air-gap area, but are graduated + into alternate bands of dense and weak induction corresponding to the + teeth and slots. Further, the lines curve round into the sides of the + teeth, so that their average length of path in the air and the air-gap + reluctance is not so easily calculated. Allowance must be made for + this by taking an increased length of air-gap = ml_g, where m is the + ratio _maximum density/mean density_, of which the value is chiefly + determined by the ratios of the width of tooth to width of slot and of + the width of slot to the air-gap between pole-face and surface of the + armature core. + + The _armature core_ must be divided into the teeth and the core proper + below the teeth. Owing to the tapering section of the teeth, the + density rises towards their root, and when this reaches a high value, + such as 18,000 or more lines per sq. cm., the saturation of the iron + again forces an increasing proportion of the lines outwards into the + slot. A distinction must then be drawn between the "apparent" + induction which would hold if all the lines were concentrated in the + teeth, and the "real" induction. The area of the iron is obtained by + multiplying the number of teeth under the pole-face by their width and + by the net length of the iron core parallel to the axis of rotation. + The latter is the gross length of the armature less the space lost + through the insulating varnish or paper between the disks or through + the presence of ventilating ducts, which are introduced at intervals + along the length of the core. The former deduction averages about 7 to + 10% of the gross length, while the latter, especially in large + multipolar machines, is an even more important item. Alter calculating + the density at different sections of the teeth, reference has now to + be made to a (B, H) or flux-density curve, from which may be found the + number of ampere-turns required per cm. length of path. This number + may be expressed as a function of the density in the teeth, and f(B_t) + be its average value over the length of a tooth, the ampere-turns of + excitation required over the teeth on either side of the core as the + lines of one field enter or leave the armature is X_t = f(B_t).2l_t, + where l_t is the length of a single tooth in cm. + + In the core proper below the teeth the length of path continually + shortens as we pass from the middle of the pole towards the centre + line of symmetry. On the other hand, as the lines gradually accumulate + in the core, their density increases from zero midway under the poles + until it reaches a maximum on the line of symmetry. The two effects + partially counteract one another, and tend to equalize the difference + of magnetic potential required over the paths of varying lengths; but + since the reluctivity of the iron increases more rapidly than the + density of the lines, we may approximately take for the length of path + (l_a) the minimum peripheral distance between the edges of adjacent + pole-faces, and then assume the maximum value of the density of the + lines as holding throughout this entire path. In ring and drum + machines the flux issuing from one pole divides into two halves in the + armature core, so that the maximum density of lines in the armature is + B_a = Z_a/2ab, where a = the radial depth of the disks in centimetres + and b = the net length of iron core. The total exciting power required + between the pole-pieces is therefore, at no load, X_p = X_g + X_t + + X_a, where X_a = f(B_a).l_a; in order, however, to allow for the + effect of the armature current, which increases with the load, a + further term X_b, must be added. + + [Illustration: Fig. 30.] + + In the continuous-current dynamo it may be, and usually is, necessary + to move the brushes forward from the interpolar line of symmetry + through a small angle in the direction of rotation, in order to avoid + sparking between the brushes and the commutator (_vide infra_). When + the dynamo is giving current, the wires on either side of the diameter + of commutation form a current-sheet flowing along the surface of the + armature from end to end, and whatever the actual end-connexions of + the wires, the wires may be imagined to be joined together into a + system of loops such that the two sides of each loop are carrying + current in opposite directions. Thus a number of armature ampere-turns + are formed, and their effect on the entire system of magnet and + armature must be taken into account. So long as the diameter of + commutation coincides with the line of symmetry, the armature may be + regarded as a cylindrical electromagnet producing a flux of lines, as + shown in fig. 30. The direction of the self-induced flux in the + air-gaps is the same as that of the lines of the external field in one + quadrant on one side of DC, but opposed to it in the other quadrant on + the same side of DC; hence in the resultant field due to the combined + action of the field-magnet and armature ampere-turns, the flux is as + much strengthened over the one half of each polar face as it is + weakened over the other, and the total number of lines is unaffected, + although their distribution is altered. The armature ampere-turns are + then called _cross-turns_, since they produce a cross-field, which, + when combined with the symmetrical field, causes the leading + pole-corners ll to be weakened and the trailing pole-corners tt to be + strengthened, the neutral line of zero field being thus twisted + forwards in the direction of rotation. But when the brushes and + diameter of commutation are shifted forward, as shown in fig. 31, it + will be seen that a number of ampere-turns, forming a zone between the + lines Dn and mC, are in effect wound immediately on the magnetic + circuit proper, and this belt of ampere-turns is in direct opposition + to the ampere-turns of the field, as shown by the dotted and crossed + wires on the pole-pieces. The armature ampere-turns are then divisible + into the two bands, the _back-turns_, included within twice the angle + of lead [lambda], weakening the field, and the cross-turns, bounded by + the lines Dm, nC, again producing distortion of the weakened + symmetrical field. If, therefore, a certain flux is to be passed + through the armature core in opposition to the demagnetizing turns, + the difference of magnetic potential between the pole-faces must + include not only X_a, X_t, and X_g, but also an item X_b, in order to + balance the "back" ampere-turns of the armature. The amount by which + the brushes must be shifted forward increases with the armature + current, and in corresponding proportion the back ampere-turns are + also increased, their value being c[tau]2[lambda]/360 deg., where c = the + current carried by each of the [tau] active wires. Thus the term X_b, + takes into account the effect of the armature reaction on the total + flux; it varies as the armature current and angle of lead required to + avoid sparking are increased; and the reason for its introduction in + the fourth place (X_p = X_g + X_t + X_a + X_b), is that it increases + the magnetic difference of potential which must exist between the + poles of the dynamo, and to which the greater part of the leakage is + due. The leakage paths which are in parallel with the armature across + the poles must now be estimated, and so a new value be derived for the + flux at the commencement of the _iron-magnet_ path. If P = their joint + permeance, the leakage flux due to the difference of potential at the + poles is z_l = 1.257X_p x P, and this must be added to the useful flux + Z_a, or Z_p = Z_a + Z_l. There are also certain leakage paths in + parallel with the magnet cores, and upon the permeance of these a + varying number of ampere-turns is acting as we proceed along the + magnet coils; the magnet flux therefore increases by the addition of + leakage along the length of the limbs, and finally reaches a maximum + near the yoke. Either, then, the density in the magnet B_m = Z_m/A_m + will vary if the same sectional area be retained throughout, or the + sectional area of the magnet must itself be progressively increased. + In general, sufficient accuracy will be obtained by assuming a certain + number of additional leakage lines z_n as traversing the entire length + of magnet limbs and yoke (= l_m), so that the density in the magnet + has the uniform value B_m = (Z_p + z_n)/A_m. The leakage flux added on + actually within the length of the magnet core or z_n will be + approximately equal to half the total M.M.F. of the coils multiplied + by the permeance of the leakage paths around one coil. The + corresponding value of H can then be obtained from the (B, H) curve of + the material of which the magnet is composed, and the ampere-turns + thus determined must be added to X_p, or X = X_p + X_m, where X_m = + f(B_m)l_m. The final equation for the exciting power required on a + magnetic circuit as a whole will therefore take the form + + X = A[Tau] = 0.8B_g.2l_g + f(B_t)2l_t + f(B_a)l_a + X_b + f(B_m)l_m. (3) + + If the magnet cores are of wrought iron or cast steel, and the yoke is + of cast iron, the last term must be divided into two portions + corresponding to the different materials, i.e. into f(B_m)l_m + + f(B_y)l_y. In the ordinary multipolar machine with as many + magnet-coils as there are poles, each coil must furnish half the above + number of ampere-turns. + + [Illustration: FIG. 31.] + + + Magnetic leakage. + + Since no substance is impermeable to the passage of magnetic flux, the + only form of magnetic circuit free from leakage is one uniformly wound + with ampere-turns over its whole length. The reduction of the + _magnetic leakage_ to a minimum in any given type is therefore + primarily a question of distributing the winding as far as possible + uniformly upon the circuit, and as the winding must be more or less + concentrated into coils, it resolves itself into the necessity of + introducing as long air-paths as possible between any surfaces which + are at different magnetic potentials. No iron should be brought near + the machine which does not form part of the magnetic circuit proper, + and especially no iron should be brought near the poles, between which + the difference of magnetic potential practically reaches its maximum + value. In default of a machine of the same size or similar type on + which to experiment, the probable direction of the leakage flux must + be assumed from the drawing, and the air surrounding the machine must + be mapped out into areas, between which the permeances are calculated + as closely as possible by means of such approximate formulae as those + devised by Professor G. Forbes. + + + Excitation of field-magnet. + + In the earliest "magneto-electric" machines permanent steel magnets, + either simple or compound, were employed, and for many years these + were retained in certain alternators, some of which are still in use + for arc lighting in lighthouses. But since the field they furnish is + very weak, a great advance was made when they were replaced by soft + iron electromagnets, which could be made to yield a much more intense + flux. As early as 1831 Faraday[18] experimented with electromagnets, + and after 1850 they gradually superseded the permanent magnet. When + the total ampere-turns required to excite the electromagnet have been + determined, it remains to decide how the excitation shall be obtained; + and, according to the method adopted, continuous-current machines may + be divided into four well-defined classes. + + [Illustration: FIG. 32.] + + The simplest method, and that which was first used, is _separate + excitation_ from some other source of direct current, which may be + either a primary or a secondary battery or another dynamo (fig. 32). + But since the armature yields a continuous current, it was early + suggested (by J. Brett in 1848 and F. Sinsteden in 1851) that this + current might be utilized to increase the flux; combinations of + permanent and electromagnets were therefore next employed, acting + either on the main armature or on separate armatures, until in 1867 Dr + Werner von Siemens and Sir C. Wheatstone almost simultaneously + discovered that the dynamo could be made _self-exciting_ through the + residual magnetism retained in the soft iron cores of the + electromagnet. The former proposed to take the whole of the current + round the magnet coils which were in series with the armature and + external circuit, while the latter proposed to utilize only a portion + derived by a shunt from the main circuit; we thus arrive at the second + and third classes, namely, _series_ and _shunt_ machines. The starting + of the process of excitation in either case is the same; when the + brushes are touching the commutator and the armature is rotated, the + small amount of flux left in the magnet is cut by the wires, and a + very small current begins to flow round the closed circuit; this + increases the flux, which in turn further increases the E.M.F. and + current, until, finally, the cumulative effect stops through the + increasing saturation of the iron cores. Fig. 33, illustrating the + _series_ machine, shows the winding of the exciting coils to be + composed of a few turns of thick wire. Since the current is undivided + throughout the whole circuit, the resistance of both the armature and + field-magnet winding must be low as compared with that of the external + circuit, if the useful power available at the terminals of the machine + is to form a large percentage of the total electrical power--in other + words, if the efficiency is to be high. Fig. 34 shows the third + method, in which the winding of the field-magnets is a _shunt_ or + fine-wire circuit of many turns applied to the terminals of the + machine; in this ease the resistance of the shunt must be high as + compared with that of the external circuit, in order that only a small + proportion of the total energy may be absorbed in the field. + + [Illustration: FIG. 33.] + + [Illustration: FIG. 34.] + + Since the whole of the armature current passes round the field-magnet + of the series machine, any alteration in the resistance of the + external circuit will affect the excitation and also the voltage. A + curve connecting together corresponding values of external current and + terminal voltage for a given speed of rotation is known as the + _external-characteristic_ of the machine; in its main features it has + the same appearance as a curve of magnetic flux, but when the current + exceeds a certain amount it begins to bend downwards and the voltage + decreases. The reason for this will be found in the armature reaction + at large loads, which gradually produces a more and more powerful + demagnetizing effect, as the brushes are shifted forwards to avoid + sparking; eventually the back ampere-turns overpower any addition to + the field that would otherwise be due to the increased current flowing + round the magnet. The "external characteristic" for a shunt machine + has an entirely different shape. The field-magnet circuit being + connected in parallel with the external circuit, the exciting current, + if the applied voltage remains the same, is in no way affected by + alterations in the resistance of the latter. As, however, an increase + in the external current causes a greater loss of volts in the armature + and a greater armature reaction, the terminal voltage, which is also + the exciting voltage, is highest at no load and then diminishes. The + fall is at first gradual, but after a certain critical value of the + armature current is reached, the machine is rapidly demagnetized and + loses its voltage entirely. + + [Illustration: FIG. 35.] + + The last method of excitation, namely, _compound-winding_ (fig. 35), + is a combination of the two preceding, and was first used by S.A. + Varley and by C.F. Brush. If a machine is in the first instance + shunt-wound, and a certain number of series-turns are added, the + latter, since they carry the external current, can be made to + counteract the effect which the increased external current would have + in lowering the voltage of the simple shunt machine. The ampere-turns + of the series winding must be such that they not only balance the + increase of the demagnetizing back ampere-turns on the armature, but + further increase the useful flux, and compensate for the loss of volts + over their own resistance and that of the armature. The machine will + then give for a constant speed a nearly constant voltage at its + terminals, and the curve of the external characteristic becomes a + straight line for all loads within its capacity. Since with most prime + movers an increase of the load is accompanied by a drop in speed, this + effect may also be counteracted; while, lastly, if the series-turns + are still further increased, the voltage may be made to rise with an + increasing load, and the machine is "over-compounded." + + + Commutation and sparking at the brushes. + +At the initial moment when an armature coil is first short-circuited by +the passage of the two sectors forming its ends under the contact +surface of a brush, a certain amount of electromagnetic energy is stored +up in its magnetic field as linked with the ampere-turns of the coil +when carrying its full share of the total armature current. During the +period of short-circuit this quantity of energy has to be dissipated as +the current falls to zero, and has again to be re-stored as the current +is reversed and raised to the same value, but in the opposite direction. +The period of short-circuit as fixed by the widths of the brush and of +the mica insulation between the sectors, and by the peripheral speed of +the commutator is extremely brief, and only lasts on an average from +(1/200)th to (1/1000)th of a second. The problem of sparkless +commutation is therefore primarily a question of our ability to +dissipate and to re-store the required amount of energy with sufficient +rapidity. + +An important aid towards the solution of this problem is found in the +effect of the varying contact-resistance between the brush and the +surfaces of the leading and trailing sectors which it covers. As the +commutator moves under the brush, the area of contact which the brush +makes with the leading sector diminishes, and the resistance between the +two rises; conversely, the area of contact between the brush and the +trailing sector increases and the resistance falls. This action tends +automatically to bring the current through each sector into strict +proportionality to the amount of its surface which is covered by the +brush, and so to keep the current-density and the loss of volts over the +contacts uniform and constant. As soon as the current-density in the two +portions of the brush becomes unequal, a greater amount of heat is +developed at the commutator surface, and this in the first place affords +an additional outlet for the dissipation of the stored energy of the +coil, while after reversal of the current it is the accompaniment of a +re-storage of the required energy. This energy, as well as that which is +spent in heating the coil, can in fact, in default of other sources, be +derived through the action of the unequal current-density from the +electrical output of the rest of the armature winding, and so only +indirectly from the prime mover. + +In practice, when the normal contact-resistance of the brushes is low +relatively to the resistance of the coil, as is the case with metal +brushes of copper or brass gauze, but little benefit can be obtained +from the action of the varying contact-resistance. It exerts no +appreciable effect until close towards the end of the period of +short-circuit, and then only with such a high-current-density at the +trailing edge of the leaving sector that at the moment of parting the +brush-tip is fused, or its metal volatilized, and sparking has in fact +set in. With such brushes, then, it becomes necessary to call in the aid +of a reversing E.M.F. impressed upon the coil by the magnetic field +through which it is moving. If such a reversing field comes into action +while the current is still unreversed, its E.M.F. is opposed to the +direction of the current, and the coil is therefore driving the armature +forward as in a motor; it thus affords a ready means of rapidly +dissipating part of the initial energy in the form of mechanical work +instead of as heat. After the current has been reversed, the converse +process sets in, and the prime mover directly expends mechanical energy +not only in heating the coil, but also in storing up electromagnetic +energy with a rapidity dependent upon the strength of the reversing +field. The required direction of external field can be obtained in the +dynamo by shifting the brushes forward, so that the short-circuited coil +enters into the fringe of lines issuing from the leading pole-tip, i.e. +by giving the brushes an "angle of lead." An objection to this process +is that the main flux is thereby weakened owing to the belt of back +ampere-turns which arises (_v. supra_). A still greater objection is +that the amount of the angle of lead must be suited to the value of the +load, the corrective power of copper brushes being very small if the +reversing E.M.F. is not closely adjusted in proportion to the armature +current. + +On this account metal brushes have been almost entirely superseded by +carbon moulded into hard blocks. With these, owing to their higher +specific contact-resistance, a very considerable reversing effect can be +obtained through the action of unequal current-density, and indeed in +favourable cases complete sparklessness can be obtained throughout the +entire range of load of the machine with a fixed position of the +brushes. Yet if the work which they are called upon to perform exceeds +certain limits, they tend to become overheated with consequent glowing +or sparking at their tips, so that, wherever possible, it is advisable +to reinforce their action by a certain amount of reversing field, the +brushes being set so that its strength is roughly correct for, say, half +load. + +In the case of dynamos driven by steam-turbines, sparkless commutation +is especially difficult to obtain owing to the high speed of rotation +and the very short space of time in which the current has to be +reversed. Special "reversing poles" then become necessary; these are +wound with magnetizing coils in series with the main armature current, +so that the strength of field which they yield is roughly proportional +to the current which has to be reversed. These again may be combined +with a "compensating winding" embedded in the pole-faces and carrying +current in the opposite direction to the armature ampere-turns, so as to +neutralize the cross effect of the latter and prevent distortion of the +resultant field. + + + Heating effects. + + From the moment that a dynamo begins to run with excited field, heat + is continuously generated by the passage of the current through the + windings of the field-magnet coils and the armature, as well as by the + action of hysteresis and eddy currents in the armature and + pole-pieces. Whether the source of the heat be in the field-magnet or + in the armature, the mass in which it originates will continue to rise + in temperature until such a difference of temperature is established + between itself and the surrounding air that the rate at which the heat + is carried off by radiation, convection and conduction is equal to the + rate at which it is being generated. Evidently, then, the temperature + which any part of the machine attains after a prolonged run must + depend on the extent and effectiveness of the cooling surface from + which radiation takes place, upon the presence or absence of any + currents of air set up by the rotation of itself or surrounding parts, + and upon the presence of neighbouring masses of metal to carry away + the heat by conduction. In the field-magnet coils the rate at which + heat is being generated is easily determined, since it is equal to the + square of the current passing through them multiplied by their + resistance. Further, the magnet is usually stationary, and only + indirectly affected by draughts of air due to the rotating armature. + Hence for machines of a given type and of similar proportions, it is + not difficult to decide upon some method of reckoning the cooling + surface of the magnet coils S_c, such that the rise of temperature + above that of the surrounding air may be predicted from an equation of + the form t deg. = kW/S_c, where W = the rate in watts at which heat is + generated in the coils, and k is some constant depending upon the + exact method of reckoning their cooling surface. As a general rule the + cooling surface of a field-coil is reckoned as equal to the exposed + outer surface of its wire, the influence of the end flanges being + neglected, or only taken into account in the case of very short + bobbins wound with a considerable depth of wire. In the case of the + rotating armature a similar formula must be constructed, but with the + addition of a factor to allow for the increase in the effectiveness of + any given cooling surface due to the rotation causing convection + currents in the surrounding air. Only experiment can determine the + exact effect of this, and even with a given type of armature it is + dependent on the number of poles, each of which helps to break up the + air-currents, and so to dissipate the heat. For example, in two-pole + machines with drum bar-armatures, if the cooling surface be reckoned + as equal to the cylindrical exterior plus the area of the two ends, + the heating coefficient for a peripheral speed of 1500 ft. per minute + is less than half of that for the same armature when at rest. A + further difficulty still meets the designer in the correct + predetermination of the total loss of watts in an armature before the + machine has been tested. It is made up of three separate items, + namely, the copper loss in the armature winding, the loss by + hysteresis in the iron, and the loss by eddy currents, which again may + be divided into those in the armature bars and end-connexions, and + those in the core and its end-plates. The two latter items are both + dependent upon the speed of the machine; but whereas the hysteresis + loss is proportional to the speed for a given density of flux in the + armature, the eddy current loss is proportional to the square of the + speed, and owing to this difference, the one loss can be separated + from the other by testing an armature at varying speeds. Thus for a + given rise of temperature, the question of the amount of current which + can be taken out of an armature at different speeds depends upon the + proportion which the hysteresis and eddy watts bear to the copper + loss, and the ratio in which the effectiveness of the cooling surface + is altered by the alteration in speed. Experimental data, again, can + alone decide upon the amount of eddy currents that may be expected in + given armatures, and caution is required in applying the results of + one machine to another in which any of the conditions, such as the + number of poles, density in the teeth, proportions of slot depth to + width, &c., are radically altered. + + It remains to add, that the rise of temperature which may be permitted + in any part of a dynamo after a prolonged run is very generally placed + at about 70 deg. Fahr. above the surrounding air. Such a limit in ordinary + conditions of working leads to a final temperature of about 170 deg. + Fahr., beyond which the durability of the insulation of the wires is + liable to be injuriously affected. Upon some such basis the output of + a dynamo in continuous working is rated, although for short periods + of, say, two hours the normal full-load current of a large machine may + be exceeded by some 25% without unduly heating the armature. + + + Uses of continuous current dynamos. + +For the electro-deposition of metals or the electrolytic treatment of +ores a continuous current is a necessity; but, apart from such use, the +purposes from which the continuous-current dynamo is well adapted are so +numerous that they cover nearly the whole field of electrical +engineering, with one important exception. To meet these various uses, +the pressures for which the machine is designed are of equally wide +range; for the transmission of power over long distances they may be as +high as 3000 volts, and for electrolytic work as low as five. Each +electrolytic bath, with its leads, requires on an average only some four +or five volts, so that even when several are worked in series the +voltage of the dynamo seldom exceeds 60. On the other hand, the current +is large and may amount to as much as from 1000 to 14,000 amperes, +necessitating the use of two commutators, one at either end of the +armature, in order to collect the current without excessive heating of +the sectors and brushes. The field-magnets are invariably shunt-wound, +in order to avoid reversal of the current through polarization at the +electrodes of the bath. For incandescent lighting by glow lamps, the +requirements of small isolated installations and of central stations for +the distribution of electrical energy over large areas must be +distinguished. For the lighting of a private house or small factory, the +dynamo giving from 5 to 100 kilo-watts of output is commonly wound for a +voltage of 100, and is driven by pulley and belt from a gas, oil or +steam-engine; or, if approaching the higher limit above mentioned, it is +often directly coupled to the crank-shaft of the steam-engine. If used +in conjunction with an accumulator of secondary cells, it is +shunt-wound, and must give the higher voltage necessary to charge the +battery; otherwise it is compound-wound, in order to maintain the +pressure on the lamps constant under all loads within its capacity. The +compound-wound dynamo is likewise the most usual for the lighting of +steamships, and is then directly coupled to its steam-engine; its output +seldom exceeds 100 kilo-watts, at a voltage of 100 or 110. For larger +installations a voltage of 250 is commonly used, while for +central-station work, economy in the distributing mains dictates a +higher voltage, especially in connexion with a three-wire system; the +larger dynamos may then give 500 volts, and be connected directly across +the two outer wires. A pair of smaller machines coupled together, and +each capable of giving 250 volts, are often placed in series across the +system, with their common junction connected to the middle wire; the one +which at any time is on the side carrying the smaller current will act +as a motor and drive the other as a dynamo, so as to balance the system. +The directly-coupled steam dynamo may be said to have practically +displaced the belt- or rope-driven sets which were formerly common in +central stations. The generating units of the central station are +arranged in progressive sizes, rising from, it may be, 250 or 500 +horse-power up to 750 or 1000, or in large towns to as much as 5000 +horse-power. If for lighting only, they are usually shunt-wound, the +regulation of the voltage, to keep the pressure constant on the +distributing system under the gradual changes of load, being effected by +variable resistances in the shunt circuit of the field-magnets. + +Generators used for supplying current to electric tramways are commonly +wound for 500 volts at no load and are over-compounded, so that the +voltage rises to 550 volts at the maximum load, and thus compensates for +the loss of volts over the transmitting lines. For arc lighting it was +formerly usual to employ a class of dynamo which, from the nature of its +construction, was called an "open-coil" machine, and which gave a +unidirectional but pulsating current. Of such machines the Brush and +Thomson-Houston types were very widely used; their E.M.F. ranged from +2000 to 3000 volts for working a large number of arcs in series, and by +means of special regulators their current was maintained constant over a +wide range of voltage. But as their efficiency was low and they could +not be applied to any other purpose, they have been largely superseded +in central stations by closed-coil dynamos or alternators, which can +also be used for incandescent lighting. In cases where the central +station is situated at some distance from the district to which the +electric energy is to be supplied, voltages from 1000 to 2000 are +employed, and these are transformed down at certain distributing centres +by continuous-current transformers (see TRANSFORMERS and ELECTRICITY +SUPPLY). These latter machines are in reality motor-driven dynamos, and +hence are also called _motor-generators_; the armatures of the motor and +dynamo are often wound on the same core, with a commutator at either +end, the one to receive the high-pressure motor current, and the other +to collect the low-pressure current furnished by the dynamo. + + In all large central stations it is necessary that the dynamos should + be capable of being run _in parallel_, so that their outputs may be + combined on the same "omnibus bars" and thence distributed to the + network of feeders. With simple shunt-wound machines this is easily + effected by coupling together terminals of like sign when the voltage + of the two or more machines are closely equal. With compound-wound + dynamos not only must the external terminals of like sign be coupled + together, but the junctions of the brush leads with the series winding + must be connected by an "equalizing" lead of low resistance; + otherwise, should the E.M.F. of one machine for any reason fall below + the voltage of the omnibus bars, there is a danger of its polarity + being reversed by a back current from the others with which it is in + parallel. + + Owing to the necessary presence in the continuous-current dynamo of + the commutator, with its attendant liability to sparking at the + brushes, and further, owing to the difficulty of insulating the + rotating armature wires, a pressure of 3000 volts has seldom been + exceeded in any one continuous-current machine, and has been given + above as the limiting voltage of the class. If therefore it is + required to work with higher pressures in order to secure economy in + the transmitting lines, two or more machines must be coupled _in + series_ by connecting together terminals which are of unlike sign.[19] + The stress of the total voltage may still fall on the insulation of + the winding from the body of the machine; hence for high-voltage + transmission of power over very long distances, the continuous-current + dynamo in certain points yields in convenience to the alternator. In + this there is no commutator, the armature coils may be stationary and + can be more thoroughly insulated, while further, if it be thought + undesirable to design the machine for the full transmitting voltage, + it is easy to wind the armature for a low pressure; this can be + subsequently transformed up to a high pressure by means of the + alternating-current transformer, which has stationary windings and so + high an efficiency that but little loss arises from its use. With + these remarks, the transition may be made to the fuller discussion of + the alternator. + + +_Alternators._ + + Frequency. + +The frequency employed in alternating-current systems for distributing +power and light varies between such wide limits as 25 and 133; yet in +recent times the tendency has been towards standard frequencies of 25, +50 and 100 as a maximum. High frequencies involve more copper in the +magnet coils, owing to the greater number of poles, and a greater loss +of power in their excitation, but the alternator as a whole is somewhat +lighter, and the transformers are cheaper. On the other hand, high +frequency may cause prejudicial effects, due to the inductance and +capacity of the distributing lines; and in asynchronous motors used on +polyphase systems the increased number of poles necessary to obtain +reasonable speeds reduces their efficiency, and is otherwise +disadvantageous, especially for small horse-powers. A frequency lower +than 40 is, however, not permissible where arc lighting is to form any +considerable portion of the work and is to be effected by the +alternating current without rectification, since below this value the +eye can detect the periodic alteration in the light as the carbons +alternately cool and become heated. Thus for combined lighting and power +50 or 60 are the most usual frequencies; but if the system is designed +solely or chiefly for the distribution of power, a still lower frequency +is preferable. On this account 25 was selected by the engineers for the +Niagara Falls power transmission, after careful consideration of the +problem, and this frequency has since been widely adopted in similar +cases. + + + Alternator construction. + +The most usual type of heteropolar alternator has an internal rotating +field-magnet system, and an external stationary armature, as in fig. 10. +The coils of the armature, which must for high voltages be heavily +insulated, are then not subjected to the additional stresses due to +centrifugal force; and further, the collecting rings which must be +attached to the rotating portion need only transmit the exciting current +at a low voltage. + +[Illustration: FIG. 36.] + +The homopolar machine possesses the advantages that only a single +exciting coil is required, whatever the number of polar projections, and +that both the armature and field-magnet coils may be stationary. From +fig. 8 it will be seen that it is not essential that the exciting coil +should revolve with the internal magnet, but it may be supported from +the external stationary armature while still embracing the central part +of the rotor. The E.M.F. is set up in the armature coils through the +periodic variation of the flux through them as the iron projections +sweep past, and these latter may be likened to a number of "keepers," +which complete the magnetic circuit. From the action of the rotating +iron masses they may also be considered as the inducing elements or +"inductors," and the homopolar machine is thence also known as the +"inductor alternator." If the end of the rotor marked S in fig. 8 is +split up into a number of S polar projections similar to the N poles, a +second set of armature coils may be arranged opposite to them, and we +obtain an inductor alternator with double armature. Or the polar +projections at the two ends may be staggered, and a single armature +winding be passed straight through the armature, as in fig. 36, which +shows at the side the appearance of the revolving inductor with its +crown of polar projections in one ring opposite to the gaps between the +polar projections of the other ring. But in spite of its advantage of +the single stationary exciting coil, the inductor alternator has such a +high degree of leakage, and the effect of armature reaction is so +detrimental in it, that the type has been gradually abandoned, and a +return has been almost universally made to the heteropolar alternator +with internal poles radiating outwards from a circular yoke-ring. The +construction of a typical machine of this class is illustrated in fig. +37. + +[Illustration: FIG. 37.] + +Since the field-magnet coils rotate, they must be carefully designed to +withstand centrifugal force, and are best composed of flat copper strip +wound on edge with thin insulation between adjacent layers. The coil is +secured by the edges of the pole-shoes which overhang the pole and +tightly compress the coil against the yoke-ring; the only effect from +centrifugal force is then to compress still further the flat turns of +copper against the pole-shoes without deformation. The poles are either +of cast steel of circular or oblong section, bolted to the rim of the +yoke-ring, or are built up of thin laminations of sheet steel. When the +peripheral speed is very high, the yoke-ring will be of cast steel or +may itself be built up of sheet steel laminations, this material being +reliable and easily tested to ensure its sound mechanical strength. If +the armature slots are open, the pole-pieces will in any case be +laminated to reduce the eddy currents set up by the variation of the +flux-density. + +Owing to the great number of poles[20] of the alternator when driven by +a reciprocating steam-engine, the diameter of its rotor is usually +larger and its length less than in the continuous-current dynamo of +corresponding output. The support of the armature core when of large +diameter is therefore a more difficult problem, since, apart from any +magnetic strains to which it may be subjected, its own weight tends to +deform it. The segmental core-disks are usually secured to the internal +circumference of a circular cast iron frame; the latter has a box +section of considerable radial depth to give stiffness to it, and the +disks are tightly clamped between internal flanges, one being a fixed +part of the frame and the other loose, with transverse bolts passing +right through from side to side (fig. 37). In order to lessen the weight +of the structure and its expense in material, the cast iron frame has in +some cases been entirely dispensed with, and braced tie-rods have been +used to render the effective iron of the armature core-disks +self-supporting. + +[Illustration: FIG. 38.] + +Owing to the high speed of the turbo-alternator, its rotor calls for the +utmost care in its design to withstand the effect of centrifugal force +without any shifting of the exciting coils, and to secure a perfect +balance. + +The appearance of the armature of a typical three-phase alternator is +illustrated in fig. 38, which shows a portion of the lower half after +removal of the field-magnet. + +With open slots the coils, after being wound on formers to the required +shape, are thoroughly impregnated with insulating compound, dried, and +after a further wrapping with several layers of insulating material, +finally pressed into the slots together with a sheet of leatheroid or +flexible micanite. The end-connexions of each group of coils of one +phase project straight out from the slots or are bent upwards +alternately with those of the other phases, so that they may clear one +another (fig. 37). A wooden wedge driven into a groove at the top of +each slot is often used to lock the coil in place. With slots nearly +closed at the top, the coils are formed by hand by threading the wire +through tubes of micanite or specially prepared paper lining the slots; +or with single-turn loops, stout bars of copper of [U]-shape can be +driven through the slots and closed by soldered connexions at the other +end. + + + Shape of E.M.F. curve. + + The first experimental determination of the shape of the E.M.F. curve + of an alternator was made by J. Joubert in 1880. A revolving + contact-maker charged a condenser with the E.M.F. produced by the + armature at a particular instant during each period. The condenser was + discharged through a ballistic galvanometer, and from the measured + throw the instantaneous E.M.F. could be deduced. The contact-maker was + then shifted through a small angle, and the instantaneous E.M.F. at + the new position corresponding to a different moment in the period was + measured; this process was repeated until the E.M.F. curve for a + complete period could be traced. Various modifications of the same + principle have since been used, and a form of "oscillograph" (q.v.) + has been perfected which is well adapted for the purpose of tracing + the curves both of E.M.F. and of current. The machine on which Joubert + carried out his experiments was a Siemens disk alternator having no + iron in its armature, and it was found that the curve of E.M.F. was + practically identical with a sine curve. The same law has also been + found to hold true for a smooth-core ring or drum armature, but the + presence of the iron core enables the armature current to produce + greater distorting effect, so that the curves under load may vary + considerably from their shape at no load. In toothed armatures, the + broken surface of the core, and the still greater reaction from the + armature current, may produce wide variations from the sine law, the + general tendency being to give the E.M.F. curve a more peaked form. + The great convenience of the assumption that the E.M.F. obeys the sine + law has led to its being very commonly used as the basis for the + mathematical analysis of alternator problems; but any deductions made + from this premiss require to be applied with caution if they are + likely to be modified by a different shape of the curve. Further, the + same alternator will give widely different curves even of E.M.F., and + still more so of current, according to the nature of the external + circuit to which it is connected. As will be explained later, the + phase of the current relatively to the E.M.F. depends not only on the + inductance of the alternator itself, but also upon the inductance and + capacity of the external circuit, so that the same current will + produce different effects according to the amount by which it lags or + leads. The question as to the relative advantages of differently + shaped E.M.F. curves has led to much discussion, but can only be + answered by reference to the nature of the work that the alternator + has to do--i.e. whether it be arc lighting, motor driving, or + incandescent lighting through transformers. The shape of the E.M.F. + curve is, however, of great importance in one respect, since upon it + depends the ratio of the maximum instantaneous E.M.F. to the effective + value, and the insulation of the entire circuit, both external and + internal, must be capable of withstanding the maximum E.M.F. While the + maximum value of the sine curve is [root]2 or 1.414 times the + effective value, the maximum value of a [Lambda] curve is 1.732 times + the effective value, so that for the same effective E.M.F. the + armature wires must not only be more heavily insulated than in the + continuous-current dynamo, but also the more peaked the curve the + better must be the insulation. + + + Excitation. + + Since an alternating current cannot be used for exciting the + field-magnet, recourse must be had to some source of a direct current. + This is usually obtained from a small auxiliary continuous-current + dynamo, called an _exciter_, which may be an entirely separate + machine, separately driven and used for exciting several alternators, + or may be driven from the alternator itself; in the latter case the + armature of the exciter is often coupled directly to the rotating + shaft of the alternator, while its field-magnet is attached to the + bed-plate. Although separate excitation is the more usual method, the + alternator can also be made self-exciting if a part or the whole of + the alternating current is "rectified," and thus converted into a + direct current. + + + Quarter-phase alternators. + + The general idea of the polyphase alternator giving two or more + E.M.F.'s of the same frequency, but displaced in phase, has been + already described. The several phases may be entirely independent, and + such was the case with the early polyphase machines of Gramme, who + used four independent circuits, and also in the large two-phase + alternators designed by J.E.H. Gordon in 1883. If the phases are thus + entirely separate, each requires two collector rings and two wires to + its external circuit, i.e. four in all for two-phase and six for + three-phase machines. The only advantage of the polyphase machine as + thus used is that the whole of the surface of the armature core may be + efficiently covered with winding, and the output of the alternator for + a given size be thereby increased. It is, however, also possible so to + interlink the several circuits of the armature that the necessary + number of transmitting lines to the external circuits may be reduced, + and also the weight of copper in them for a given loss in the + transmission.[21] The condition which obviously must be fulfilled, + for such interlinking of the phases to be possible, is that in the + lines which are to meet at any common junction the algebraic sum of + the instantaneous currents, reckoned as positive if away from such + junction and as negative if towards it, must be zero. Thus if the + phases be diagrammatically represented by the relative angular + position of the coils in fig. 39, the current in the coils A and B + differs in phase from the current in the coils C and D by a quarter of + a period or 90 deg.; hence if the two wires b and d be replaced by the + single wire bd, this third wire will serve as a common path for the + currents of the two phases either outwards or on their return. At any + instant the value of the current in the third wire must be the vector + sum of the two currents in the other wires, and if the shape of the + curves of instantaneous E.M.F. and current are identical, and are + assumed to be sinusoidal, the effective value of the current in the + third wire will be the vector sum of the effective values of the + currents in the other wires; in other words, if the system is + balanced, the effective current in the third wire is [root]2, or 1.414 + times the current in either of the two outer wires. Since the currents + of the two phases do not reach their maximum values at the same time, + the sectional area of the third wire need not be twice that of the + others; in order to secure maximum efficiency by employing the same + current density in all three wires, it need only be 40% greater than + that of either of the outer wires. The effective voltage between the + external leads may in the same way be calculated by a vector diagram, + and with the above _star connexion_ the voltage between the outer pair + of wires a and c is [root]2, or 1.414 times the voltage between either + of the outer wires and the common wire bd. Next, if the four coils are + joined up into a continuous helix, just as in the winding of a + continuous-current machine, four wires may be attached to equidistant + points at the opposite ends of two diameters at right angles to each + other (fig. 40). Such a method is known as the _mesh connexion_, and + gives a perfectly symmetrical four-phase system of distribution. Four + collecting rings are necessary if the armature rotates, and there is + no saving in copper in the transmitting lines; but the importance of + the arrangement lies in its use in connexion with rotary converters, + in which it is necessary that the winding of the armature should form + a closed circuit. If e = the effective voltage of one phase A, the + voltage between any pair of adjacent lines in the diagram is e, and + between m and o or n and p is e [root]2. The current in any line is + the resultant of the currents in the two phases connected to it, and + its effective value is c [root]2, where c is the current of one phase. + + [Illustration: FIG. 39.] + + [Illustration: FIG. 40.] + + [Illustration: FIG. 41.] + + + Three-phase alternators. + + When we pass to machines giving three phases differing by 120 deg., the + same methods of star and mesh connexion find their analogies. If the + current in coil A (fig. 41) is flowing away from the centre, and has + its maximum value, the currents in coils B and C are flowing towards + the centre, and are each of half the magnitude of the current in A; + the algebraic sum of the currents is therefore zero, and this will + also be the case for all other instants. Hence the three coils can be + united together at the centre, and three external wires are alone + required. In this star or "Y" connexion, if e be the effective voltage + of each phase, or the voltage between any one of the three collecting + rings and the common connexion, the volts between any pair of + transmitting lines will be E = e [root]3 (fig. 41); if the load be + balanced, the effective current C in each of the three lines will be + equal, and the total output in watts will be W = 3Ce = 3CE/[root]3 = + 1.732 EC, or 1.732 times the product of the effective voltage between + the lines and the current in any single line. Next, if the three coils + are closed upon themselves in a mesh or _delta_ fashion (fig. 42), the + three transmitting wires may be connected to the junctions of the + coils (by means of collecting rings if the armature rotates). The + voltage E between any pair of wires is evidently that generated by + one phase, and the current in a line wire is the resultant of that in + two adjacent phases; or in a balanced system, if c be the current in + each phase, the current in the line wire beyond a collecting ring is C + = c [root]3, hence the watts are W = 3cE = 3CE/[root]3 = 1.732 EC, as + before. Thus any three-phase winding may be changed over from the star + to the delta connexion, and will then give 1.732 times as much + current, but only 1/1.732 times the voltage, so that the output + remains the same. + + [Illustration: FIG. 42.] + + + Armature reaction in alternators + + The "armature reaction" of the alternator, when the term is used in + its widest sense to cover all the effects of the alternating current + in the armature as linked with a magnetic circuit or circuits, may be + divided into three items which are different in their origin and + consequences. In the first place the armature current produces a + self-induced flux in local circuits independent of the main magnetic + circuit, as e.g. linked with the ends of the coils as they project + outwards from the armature core; such lines may be called "secondary + leakage," of which the characteristic feature is that its amount is + independent of the position of the coils relatively to the poles. The + alternations of this flux give rise to an inductive voltage lagging + 90 deg. behind the phase of the current, and this leakage or reactance + voltage must be directly counterbalanced electrically by an equal + component in the opposite sense in the voltage from the main field. + The second and third elements are more immediately magnetic and are + entirely dependent upon the position of the coils in relation to the + poles and in relation to the phase of the current which they then + carry. When the side of a drum coil is immediately under the centre of + a pole, its ampere-turns are cross-magnetizing, i.e. produce a + distortion of the main flux, displacing its maximum density to one or + other edge of the pole. When the coil-side is midway between the poles + and the axes of coil and pole coincide, the coil stands exactly + opposite to the pole and embraces the same magnetic circuit as the + field-magnet coils; its turns are therefore directly magnetizing, + either weakening or strengthening the main flux according to the + direction of the current. In intermediate positions the ampere-turns + of the coil gradually pass from cross to direct and vice versa. When + the instantaneous values of either the cross or direct magnetizing + effect are integrated over a period and averaged, due account being + taken of the number of slots per coil-side and of the different phases + of the currents in the polyphase machine, expressions are obtained for + the equivalent cross and direct ampere-turns of the armature as acting + upon a pair of poles. For a given winding and current, the determining + factor in either the one or the other is found to be the relative + phase angle between the axis of a coil in its position when carrying + the maximum current and the centre of a pole, the transverse reaction + being proportional to the cosine of this angle, and the direct + reaction to its sine. If the external circuit is inductive, the + maximum value of the current lags behind the E.M.F. and so behind the + centre of the pole; such a negative angle of lag causes the direct + magnetizing turns to become back turns, directly weakening the main + field and lowering the terminal voltage. Thus, just as in the + continuous-current dynamo, for a given voltage under load the + excitation between the pole-pieces X_p must not only supply the net + excitation required over the air-gaps, armature core and teeth, but + must also balance the back ampere-turns X_b of the armature. + + Evidently therefore the characteristic curve connecting armature + current and terminal volts will with a constant exciting current + depend on the nature of the load, whether inductive or non-inductive, + and upon the amount of inductance already possessed by the armature + itself. With an inductive load it will fall more rapidly from its + initial maximum value, or, conversely, if the initial voltage is to be + maintained under an increasing load, the exciting current will have to + be increased more than if the load were non-inductive. In practical + working many disadvantages result from a rapid drop of the terminal + E.M.F. under increasing load, so that between no load and full load + the variation in terminal voltage with constant excitation should not + exceed 15%. Thus the output of an alternator is limited either by its + heating or by its armature reaction, just as is the output of a + continuous-current dynamo; in the case of the alternator, however, the + limit set by armature reaction is not due to any sparking at the + brushes, but to the drop in terminal voltage as the current is + increased, and the consequent difficulty in maintaining a constant + potential on the external circuit. + + + The coupling of alternators. + + The joint operation of several alternators so that their outputs may + be delivered into the same external circuit is sharply distinguished + from the corresponding problem in continuous-current dynamos by the + necessary condition that they must be in synchronism, i.e. not only + must they be so driven that their frequency is the same, but their + E.M.F.'s must be in phase or, as it is also expressed, the machines + must be in step. Although in practice it is impossible to run two + alternators in series unless they are rigidly coupled together--which + virtually reduces them to one machine--two or more machines can be run + in parallel, as was first described by H. Wilde in 1868 and + subsequently redemonstrated by J. Hopkinson and W.G. Adams in 1884. + Their E.M.F.'s should be as nearly as possible in synchronism, but, + as contrasted with series connexion, parallel coupling gives them a + certain power of recovery if they fall out of step, or are not in + exact synchronism when thrown into parallel. In such circumstances a + synchronizing current passes between the two machines, due to the + difference in their instantaneous pressures; and as this current + agrees in phase more nearly with the leading than with the lagging + machine, the former machine does work as a generator on the latter as + a motor. Hence the lagging machine is accelerated and the leading + machine is retarded, until their frequencies and phase are again the + same. + + + Uses of alternators. + +The chief use of the alternator has already been alluded to. Since it +can be employed to produce very high pressures either directly or +through the medium of transformers, it is specially adapted to the +electrical transmission of energy over long distances.[22] In the early +days of electric lighting, the alternate-current system was adopted for +a great number of central stations; the machines, designed to give a +pressure of 2000 volts, supplied transformers which were situated at +considerable distances and spread over large areas, without an undue +amount of copper in the transmitting lines. While there was later a +tendency to return to the continuous current for central stations, owing +to the introduction of better means for economizing the weight of copper +in the mains, the alternating current again came into favour, as +rendering it possible to place the central station in some convenient +site far away from the district which it was to serve. The pioneer +central station in this direction was the Deptford station of the London +Electric Supply Corporation, which furnished current to the heart of +London from a distance of 7 m. In this case, however, the alternators +were single-phase and gave the high pressure of 10,000 volts +immediately, while more recently the tendency has been to employ step-up +transformers and a polyphase system. The advantage of the latter is that +the current, after reaching the distant sub-stations, can be dealt with +by rotary converters, through which it is transformed into a continuous +current. The alternator is also used for welding, smelting in electric +furnaces, and other metallurgical processes where heating effects are +alone required; the large currents needed therein can be produced +without the disadvantage of the commutator, and, if necessary, +transformers can be interposed to lower the voltage and still further +increase the current. The alternating system can thus meet very various +needs, and its great recommendation may be said to lie in the +flexibility with which it can supply electrical energy through +transformers at any potential, or through rotary converters in +continuous-current form. + + AUTHORITIES.--For the further study of the dynamo, the following may + be consulted, in addition to the references already given:-- + + _General_: S.P. Thompson, _Dynamo-Electric + Machinery--Continuous-Current Machines_ (1904), _Alternating-Current + Machinery_ (1905, London); G. Kapp, _Dynamos, Alternators and + Transformers_ (London, 1893); _Id., Electric Transmission of Energy_ + (London, 1894); Id., _Dynamo Construction; Electrical and Mechanical_ + (London, 1899); H.F. Parshall and H.M. Hobart, _Electric Generators_ + (London, 1900); C.C. Hawkins and F. Wallis, _The Dynamo_ (London, + 1903); E. Arnold, _Konstruktionstafeln fuer den Dynamobau_ (Stuttgart, + 1902); C.P. Steinmetz, _Elements of Electrical Engineering_ (New York, + 1901). + + _Continuous-Current Dynamos_: J. Fischer-Hinnen, _Continuous-Current + Dynamos_ (London, 1899); E. Arnold, _Die Gleichstrommaschine_ (Berlin, + 1902); F. Niethammer, _Berechnung und Konstruktion der + Gleichstrommaschinen und Gleichstrommotoren_ (Stuttgart, 1904). + + _Alternators_: D.C. Jackson and J.P. Jackson, _Alternating Currents + and Alternating Current Machinery_ (New York, 1903); J.A. Fleming, + _The Alternate Current Transformer_ (London, 1899); C.P. Steinmetz, + _Alternating Current Phenomena_ (New York, 1900); E. Arnold, _Die + Wechselstromtechnik_ (Berlin, 1904); S.P. Thompson, _Polyphase + Electric Currents_ (London, 1900); A. Stewart, _Modern Polyphase + Machinery_ (London, 1906); M. Oudin, _Standard Polyphase Apparatus and + Systems_ (New York, 1904). (C. C. H.) + + +FOOTNOTES: + + [1] _Experimental Researches in Electricity_, series ii. Sec. 6, pars. + 256, 259-260, and series xxviii. Sec. 34. + + [2] _Ibid._ series i. Sec. 4, pars. 84-90. + + [3] "On the Physical Lines of Magnetic Force," _Phil. Mag._, June + 1852. + + [4] Faraday, _Exp. Res._ series xxviii. Sec. 34, pars. 3104, 3114-3115. + + [5] _Id._, ib. series i. Sec. 4, pars. 114-119. + + [6] _Id._, ib. series ii. Sec. 6, pars. 211, 213; series xxviii. Sec. 34, + par. 3152. + + [7] Invented by Nikola Tesla (_Elec. Eng._ vol. xiii. p. 83. Cf. + Brit. Pat. Spec. Nos. 2801 and 2812, 1894). Several early inventors, + e.g. Salvatore dal Negro in 1832 (_Phil. Mag._ third series, vol. i. + p. 45), adopted reciprocating or oscillatory motion, and this was + again tried by Edison in 1878. + + [8] The advantage to be obtained by making the poles closely embrace + the armature core was first realized by Dr Werner von Siemens in his + "shuttle-wound" armature (Brit. Pat. No. 2107, 1856). + + [9] _Nuovo Cimento_ (1865), 19, 378. + + [10] Brit. Pat. No. 1668 (1870); _Comptes rendus_ (1871), 73, 175. + + [11] _Ann. Chim. Phys._ l. 322. + + [12] Ibid. li. 76. Since in H. Pixii's machine the armature was + stationary, while both magnet and commutator rotated, four brushes + were used, and the arrangement was not so simple as the split-ring + described above, although the result was the same. J. Saxton's + machine (1833) and E.M. Clarke's machine (1835, see Sturgeon's + _Annals of Electricity_, i. 145) were similar to one another in that + a unidirected current was obtained by utilizing every alternate + half-wave of E.M.F., but the former still employed mercury collecting + cups, while the latter employed metal brushes. W. Sturgeon in 1835 + followed Pixii in utilizing the entire wave of E.M.F., and abandoned + the mercury cups in favour of metal brushes pressing on four + semicircular disks (_Scientific Researches_, p. 252). The simple + split-ring is described by Sir C. Wheatstone and Sir W.F. Cooke in + their Patent No. 8345 (1840). + + [13] By the "leading" side of the tooth or of an armature coil or + sector is to be understood that side which first enters under a pole + after passing through the interpolar gap, and the edge of the pole + under which it enters is here termed the "leading" edge as opposed to + the "trailing" edge or corner from under which a tooth or coil + emerges into the gap between the poles; cf. fig. 30, where the + leading and trailing pole-corners are marked ll and tt. + + [14] Such was the arrangement of Wheatstone's machine (Brit. Pat. No. + 9022) of 1841, which was the first to give a more nearly "continuous" + current, the number of sections and split-rings being five. + + [15] Its development from the split-ring was due to Pacinotti and + Gramme (Brit. Pat. No. 1668, 1870) in connexion with their ring + armatures. + + [16] And extended by G. Kapp, "On Modern Continuous-Current + Dynamo-Electric Machines," _Proc. Inst. C.E._ vol. lxxxiii. p. 136. + + [17] Drs J. and E. Hopkinson, "Dynamo-Electric Machinery," Phil. + Trans., May 6, 1886; this was further expanded in a second paper on + "Dynamo-Electric Machinery," _Proc. Roy. Soc._, Feb. 15, 1892, and + both are reprinted in _Original Papers on Dynamo-Machinery and Allied + Subjects_. + + [18] _Exp. Res._, series i. Sec. 4, par. 111. In 1845 Wheatstone and + Cooke patented the use of "voltaic" magnets in place of permanent + magnets (No. 10,655). + + [19] Between Moutiers and Lyons, a distance of 115 m., energy is + transmitted on the Thury direct-current system at a maximum pressure + of 60,000 volts. Four groups of machines in series are employed, each + group consisting of four machines in series; the rated output of each + component machine is 75 amperes at 3900 volts or 400 h.p. A water + turbine drives two pairs of such machines through an insulating + coupling, and the sub-base of each pair of machines is separately + insulated from earth, the foundation being also of special insulating + materials. + + [20] For experiments on high-frequency currents, Nikola Tesla + constructed an alternator having 384 poles and giving a frequency of + about 10,000 (_Journ. Inst. Elec. Eng._ 1892, 21, p. 82). The + opposite extreme is found in alternators directly coupled to the + Parsons steam-turbine, in which, with a speed of 3000 revs. per min., + only two poles are required to give a frequency of 50. By a + combination of a Parsons steam-turbine running at 12,000 revs. per + min. with an alternator of 140 poles a frequency of 14,000 has been + obtained (_Engineering_, 25th of August 1899). For description of an + experimental machine for 10,000 cycles per second when running at + 3000 revs. per min., see _Trans. Amer. Inst. Elect. Eng._ vol. xxiii. + p. 417. + + [21] As in the historical transmission of energy from Lauffen to + Frankfort (1891). + + [22] In the pioneer three-phase transmission between Laufen and + Frankfort (_Electrician_, vol. xxvi. p. 637, and xxvii. p. 548), the + three-phase current was transformed up from about 55 to 8500 volts, + the distance being 110 m. A large number of installations driven by + water power are now at work, in which energy is transmitted on the + alternating-current system over distances of about 100 m. at + pressures ranging from 20,000 to 67,000 volts. + + + + +DYNAMOMETER (Gr. [Greek: dynamis], strength, and [Greek: metron], a +measure), an instrument for measuring force exerted by men, animals and +machines. The name has been applied generally to all kinds of +instruments used in the measurement of a force, as for example electric +dynamometers, but the term specially denotes apparatus used in connexion +with the measurement of work, or in the measurement of the horse-power +of engines and motors. If P represent the average value of the component +of a force in the direction of the displacement, s, of its point of +application, the product Ps measures the work done during the +displacement. When the force acts on a body free to turn about a fixed +axis only, it is convenient to express the work done by the transformed +product T[theta], where T is the average turning moment or torque acting +to produce the displacement [theta] radians. The apparatus used to +measure P or T is the dynamometer. The factors s or [theta] are observed +independently. Apparatus is added to some dynamometers by means of which +a curve showing the variations of P on a distance base is drawn +automatically, the area of the diagram representing the work done; with +others, integrating apparatus is combined, from which the work done +during a given interval may be read off directly. It is convenient to +distinguish between absorption and transmission dynamometers. In the +first kind the work done is converted into heat; in the second it is +transmitted, after measurement, for use. + + _Absorption Dynamometers._--Baron Prony's dynamometer (_Ann. Chim. + Phys._ 1821, vol. 19), which has been modified in various ways, + consists in its original form of two symmetrically shaped timber beams + clamped to the engine-shaft. When these are held from turning, their + frictional resistance may be adjusted by means of nuts on the screwed + bolts which hold them together until the shaft revolves at a given + speed. To promote smoothness of action, the rubbing surfaces are + lubricated. A weight is moved along the arm of one of the beams until + it just keeps the brake steady midway between the stops which must be + provided to hold it when the weight fails to do so. The general theory + of this kind of brake is as follows:-Let F be the whole frictional + resistance, r the common radius of the rubbing surfaces, W the force + which holds the brake from turning and whose line of action is at a + perpendicular distance R from the axis of the shaft, N the revolutions + of the shaft per minute, [omega] its angular velocity in radians per + second; then, assuming that the adjustments are made so that the + engine runs steadily at a uniform speed, and that the brake is held + still, clear of the stops and without oscillation, by W, the torque T + exerted by the engine is equal to the frictional torque Fr acting at + the brake surfaces, and this is measured by the statical moment of the + weight W about the axis of revolution; that is-- + + T = Fr = WR. (1) + + Hence WR measures the torque T. + + If more than one force be applied to hold the brake from turning, Fr, + and therefore T, are measured by the algebraical sum of their + individual moments with respect to the axis. If the brake is not + balanced, its moment about the axis must be included. Therefore, quite + generally, + + T = [Sigma]WR. (2) + + The factor [theta] of the product T[theta] is found by means of a + revolution counter. The power of a motor is measured by the rate at + which it works, and this is expressed by T[omega] = T2[pi]N/60 in + foot-pounds per second, or T2[pi]N/33,000 in horse-power units. The + latter is commonly referred to as the "brake horse-power." The + maintenance of the conditions of steadiness implied in equation (1) + depends upon the constancy of F, and therefore of the coefficient of + friction mu between the rubbing surfaces. The heating at the surfaces, + the variations in their smoothness, and the variations of the + lubrication make [mu] continuously variable, and necessitate frequent + adjustment of W or of the nuts. J.V. Poncelet (1788-1867) invented a + form of Prony brake which automatically adjusted its grip as [mu] + changed, thereby maintaining F constant. + + The principle of the compensating brake devised by J.G. Appold + (1800-1865) is shown in fig. 1. A flexible steel band, lined with wood + blocks, is gripped on the motor fly-wheel or pulley by a screw A, + which, together with W, is adjusted to hold the brake steady. + Compensation is effected by the lever L inserted at B. This has a + slotted end, engaged by a pin P fixed to the framing, and it will be + seen that its action is to slacken the band if the load tends to rise + and to tighten it in the contrary case. The external forces holding + the brake from turning are W, distant R from the axis, and the + reaction, W1 say, of the lever against the fixed pin P, distant R1 + from the axis. The moment of W1 may be positive or negative. The + torque T at any instant of steady running is therefore {WR +- W1R1}. + + [Illustration: FIG. 1.] + + Lord Kelvin patented a brake in 1858 (fig. 2) consisting of a rope or + cord wrapped round the circumference of a rotating wheel, to one end + of which is applied a regulated force, the other end being fixed to a + spring balance. The ropes are spaced laterally by the blocks B, B, B, + B, which also serve to prevent them from slipping sideways. When the + wheel is turning in the direction indicated, the forces holding the + band still are W, and p, the observed pull on the spring balance. Both + these forces usually act at the same radius R, the distance from the + axis to the centre line of the rope, in which case the torque T is (W + - p)R, and consequently the brake horse-power is + + (W - p)R x 2[pi]N + -----------------. + 33,000 + + When mu changes the weight W rises or falls against the action of the + spring balance until a stable condition of running is obtained. The + ratio {W/p} is given by e^{ mu[theta]}, where e = 2.718; mu is the + coefficient of friction and [theta] the angle, measured in radians, + subtended by the arc of contact between the rope and the wheel. In + fig. 2 [theta] = 2[pi]. The ratio W/p increases very rapidly as + [theta] is increased, and therefore, by making [theta] sufficiently + large, p may conveniently be made a small fraction of W, thereby + rendering errors of observation of the spring balance negligible. Thus + this kind of brake, though cheap to make, is, when [theta] is large + enough, an exceedingly accurate measuring instrument, readily applied + and easily controlled. It has come into very general use in recent + years, and has practically superseded the older forms of block brakes. + + [Illustration: FIG. 2.] + + It is sometimes necessary to use water to keep the brake wheel cool. + Engines specially designed for testing are usually provided with a + brake wheel having a trough-shaped rim. Water trickles continuously + into the trough, and the centrifugal action holds it as an inside + lining against the rim, where it slowly evaporates. + + Fig. 3 shows a band-brake invented by Professor James Thomson, + suitable for testing motors exerting a constant torque (see + _Engineering_, 22nd October 1880). To maintain e^{ mu[theta]} constant, + compensation for variation of [mu] is made by inversely varying + [theta]. A and B are fast and loose pulleys, and the brake band is + placed partly over the one and partly over the other. Weights W and w + are adjusted to the torque. The band turns with the fast pulley if + [mu] increase, thereby slightly turning the loose pulley, otherwise at + rest, until [theta] is adjusted to the new value of [mu]. This form of + brake was also invented independently by J.A.M.L. Carpentier, and the + principle has been used in the Raffard brake. A self-compensating + brake of another kind, by Marcel Deprez, was described with + Carpentier's in 1880 (_Bulletin de la societe d'encouragement_, + Paris). W.E. Ayrton and J. Perry used a band or rope brake in which + compensation is effected by the pulley drawing in or letting out a + part of the band or rope which has been roughened or in which a knot + has been tied. + + In an effective water-brake invented by W. Froude (see _Proc. Inst. M. + E._ 1877), two similar castings, A and B, each consisting of a boss + and circumferential annular channel, are placed face to face on a + shaft, to which B is keyed, A being free (fig. 4). A ring tube of + elliptical section is thus formed. Each channel is divided into a + series of pockets by equally spaced vanes inclined at 45 deg.. When A is + held still, and B rotated, centrifugal action sets up vortex currents + in the water in the pockets; thus a continuous circulation is caused + between B and A, and the consequent changes of momentum give rise to + oblique reactions. The moments of the components of these actions and + reactions in a plane to which the axis of rotation is at right angles + are the two aspects of the torque acting, and therefore the torque + acting on B through the shaft is measured by the torque required to + hold A still. Froude constructed a brake to take up 2000 H.P. at 90 + revs. per min. by duplicating this apparatus. This replaced the + propeller of the ship whose engines were to be tested, and the outer + casing was held from turning by a suitable arrangement of levers + carried to weighing apparatus conveniently disposed on the wharf. The + torque corresponding to 2000 H.P. at 90 revs. per min. is 116,772 + foot-pounds, and a brake 5 ft. in diameter gave this resistance. Thin + metal sluices were arranged to slide between the wheel and casing, and + by their means the range of action could be varied from 300 H.P. at + 120 revs. per min. to the maximum. + + [Illustration: FIG. 3.] + + [Illustration: FIG. 4.] + + Professor Osborne Reynolds in 1887 patented a water-brake (see _Proc. + Inst. C.E._ 99, p. 167), using Froude's turbine to obtain the highly + resisting spiral vortices, and arranging passages in the casing for + the entry of water at the hub of the wheel and its exit at the + circumference. Water enters at E (fig. 5), and finds its way into the + interior of the wheel, A, driving the air in front of it through the + air-passages K, K. Then following into the pocketed chambers V1, V2, + it is caught into the vortex, and finally escapes at the + circumference, flowing away at F. The air-ways k, k, in the fixed + vanes establish communication between the cores of the vortices and + the atmosphere. From {1/5} to 30 H.P. may be measured at 100 revs. per + min. by a brake-wheel of this kind 18 in. in diameter. For other + speeds the power varies as the cube of the speed. The casing is held + from turning by weights hanging on an attached arm. The cocks + regulating the water are connected to the casing, so that any tilting + automatically regulates the flow, and therefore the thickness of the + film in the vortex. In this way the brake may be arranged to maintain + a constant torque, not withstanding variation of the speed. In G.I. + Alden's brake (see _Trans. Amer. Soc. Eng._ vol. xi.) the resistance + is obtained by turning a cast iron disk against the frictional + resistance of two thin copper plates, which are held in a casing free + to turn upon the shaft, and are so arranged that the pressure between + the rubbing surfaces is controlled, and the heat developed by friction + carried away, by the regulated flow of water through the casing. The + torque required to hold the casing still against the action of the + disk measures the torque exerted by the shaft to which the disk is + keyed. + + [Illustration: Fig. 5.] + + _Transmission Dynamometers._--The essential part of many transmission + dynamometers is a spring whose deformation indirectly measures the + magnitude of the force transmitted through it. For many kinds of + spring the change of form is practically proportional to the force, + but the relation should always be determined experimentally. General + A.J. Morin (see _Notice sur divers appareils dynamometriques_, Paris, + 1841), in his classical experiments on traction, arranged his + apparatus so that the change in form of the spring was continuously + recorded on a sheet of paper drawn under a style. For longer + experiments he used a "Compteur" or mechanical integrator, suggested + by J.V. Poncelet, from which the work done during a given displacement + could be read off directly. This device consists of a roller of radius + r, pressed into contact with a disk. The two are carried on a common + frame, so arranged that a change in form of the spring causes a + relative displacement of the disk and roller, the point of contact + moving radially from or towards the centre of the disk. The radial + distance x is at any instant proportional to the force acting through + the spring. The angular displacement, [theta], of the disk is made + proportional to the displacement, s, of the point of application of + the force by suitable driving gear. If d[phi] is the angular + displacement of the roller corresponding to displacements, d[theta] of + the disk, and ds of the point of application of P, a, and C constants, + then + + xd[theta] a + d[phi] = --------- = -- P ds = C.P ds, + r r + _ + /s2 + and therefore [phi] = C | P ds; + _/s1 + + that is, the angular displacement of the roller measures the work done + during the displacement from s1 to s2. The shaft carrying the roller + is connected to a counter so that [phi] may be observed. The angular + velocity of the shaft is proportional to the rate of working. Morin's + dynamometer is shown in fig. 6. The transmitting spring is made up of + two flat bars linked at their ends. Their centres s1, s2, are held + respectively by the pieces A, B, which together form a sliding pair. + The block A carries the disk D, B carries the roller R and counting + gear. The pulley E is driven from an axle of the carriage. In a + dynamometer used by F.W. Webb to measure the tractive resistance of + trains on the London & North-Western railway, a tractive pull or push + compresses two spiral springs by a definite amount, which is recorded + to scale by a pencil on a sheet of paper, drawn continuously from a + storage drum at the rate of 3 in. per mile, by a roller driven from + one of the carriage axles. Thus the diagram shows the tractive force + at any instant. A second pencil electrically connected to a clock + traces a time line on the diagram with a kick at every thirty seconds. + A third pencil traces an observation line in which a kick can be made + at will by pressing any one of the electrical pushes placed about the + car, and a fourth draws a datum line. The spring of the dynamometer + car used by W. Dean on the Great Western railway is made up of thirty + flat plates, 7 ft. 6 in. long, 5 in. x 5/8 in. at the centre, spaced + by distance pieces nibbed into the plates at the centre and by rollers + at the ends. The draw-bar is connected to the buckle, which is carried + on rollers, the ends of the spring resting on plates fixed to the + under-frame. The gear operating the paper roll is driven from the axle + of an independent wheel which is let down into contact with the rail + when required. This wheel serves also to measure the distance + travelled. A Morin disk and roller integrator is connected with the + apparatus, so that the work done during a journey may be read off. + Five lines are traced on the diagram. + + [Illustration: FIG. 6.] + + In spring dynamometers designed to measure a transmitted torque, the + mechanical problem of ascertaining the change of form of the spring is + complicated by the fact that the spring and the whole apparatus are + rotating together. In the Ayrton and Perry transmission dynamometer or + spring coupling of this type, the relative angular displacement is + proportional to the radius of the circle described by the end of a + light lever operated by mechanism between the spring-connected parts. + By a device used by W.E. Dalby (_Proc. Inst. C.E._ 1897-1898, p. 132) + the change in form of the spring is shown on a fixed indicator, which + may be placed in any convenient position. Two equal sprocket wheels + Q1, Q2, are fastened, the one to the spring pulley, the other to the + shaft. An endless band is placed over them to form two loops, which + during rotation remain at the same distance apart, unless relative + angular displacement occurs between Q1 and Q2 (fig. 7) due to a change + in form of the spring. The change in the distance d is proportional to + the change in the torque transmitted from the shaft to the pulley. To + measure this, guide pulleys are placed in the loops guided by a + geometric slide, the one pulley carrying a scale, and the other an + index. A recording drum or integrating apparatus may be arranged on + the pulley frames. A quick variation, or a periodic variation of the + magnitude of the force or torque transmitted through the springs, + tends to set up oscillations, and this tendency increases the nearer + the periodic time of the force variation approaches a periodic time of + the spring. Such vibrations may be damped out to a considerable extent + by the use of a dash-pot, or may be practically prevented by using a + relatively stiff spring. + + [Illustration: FIG. 7.] + + Every part of a machine transmitting force suffers elastic + deformation, and the force may be measured indirectly by measuring the + deformation. The relation between the two should in all cases be found + experimentally. G.A. Hirn (see _Les Pandynamometres_, Paris, 1876) + employed this principle to measure the torque transmitted by a shaft. + Signor Rosio used a telephonic method to effect the same end, and + mechanical, optical and telephonic devices have been utilized by the + Rev. F.J. Jervis-Smith. (See _Phil. Mag._ February 1898.) + + H. Frahm,[1] during an important investigation on the torsional + vibration of propeller shafts, measured the relative angular + displacement of two flanges on a propeller shaft, selected as far + apart as possible, by means of an electrical device (_Engineering_, + 6th of February 1903). These measurements were utilized in combination + with appropriate elastic coefficients of the material to find the + horse-power transmitted from the engines along the shaft to the + propeller. In this way the effective horse-power and also the + mechanical efficiency of a number of large marine engines, each of + several thousand horse-power, have been determined. + + [Illustration: FIG. 8.] + + When a belt, in which the maximum and minimum tensions are + respectively P and p lb., drives a pulley, the torque exerted is (P - + p)r lb. ft., r being the radius of the pulley plus half the thickness + of the belt. P and p may be measured directly by leading the belt + round two freely hanging guide pulleys, one in the tight, the other in + the slack part of the belt, and adjusting loads on them until a stable + condition of running is obtained. In W. Froude's belt dynamometer (see + _Proc. Inst. M.E._, 1858) (fig. 8) the guide pulleys G1, G2 are + carried upon an arm free to turn about the axis O. H is a pulley to + guide the approaching and receding parts of the belt to and from the + beam in parallel directions. Neglecting friction, the unbalanced + torque acting on the beam is 4r{P - p} lb. ft. If a force Q acting at + R maintains equilibrium, QR/4 = (P - p)r = T. Q is supplied by a + spring, the extensions of which are recorded on a drum driven + proportionally to the angular displacement of the driving pulley; thus + a work diagram is obtained. In the Farcot form the guide pulleys are + attached to separate weighing levers placed horizontally below the + apparatus. In a belt dynamometer built for the Franklin Institute from + the designs of Tatham, the weighing levers are separate and arranged + horizontally at the top of the apparatus. The weighing beam in the + Hefner-Alteneck dynamometer is placed transversely to the belt (see + _Electrotechnischen Zeitschrift_, 1881, 7). The force Q, usually + measured by a spring, required to maintain the beam in its central + position is proportional to (P - p). If the angle [theta]1 = [theta]2 + = 120 deg., Q = (P - p) neglecting friction. + + When a shaft is driven by means of gearing the driving torque is + measured by the product of the resultant pressure P acting between the + wheel teeth and the radius of the pitch circle of the wheel fixed to + the shaft. Fig. 9, which has been reproduced from J. White's _A New + Century of Inventions_ (Manchester, 1822), illustrates possibly the + earliest application of this principle to dynamometry. The wheel D, + keyed to the shaft overcoming the resistance to be measured, is driven + from wheel N by two bevel wheels L, L, carried in a loose pulley K. + The two shafts, though in a line, are independent. A torque applied to + the shaft A can be transmitted to D, neglecting friction, without + change only if the central pulley K is held from turning; the torque + required to do this is twice the torque transmitted. + + [Illustration: FIG. 9.] + + The torque acting on the armature of an electric motor is necessarily + accompanied by an equal and opposite torque acting on the frame. If, + therefore, the motor is mounted on a cradle free to turn about + knife-edges, the reacting torque is the only torque tending to turn + the cradle when it is in a vertical position, and may therefore be + measured by adjusting weights to hold the cradle in a vertical + position. The rate at which the motor is transmitting work is then + T2[pi]n/550 H.P., where n is the revolutions per second of the + armature. + + See James Dredge, _Electric Illumination_, vol. ii. (London, 1885); + W.W. Beaumont, "Dynamometers and Friction Brakes," _Proc. Inst. C.E._ + vol. xcv. (London, 1889); E. Brauer, "Ueber Bremsdynamometer and + verwandte Kraftmesser," _Zeitschrift des Vereins deutscher Ingenieure_ + (Berlin, 1888); J.J. Flather, _Dynamometers and the Measurement of + Power_ (New York, 1893). (W. E. D.) + + +FOOTNOTE: + + [1] H. Frahm, "Neue Untersuchungen ueber die dynamischen Vorgaenge in + den Wellenleitungen von Schiffsmaschinen mit besonderer + Beruecksichtigung der Resonanzschwingungen," _Zeitschrift des Vereins + deutscher Ingenieure_, 31st May 1902. + + + + +DYNASTY (Gr. [Greek: dynasteia], sovereignty, the position of a [Greek: +dynastes], lord, ruler, from [Greek: dynasthai], to be able, [Greek: +dynamis], power), a family or line of rulers, a succession of sovereigns +of a country belonging to a single family or tracing their descent to a +common ancestor. The term is particularly used in the history of ancient +Egypt as a convenient means of arranging the chronology. + + + + +DYSART, a royal and police burgh and seaport of Fifeshire, Scotland, on +the shore of the Firth of Forth, 2 m. N.E. of Kirkcaldy by the North +British railway. Pop. (1901) 3562. It has a quaint old-fashioned +appearance, many ancient houses in High Street bearing inscriptions and +dates. The public buildings include a town hall, library, cottage +hospital, mechanics' institute and memorial hall. Scarcely anything is +left of the old chapel dedicated to St Dennis, which for a time was used +as a smithy; and of the chapel of St Serf, the patron saint of the +burgh, only the tower remains. The chief industries are the manufacture +of bed and table linen, towelling and woollen cloth, shipbuilding and +flax-spinning. There is a steady export of coal, and the harbour is +provided with a wet dock and patent slip. In smuggling days the "canty +carles" of Dysart were professed "free traders." In the 15th and 16th +centuries the town was a leading seat of the salt industry ("salt to +Dysart" was the equivalent of "coals to Newcastle"), but the salt-pans +have been abandoned for a considerable period. Nail-making, once famous, +is another extinct industry. During the time of the alliance between +Scotland and Holland, which was closer in Fifeshire than in other +counties, Dysart became known as Little Holland. To the west of the town +is Dysart House, the residence of the earl of Rosslyn. With Burntisland +and Kinghorn Dysart forms one of the Kirkcaldy district group of +parliamentary burghs. The town is mentioned as early as 874 in connexion +with a Danish invasion. Its name is said to be a corruption of the Latin +_desertum_, "a desert," which was applied to a cave on the seashore +occupied by St Serf. In the cave the saint held his famous colloquy with +the devil, in which Satan was worsted and contemptuously dismissed. From +James V. the town received the rights of a royal burgh. In 1559 it was +the headquarters of the Lords of the Congregation, and in 1607 the scene +of the meetings of the synod of Fife known as the Three Synods of +Dysart. Ravensheugh Castle, on the shore to the west of the town, is the +Ravenscraig of Sir Walter Scott's ballad of "Rosabelle." + +William Murray, a native of the place, was made earl of Dysart in 1643, +and his eldest child and heir, a daughter, Elizabeth, obtained in 1670 a +regrant of the title, which passed to the descendants of her first +marriage with Sir Lionel Tollemache, Bart., of Helmingham; she married +secondly the 1st duke of Lauderdale, but had no children by him, and +died in 1698. This countess of Dysart (afterwards duchess of Lauderdale) +was a famous beauty of the period, and notorious both for her amours and +for her political influence. She was said to have been the mistress of +Oliver Cromwell, and also of Lauderdale before her first husband's +death, and was a leader at the court of Charles II. Wycherley is +supposed to have aimed at her in his Widow Blackacre in the _Plain +Dealer_. Her son, Lionel Tollemache (d. 1727), transmitted the earldom +to his grandson Lionel (d. 1770), whose sons Lionel (d. 1799) and +Wilbraham (d. 1821) succeeded; they died without issue, and their sister +Louisa (d. 1840), who married John Manners, an illegitimate son of the +second son of the 2nd duke of Rutland, became countess in her own right, +being succeeded by her grandson (d. 1878), and his grandson, the 8th +earl. + +The earldom of Dysart must not be confounded with that of Desart +(Irish), created (barony 1733) in 1793, and held in the Cuffe family, +who were originally of Creech St Michael, Somerset, the Irish branch +dating from Queen Elizabeth's time. + + + + +DYSENTERY (from the Gr. prefix [Greek: dys]-, in the sense of "bad," and +[Greek: enteron], the intestine), also called "bloody flux," an +infectious disease with a local lesion in the form of inflammation and +ulceration of the lower portion of the bowels. Although at one time a +common disease in Great Britain, dysentery is now very rarely met with +there, and is for the most part confined to warm countries, where it is +the cause of a large amount of mortality. (For the pathology see +DIGESTIVE ORGANS.) + +Recently considerable advance has been made in our knowledge of +dysentery, and it appears that there are two distinct types of the +disease: (1) amoebic dysentery, which is due to the presence of the +amoeba histolytica (of Schaudinn) in the intestine; (2) bacillary +dysentery, which has as causative agent two separate bacteria, (a) that +discovered by Shiga in Japan, (b) that discovered by Flexner in the +Philippine Islands. With regard to the bacillary type, at first both +organisms were considered to be identical, and the name _bacillus +dysenteriae_ was given to them; but later it was shown that these +bacilli are different, both in regard to their cultural characteristics +and also in that one (Shiga) gives out a soluble toxin, whilst the +other has so far resisted all efforts to discover it. Further, the +serum of a patient affected with one of the types has a marked +agglutinative power on the variety with which he is infected and not on +the other. + +Clinically, dysentery manifests itself with varying degrees of +intensity, and it is often impossible without microscopical examination +to determine between the amoebic and bacillary forms. In well-marked +cases the following are the chief symptoms. The attack is commonly +preceded by certain premonitory indications in the form of general +illness, loss of appetite, and some amount of diarrhoea, which gradually +increases in severity, and is accompanied with griping pains in the +abdomen (tormina). The discharges from the bowels succeed each other +with great frequency, and the painful feeling of pressure downwards +(tenesmus) becomes so intense that the patient is constantly desiring to +defecate. The matters passed from the bowels, which at first resemble +those of ordinary diarrhoea, soon change their character, becoming +scanty, mucous or slimy, and subsequently mixed with, or consisting +wholly of, blood, along with shreds of exudation thrown off from the +mucous membrane of the intestine. The evacuations possess a peculiarly +offensive odour characteristic of the disease. Although the +constitutional disturbance is at first comparatively slight, it +increases with the advance of the disease, and febrile symptoms come on +attended with urgent thirst and scanty and painful flow of urine. Along +with this the nervous depression is very marked, and the state of +prostration to which the patient is reduced can scarcely be exceeded. +Should no improvement occur death may take place in from one to three +weeks, either from repeated losses of blood, or from gradual exhaustion +consequent on the continuance of the symptoms, in which case the +discharges from the bowels become more offensive and are passed +involuntarily. + +When, on the other hand, the disease is checked, the signs of +improvement are shown in the cessation of the pain, in the evacuations +being less frequent and more natural, and in relief from the state of +extreme depression. Convalescence is, however, generally slow, and +recovery may be imperfect--the disease continuing in a chronic form, +which may exist for a variable length of time, giving rise to much +suffering, and not unfrequently leading to an ultimately fatal result. + +The dysentery poison appears to exert its effects upon the glandular +structures of the large intestine, particularly in its lower part. In +the milder forms of the disease there is simply a congested or inflamed +condition of the mucous membrane, with perhaps some inflammatory +exudation on its surface, which is passed off by the discharges from the +bowels. But in the more severe forms ulceration of the mucous membrane +takes place. Commencing in and around the solitary glands of the large +intestine in the form of exudations, these ulcers, small at first, +enlarge and run into each other, till a large portion of the bowel may +be implicated in the ulcerative process. Should the disease be arrested +these ulcers may heal entirely, but occasionally they remain, causing +more or less disorganization of the coats of the intestines, as is often +found in chronic dysentery. Sometimes, though rarely, the ulcers +perforate the intestines, causing rapidly fatal inflammation of the +peritoneum, or they may erode a blood vessel and produce violent +haemorrhage. Even where they undergo healing they may cause such a +stricture of the calibre of the intestinal canal as to give rise to the +symptoms of obstruction which ultimately prove fatal. One of the +severest complications of the disease is abscess of the liver, usually +said to be solitary, and known as tropical abscess of the liver, but +probably is more frequently multiple than is usually thought. + +_Treatment._--Where the disease is endemic or is prevailing +epidemically, it is of great importance to use all preventive measures, +and for this purpose the avoidance of all causes likely to precipitate +an attack is to be enjoined. Exposure to cold after heat, the use of +unripe fruit, and intemperance in eating and drinking should be +forbidden; and the utmost care taken as to the quality of the food and +drinking water. In houses or hospitals where cases of the disease are +under treatment, disinfectants should be freely employed, and the +evacuations of the patients removed as speedily as possible, having +previously been sterilized in much the same manner as is employed in +typhoid fever. In the milder varieties of this complaint, such as those +occurring sporadically, and where the symptoms are probably due to +matters in the bowels setting up the dysenteric irritation, the +employment of diaphoretic medicines is to be recommended, and the +administration of such a laxative as castor oil, to which a small +quantity of laudanum has been added, will often, by removing the source +of the mischief, arrest the attack; but a method of treatment more to be +recommended is the use of salines in large doses, such as one drachm of +sodium sulphate from four to eight times a day. This treatment may with +advantage be combined with the internal administration of ipecacuanha, +which still retains its reputation in this disease. Latterly, free +irrigation of the bowel with astringents, such as silver nitrate, +tannalbin, &c., has been attended with success in those cases which have +been able to tolerate the injections. In many instances they cannot be +used owing to the extreme degree of irritability of the bowel. The +operation of appendicostomy, or bringing the appendix to the surface and +using it as the site for the introduction of the irrigating fluid, has +been attended with considerable success. + +In those cases due to Shiga's bacillus the ideal treatment has been put +at our disposal by the preparation of a specific antitoxin; this has +been given a trial in several grave epidemics of late, and may be said +to be the most satisfactory treatment and offer the greatest hope of +recovery. It is also of great use as a prophylactic. + +The preparations of morphia are of great value in the symptomatic +treatment of the disease. They may be applied externally as +fomentations, for the relief of tormina; by rectal injection for the +relief of the tenesmus and irritability of the bowel; hypodermically in +advanced cases, for the relief of the general distress. In amoebic +dysentery, warm injections of quinine _per rectum_ have proved very +efficacious, are usually well tolerated, and are not attended with any +ill effects. The diet should be restricted, consisting chiefly of soups +and farinaceous foods; more especially is this of importance in the +chronic form. For the thirst ice may be given by the mouth. Even in the +chronic forms, confinement to bed and restriction of diet are the most +important elements of the treatment. Removal from the hot climate and +unhygienic surroundings must naturally be attended to. + + BIBLIOGRAPHY.--Allbutt and Rolleston, _System of Medicine_, vol. ii. + part ii. (1907), "Dysentery," Drs Andrew Davidson and Simon Flexner; + Davidson, _Hygiene and Diseases of Warm Climates_ (Edinburgh, 1903); + Fearnside in _Ind. Med. Gaz._ (July 1905); Ford in _Journal of + Tropical Medicine_ (July 15, 1904); Korentchewsky in _Bulletin de + l'Institut Pasteur_ (February 1905); Shiga: Osier and M'Crae's _System + of Medicine_, vol. ii. p. 781 (1907); Skschivan and Stefansky in + _Berliner klinische Wochenschrift_ (February 11, 1907); Vaillard and + Dopter, on the treatment by antidysenteric serum, _Annales de + l'Institut Pasteur_, No. 5, p. 326 (1906); J.A. Pottinger, + "Appendicostomy in Chronic Dysentery," _Lancet_ (December 28, 1907); + Robert Doerr, _Das Dysenterietoxin_ (Gustav Fischer, Jena, 1907); F.M. + Sandwith, "Hunterian Lecture on the Treatment of Dysentery," _Lancet_ + (December 7, 1907). + + + + +DYSPEPSIA (from the Gr. prefix [Greek: dys-], hard, ill, and [Greek: +peptein], to digest), or indigestion, a term vaguely given to a group of +pathological symptoms. There are comparatively few diseases of any +moment where some of the phenomena of dyspepsia are not present as +associated symptoms, and not infrequently these exist to such a degree +as to mask the real disease, of which they are only complications. This +is especially the case in many organic diseases of the alimentary canal, +in which the symptoms of dyspepsia are often the most prominent. In its +restricted meaning, however (and it is to this that the present article +applies), the term is used to describe a functional derangement of the +natural process of digestion, apart from any structural change in the +organs concerned in the act. + +The causes of this trouble may be divided into (a) those which concern +the food, and (b) those which concern the organism. Among the causes +connected with the food are not only the indulgence in indigestible +articles of diet, but the too common practice of eating too much of +what may be otherwise quite wholesome and digestible; and irregular, too +frequent or too infrequent meals. The quantity of food required by +different individuals varies between wide limits, but also the quantity +required by the same individual varies considerably according to +circumstances, more food being needed in cold than in warm weather, and +more in an active open-air occupation than in a sedentary one. The +thorough mastication of the food is a very important precursor of +digestion,[1] and this only too often fails, either owing to haste over +meals or because of painful or deficient teeth. Again, the quality of +the food is of importance, some kinds of flesh being harder and more +difficult of mastication than others. This is especially the case with +meat that has been smoked or salted, and with that cooked too soon after +the death of the animal. Drinks are a common source of dyspepsia. Beer +when new and its fermentation not completed is especially bad. Vinegar +and acid wines, if taken in large quantities, tend to produce gastric +catarrh, and tea is a very fruitful source of this trouble. Even too +much water at meal-times may cause indigestion, since the food in the +mouth is apt to be softened by the water instead of saliva, and also the +gastric juice becomes unduly diluted, rendering the digestion in the +stomach too slow and prolonged. Carious teeth and oral sepsis, from +whatsoever cause, lead to the same trouble. + +Of the causes which concern the organism, nervous influences come first. +Bad news may take away all power of digestion and even provoke vomiting, +and any worry or mental trouble tends to bring on this condition. +General weakness and atony of the body affects the stomach in like +degree, and, if the muscles of the abdominal wall be much wasted, they +become too weak to support the abdominal viscera in place. Hence results +a general tendency for these organs to fall, giving rise to a condition +of visceroptosis, of which an obstinate dyspepsia is a very marked +feature. Adhesions of the intestines from old inflammatory troubles, +floating kidney and bad circulation may each be a cause of painful +digestion. Again, a dyspepsia that will not yield to treatment is often +one of the symptoms of renal disease, or, in young people of fifteen to +twenty years of age, it may be the earliest sign of a gouty diathesis, +or even of a more serious condition still--incipient phthisis. Chronic +dyspepsia, by weakening the organism, renders it more liable to fall a +prey to the attacks of the tubercle bacillus, but, on the other hand, +the tuberculous lesion in the lung is often accompanied by a most +intractable form of dyspepsia. From this it is clear that any condition +which lessens the general well-being of the organism as a whole, apart +from its producing any permanent morbid condition in the stomach, may +yet interfere with the normal digestive processes and so give rise to +dyspepsia. + +The symptoms of dyspepsia, even when due to a like cause, are so +numerous and diversified in different individuals that probably no +description could exactly represent them as they occur in any given +case. All that can be here attempted is to mention some of the more +prominent morbid phenomena usually present in greater or less degree. + +Very briefly, a furred tongue, foul breath, disturbance of appetite, +nausea and vomiting, oppression in the chest, pain, flatulence and +distension, acidity, pyrosis and constipation or diarrhoea are a few of +the commonest symptoms. + +When the attack is dependent on some error in diet, and the dyspepsia +consequently more of an acute character, there is often pain followed +with sickness and vomiting of the offensive matters, after which the +patient soon regains his former healthy state. What are commonly known +as "bilious attacks" are frequently of this character. In the more +chronic cases of dyspepsia the symptoms are somewhat different. A +sensation of discomfort comes on shortly after a meal, and is more of +the nature of weight and distension in the stomach than of actual pain, +although this too may be present. These feelings may come on after each +meal, or only after certain meals, and they may arise irrespective of +the kind of food taken, or only after certain articles of diet. As in +most of such cases the food is long retained in the stomach, it is apt +to undergo fermentive changes, one of the results of which is the +accumulation of gases which cause flatulence and eructations of an acid +or foul character. Occasionally quantities of hot, sour, tasteless or +bitter fluid--pyrosis--or mouthfuls of half-digested food, regurgitate +from the stomach. Temporary relief may be obtained when another meal is +taken, but soon the uncomfortable sensations return as before. The +appetite may be craving or deficient, or desirous of abnormal kinds of +food. The tongue registers the gastric condition with great delicacy;--a +pasty white fur on the tongue is considered a sign of weakness or atony +of the digestive tract; a clean pointed tongue with large papillae, and +rather red at the edges and tip, is a sign of gastric irritation; and a +pale flabby tongue suggests the need of stimulating treatment. +Constipation is more common in the chronic forms of dyspepsia, diarrhoea +in the acute. + +Numerous disagreeable and painful sensations in other parts are +experienced, and are indeed often more distressing than the merely +gastric symptoms. Pains in the chest, shortness of breathing, +palpitation, headache, giddiness, affections of vision, coldness of the +extremities, and general languor are common accompaniments of dyspepsia; +while the nervous phenomena are specially troublesome in the form of +sleeplessness, irritability, despondency and hypochondriasis. + +As regards _treatment_ only a few general observations can be made. The +careful arrangement of the diet is a matter of first importance. +Quantity must be regulated by the digestive capabilities of the +individual, his age, and the demands made upon his strength by work. +There is little doubt that the danger is in most instances on the side +of excess, and the rule which enjoins the cessation from eating before +the appetite is satisfied is a safe one for dyspeptics. Due time, too, +must be given for the digestion of a meal, and from four to six hours +are in general required for this purpose. Long fasts, however, are +nearly as hurtful as too frequent meals. Of no less importance is the +kind of food taken, and on this point those who suffer from indigestion +must ever exercise the greatest care. It must be borne in mind that +idiosyncrasy often plays an important part in digestion, some persons +being unable to partake without injury of substances which are generally +regarded as wholesome and digestible. In most cases it is found very +helpful to separate the protein from the farinaceous food, and the more +severe the dyspepsia the more thoroughly should this be done, only +relaxing as the dyspepsia yields. No fluid should be drunk at +meal-times, but from one to two tumblers of hot water should be drunk +from an hour to an hour and a half before food. This washes any remnant +of the last meal from the stomach, and also supplies material for the +free secretion of saliva and gastric juice, thus promoting and +accelerating digestion. The only exception to this is in the case of a +dilated stomach, when it is wholly contra-indicated. With regard to +mastication, Sir Andrew Clark's rule is a very good one, and is more +easily followed than the ideal theory laid down by Horace Fletcher, +according to whom any food is digestible if properly treated while still +in the mouth. Clark's rule is that as the mouth normally contains +thirty-two teeth, thirty-two bites should be given before the food is +swallowed. This, of course, is a practical doctor's concession to human +weakness. Mr Fletcher would train every one to "chew" till the contents +of the mouth were swallowed by reflex action without deliberate act; and +he applies this theory of mastication and salivation also to drinks +(except water). Again, a lack of warmth being a source of dyspepsia, +this should be attended to, the back of the neck, the front of the +abdomen and the feet being the parts that require special attention. The +feet should be raised on a stool, the ankles protected with warm +stockings and a woollen "cummerbund" wound two or three times round the +body. Experience has shown that in this complaint no particular kind of +food or avoidance of food is absolutely to be relied on, but that in +general the best diet is one of a mixed animal and vegetable kind, +simply but well cooked. The partaking of many dishes, of highly-seasoned +or salted meats, raw vegetables, newly-baked bread, pastry and +confectionery are all well-known common causes of dyspepsia, and should +be avoided. When even the simple diet usually taken is found to +disagree, it may be necessary to change it temporarily for a still +lighter form, such as a milk diet, and that even in very moderate +quantity. + +The employment of alcoholic stimulants to assist digestion is largely +resorted to, both with and without medical advice. While it seems +probable that in certain cases of atonic dyspepsia, particularly in the +feeble and aged, the moderate administration of alcohol has the effect +of stimulating the secretion of gastric juice, and is an important +adjuvant to other remedies, the advantages of its habitual use as an aid +to digestion by the young and otherwise healthy, is more than +questionable, and it will generally be found that among them, those are +least troubled with indigestion who abstain from it. Rest should be +taken both before and after food, and general hygienic measures are +highly important, since whatever improves the state of the health will +have a favourable influence on digestion. Hence regular exercise in the +open air, early rising and the cold bath are to be strongly recommended. + +The medicinal treatment of dyspepsia can only be undertaken by a +physician, but the following is a very brief resume of the drugs he +depends on to-day. Bicarbonate of soda with some bitter, as quassia, +gentian or columba, is much in vogue as a direct gastric stimulant. In +irritable dyspepsia some form of bismuth in solution or powder; and, to +assist digestion through the nervous system, nux vomica and strychnine +can be relied on. To give directly digestive material, hydrochloric +acid, pepsin and rennet are prescribed in many forms, but where there is +much vomiting ingluvin is more efficacious than pepsin. When farinaceous +food is badly borne, diastase is helpful, given either before or with +the meal. To prevent fermentation, phenol, creasote and sulpho-carbolate +of soda are all extremely useful in skilled hands; and for intestinal +decomposition and flatulent distension, bismuth salicylate with salol or +ss-naphthol is much used. Cyllin, and charcoal in many forms, may be +taken both for gastric and intestinal flatulence. But all these drugs, +of proved value though they are, must be modified and combined to suit +the special idiosyncrasy of the patient, and are therefore often worse +than useless in inexperienced hands. The condition of the bowels must +always have due attention. + + See also DIGESTIVE ORGANS; NUTRITION and DIETETICS. + + +FOOTNOTE: + + [1] This aspect of the matter--"buccal digestion"--has been specially + emphasized in recent years by Horace Fletcher of the United States, + whose experience of the results of systematic "chewing," confirmed by + Sir M. Foster, Prof. Chittenden and others, has almost revolutionized + the science of dietetics. + + + + +DYSTELEOLOGY, a modern word invented by Haeckel (_Evolution of Man_) for +the doctrine of purposelessness, as opposed to the philosophical +doctrine of design (Teleology). + + + + +DZUNGARIA, DSONGARIA, or JUNGARIA, a former Mongolian kingdom of Central +Asia, raised to its highest pitch by Kaldan or Bushtu Khan in the latter +half of the 17th century, but completely destroyed by Chinese invasion +about 1757-1759. It has played an important part in the history of +Mongolia and the great migrations of Mongolian stems westward. Now its +territory belongs partly to the Chinese empire (east Turkestan and +north-western Mongolia) and partly to Russian Turkestan (provinces of +Semiryechensk and Semipalatinsk). It derived its name from the Dsongars, +or Songars, who were so called because they formed the left wing +(_dson_, left; _gar_, hand) of the Mongolian army. Its widest limit +included Kashgar, Yarkand, Khotan, the whole region of the T'ien Shan, +or Tian-shan, Mountains, and in short the greater proportion of that +part of Central Asia which extends from 35 deg. to 50 deg. N. and from 72 deg. to +97 deg. E. The name, however, is more properly applied only to the present +Chinese province of T'ien Shan-pei-lu and the country watered by the +Ili. As a political or geographical term it has practically disappeared +from the map; but the range of mountains stretching north-east along the +southern frontier of the Land of the Seven Streams, as the district to +the south-east of the Balkhash Lake is called, preserves the name of +Dzungarian Range. + + + + +E The fifth symbol in the English alphabet occupies also the same +position in Phoenician and in the other alphabets descended from +Phoenician. As the Semitic alphabet did not represent vowels, E was +originally an aspirate. Its earliest form, while writing is still from +right to left, is [symbol], the upright being continued some distance +below the lowest of the cross-strokes. In some of the Greek alphabets it +appears as [symbol] with the upright prolonged at both top and bottom, +but it soon took the form with which we are familiar, though in the +earlier examples of this form the cross-strokes are not horizontal but +drop at an angle, [symbol]. In Corinth and places under its early +influence like Megara, or colonized from it like Corcyra, the symbol for +_e_ takes the form [symbol] or [symbol], while at Sicyon in the 6th and +5th centuries B.C. it is represented by [symbol]. In early Latin it was +sometimes represented by two perpendicular strokes of equal length, +[symbol]. + +In the earliest Greek inscriptions and always in Latin the symbol E +represented both the short and the long _e_-sound. In Greek also it was +often used for the close long sound which arose either by contraction of +two short _e_-sounds or by the loss of a consonant, after a short +_e_-sound, as in [Greek: phileite], "you love," for [Greek: phileete], +and [Greek: phaeinos], "bright," out of an earlier [Greek: phaesnos]. +The Ionian Greeks of Asia Minor, who had altogether lost the aspirate, +were the first to use the symbol H for the long _e_-sound, and in +official documents at Athens down to 403 B.C., when the Greek alphabet +as still known was adopted by the state, E represented [epsilon], [eta] +and the sound arising by contraction or consonant loss as mentioned +above which henceforth was written with two symbols, [Greek: ei], and +being really a single sound is known as the "spurious diphthong." There +were some minor distinctions in usage of the symbols E and H which need +not here be given in detail. The ancient Greek name was [Greek: ei], not +_Epsilon_ as popularly supposed; the names of the Greek letters are +given from Kallias, an earlier contemporary of Euripides, in Athenaeus +x. p. 453 d. + +In Greek the short _e_-sound to which E was ultimately limited was a +close sound inclining more towards _i_ than _a_; hence the +representation of the contraction of [Greek: ee] by [Greek: ei]. Its +value in Latin was exactly the opposite, the Latin short _e_ being open, +and the long close. In English there has been a gradual narrowing of the +long vowels, _a_ becoming approximately _ei_ and _e_ becoming _i_ +(Sweet, _History of English Sounds_, Sec.Sec. 781, 817 ff. 2nd ed.). In +languages where the diphthong _ai_ has become a monophthong, the +resulting sound is some variety of long _e_. Often the gradual +assimilation can be traced through the intermediate stage of _ae_ to +_e_, as in the Old Latin _aidilis_, which in classical Latin is +_aedilis_, and in medieval MSS. _edilis_. + +The variety of spelling in English for the long and short _e_-sounds is +conveniently illustrated in Miss Soames's _Introduction to the Study of +Phonetics_, pp. 16 and 20. (P. Gi.) + + + + +EA (written by means of two signs signifying "house" and "water"), in +the Babylonian religion, originally the patron deity of Eridu, situated +in ancient times at the head of the Persian Gulf, but now, by reason of +the constant accumulation of soil in the Euphrates valley, at some +distance from the gulf. Eridu, meaning "the good city," was one of the +oldest settlements in the Euphrates valley, and is now represented by +the mounds known as Abu Shahrein. In the absence of excavations on that +site, we are dependent for our knowledge of Ea on material found +elsewhere. This is, however, sufficient to enable us to state definitely +that Ea was a water-deity, and there is every reason to believe that the +Persian Gulf was the body of water more particularly sacred to him. +Whether Ea (or A-e as some scholars prefer) represents the real +pronunciation of his name we do not know. All attempts to connect Ea +with Yah and Yahweh are idle conjectures without any substantial basis. +He is figured as a man covered with the body of a fish, and this +representation, as likewise the name of his temple E-apsu, "house of +the watery deep," points decidedly to his character as a god of the +waters (see OANNES). Of his cult at Eridu, which reverts to the oldest +period of Babylonian history, nothing definite is known beyond the fact +that the name of his temple was E-saggila, "the lofty house"--pointing +to a staged tower as in the case of the temple of Bel (q.v.) at Nippur, +known as E-Kur, i.e. "mountain house"--and that incantations, involving +ceremonial rites, in which water as a sacred element played a prominent +part, formed a feature of his worship. Whether Eridu at one time also +played an important political role is not certain, though not +improbable. At all events, the prominence of the Ea cult led, as in the +case of Nippur, to the survival of Eridu as a sacred city, long after it +had ceased to have any significance as a political centre. Myths in +which Ea figures prominently have been found in Assur-bani-pal's +library, indicating that Ea was regarded as the protector and teacher of +mankind. He is essentially a god of civilization, and it was natural +that he was also looked upon as the creator of man, and of the world in +general. Traces of this view appear in the Marduk epic celebrating the +achievements of this god, and the close connexion between the Ea cult at +Eridu and that of Marduk also follows from two considerations: (1) that +the name of Marduk's sanctuary at Babylon bears the same name, +E-saggila, as that of Ea in Eridu, and (2) that Marduk is generally +termed the son of Ea, who derives his powers from the voluntary +abdication of the father in favour of his son. Accordingly, the +incantations originally composed for the Ea cult were re-edited by the +priests of Babylon and adapted to the worship of Marduk, and, similarly, +the hymns to Marduk betray traces of the transfer of attributes to +Marduk which originally belonged to Ea. + +It is, however, more particularly as the third figure in the triad, the +two other members of which were Anu (q.v.) and Bel (q.v.), that Ea +acquires his permanent place in the pantheon. To him was assigned the +control of the watery element, and in this capacity he becomes the _shar +apsi_, i.e. king of the Apsu or "the deep." The Apsu was figured as an +ocean encircling the earth, and since the gathering place of the dead, +known as Aralu, was situated near the confines of the Apsu, he was also +designated as En-Ki, i.e. "lord of that which is below," in contrast to +Anu, who was the lord of the "above" or the heavens. The cult of Ea +extended throughout Babylonia and Assyria. We find temples and shrines +erected in his honour, e.g. at Nippur, Girsu, Ur, Babylon, Sippar and +Nineveh, and the numerous epithets given to him, as well as the various +forms under which the god appears, alike bear witness to the popularity +which he enjoyed from the earliest to the latest period of +Babylonian-Assyrian history. The consort of Ea, known as Damkina, "lady +of that which is below," or Nin-Ki, having the same meaning, or +Damgal-nunna, "great lady of the waters," represents a pale reflection +of Ea and plays a part merely in association with her lord. (M. Ja.) + + + + +EABANI, the name of the friend of Gilgamesh, the hero in the Babylonian +epic (see GILGAMESH, EPIC OF). Eabani, whose name signifies "Ea +creates," pointing to the tradition which made the god Ea (q.v.) the +creator of mankind, is represented in the epic as the type of the +primeval man. He is a wild man who lives with the animals of the field +until lured away from his surroundings by the charms of a woman. Created +to become a rival to Gilgamesh, he strikes up a friendship with the +hero, and together they proceed to a cedar forest guarded by Khumbaba, +whom they kill. The goddess Irnina (a form of Ishtar, q.v.) in revenge +kills Eabani, and the balance of the epic is taken up with Gilgamesh's +lament for his friend, his wanderings in quest of a remote ancestor, +Ut-Napishtim, from whom he hopes to learn how he may escape the fate of +Eabani, and his finally learning from his friend of the sad fate in +store for all mortals except the favourites of the god, like +Ut-Napishtim, to whom immortal life is vouchsafed as a special boon. + (M. Ja.) + + + + +EACHARD, JOHN (1636?-1697), English divine, was born in Suffolk, and was +educated at Catharine Hall, Cambridge, of which he became master in 1675 +in succession to John Lightfoot. He was created D.D. in 1676 by royal +mandate, and was twice (in 1679 and 1695) vice-chancellor of the +university. He died on the 7th of July 1697. In 1670 he had published +anonymously a humorous satire entitled _The Ground and Occasions of the +Contempt of the Clergy enquired into in a letter to R. L._, which +excited much attention and provoked several replies, one of them being +from John Owen. These were met by _Some Observations, &c., in a second +letter to R. L._ (1671), written in the same bantering tone as the +original work. Eachard attributed the contempt into which the clergy had +fallen to their imperfect education, their insufficient incomes, and the +want of a true vocation. His descriptions, which were somewhat +exaggerated, were largely used by Macaulay in his _History of England_. +He gave amusing illustrations of the absurdity and poverty of the +current pulpit oratory of his day, some of them being taken from the +sermons of his own father. He attacked the philosophy of Hobbes in his +_Mr Hobb's State of Nature considered; in a dialogue between Philautus +and Timothy_ (1672), and in his _Some Opinions of Mr Hobbs considered in +a second dialogue_ (1673). These were written in their author's chosen +vein of light satire, and Dryden praised them as highly effective within +their own range. Eachard's own sermons, however, were not superior to +those he satirized. Swift (_Works_, xii. 279) alludes to him as a signal +instance of a successful humorist who entirely failed as a serious +writer. + + A collected edition of his works in three volumes, with a notice of + his life, was published in 1774. The _Contempt of the Clergy_ was + reprinted in E. Arber's _English Garner_. _A Free Enquiry into the + Causes of the very great Esteem that the Nonconforming Preachers are + generally in with their Followers_ (1673) has been attributed to + Eachard on insufficient grounds. + + + + +EADBALD (d. 640), king of Kent, succeeded to the throne on the death of +his father AEthelberht in 616. He had not been influenced by the teaching +of the Christian missionaries, and his first step on his accession was +to marry his father's widow. After his subsequent conversion by +Laurentius, archbishop of Canterbury, he recalled the bishops Mellitus +and Justus, and built a church dedicated to the Virgin at Canterbury. He +arranged a marriage between his sister AEthelberg and Edwin of +Northumbria, on whose defeat and death in 633 he received his sister and +Paulinus, and offered the latter the bishopric of Rochester. Eadbald +married Emma, a Frankish princess, and died on the 20th of January 640. + + See Bede, _Historia ecclesiastica_ (ed. C. Plummer, Oxford, 1896); + _Saxon Chronicle_ (ed. J. Earle and C. Plummer, Oxford, 1899). + + + + +EADIE, JOHN (1810-1876), Scottish theologian and biblical critic, was +born at Alva, in Stirlingshire, on the 9th of May 1810. Having taken the +arts curriculum at Glasgow University, he studied for the ministry at +the Divinity Hall of the Secession Church, a dissenting body which, on +its union a few years later with the Relief Church, adopted the title +United Presbyterian. In 1835 he became minister of the Cambridge Street +Secession church in Glasgow, and for many years he was generally +regarded as the leading representative of his denomination in Glasgow. +As a preacher, though he was not eloquent, he was distinguished by good +sense, earnestness and breadth of sympathy. In 1863 he removed with a +portion of his congregation to a new church at Lansdowne Crescent. In +1843 Eadie was appointed professor of biblical literature and +hermeneutics in the Divinity Hall of the United Presbyterian body. He +held this appointment along with his ministerial charge till the close +of his life. Though not a profound scholar, he was surpassed by few +biblical commentators of his day in range of learning, and in soundness +of judgment. In the professor's chair, as in the pulpit, his strength +lay in the tact with which he selected the soundest results of biblical +criticism, whether his own or that of others, and presented them in a +clear and connected form, with a constant view to their practical +bearing. He received the degree of LL.D. from Glasgow in 1844, and that +of D.D. from St Andrews in 1850. + +His publications were connected with biblical criticism and +interpretation, some of them being for popular use and others more +strictly scientific. To the former class belong the _Biblical +Cyclopaedia_, his edition of _Cruden's Concordance_, his _Early Oriental +History_, and his discourses on the _Divine Love_ and on _Paul the +Preacher_; to the latter his commentaries on the Greek text of St Paul's +epistles to the Ephesians, Colossians, Philippians and Galatians, +published at intervals in four volumes. His last work was the _History +of the English Bible_ (2 vols., 1876). He rendered good service as one +of the revisers of the authorized version. He died at Glasgow on the 3rd +of June 1876. His valuable library was bought and presented to the +United Presbyterian College. + + + + +EADMER, or EDMER (c. 1060-c. 1124), English historian and ecclesiastic, +was probably, as his name suggests, of English, and not of Norman +parentage. He became a monk in the Benedictine monastery of Christ +Church, Canterbury, where he made the acquaintance of Anselm, at that +time visiting England as abbot of Bec. The intimacy was renewed when +Anselm became archbishop of Canterbury in 1093; thenceforward Eadmer was +not only his disciple and follower, but his friend and director, being +formally appointed to this position by Pope Urban II. In 1120 he was +nominated to the archbishopric of St Andrews, but as the Scots would not +recognize the authority of the see of Canterbury he was never +consecrated, and soon afterwards he resigned his claim to the +archbishopric. His death is generally assigned to the year 1124. + +Eadmer left a large number of writings, the most important of which is +his _Historiae novorum_, a work which deals mainly with the history of +England between 1066 and 1122. Although concerned principally with +ecclesiastical affairs scholars agree in regarding the _Historiae_ as +one of the ablest and most valuable writings of its kind. It was first +edited by John Selden in 1623 and, with Eadmer's _Vita Anselmi_, has +been edited by Martin Rule for the "Rolls Series" (London, 1884). The +_Vita Anselmi_, first printed at Antwerp in 1551, is probably the best +life of the saint. Less noteworthy are Eadmer's lives of St Dunstan, St +Bregwin, archbishop of Canterbury, and St Oswald, archbishop of York; +these are all printed in Henry Wharton's _Anglia Sacra_, part ii. +(1691), where a list of Eadmer's writings will be found. The manuscripts +of most of Eadmer's works are preserved in the library of Corpus Christi +College, Cambridge. + + See M. Rule, _On Eadmer's Elaboration of the first four Books of + "Historiae novorum"_ (1886); and Pere Ragey, _Eadmer_ (Paris, 1892). + + + + +EADS, JAMES BUCHANAN (1820-1887), American engineer, was born at +Lawrenceburg, Indiana, on the 23rd of May 1820. His first engineering +work of any importance was in raising sunken steamers. In 1845 he +established glass works in St Louis. During the Civil War he constructed +ironclad steamers and mortar boats for the Federal government. His next +important engineering achievement was the construction of the great +steel arch bridge across the Mississippi at St Louis (see BRIDGE, fig. +29), upon which he was engaged from 1867 till 1874. The work, however, +upon which his reputation principally rests was his deepening and fixing +the channel at the mouths of the Mississippi by means of jetties, +whereby the narrowed stream was made to scour out its own channel and +carry the sediment out to sea. Shortly before his death he projected a +scheme for a ship railway across the Isthmus of Tehuantepec, in lieu of +an isthmian canal. He died at Nassau, in the Bahamas, on the 8th of +March 1887. + + + + +EAGLE (Fr. _aigle_, from the Lat. _aquila_), the name generally given to +the larger diurnal birds of prey which are not vultures; but the limits +of the subfamily _Aquilinae_ have been very variously assigned by +different writers on systematic ornithology, and there are eagles +smaller than certain buzzards. By some authorities the _Laemmergeier_ of +the Alps, and other high mountains of Europe, North Africa and Asia, is +accounted an eagle, but by others the genus _Gypaetus_ is placed with +the _Vulturidae_ as its common English name (bearded vulture) +shows. There are also other forms, such as the South American _Harpyia_ +and its allies, which though generally called eagles have been ranked as +buzzards. In the absence of any truly scientific definition of the +family _Aquilinae_ it is best to leave these and many other more or less +questionable members of the group--such as the genera _Spizaetus_, +_Circaetus_, _Spilornis_, _Helotarsus_, and so forth--and to treat here +of those whose position cannot be gainsaid. + +[Illustration: FIG. 1.--Sea-Eagle.] + +True eagles inhabit all the regions of the world, and some seven or +eight species at least are found in Europe, of which two are resident in +the British Islands. In England and in the Lowlands of Scotland eagles +only exist as stragglers; but in the Hebrides and some parts of the +Highlands a good many may yet be found, and their numbers appear to have +rather increased of late years than diminished; for the foresters and +shepherds, finding that a high price can be got for their eggs, take +care to protect the owners of the eyries, which are nearly all well +known, and to keep up the stock by allowing them at times to rear their +young. There are also now not a few occupiers of Scottish forests who +interfere so far as they can to protect the king of birds.[1] In Ireland +the extirpation of eagles seems to have been carried on almost +unaffected by the prudent considerations which in the northern kingdom +have operated so favourably for the race, and except in the wildest +parts of Donegal, Mayo and Kerry, eagles in the sister island are almost +birds of the past. + +Of the two British species the erne (Icel. _Oern_) or sea-eagle (by some +called also the white-tailed and cinereous eagle)--_Haliaetus +albicilla_--affects chiefly the coast and neighbourhood of inland +waters, living in great part on the fish and refuse that is thrown up on +the shore, though it not unfrequently takes living prey, such as lambs, +hares and rabbits. On these last, indeed, young examples mostly feed +when they wander southward in autumn, as they yearly do, and appear in +England. The adults (fig. 1) are distinguished by their prevalent +greyish-brown colour, their pale head, yellow beak and white +tail--characters, however, wanting in the immature, which do not assume +the perfect plumage for some three or four years. The eyry is commonly +placed in a high cliff or on an island in a lake--sometimes on the +ground, at others in a tree--and consists of a vast mass of sticks in +the midst of which is formed a hollow lined with _Luzula sylvatica_ (as +first observed by John Wolley) or some similar grass, and here are laid +the two or three white eggs. In former days the sea-eagle seems to have +bred in several parts of England--as the Lake district, and possibly +even in the Isle of Wight and on Dartmoor. This species inhabits all the +northern part of the Old World from Iceland to Kamchatka, and breeds in +Europe so far to the southward as Albania. In the New World, however, it +is only found in Greenland, being elsewhere replaced by the white-headed +or bald eagle, _H. leucocephalus_, a bird of similar habits, and the +chosen emblem of the United States of America. In the far east of Asia +occurs a still larger and finer sea-eagle, _H. pelagicus_, remarkable +for its white thighs and upper wing-coverts. South-eastern Europe and +India furnish a much smaller species, _H. leucoryphus_, which has its +representative, _H. leucogaster_, in the Malay Archipelago and +Australia, and, as allies in South Africa and Madagascar, _H. vocifer_ +and _H. vociferoides_ respectively. All these eagles may be +distinguished by their scaly tarsi, while the group next to be treated +of have the tarsi feathered to the toes. + +[Illustration: FIG. 2.--Mountain-Eagle.] + +The golden or mountain eagle, _Aquila chrysaetus_, is the second British +species. This also formerly inhabited England, and a nest, found in 1668 +in the Peak of Derbyshire, is well described by Willughby, in whose time +it was said to breed also in the Snowdon range. It seldom if ever +frequents the coast, and is more active on the wing than the sea-eagle, +being able to take some birds as they fly, but a large part of its +sustenance is the flesh of animals that die a natural death. Its eyry is +generally placed and built like that of the other British species,[2] +but the neighbourhood of water is not requisite. The eggs, from two to +four in number, vary from a pure white to a mottled, and often highly +coloured, surface, on which appear different shades of red and purple. +The adult bird (fig. 2) is of a rich dark brown, with the elongated +feathers of the neck, especially on the nape, light tawny, in which +imagination sees a "golden" hue, and the tail marbled with brown and +ashy-grey. In the young the tail is white at the base, and the neck has +scarcely any tawny tint. The golden eagle does not occur in Iceland, but +occupies suitable situations over the rest of the Palaearctic Region and +a considerable portion of the Nearctic--though the American bird has +been, by some, considered a distinct species. Domesticated, it has many +times been trained to take prey for its master in Europe, and to this +species is thought to belong an eagle habitually used by the Kirghiz +Tatars, who call it _Bergut_ or _Bearcoot_, for the capture of +antelopes, foxes and wolves. It is carried hooded on horseback or on a +perch between two men, and released when the quarry is in sight. Such a +bird, when well trained, is valued, says P.S. Pallas, at the price of +two camels. It is quite possible, however, that more than one kind of +eagle is thus used, and the services of _A. heliaca_ (which is the +imperial eagle of some writers[3]) and of _A. mogilnik_--both of which +are found in central Asia, as well as in south-eastern Europe--may also +be employed. + +A smaller form of eagle, which has usually gone under the name of _A. +naevia_, is now thought by the best authorities to include three local +races, or, in the eyes of some, species. They inhabit Europe, North +Africa and western Asia to India, and two examples of one of them--_A. +clanga_, the form which is somewhat plentiful in north-eastern +Germany--have occurred in Cornwall. The smallest true eagle is _A. +pennata_, which inhabits southern Europe, Africa and India. Differing +from other eagles of their genus by its wedge-shaped tail, though +otherwise greatly resembling them, is the _A. audax_ of Australia. +Lastly may be noticed here a small group of eagles, characterized by +their long legs, forming the genus _Nisaetus_, of which one species, _N. +fasciatus_, is found in Europe. (A. N.) + + +FOOTNOTES: + + [1] Lord Breadalbane (d. 1871) was perhaps the first large landowner + who set the example that has been since followed by others. On his + unrivalled forest of Black Mount, eagles--elsewhere persecuted to the + death--were by him ordered to be unmolested so long as they were not + numerous enough to cause considerable depredations on the farmers' + flocks. He thought that the spectacle of a soaring eagle was a + fitting adjunct to the grandeur of his Argyllshire mountain scenery, + and a good equivalent for the occasional loss of a lamb, or the + slight deduction from the rent paid by his tenantry in consequence. + + [2] As already stated, the site chosen varies greatly. Occasionally + placed in a niche in what passes for a perpendicular cliff to which + access could only be gained by a skilful cragsman with a rope, the + writer has known a nest to within 10 or 15 yds. of which he rode on a + pony. Two beautiful views of as many golden eagles' nests, drawn on + the spot by Joseph Wolf, are given in the _Ootheca Wolleyana_, and a + fine series of eggs is also figured in the same work. + + [3] Which species may have been the traditional emblem of Roman + power, and the _Ales Jovis_, is very uncertain. + + + + +EAGLEHAWK, a borough of Bendigo county, Victoria, Australia, 105 m. by +rail N.N.W. of Melbourne and 4 m. from Bendigo, with which it is +connected by steam tramway. Pop. (1901) 8130. It stands on the Bendigo +gold-bearing reef, and its mines are important. + + + + +EAGRE (a word of obscure origin; the earliest form seems to be _higre_, +Latinized as _higra_, which William of Malmesbury gives as the name of +the bore in the Severn; the _New English Dictionary_ rejects the usual +derivations from the O. Eng. _eagor_ or _egor_, which is seen in +compounds meaning "flood," and also the connexion with the Norse sea-god +_Aegir_), a tide wave of great height rushing up an estuary (see BORE), +used locally of the Humber and Trent. + + + + +EAKINS, THOMAS (1844- ), American portrait and figure painter, was +born at Philadelphia, on the 25th of July 1844. A pupil of J.L. Gerome, +in the Ecole des Beaux-Arts, Paris, and Also of Leon Bonnat, besides +working in the studio of the sculptor Dumont, he became a prolific +portrait painter. He also painted genre pictures, sending to the +Centennial Exhibition at Philadelphia, in 1876, the "Chess Players," now +in the Metropolitan Museum of Art, New York. A large canvas, "The +Surgical Clinic of Professor Gross," owned by Jefferson Medical College, +Philadelphia, contains many life-sized figures. Eakins, with his pupil +Samuel Murray (b. 1870), modelled the heroic "Prophets" for the +Witherspoon Building, Philadelphia, and his work in painting has a +decided sculptural quality. He was for some years professor of anatomy +at the schools of the Pennsylvania Academy of Fine Arts in Philadelphia. +A man of great inventiveness, he experimented in many directions, +depicting on canvas modern athletic sports, the negro, and early +American life, but he is best known by his portraits. He received awards +at the Columbian (1893), Paris (1900), Pan-American (1900), and the St +Louis (1904), Expositions; and won the Temple medal in the Pennsylvania +Academy of Fine Arts, and the Proctor prize of the National Academy of +Design. + + + + +EALING, a municipal borough in the Ealing parliamentary division of +Middlesex, England, suburban to London, 9 m. W. of St Paul's cathedral. +Pop. (1891) 23,979; (1901) 33,031. The nucleus of the town, the ancient +village, lies south of the highroad to Uxbridge, west of the open Ealing +Common. The place is wholly residential. At St Mary's church, almost +wholly rebuilt c. 1870, are buried John Oldmixon, the historian (d. +1742), and Horne Tooke (d. 1812). The church of All Saints (1905) +commemorates Spencer Perceval, prime minister, who was assassinated in +the House of Commons in 1812. It was erected under the will of his +daughter Frederica, a resident of Ealing. Gunnersbury Park, south of +Ealing Common, is a handsome Italian mansion. Among former owners of the +property was Princess Amelia, daughter of George II., who lived here +from 1761 till her death in 1786. The name of Gunnersbury is said to be +traceable to the residence here of Gunilda, niece of King Canute. The +manor of Ealing early belonged to the see of London, but it is not +mentioned in Domesday and its history is obscure. + + + + +EAR (common Teut.; O.E. _eare_, Ger. _Ohr_, Du. _oor_, akin to Lat. +_auris_, Gr. [Greek: ous]), in anatomy, the organ of hearing. The human +ear is divided into three parts--external, middle and internal. The +external ear consists of the pinna and the external auditory meatus. The +pinna is composed of a yellow fibro-cartilaginous framework covered by +skin, and has an external and an internal or cranial surface. Round the +margin of the external surface in its upper three quarters is a rim +called the helix (fig. 1, a), in which is often seen a little prominence +known as Darwin's tubercle, representing the folded-over apex of a +prick-eared ancestor. Concentric with the helix and nearer the meatus is +the antihelix (c), which, above, divides into two limbs to enclose the +triangular fossa of the antihelix. Between the helix and the antihelix +is the fossa of the helix. In front of the antihelix is the deep fossa +known as the concha (fig. 1, d), and from the anterior part of this the +meatus passes inward into the skull. Overlapping the meatus from in +front is a flap called the tragus, and below and behind this is another +smaller flap, the antitragus. The lower part of the pinna is the lobule +(e), which contains no cartilage. On the cranial surface of the pinna +elevations correspond to the concha and to the fossae of the helix and +antihelix. The pinna can be slightly moved by the anterior, superior and +posterior auricular muscles, and in addition to these there are four +small intrinsic muscles on the external surface, known as the helicis +major and minor, the tragicus and the antitragicus, and two on the +internal surface called the obliquus and transversus. The external +auditory meatus (fig. 1, n) is a tube running at first forward and +upward, then a little backward and then forward and slightly downward; +of course all the time it is also running inward until the tympanic +membrane is reached. The tube is about an inch long, its outer third +being cartilaginous and its inner two-thirds bony. It is lined by skin +in its whole length, the sweat glands of which are modified to secrete +the wax or cerumen. + +[Illustration: FIG. 1.--The Ear as seen in Section. + + a, Helix. m, Tip of petrous process. + b, Antitragus. n, External auditory meatus. + c, Antihelix. o, Membrana tympani. + d, Concha. p, Tympanum. + e, Lobule. 1, points to malleus. + f, Mastoid process. 2, to incus. + g, Portio dura. 3, to stapes. + h, Styloid process. 4, to cochlea. + k, Internal carotid artery. 5, 6, 7, the three semicircular canals. + l, Eustachian tube. 8 and 9, facial and auditory nerves.] + +The middle ear or tympanum (fig. 1, p) is a small cavity in the temporal +bone, the shape of which may perhaps be realized by imagining a hock +bottle subjected to lateral pressure in such a way that its circular +section becomes triangular, the base of the triangle being above. The +neck of the bottle, also laterally compressed, will represent the +Eustachian tube (fig. 1, l), which runs forward, inward and downward, to +open into the naso-pharynx, and so admits air into the tympanum. The +bottom of the bottle will represent the posterior wall of the tympanum, +from the upper part of which an opening leads backward into the mastoid +antrum and so into the air-cells of the mastoid process. Lower down is a +little pyramid which transmits the stapedius muscle, and at the base of +this is a small opening known as the iter chordae posterius, for the +chorda tympani to come through from the facial nerve. The roof is formed +by a very thin plate of bone, called the tegmen tympani, which separates +the cavity from the middle fossa of the skull. Below the roof the upper +part of the tympanum is somewhat constricted off from the rest, and to +this part the term "attic" is often applied. The floor is a mere groove +formed by the meeting of the external and internal walls. The outer wall +is largely occupied by the tympanic membrane (fig. 1, o), which entirely +separates the middle ear from the external auditory meatus; it is +circular, and so placed that it slopes from above, downward and inward, +and from behind, forward and inward. Externally it is lined by skin, +internally by mucous membrane, while between the two is a firm fibrous +membrane, convex inward about its centre to form the umbo. Just in front +of the membrane on the outer wall is the Glaserian fissure leading to +the glenoid cavity, and close to this is the canal of Huguier for the +chorda tympani nerve. The inner wall shows a promontory caused by the +cochlea and grooved by the tympanic plexus of nerves; above and behind +it is the fenestra ovalis, while below and behind the fenestra rotunda +is seen, closed by a membrane. Curving round, above and behind the +promontory and fenestrae, is a ridge caused by the aqueductus Fallopii +or canal for the facial nerve. The whole tympanum is about half an inch +from before backward, and half an inch high, and is spanned from side to +side by three small bones, of which the malleus (fig. 1, 1) is the most +external. This is attached by its handle to the umbo of the tympanic +membrane, while its head lies in the attic and articulates posteriorly +with the upper part of the next bone or incus (fig. 1, 2). The long +process of the incus runs downward and ends in a little knob called the +os orbiculare, which is jointed on to the stapes or stirrup bone (fig. +1, 3). The two branches of the stapes are anterior and posterior, while +the footplate fits into the fenestra ovalis and is bound to it by a +membrane. It will thus be seen that the stapes lies nearly at right +angles to the long process of the incus. From the front of the malleus a +slender process projects forward into the Glaserian fissure, while from +the back of the incus the posterior process is directed backward and is +attached to the posterior wall of the tympanum. These two processes form +a fulcrum by which the lever action of the malleus and incus is brought +about, so that when the handle of the malleus is pushed in by the +membrane the head moves out; the top of the incus, attached to it, also +moves out, and the os orbiculare moves in, and so the stapes is pressed +into the fenestra ovalis. The stapedius and tensor tympanic muscles, the +latter of which enters the tympanum in a canal just above the +Eustachian tube to be attached to the malleus, modify the movements of +the ossicles. + +The mucous membrane lining the tympanum is continuous through the +Eustachian tube with that of the naso-pharynx, and is reflected on to +the ossicles, muscles and chorda tympani nerve. It is ciliated except +where it covers the membrana tympani, ossicles and promontory; here it +is stratified. + +[Illustration: FIG. 2.--Diagram of the Membranous Labyrinth. + + DC, Ductus cochlearis. + dr, Ductus reuniens. + S, Sacculus. + U, Utriculus. + dv, Ductus endolymphaticus. + SC, Semicircular canals. + (After Waldeyer.)] + +The internal ear or labyrinth consists of a bony and a membranous part, +the latter of which is contained in the former. The bony labyrinth is +composed of the vestibule, the semicircular canals and the cochlea. The +vestibule lies just internal to the posterior part of the tympanum, and +there would be a communication between the two, through the fenestra +ovalis, were it not that the footplate of the stapes blocks the way. The +inner wall of the vestibule is separated from the bottom of the internal +auditory meatus by a plate of bone pierced by many foramina for branches +of the auditory nerve (fig. 1, 9), while at the lower part is the +opening of the aqueductus vestibuli, by means of which a communication +is established with the posterior cranial fossa. Posteriorly the three +semicircular canals open into the vestibule; of these the external (fig. +1, 7) has two independent openings, but the superior and posterior (fig. +1, 5 and 6) join together at one end and so have a common opening, while +at their other ends they open separately. The three canals have +therefore five openings into the vestibule instead of six. One end of +each canal is dilated to form its ampulla. The superior semicircular +canal is vertical, and the two pillars of its arch are nearly external +and internal; the external canal is horizontal, its two pillars being +anterior and posterior, while the convexity of the arch of the posterior +canal is backward and its two pillars are superior and inferior. +Anteriorly the vestibule leads into the cochlea (fig. 1, 4), which is +twisted two and a half times round a central pillar called the modiolus, +the whole cochlea forming a rounded cone something like the shell of a +snail though it is only about 5 mm. from base to apex. Projecting from +the modiolus is a horizontal plate which runs round it from base to apex +like a spiral staircase; this is known as the lamina spiralis, and it +stretches nearly half-way across the canal of the cochlea. At the summit +it ends in a little hook named the hamulus. The modiolus is pierced by +canals which transmit branches of the auditory nerve to the lamina +spiralis. + +[Illustration: FIG. 3.--cl, Columnar cells covering the crista acustica; +p, peripheral, and c, central processes of auditory cells; n, nerve +fibres. (After Ruedinger.)] + +The membranous labyrinth lies in the bony labyrinth, but does not fill +it; between the two is the fluid called perilymph, while inside the +membranous labyrinth is the endolymph. In the bony vestibule lie two +membranous bags, the saccule (fig. 2, S) in front, and the utricle (fig. +2, U) behind; each of these has a special patch or macula to which twigs +of the auditory nerve are supplied, and in the mucous membrane of which +specialized hair cells are found (fig. 3, p). + +Attached to the maculae are crystals of carbonate of lime called +otoconia. The membranous semicircular canals are very much smaller in +section than the bony; in the ampulla of each is a ridge, the crista +acustica, which is covered by a mucous membrane containing sensory hair +cells like those in the maculae. All the canals open into the utricle. +From the lower part of the saccule a small canal called the ductus +endolymphaticus (fig. 2, dv) runs into the aqueductus vestibuli; it is +soon joined by a small duct from the utricle, and ends, close to the +dura mater of the posterior fossa of the cranium, as the saccus +endolymphaticus, which may have minute perforations through which the +endolymph can pass. Anteriorly the saccule communicates with the +membranous cochlea or scala media by a short ductus reuniens (fig. 2, +dr). A section through each turn of the cochlea shows the bony lamina +spiralis, already noticed, which is continued right across the canal by +the basilar membrane (fig. 4, bm), thus cutting the canal into an upper +and lower half and connected with the outer wall by the strong spiral +ligament (fig. 4, sl). Near the free end of the lamina spiralis another +membrane called the membrane of Reissner (fig. 4, mR) is attached, and +runs outward and upward to the outer wall, taking a triangular slice out +of the upper half of the section. There are now three canals seen in +section, the upper of which is the scala vestibuli (fig. 4, SV), the +middle and outer the scala media, ductus cochlearis or true membranous +cochlea (fig. 4, DC), while the lower is the scala tympani (fig. 4, ST). +The scala vestibuli and scala tympani communicate at the apex of the +cochlea by an opening known as the helicotrema, so that the perilymph +can here pass from one canal to the other. At the base of the cochlea +the perilymph in the scala vestibuli is continuous with that in the +vestibule, but that in the scala tympani bathes the inner surface of the +membrane stretched across the fenestra rotunda, and also communicates +with the subarachnoid space through the aqueductus cochleae, which opens +into the posterior cranial fossa. The scala media containing endolymph +communicates, as has been shown, with the saccule through the canalis +reuniens, while, at the apex of the cochlea, it ends in a blind +extremity of considerable morphological interest called the lagena. + +[Illustration: FIG. 4.--Transverse Section through the Tube of the +Cochlea. + + m, Modiolus. bm, Basilar membrane. + 0, Outer wall of cochlea. cs, Crista spiralis. + SV, Scala vestibuli. sl, Spiral ligament. + ST, Scala tympani. sg, Spiral ganglion of auditory nerve. + DC, Ductus cochlearis. oc, Organ of Corti. + mR, Membrane of Reissner.] + +The scala media contains the essential organ of hearing or organ of +Corti (fig. 4, oc), which lies upon the inner part of the basilar +membrane; it consists of a tunnel bounded on each side of the inner and +outer rods of Corti; on each side of these are the inner and outer hair +cells, between the latter of which are found the supporting cells of +Deiters. Most externally are the large cells of Hensen. A delicate +membrane called the lamina reticularis covers the top of all these, and +is pierced by the hairs of the hair cells, while above this is the loose +membrana tectoria attached to the periosteum of the lamina spiralis, +near its tip, internally, and possibly to some of Deiter's cells +externally. The cochlear branch of the auditory nerve enters the lamina +spiralis, where a spiral ganglion (fig. 4, sg) is developed on it; after +this it is distributed to the inner and outer hair cells. + +[Illustration: FIG. 5.--Transverse Section of Corti's Organ from the +Central Coil of Cochlea (Retzius). + +(From R. Howden--Cunningham's _Text-Book of Anatomy_.)] + + For further details see _Text-Book of Anatomy_, edited by D.J. + Cunningham (Edinburgh, 1906); Quain's _Elements of Anatomy_ (London, + 1893); Gray's _Anatomy_ (London, 1905); _A Treatise on Anatomy_, + edited by H. Morris (London, 1902); _A Text-Book of Human Anatomy_, by + A. Macalister (London, 1889). + +_Embryology._--The pinna is formed from six tubercles which appear round +the dorsal end of the hyomandibular cleft or, more strictly speaking, +pouch. Those for the tragus and anterior part of the helix belong to the +first or mandibular arch, while those for the antitragus, antihelix and +lobule come from the second or hyoid arch. The tubercle for the helix is +dorsal to the end of the cleft where the two arches join. The external +auditory meatus, tympanum and Eustachian tube are remains of the +hyomandibular cleft, the membrana tympani being a remnant of the cleft +membrane and therefore lined by ectoderm outside and entoderm inside. +The origin of the ossicles is very doubtful. H. Gadow's view, which is +one of the latest, is that all three are derived from the hyomandibular +plate which connects the dorsal ends of the hyoid and mandibular bars +(_Anatomischer Anzeiger_, Bd. xix., 1901, p. 396). Other papers which +should be consulted are those of E. Gaupp, _Anatom. Hefte, Ergebnisse_, +Bd. 8, 1898, p. 991, and J.A. Hammar, _Archiv f. mikr. Anat._ lix., +1902. These papers will give a clue to the immense literature of the +subject. The internal ear first appears as a pit from the cephalic +ectoderm, the mouth of which in Man and other mammals closes up, so that +a pear-shaped cavity is left. The stalk of the pear which is nearest the +point of invagination is called the recessus labyrinthi, and this, after +losing its connexion with the surface of the embryo, grows backward +toward the posterior cranial fossa and becomes the ductus +endolymphaticus. The lower part of the vesicle grows forward and becomes +the cochlea, while from the upper part three hollow circular plates grow +out, the central parts of which disappear, leaving the margin as the +semicircular canals. Subsequently constrictions appear in the vesicle +marking off the saccule and utricle. From the surrounding mesoderm the +petrous bone is formed by a process of chondrification and ossification. + + See W. His, Junr., _Archiv f. Anat. und Phys._, 1889, supplement, p. + 1; also Streeter, _Am. Journ. of Anat._ vi., 1907. + +_Comparative Anatomy._--The ectodermal inpushing of the internal ear has +probably a common origin with the organs of the lateral line of fish. In +the lower forms the ductus endolymphaticus retains its communication +with the exterior on the dorsum of the head, and in some Elasmobranchs +the opening is wide enough to allow the passage of particles of sand +into the saccule. It is probable that this duct is the same which, +taking a different direction and losing its communication with the skin, +abuts on the posterior cranial fossa of higher forms (see Rudolf Krause, +"Die Entwickelung des Aq. vestibuli seu d. Endelymphaticus," _Anat. +Anzeiger_, Bd. xix., 1901, p. 49). In certain Teleostean fishes the swim +bladder forms a secondary communication with the internal ear by means +of special ossicles (see G. Ridewood, _Journ. Anat. & Phys._ vol. +xxvi.). Among the Cyclostomata the external semicircular canals are +wanting; Petromyzon has the superior and posterior only, while in Myxine +these two appear to be fused so that only one is seen. In higher types +the three canals are constant. Concretions of carbonate of lime are +present in the internal ears of almost all vertebrates; when these are +very small they are called otoconia, but when, as in most of the +teleostean fishes, they form huge concretions, they are spoken of as +otoliths. One shark, Squatina, has sand instead of otoconia (C. Stewart, +_Journ. Linn. Society_, xxix. 409). The utricle, saccule, semicircular +canals, ductus endolymphaticus and a short lagena are the only parts of +the ear present in fish. + +The Amphibia have an important sensory area at the base of the lagena +known as the macula acustica basilaris, which is probably the first +rudiment of a true cochlea. The ductus endolymphaticus has lost its +communication with the skin, but it is frequently prolonged into the +skull and along the spinal canal, from which it protrudes, through the +intervertebral foramina, bulging into the coelom. This is the case in +the common frog (A. Coggi, _Anat. Anz._ 5. Jahrg., 1890, p. 177). In +this class the tympanum and Eustachian tube are first developed; the +membrana tympani lies flush with the skin of the side of the head, and +the sound-waves are transmitted from it to the internal ear by a single +bony rod--the columella. + +In the Reptilia the internal ear passes through a great range of +development. In the Chelonia and Ophidia the cochlea is as rudimentary +as in the Amphibia, but in the higher forms (Crocodilia) there is a +lengthened and slightly twisted cochlea, at the end of which the lagena +forms a minute terminal appendage. At the same time indications of the +scalae tympani and vestibuli appear. As in the Amphibia the ductus +endolymphaticus sometimes extends into the cranial cavity and on into +other parts of the body. Snakes have no tympanic membrane. In the birds +the cochlea resembles that of the crocodiles, but the posterior +semicircular canal is above the superior where they join one another. In +certain lizards and birds (owls) a small fold of skin represents the +first appearance of an external ear. In the monotremes the internal ear +is reptilian in its arrangement, but above them the mammals always have +a spirally twisted cochlea, the number of turns varying from one and a +half in the Cetacea to nearly five in the rodent _Coelogenys_. The +lagena is reduced to a mere vestige. The organ of Corti is peculiar to +mammals, and the single columella of the middle ear is replaced by the +three ossicles already described in Man (see Alban Doran, "Morphology of +the Mammalian Ossicula auditus," _Proc. Linn. Soc._, 1876-1877, xiii. +185; also _Trans. Linn. Soc._ 2nd Ser. Zool. i. 371). In some mammals, +especially Carnivora, the middle ear is enlarged to form the tympanic +bulla, but the mastoid cells are peculiar to Man. + + For further details see G. Retzius, _Das Gehoerorgan der Wirbelthiere_ + (Stockholm, 1881-1884); Catalogue of the Museum of the R. College of + Surgeons--Physiological Series, vol. iii. (London, 1906); R. + Wiedersheim's _Vergleichende Anatomie der Wirbeltiere_ (Jena, 1902). + (F. G. P.) + + +DISEASES OF THE EAR + +Modern scientific aural surgery and medicine (commonly known as Otology) +dates from the time of Sir William Wilde of Dublin (1843), whose work +marked a great advance in the application of anatomical, physiological +and therapeutical knowledge to the study of this organ. Less noticeable +contributions to the subject had not long before been made by Saunders +(1827), Kramer (1833), Pilcher (1841) and Yearsley (1841). The next +important event in the history of otology was the publication of J. +Toynbee's book in 1860 containing his valuable anatomical and +pathological observations. Von Troeltsch of Wuerzburg, following on the +lines of Wilde and Toynbee, produced two well-known works in 1861 and +1862, laying the foundation of the study in Germany. In that country and +in Austria he was followed by Hermann Schwartze, Politzer, Gruber, +Weber-Liel, Ruedinger, Moos and numerous others. France produced Itard, +de la Charriere, Meniere, Loewenberg and Bonnafont; and Belgium, Charles +Delstanche, father and son. In Great Britain the work was carried on by +James Hinton (1874), Peter Allen (1871), Patterson Cassells and Sir +William Dalby. In America we may count among the early otologists Edward +H. Clarke (1858), D.B. St John Roosa, H. Knapp, Clarence J. Blake, +Albert H. Buck and Charles Burnett. Other workers all over the world are +too numerous to mention. + +_Various Diseases and Injuries._--Diseases of the ear may affect any of +the three divisions, the external, middle or internal ear. The commoner +affections of the _auricle_ are eczema, various tumours (simple and +malignant), and serous and sebaceous cysts. Haematoma auris +(othaematoma), or effusion of blood into the auricle, is often due to +injury, but may occur spontaneously, especially in insane persons. The +chief diseases of the _external auditory canal_ are as follows:--impacted +cerumen (or wax), circumscribed (or furuncular) inflammation, diffuse +inflammation, strictures due to inflammatory affections, bony growths, +fungi (otomycosis), malignant disease, caries and necrosis, and foreign +bodies. + +Diseases of the _middle ear_ fall into two categories, suppurative and +non-suppurative (i.e. with and without the formation of pus). +Suppurative inflammation of the middle ear is either acute or chronic, +and is in either case accompanied by perforation of the drum head and +discharge from the ear. The chief importance of these affections, in +addition to the symptoms of pain, deafness, discharge, &c., is the +serious complications which may ensue from their neglect, viz. aural +polypi, caries and necrosis of the bone, affections of the mastoid +process, including the mastoid antrum, paralysis of the facial nerve, +and the still more serious intracranial and vascular infective diseases, +such as abscess in the brain (cerebrum or cerebellum), meningitis, with +subdural and extradural abscesses, septic thrombosis of the sigmoid and +other venous sinuses, and pyaemia. It is owing to the possibility of +these complications that life insurance companies usually, and rightly, +inquire as to the presence of ear discharge before accepting a life. +Patterson Cassells of Glasgow urged this special point as long ago as +1877. Acute suppurative disease of the middle ear is often due to the +exanthemata, scarlatina, measles and smallpox, and to bathing and +diving. It may also be caused by influenza, diphtheria and pulmonary +phthisis. + +Non-suppurative disease of the middle ear may be acute or chronic. In +the acute form the inflammation is less violent than in the acute +suppurative inflammation, and is rarely accompanied by perforation. +Chronic non-suppurative inflammation may be divided into the moist form, +in which the symptoms are improved by inflation of the tympanum through +the Eustachian tube, and the dry form (including sclerosis), which is +more intractable and in which this procedure has little or no beneficial +effect. Diseases of the _internal ear_ may be primary or secondary to an +affection of the tympanum or to intracranial disease. + +Injuries to any part of the ear may occur, among the commoner being +injuries to the auricle, rupture of the drum head (from explosions, +blows on the ear or the introduction of sharp bodies into the ear +canal), and injuries from fractured skull. Congenital malformations of +the ear are most frequently met with in the auricle and external canal. + +_Methods of Examination._--The methods of examining the ear are roughly +threefold:--(1) Testing the hearing with watch, voice and tuning-fork. +The latter is especially used to distinguish between disease of the +middle ear (conducting apparatus) and that of the internal ear +(perceptive apparatus). Our knowledge of the subject has been brought to +its present state by the labours of many observers, notably Weber, +Rinne, Schwabach, Lucae and Gelle. (2) Examination of the canal and +drum-head with speculum and reflector, introduced by Kramer, Wilde and +von Troeltsch. (3) Examination of the drum-cavity through the Eustachian +tube by the various methods of inflation. + +_Symptoms._--The chief symptoms of ear diseases are deafness, noises in +the ear (tinnitus aurium), giddiness, pain and discharge. Deafness (or +other disturbance of hearing) and noises may occur from disease in +almost any part of the ear. Purulent discharge usually comes from the +middle ear. Giddiness is more commonly associated with affections of the +internal ear. + +_Treatment._--Ear diseases are treated on ordinary surgical and medical +lines, due regard being had to the anatomical and physiological +peculiarities of this organ of sense, and especially to its close +relationship, on the one hand to the nose and naso-pharynx, and on the +other hand to the cranium and its contents. The chief advance in aural +surgery in recent years has been in the surgery of the mastoid process +and antrum. The pioneers of this work were H. Schwartze of Halle, and +Stacke of Erfurt, who have been followed by a host of workers in all +parts of the world. This development led to increased attention being +paid to the intracranial complications of suppurative ear disease, in +the treatment of which great strides have been made in the last few +years. + +_Effects of Diseases of the Nose on the Ear._--The influence of diseases +of the nose and naso-pharynx on ear diseases was brought out by +Loewenberg of Paris, Voltolini of Breslau, and especially by Wilhelm +Meyer of Copenhagen, the discoverer of adenoid vegetations of the +naso-pharynx ("adenoids"), who recognized the great importance of this +disease and gave an inimitable account of it in the _Trans. of the Royal +Medical and Chirurgical Society of London_, 1870, and the _Archiv fuer +Ohrenheilkunde_, 1873. Adenoid vegetations, which consist of an abnormal +enlargement of Luschka's tonsil in the vault of the pharynx, frequently +give rise to ear disease in children, and, if not attended to, lay the +foundation of nasal and ear troubles in after life. They are often +associated with enlargement of the faucial tonsils. + + _Journals._--In 1864 the _Archiv fuer Ohrenheilkunde_ was started by + Politzer and Schwartze, and, in 1867, the _Monatsschrift fuer + Ohrenheilkunde_ (a monthly publication) was founded by Voltolini, + Gruber, Weber-Liel and Ruedinger. Appearing first as the _Archives of + Ophthalmology and Otology_, simultaneously in English and German, in + 1869, the _Archives of Otology_ became a separate publication under + the editorship of Knapp, Moos and Roosa in 1879. Amongst other + journals now existing are _Annales des maladies de l'oreille et du + larynx_ (Paris), _Journal of Laryngology_ (London), _Centralblatt fuer + Ohrenheilkunde_ (Leipzig), &c. + + _Societies._--The earliest society formed was the American Otological + Society (1868), which held annual meetings and published yearly + transactions. Flourishing societies for the study of otology + (sometimes combined with laryngology) exist in almost all civilized + countries, and they usually publish transactions consisting of + original papers and cases. The Otological Society of the United + Kingdom was founded in 1900. + + _International Congresses._--International Otological congresses have + been held at intervals of about four years at New York, Milan, Basel, + Brussels, Florence, London and Bordeaux (1904). The proceedings of the + congresses appear as substantial volumes. + + _Hospitals._--The earliest record of a public institution for the + treatment of ear diseases is a Dispensary for Diseases of the Eye and + Ear in London, started by Saunders and Cooper, which existed in 1804; + the aural part, however, was soon closed, so that the actual oldest + institution appears to be the Royal Ear Hospital, London, which was + founded by Curtis in 1816. Four years later there was started the New + York Eye and Ear Infirmary. At the present time in every large town of + Europe and America ear diseases are treated either in separate + departments of general hospitals or in institutions especially devoted + to the purpose. + + For a history of otology from the earliest times refer to _A Practical + Treatise on the Diseases of the Ear_, by D.B. St John Roosa, M.D., + LL.D. (6th edition, New York, 1885), and for a general account of the + present state of otological science to _A Text-Book of the Diseases of + the Ear for Students and Practitioners_, by Professor Dr Adam + Politzer, transl. by Milton J. Ballin, Ph.B., M.D., and Clarence J. + Heller, M.D. (4th edition, London, 1902). (E. C. B.*) + + + + +EARL, a title and rank of nobility (corresponding to Lat. _comes_; Fr. +_comte_), now the third in order of the British peerage, and accordingly +intervening between marquess and viscount. Earl, however, is the oldest +title and rank of English nobles, and was the highest until the year +1337, when the Black Prince was created duke of Cornwall by Edward III. + +The nature of a modern earldom is readily understood, since it is a rank +and dignity of nobility which, while it confers no official power or +authority, is inalienable, indivisible, and descends in regular +succession to all the heirs under the limitation in the grant until, on +their failure, it becomes extinct. + +The title is of Scandinavian origin, and first appears in England under +Canute as _jarl_, which was englished as _eorl_. Like the _ealdorman_, +whose place he took, the _eorl_ was a great royal officer, who might be +set over several counties, but who presided separately in the county +court of each with the bishop of the diocese. Although there were counts +in Normandy before the Norman Conquest, they differed in character from +the English earls, and the earl's position appears to have been but +slightly modified by the Conquest. He was still generally entitled to +the "third penny" of the county, but his office tended, under Norman +influence, to become an hereditary dignity and his sphere was restricted +by the Conqueror to a single county. The right to the "third penny" is a +question of some obscurity, but its possession seems to have been deemed +the distinctive mark of an earl, while the girding with "the sword of +the county" formed the essential feature in his creation or investiture, +as it continued to do for centuries later. The fact that every earl was +the earl of a particular county has been much obscured by the loose +usage of early times, when the style adopted was sometimes that of the +noble's surname (e.g. the Earls Ferrers), sometimes that of his chief +seat (e.g. the Earls of Arundel), and sometimes that of the county. +Palatine earldoms, or palatinates, were those which possessed _regalia_, +i.e. special privileges delegated by the crown. The two great examples, +which dated from Norman times, were Chester and Durham, where the earl +and the bishop respectively had their own courts and jurisdiction, and +were almost petty sovereigns. + +The earliest known charter creating an earl is that by which Stephen +bestowed on Geoffrey de Mandeville, in or about 1140, the earldom of +Essex as an hereditary dignity. Several other creations by Stephen and +the empress Maud followed in quick succession. From at least the time of +the Conquest the earl had a double character; he was one of the +"barons," or tenants in chief, in virtue of the fief he held of the +crown, as well as an earl in virtue of his "belting" (with the sword) +and his "third penny" of the county. His fief would descend to the heirs +of his body; and the earliest charters creating earldoms were granted +with the same "limitation." The dignity might thus descend to a woman, +and, in that case, like the territorial fief, it would be held by her +husband, who might be summoned to parliament in right of it. The earldom +of Warwick thus passed through several families till it was finally +obtained, in 1449, by the Kingmaker, who had married the heiress of the +former earls. But in the case of "co-heiresses" (more daughters than +one), the king determined which, if any, should inherit the dignity. + +The 14th century saw some changes introduced. The earldom of March, +created in 1328, was the first that was not named from a county or its +capital town. Under Edward III. also an idea appears to have arisen that +earldoms were connected with the tenure of lands, and in 1337 several +fresh ones were created and large grants of lands made for their +support. The first earldom granted with limitation to the heirs male of +the grantee's body was that of Nottingham in 1383. Another innovation +was the grant of the first earldom for life only in 1377. The girding +with the sword was the only observance at a creation till the first year +of Edward VI., when the imposition of the cap of dignity and a circlet +of gold was added. Under James I. the patent of creation was declared to +be sufficient without any ceremony. An earl's robe of estate has three +bars of ermine, but possibly it had originally four. + +Something should be said of anomalous earldoms with Norman or Scottish +styles. The Norman styles originated either under the Norman kings or at +the time of the conquest of Normandy by the house of Lancaster. To the +former period belonged that of Aumale, which successive fresh creations, +under the Latinized form "Albemarle" have perpetuated to the present day +(see ALBEMARLE, EARLS AND DUKES OF). The so-called earls of Eu and of +Mortain, in that period, were really holders of Norman _comtes_. Henry +V. and his son created five or six, it is said, but really seven at +least, Norman countships or earldoms, of which Harcourt (1418), Perche +(1419), Dreux (1427) and Mortain (? 1430) were bestowed on English +nobles, Eu (1419), and Tankerville (1419) on English commoners, and +Longueville (1419) on a foreigner, Gaston de Foix. Of these the earldom +of "Eu" was assumed by the earls of Essex till the death of Robert, the +parliament's general (1646), while the title of Tankerville still +survives under a modern creation (1714). An anomalous royal licence of +1661 permitted the earl of Bath to use the title of earl of Corbeil by +alleged hereditary right. Of Scottish earldoms recognized in the English +parliament the most remarkable case is that of the Lords Umfraville, who +were summoned for three generations (1297-1380), as earls of Angus; +Henry, Lord Beaumont, also was summoned as earl of Buchan from 1334 to +1339. + +The earldom of Chester is granted to the princes of Wales on their +creation, and the Scottish earldom of Carrick is held by the eldest son +of the sovereign under act of parliament. + +The premier earldom is that of Arundel (q.v.), but as this is at present +united with the dukedom of Norfolk, the oldest earldom not merged in a +higher title is that of Shrewsbury (1442), the next in seniority being +Derby (1485), and Huntingdon (1529). These three have been known as "the +catskin earls," a term of uncertain origin. The ancient earldom of +Wiltshire (1397) was unsuccessfully claimed in 1869 by Mr Scrope of +Danby, and that of Norfolk (1312), in 1906, by Lord Mowbray and +Stourton. + +The premier earldom of Scotland as recognized by the Union Roll (1707), +is that of Crawford, held by the Lindsays since its creation in 1398; +but it is not one of the ancient "seven earldoms." The Decreet of +Ranking (1606) appears to have recognized the earldom of Sutherland as +the most ancient in virtue of a charter of 1347, but the House of Lords' +decision of 1771 recognized it as having descended from at least the +year 1275, and it may be as old as 1228. It is at present united with +the dukedom of Sutherland. The original "seven earldoms" (of which it +was one) represented seven provinces, each of which was under a +"_mormaer_." This Celtic title was rendered "_jarl_" by the Norsemen, +and under Alexander I. (c. 1115) began to be replaced by earl (_comes_), +owing to Anglo-Norman influence, which also tended to make these +earldoms less official and more feudal. + +In Ireland the duke of Leinster is, as earl of Kildare, premier earl as +well as premier duke. + +An earl is "Right Honourable," and is styled "My Lord." His eldest son +bears his father's "second title," and therefore, that second title +being in most cases a viscounty, he generally is styled "Viscount"; +where, as with Devon and Huntingdon, there is no second title, one may +be assumed for convenience; under all circumstances, however, the eldest +son of an earl takes precedence immediately after the viscounts. The +younger sons of earls are "Honourable," but all their daughters are +"Ladies." In formal documents and instruments, the sovereign, when +addressing or making mention of any peer of the degree of an earl, +usually designates him "trusty and well-beloved cousin,"--a form of +appellation first adopted by Henry IV., who either by descent or +alliance was actually related to every earl and duke in the realm. The +wife of an earl is a countess; she is "Right Honourable," and is styled +"My Lady." For the earl's coronet see CROWN AND CORONET. + + See Lord's _Reports on the Dignity of a Peer_; Pike's _Constitutional_ + _History of the House of Lords_; Selden's _Titles of Honour_; G.E. + C(okayne)'s _Complete Peerage_; Round's _Geoffrey de Mandeville_. + (J. H. R.) + + + + +EARLE, JOHN (c. 1601-1665), English divine, was born at York about 1601. +He matriculated at Christ Church, Oxford, but migrated to Merton, where +he obtained a fellowship. In 1631 he was proctor and also chaplain to +Philip, earl of Pembroke, then chancellor of the university, who +presented him to the rectory of Bishopston in Wiltshire. His fame +spread, and in 1641 he was appointed chaplain and tutor to Prince +Charles. In 1643 he was elected one of the Assembly of Divines at +Westminster, but his sympathies with the king and with the Anglican +Church were so strong that he declined to sit. Early in 1643 he was +chosen chancellor of the cathedral of Salisbury, but of this preferment +he was soon deprived as a "malignant." After Cromwell's great victory at +Worcester, Earle went abroad, and was named clerk of the closet and +chaplain to Charles II. He spent a year at Antwerp in the house of Isaac +Walton's friend, George Morley, who afterwards became bishop of +Winchester. He next joined the duke of York (James II.) at Paris, +returning to England at the Restoration. He was at once appointed dean +of Westminster, and in 1661 was one of the commissioners for revising +the liturgy. He was on friendly terms with Richard Baxter. In November +1662 he was consecrated bishop of Worcester, and was translated, ten +months later, to the see of Salisbury, where he conciliated the +nonconformists. He was strongly opposed to the Conventicle and Five Mile +Acts. During the great plague Earle attended the king and queen at +Oxford, and there he died on the 17th of November 1665. + +Earle's chief title to remembrance is his witty and humorous work +entitled _Microcosmographie, or a Peece of the World discovered, in +Essayes and Characters_, which throws light on the manners of the time. +First published anonymously in 1628, it became very popular, and ran +through ten editions in the lifetime of the author. The style is quaint +and epigrammatic; and the reader is frequently reminded of Thomas Fuller +by such passages as this: "A university dunner is a gentlemen follower +cheaply purchased, for his own money has hyr'd him." Several reprints of +the book have been issued since the author's death; and in 1671 a French +translation by J. Dymock appeared with the title of _Le Vice ridicule_. +Earle was employed by Charles II. to make the Latin translation of the +_Eikon Basilike_, published in 1649. A similar translation of R. +Hooker's _Ecclesiastical Polity_ was accidentally destroyed. + +"Dr Earle," says Lord Clarendon in his _Life_, "was a man of great piety +and devotion, a most eloquent and powerful preacher, and of a +conversation so pleasant and delightful, so very innocent, and so very +facetious, that no man's company was more desired and loved. No man was +more negligent in his dress and habit and mien, no man more wary and +cultivated in his behaviour and discourse. He was very dear to the Lord +Falkland, with whom he spent as much time as he could make his own." + + See especially Philip Bliss's edition of the _Microcosmographie_ + (London, 1811), and E. Arber's Reprint (London, 1868). + + + + +EARLE, RALPH (1751-1801), American historical and portrait painter, was +born at Leicester, Massachusetts, on the 11th of May 1751. Like so many +of the colonial craftsmen, Earle was self-taught, and for many years was +an itinerant painter. He went with the Governor's Guard to Lexington and +made battle sketches, from which in 1775 he painted four scenes, +engraved by Amos Doolittle, which are probably the first historical +paintings by an American. After the War of Independence, Earle went to +London, entered the studio of Benjamin West, and painted the king and +many notables. After his return to America in 1786 he made portraits of +Timothy Dwight, Governor Caleb Strong, Roger Sherman, and other +prominent men. He also painted a large picture of Niagara Falls. He died +at Bolton, Connecticut, on the 16th of August 1801. + + + + +EARL MARSHAL, in England, a functionary who ranks as the eighth of the +great officers of state. He is the head of the college of arms, and has +the appointment of the kings-of-arms, heralds and pursuivants at his +discretion. He attends the sovereign in opening and closing the session +of parliament, walking opposite to the lord great chamberlain on his or +her right hand. It is his duty to make arrangements for the order of all +state processions and ceremonials, especially for coronations and royal +marriages and funerals. Like the lord high constable he rode into +Westminster Hall with the champion after a coronation, till the +coronation banquet was abandoned, taking his place on the left hand, and +with the lord great chamberlain he assists at the introduction of all +newly-created peers into the House of Lords. + +The marshal appears in the feudal armies to have been in command of the +cavalry under the constable, and to have in some measure superseded him +as master of the horse in the royal palace. He exercised joint and +co-ordinate jurisdiction with the constable in the court of chivalry, +and afterwards became the sole judge of that tribunal till its +obsolescence. The marshalship of England was formerly believed to have +been inherited from the Clares by the Marshal family, who had only been +marshals of the household. It was held, however, by the latter family, +as the office of chief (_magister_) marshal, as early as the days of +Henry I. Through them, under Henry III., it passed to the Bigods, as +their eldest co-heirs. In 1306 it fell to the crown on the death of the +last Bigod, earl of Norfolk, who had made Edward I. his heir, and in +1316 it was granted by Edward II. to his own younger brother, Thomas "of +Brotherton," earl of Norfolk. As yet the style of the office was only +"marshal" although the last Bigod holder, being an earl, was sometimes +loosely spoken of as the earl marshal. The office, having reverted to +the crown, was granted out anew by Richard II., in 1385, to Thomas +Mowbray, earl of Nottingham, the representative of Thomas "of +Brotherton." In 1386 the style of "earl marshal" was formally granted to +him in addition. After several attainders and partial restorations in +the reigns of the Tudors and the Stuarts, the earl marshalship was +granted anew to the Howards by Charles II. in 1672 and entailed on their +male line, with many specific remainders and limitations, under which +settlement it has regularly descended to the present duke of Norfolk. +Its holders, however, could not execute the office until the Roman +Catholic emancipation, and had to appoint deputies. The duke is styled +earl marshal "and hereditary marshal of England," but the double style +would seem to be an error, though the Mowbrays, with their double +creation (1385, 1386) might have claimed it. His Grace appends the +letters "E.M." to his signature, and bears behind his shield two batons +crossed in saltire, the marshal's rod (_virga_) having been the badge of +the office from Norman times. There appear to have been hereditary +marshals of Ireland, but their history is not well ascertained. The +Keiths were Great Marischals of Scotland from at least the days of +Robert Bruce, and were created earls marischal in or about 1458, but +lost both earldom and office by the attainder of George, the 10th earl, +in 1716. (See also MARSHAL; STATE, GREAT OFFICERS OF.) + + See "The Marshalship of England," in J.H. Round, _Commune of London + and Other Studies_ (London, 1899); G.E. C(okayne)'s _Complete + Peerage_. (J. H. R.) + + + + +EARLOM, RICHARD (1742-1822), English mezzotint engraver, was born and +died in London. His natural faculty for art appears to have been first +called into exercise by admiration for the lord mayor's state coach, +just decorated by Cipriani. He tried to copy the paintings, and was sent +to study under Cipriani. He displayed great skill as a draughtsman, and +at the same time acquired without assistance the art of engraving in +mezzotint. In 1765 he was employed by Alderman Boydell, then one of the +most liberal promoters of the fine arts, to make a series of drawings +from the pictures at Houghton Hall; and these he afterwards engraved in +mezzotint. His most perfect works as engraver are perhaps the fruit and +flower pieces after the Dutch artists Van Os and Van Huysum. Amongst his +historical and figure subjects are--"Agrippina," after West; "Love in +Bondage," after Guido Reni; the "Royal Academy," the "Embassy of +Hyderbeck to meet Lord Cornwallis," and a "Tiger Hunt," the last three +after Zoffany; and "Lord Heathfield," after Sir Joshua Reynolds. Earlom +also executed a series of 200 facsimiles of the drawings and sketches +of Claude Lorraine, which was published in 3 vols. folio, under the +title of _Liber veritatis_ (1777-1819). + + + + +EARLSTON (formerly ERCILDOUNE, of which it is a corruption), a parish +and market town of Berwickshire, Scotland. Pop. (1901) 1049. It is +situated on Leader Water in Lauderdale, 721/2 m. S.E. of Edinburgh by the +North British railway branch line from Reston Junction to St Boswells, +and about 4 m. N.E. of Melrose. When the place was a hamlet of rude huts +it was called Arcioldun or "Prospect Fort," with reference to Black Hill +(1003 ft.), on the top of which may yet be traced the concentric rings +of the British fort by which it was crowned. It is said to be possible +to make out the remains of the cave-dwellings of the Ottadeni, the +aborigines of the district. In the 12th and 13th centuries the Lindsays +and the earls of March and Dunbar were the chief baronial families. The +particular link with the remote past, however, is the ivy-clad ruin of +the ancient tower, "The Rhymer's Castle," the traditional residence of +Thomas Learmont, commonly called Thomas of Ercildoune, or Thomas the +Rhymer, poet and prophet, and friend of the Fairies, who was born here +about 1225. Rhymer's Tower was crumbling to pieces, and its stones were +being used in the erection of dykes, cottages and houses, when the +Edinburgh Border Counties Association acquired the relic and surrounding +lands in 1895, and took steps to prevent further spoliation and decay. +The leading manufactures are ginghams, tweeds and shirtings, and the +town is also an important agricultural centre, stock sales taking place +at regular intervals and cattle and horse fairs being held every year. +Some 3 m. away is the estate of Bemersyde, said to have been in the +possession of the Haigs for nearly 1000 years. The prospect from +Bemersyde Hill was Sir Walter Scott's favourite view. The castle at +Bemersyde was erected in 1535 to secure the peace of the Border. + + + + +EARLY, JUBAL ANDERSON (1816-1894), American soldier and lawyer, was born +in Franklin county, Virginia, on the 3rd of November 1816, and graduated +at the U.S. Military Academy in 1837. He served in the Seminole War of +1837-38, after which he resigned in order to practise law in Franklin +county, Va. He also engaged in state politics, and served in the Mexican +War as a major of Virginia volunteers. He was strongly opposed to +secession, but thought it his duty to conform to the action of his +state. As a colonel in the Confederate army, he rendered conspicuous +service at the first battle of Bull Run (q.v.). Promoted +brigadier-general, and subsequently major-general, Early served +throughout the Virginian campaigns of 1862-63, and defended the lines of +Fredericksburg during the battle of Chancellorsville. At Gettysburg he +commanded his division of Ewell's corps. In the campaign of 1864 Early, +who had now reached the rank of lieutenant-general, commanded the +Confederate forces in the Shenandoah Valley. The action of Lynchburg +left him free to move northwards, his opponent being compelled to march +away from the Valley. Early promptly utilized his advantage, crossed the +Potomac, and defeated, on the Monocacy, all the troops which could be +gathered to meet him. He appeared before the lines of Washington, put +part of Maryland and Pennsylvania under contribution, and only retired +to the Valley when threatened by heavy forces hurriedly sent up to +Washington. He then fought a successful action at Winchester, reappeared +on the Potomac, and sent his cavalry on a raid into Pennsylvania. A +greatly superior army was now formed under General Sheridan to oppose +Early. In spite of his skill and energy the Confederate leader was +defeated in the battles of Winchester and Fisher's Hill. Finally, on the +19th of October, after inflicting at first a severe blow upon the +Federal army in its camps on Cedar Creek, he was decisively beaten by +Sheridan. (See SHENANDOAH VALLEY CAMPAIGNS.) Waynesboro (March 1865) was +his last fight, after which he was relieved from his command. General +Early was regarded by many as the ablest soldier, after Lee and Jackson, +in the Army of Northern Virginia, and one of the ablest in the whole +Confederate army. That he failed to make headway against an army far +superior in numbers, and led by a general of the calibre of Sheridan, +cannot be held to prove the falsity of this judgment. After the peace +he went to Canada, but in 1867 returned to resume the practice of law. +For a time he managed in conjunction with General Beauregard the +Louisiana lottery. He died at Lynchburg, Va., on the 2nd of March 1894. +General Early was for a time president of the Southern Historical +Society, and wrote, besides various essays and historical papers, _A +Memoir of the Last Year of the War, &c._ (1867). + + + + +EARLY ENGLISH PERIOD, in architecture, the term given by Rickman to the +first pointed or Gothic style in England, nominally 1189-1307, which +succeeded the Romanesque or Norman period towards the end of the 12th +century, and developed into the Decorated period in the commencement of +the 14th century. It is chiefly characterized by the almost universal +employment of the pointed arch, not only in arches of wide span such as +those of the nave arcade, but for doorways and windows. The actual +introduction of the pointed arch took place at a much earlier date, as +in the nave arcade of the Cistercian Abbey of Buildwas (1140), though +the clerestory window above has semicircular arches. It is customary, +therefore, to make allowance for a transitional epoch from the middle of +the 12th century. Although the pointed arches used are sometimes +equilateral and sometimes drop-arches, the lancet-arch is the most +characteristic. The period is best recognized in England by the great +depth given to the hollows of the mouldings, alternating with fillets +and rolls, by the decoration of the hollows with the dog-tooth ornament, +by the circular abacus of the capitals, and the employment of slender +detached shafts of Purbeck marble which are attached to piers by +circular moulded shaft-rings (Fr. _anneau_). + +The arches are sometimes cusped; circles with trefoils, quatrefoils, +&c., are introduced into the tracery, and large rose windows in the +transept or nave, as at Lincoln (1220). The conventional foliage +decorating the capitals is of great beauty and variety, and extends to +spandrils, bosses, &c. In the spandrils of the arches of the nave, +transept or choir arcades, diaper work is occasionally found, as in the +transept of Westminster Abbey. The latter is one of the chief examples +of the period, to which must be added the cathedral of Salisbury (except +the tower); the Galilee at Ely; nave and transept of Wells (1225-1240); +nave of Lincoln; west front of Peterborough; and the minster at +Beverley. (R. P. S.) + + + + +EARN, the name of a loch and river in Perthshire, Scotland. The loch, +lying almost due east and west, is 61/2 m. long and {4/5} m. in maximum +breadth, 287 ft. deep, with a mean depth of 138 ft., covers an area of +nearly 4 sq. m., has a drainage basin of over 541/2 sq. m., and stands 317 +ft. above the sea. Its waters are said never to freeze. It discharges by +the river Earn. The points of interest on its shores are Lochearnhead +(at the southern extremity of Glen Ogle), which has a station on the +Callander-Oban railway, and the ruins of St Blane's chapel; Edinample +Castle, an old turreted mansion belonging to the marquess of +Breadalbane, situated in well-wooded grounds near the pretty falls of +the Ample; Ardvorlich House, the original of Darlinvarach in Scott's +_Legend of Montrose_, and the village of St Fillans at the foot of the +loch, once the terminus of the branch of the Caledonian railway from +Perth. The river flows out of Loch Earn, pursues an eastward course with +a gentle inclination towards the south, and reaches the Firth of Tay, 61/2 +m. below Perth, after a total run of 49 m. Its chief tributaries on the +right are the Ruchil, Machany, Ruthven, May and Farg, and on the left, +the Lednock and Turret. It is navigable by vessels of 50 tons as far up +as Bridge of Earn, and is a notable fishing stream, abounding with +salmon and trout, perch and pike being also plentiful. On the Lednock +are the falls of the Devil's Cauldron and on the Turret and its feeders +several graceful cascades. The principal places of interest on the banks +of the Earn are Dunira, the favourite seat of Henry Dundas, 1st Viscount +Melville, who took the title of his barony from the estate and to whose +memory an obelisk was raised on the adjoining hill of Dunmore; the +village of Comrie; the town of Crieff; the ruined castle of +Innerpeffray, founded in 1610 by the 1st Lord Maderty, close to which is +the library founded in 1691 by the 3rd Lord Maderty, containing some +rare black-letter books and the Bible that belonged to the marquess of +Montrose; Gascon Hall, now in ruins, but with traditions reaching back +to the days of Wallace; Dupplin Castle, a fine Tudor mansion, seat of +the earl of Kinnoull, who derives from it the title of his viscounty; +Aberdalgie, Forgandenny and Bridge of Earn, a health resort situated +amidst picturesque surroundings. Strathearn, as the valley of the Earn +is called, extending from the loch to the Firth of Tay, is a beautiful +and, on the whole, fertile tract, though liable at times to heavy +floods. The earl of Perth is hereditary steward of Strathearn. + + + + +EARNEST (probably a corruption of the obsolete _arles_ or _erles_, +adapted from Lat. equivalent _arrha_, due to a confusion with the +adjective "earnest," serious, O. Eng. _eornust_, cognate with Ger. +_ernst_), the payment of a sum of money by the buyer of goods to the +seller on the conclusion of a bargain as a pledge for its due +performance. It is almost similar to the _arrha_ of the Roman law, which +may be traced back in the history of legal institutions to a period when +the validity of a contract depended not so much upon the real intention +of the parties, as upon the due observance of a prescribed ceremony. But +_earnest_ was never part payment, which _arrha_ might have been. Apart +from its survival as a custom, its chief importance in English law is +its recognition by the Statute of Frauds as giving validity to contracts +for the sale of goods of a value exceeding L10 (see SALE OF GOODS). It +is in that statute clearly distinguished from part payment, consequently +any sum, however small, would be sufficient as earnest, being given as a +token that the contract is binding and should be expressly stated so by +the giver. The giving of earnest, or _hand-money_, as it is sometimes +called, has now fallen into very general disuse. + + + + +EAR-RING, an ornament worn pendent from the ear, and generally suspended +(especially among the more civilized races) by means of a ring or hook +passing through the pendulous lobe of the ear. Among savage races the +impulse to decorate, or at any rate to modify the appearance of the ear, +is almost universal. With such peoples the ear appendage is chiefly +remarkable for its extravagant dimensions. Many examples may be seen in +the ethnographic galleries of the British Museum. The Berawan people of +Borneo use plugs through the lobe of the ear 33/4 in. in diameter. More +extraordinary still is an example of a stone ear-plug worn by a Masai, +41/2 in. in diameter and weighing 2 lb. 14 oz. (_Man_, 1905, p. 22). It is +stated that according to the Masai standard of fashion, the lobes of the +ears should be enlarged so as to be capable of meeting above the head. +Among the superior races, though ear ornaments of extravagant size and +elaboration are not unknown, moderation in size is commonly observed, +and greater attention is paid to workmanship and fineness of material. + +The general usage appears to have been to have ear-rings worn in pairs, +the two ornaments in all respects resembling each other; in ancient +times, or more recently among Oriental races, a single ear-ring has +sometimes been worn. The use of this kind of ornament, which constantly +was of great value, dates from the remotest historical antiquity, the +earliest mention of ear-rings occurring in the book of Genesis. It +appears probable that the ear-rings of Jacob's family, which he buried +with his strange idols at Bethel, were regarded as amulets or talismans, +such unquestionably being the estimation in which some ornaments of this +class have been held from a very early period, as they still are held in +the East. Thus in New Zealand ear-rings are decorated with the teeth of +enemies, and with talismanic sharks' teeth. Among all the Oriental races +of whom we have any accurate knowledge, the Hebrews and Egyptians +excepted, ear-rings always have been in general use by both sexes; while +in the West, as well as by the Hebrews and Egyptians, as a general rule +they have been considered exclusively female ornaments. By the Greeks +and Romans also ear-rings were worn only by women, and the wearing of +them by a man is often spoken of as distinctively oriental. + +[Illustration: From _La Grande Encyclopedie_. + +FIG. 1.--Ear-ring from an Assyrian bas relief.] + +In archaic art, ear-rings are frequently represented or their traces are +left in the perforated ear lobes of early statues. After the 4th century +such perforations occur seldom. In one instance, a Greek inscription +records the weight of the detachable gold ornaments on a statue, among +which a pair of ear-rings is included. Ear-rings of characteristic form +are frequently discovered by excavation. In Egypt, a system of pendent +chains is found hanging from a disk. In Assyria the decoration consists +of pendants or knobs attached to a rigid ring. In the early civilization +represented by Dr Schliemann's Trojan investigations, pieces of gold +plate are suspended by parallel chains. In the Mycenaean period, +ear-rings are infrequent in Greece, but have been found in abundance in +the Mycenaean finds of Enkomi (Cyprus) in the form of pendent +bulls'-heads, or of decorative forms based on the bull's head. In the +tombs of the Greek settlers in the Crimea (4th century B.C.), ear-rings +are found of marvellous complexity and beauty. The lexicographer Pollux, +speaking of the names given to ear-rings, derived from their forms, +mentions caryatids, hippocamps and centauresses. Jewels of the same +class, of exquisite beauty and of workmanship that is truly wonderful, +have been rescued from the sepulchres of ancient Etruria. Ear-rings of +comparatively simple forms, but set with pearls and other stones, were +the mode in Rome. In some instances, the stones were of fabulous value. +During the Byzantine period they once more attained an extravagant size. +Researches among the burial places of Anglo-Saxon Britain have led to +the discovery of jewels in considerable numbers, which among their +varieties include ear-rings executed in a style that proves the +Anglo-Saxons to have made no inconsiderable advances in the arts of +civilization. + +[Illustration: From _La Grande Encyclopedie_. + +FIG. 2.--Thetis crossing the sea, with the armour of Achilles. Ear-ring +from the Crimea, Hermitage museum.] + +These same ornaments, which never have fallen into disuse, enjoy at the +present day a considerable degree of favour, and the tide of fashion has +set towards their increased use. Like all other modern jewels, however, +the ear-rings of our own times as works of art can claim no historical +attributes, because they consist as well of reproductions from all past +ages and of every race as of fanciful productions that certainly can be +assigned to no style of art whatever. As one of the curiosities of the +subject it may be mentioned that Antonia, wife of Drusus, is said by +Pliny to have attached a pair of ear-rings to her pet lamprey. + + + + +EARTH (a word common to Teutonic languages, cf. Ger. _Erde_, Dutch +_aarde_, Swed. and Dan. _jord_; outside Teutonic it appears only in the +Gr. [Greek: eraze], on the ground; it has been connected by some +etymologists with the Aryan root _ar-_, to plough, which is seen in the +Lat. _arare_, obsolete Eng. "ear," and Gr. [Greek: aroun], but this is +now considered very doubtful; see G. Curtius, _Greek Etymology_, Eng. +trans., i. 426; Max Mueller, _Lectures_, 8th ed. i. 294). From early +times the word "earth" has been used in several connexions--from that of +soil or ground to that of the planet which we inhabit, but it is +difficult to trace the exact historic sequence of the diverse usages. In +the cosmogony of the Pythagoreans, Platonists and other philosophers, +the term or its equivalent denoted an element or fundamental quality +which conferred upon matter the character of earthiness; and in the +subsequent development of theories as to the ultimate composition of +matter by the alchemists, iatrochemists, and early phlogistonists an +element of the same name was retained (see ELEMENT). In modern +chemistry, the common term "earth" is applied to certain oxides:--the +"alkaline earths" (q.v.) are the oxides of calcium (lime), barium +(baryta) and strontium (strontia); the "rare earths" (q.v.) are the +oxides of a certain class of rare metals. + + +THE EARTH + +The terrestrial globe is a member of the Solar system, the third in +distance from the Sun, and the largest within the orbit of Jupiter. In +the wider sense it may be regarded as composed of a gaseous atmosphere +(see METEOROLOGY), which encircles the crust or lithosphere (see +GEOGRAPHY), and surface waters or hydrosphere (see OCEAN AND +OCEANOGRAPHY). The description of the surface features is a branch of +Geography, and the discussions as to their origin and permanence belongs +to Physiography (in the narrower sense), physiographical geology, or +physical geography. The investigation of the crust belongs to geology +and of rocks in particular to petrology. + +In the present article we shall treat the subject matter of the Earth as +a planet under the following headings:--(1) Figure and Size, (2) Mass +and Density, (3) Astronomical Relations, (4) Evolution and Age. These +subjects will be treated summarily, readers being referred to the +article ASTRONOMY and to the cross-references for details. + +1. _Figure and Size._--To primitive man the Earth was a flat disk with +its surface diversified by mountains, rivers and seas. In many +cosmogonies this disk was encircled by waters, unmeasurable by man and +extending to a junction with the sky; and the disk stood as an island +rising up through the waters from the floor of the universe, or was +borne as an immovable ship on the surface. Of such a nature was the +cosmogony of the Babylonians and Hebrews; Homer states the same idea, +naming the encircling waters [Greek: Okeanos]; and Hesiod regarded it as +a disk midway between the sky and the infernal regions. The theory that +the Earth extended downwards to the limit of the universe was subjected +to modification when it was seen that the same sun and stars reappeared +in the east after their setting in the west. But man slowly realized +that the earth was isolated in space, floating freely as a balloon, and +much speculation was associated about that which supported the Earth. +Tunnels in the foundations to permit the passage of the sun and stars +were suggested; the Greeks considered twelve columns to support the +heavens, and in their mythology the god Atlas appears condemned to +support the columns; while the Egyptians had the Earth supported by four +elephants, which themselves stood on a tortoise swimming on a sea. +Earthquakes were regarded as due to a movement of these foundations; in +Japan this was considered to be due to the motion of a great spider, an +animal subsequently replaced by a cat-fish; in Mongolia it is a hog; in +India, a mole; in some parts of South America, a whale; and among some +of the North American Indians, a giant tortoise. + +The doctrine of the spherical form has been erroneously assigned to +Thales; but he accepted the Semitic conception of the disk, and regarded +the production of springs after earthquakes as due to the inrushing of +the waters under the Earth into fissures in the surface. His pupil, +Anaximander (610-547), according to Diogenes Laertius, believed it to be +spherical (see _The Observatory_, 1894, P. 208); and Anaximenes probably +held a similar view. The spherical form is undoubtedly a discovery of +Pythagoras, and was taught by the Pythagoreans and by the Eleatic +Parmenides. The expositor of greatest moment was Aristotle; his +arguments are those which we employ to-day:--the ship gradually +disappearing from hull to mast as it recedes from the harbour to the +horizon; the circular shadow cast by the Earth on the Moon during an +eclipse, and the alteration in the appearance of the heavens as one +passes from point to point on the Earth's surface.[1] He records +attempts made to determine the circumference; but the first scientific +investigation in this direction was made 150 years later by +Eratosthenes. The spherical form, however, only became generally +accepted after the Earth's circumnavigation (see GEOGRAPHY). + +The historical development of the methods for determining the figure of +the Earth (by which we mean a theoretical surface in part indicated by +the ocean at rest, and in other parts by the level to which water freely +communicating with the oceans by canals traversing the land masses would +rise) and the mathematical investigation of this problem are treated in +the articles EARTH, FIGURE OF THE, and GEODESY; here the results are +summarized. Sir Isaac Newton deduced from the mechanical consideration +of the figure of equilibrium of a mass of rotating fluid, the form of an +oblate spheroid, the ellipticity of a meridian section being {1/231}, +and the axes in the ratio 230 : 231. Geodetic measurements by the +Cassinis and other French astronomers pointed to a prolate form, but the +Newtonian figure was proved to be correct by the measurement of +meridional arcs in Peru and Lapland by the expeditions organized by the +French Academy of Sciences. More recent work points to an elliptical +equatorial section, thus making the earth pear-shaped. The position of +the longer axis is somewhat uncertain; it is certainly in Africa, Clarke +placing it in longitude 8 deg. 15' W., and Schubert in longitude 41 deg. 4' E.; +W.J. Sollas, arguing from terrestrial symmetry, has chosen the position +lat. 6 deg. N., long. 28 deg. E., i.e. between Clarke's and Schubert's +positions. For the lengths of the axes and the ellipticity of the Earth, +see EARTH, FIGURE OF THE. + +2. _Mass and Density._--The earliest scientific investigation on the +density and mass of the Earth (the problem is really single if the +volume of the Earth be known) was made by Newton, who, mainly from +astronomical considerations, suggested the limiting densities 5 and 6; +it is remarkable that this prophetic guess should be realized, the mean +value from subsequent researches being about 51/2, which gives for the +mass the value 6 x 10^21 tons. The density of the Earth has been +determined by several experimenters within recent years by methods +described in the article GRAVITATION; the most probable value is there +stated to be 5.527. + +3. _Astronomical Relations._--The grandest achievements of astronomical +science are undoubtedly to be associated with the elucidation of the +complex motion of our planet. The notion that the Earth was fixed and +immovable at the centre of an immeasurable universe long possessed the +minds of men; and we find the illustrious Ptolemy accepting this view in +the 2nd century A.D., and rejecting the notion of a rotating Earth--a +theory which had been proposed as early as the 5th century B.C. by +Philolaus on philosophical grounds, and in the 3rd century B.C. by the +astronomer Aristarchus of Samos. He argued that if the Earth rotated +then points at the equator had the enormous velocity of about 1000 m. +per hour, and as a consequence there should be terrific gales from the +east; the fact that there were no such gales invalidated, in his +opinion, the theory. The Ptolemaic theory was unchallenged until 1543, +in which year the _De Revolutionibus orbium Celestium_ of Copernicus was +published. In this work it was shown that the common astronomical +phenomena could be more simply explained by regarding the Earth as +annually revolving about a fixed Sun, and daily rotating about itself. A +clean sweep was made of the geocentric epicyclic motions of the planets +which Ptolemy's theory demanded, and in place there was substituted a +procession of planets about the Sun at different distances. The +development of the Copernican theory--the corner-stone of modern +astronomy--by Johann Kepler and Sir Isaac Newton is treated in the +article ASTRONOMY: _History_; here we shall summarily discuss the +motions of our planet and its relation to the solar system. + +The Earth has two principal motions--revolution about the Sun, rotation +about its axis; there are in addition a number of secular motions. + +_Revolution._--The Earth revolves about the Sun in an elliptical orbit +having the Sun at one focus. The plane of the orbit is termed the +ecliptic; it is inclined to the Earth's equator at an angle termed the +obliquity, and the points of intersection of the equator and ecliptic +are termed the equinoctial points. The major axis of the ellipse is the +line of apsides; when the Earth is nearest the Sun it is said to be in +perihelion, when farthest it is in aphelion. The mean distance of the +Earth from the Sun is a most important astronomical constant, since it +is the unit of linear measurement; its value is about 93,000,000 m., and +the difference between the perihelion and aphelion distances is about +3,000,000 m. The eccentricity of the orbit is 0.016751. A tabular +comparison of the orbital constants of the Earth and the other planets +is given in the article PLANET. The period of revolution with regard to +the Sun, or, in other words, the time taken by the Sun apparently to +pass from one equinox to the same equinox, is the tropical or +equinoctial year; its length is 365 d. 5 hrs. 48 m. 46 secs. It is about +20 minutes shorter than the true or sidereal year, which is the time +taken for the Sun apparently to travel from one star to it again. The +difference in these two years is due to the secular variation termed +precession (see below). A third year is named the _anomalistic year_, +which is the time occupied in the passage from perihelion to perihelion; +it is a little longer than the sidereal. + +_Rotation._--The Earth rotates about an axis terminating at the north +and south geographical poles, and perpendicular to the equator; the +period of rotation is termed the day (q.v.), of which several kinds are +distinguished according to the body or point of reference. The rotation +is performed from west to east; this daily rotation occasions the +_diurnal_ motion of the celestial sphere, the rising of the Sun and +stars in the east and their setting in the west, and also the phenomena +of day and night. The inclination of the axis to the ecliptic brings +about the presentation of places in different latitudes to the more +direct rays of the sun; this is revealed in the variation in the length +of daylight with the time of the year, and the phenomena of seasons. + +Although the rotation of the Earth was an accepted fact soon after its +suggestion by Copernicus, an experimental proof was wanting until 1851, +when Foucault performed his celebrated pendulum experiment at the +Pantheon, Paris. A pendulum about 200 ft. long, composed of a flexible +wire carrying a heavy iron bob, was suspended so as to be free to +oscillate in any direction. The bob was provided with a style which +passed over a table strewn with fine sand, so that the style traced the +direction in which the bob was swinging. It was found that the +oscillating pendulum never retraced its path, but at each swing it was +apparently deviated to the right, and moreover the deviations in equal +times were themselves equal. This means that the floor of the Pantheon +was moving, and therefore the Earth was rotating. If the pendulum were +swung in the southern hemisphere, the deviation would be to the left; if +at the equator it would not deviate, while at the poles the plane of +oscillation would traverse a complete circle in 24 hours. + +The rotation of the Earth appears to be perfectly uniform, comparisons +of the times of transits, eclipses, &c., point to a variation of less +than {1/100}th of a second since the time of Ptolemy. Theoretical +investigations on the phenomena of tidal friction point, however, to a +retardation, which may to some extent be diminished by the accelerations +occasioned by the shrinkage of the globe, and some other factors +difficult to evaluate (see TIDE). + +We now proceed to the secular variations. + +_Precession._--The axis of the earth does not preserve an invariable +direction in space, but in a certain time it describes a cone, in much +the same manner as the axis of a top spinning out of the vertical. The +equator, which preserves approximately the same inclination to the +ecliptic (there is a slight variation in the obliquity which we shall +mention later), must move so that its intersections with the ecliptic, +or equinoctial points, pass in a retrograde direction, i.e. opposite to +that of the Earth. This motion is termed the precession of the +equinoxes, and was observed by Hipparchus in the 2nd century B.C.; +Ptolemy corrected the catalogue of Hipparchus for precession by adding +2 deg. 40' to the longitudes, the latitudes being unaltered by this motion, +which at the present time is 50.26" annually, the complete circuit being +made in about 26,000 years. Owing to precession the signs of the zodiac +are traversing paths through the constellations, or, in other +words, the constellations are continually shifting with regard to the +equinoctial points; at one time the vernal equinox Aries was in the +constellations of that name; it is now in Pisces, and will then pass +into Aquarius. The pole star, i.e. the star towards which the Earth's +axis points, is also shifting owing to precession; in about 2700 B.C. +the Chinese observed [alpha] Draconis as the pole star (at present +[alpha] Ursae minoris occupies this position and will do so until 3500); +in 13600 Vega ([alpha] Lyrae) the brightest star in the Northern +hemisphere, will be nearest. + +Precession is the result of the Sun and the Moon's attraction on the +Earth not being a single force through its centre of gravity. If the +Earth were a homogeneous sphere the attractions would act through the +centre, and such forces would have no effect upon the rotation about the +centre of gravity, but the Earth being spheroidal the equatorial band +which stands up as it were beyond the surface of a sphere is more +strongly attracted, with the result that the axis undergoes a tilting. +The precession due to the Sun is termed the _solar precession_ and that +due to the Moon the _lunar precession_; the joint effect (two-thirds of +which is due to the Moon) is the _luni-solar_ precession. Solar +precession is greatest at the solstices and zero at the equinoxes; the +part of luni-solar precession due to the Moon varies with the position +of the Moon in its orbit. The obliquity is unchanged by precession (see +PRECESSION OF THE EQUINOXES). + +_Nutation._--In treating precession we have stated that the axis of the +Earth traces a cone, and it follows that the pole describes a circle +(approximately) on the celestial sphere, about the pole of the ecliptic. +This is not quite true. Irregularities in the attracting forces which +occasion precession also cause a slight oscillation backwards and +forwards over the mean precessional path of the pole, the pole tracing a +wavy line or nodding. Both the Sun and Moon contribute to this effect. +Solar nutation depends upon the position of the Sun on the ecliptic; its +period is therefore 1 year, and in extent it is only 1.2"; lunar +nutation depends upon the position of the Moon's nodes; its period is +therefore about 18.6 years, the time of revolution of the nodes, and its +extent is 9.2". There is also given to the obliquity a small oscillation +to and fro. Nutation is one of the great discoveries of James Bradley +(1747). + +_Planetary Precession._--So far we have regarded the ecliptic as +absolutely fixed, and treated precession as a real motion of the +equator. The ecliptic (q.v.), however, is itself subject to a motion, +due to the attractions of the planets on the Earth. This effect also +displaces the equinoctial points. Its annual value is 0.13". The term +General Precession in longitude is given to the displacement of the +intersection of the equator with the apparent ecliptic on the latter. +The standard value is 50.2453", which prevailed in 1850, and the value +at 1850 + t, i.e. the constant of precession, is 50.2453" + 0.0002225" +t. This value is also liable to a very small change. The nutation of the +obliquity at time 1850 + t is given by the formula 23 deg. 27' 32.0" - 0.47" +t. Complete expressions for these functions are given in Newcomb's +_Spherical Astronomy_ (1908), and in the _Nautical Almanac_. + +The variation of the _line of apsides_ is the name given to the motion +of the major axis of the Earth's orbit along the ecliptic. It is due to +the general influence of the planets, and the revolution is effected in +21,000 years. + +The variation of the eccentricity denotes an oscillation of the form of +the Earth's orbit between a circle and ellipse. This followed the +mathematical researches of Lagrange and Leverrier. It was suggested by +Sir John Herschel in 1830 that this variation might occasion great +climatic changes, and James Croll developed the theory as affording a +solution of the glacial periods in geology (q.v.). + +_Variation of Latitude._--Another secular motion of the Earth is due to +the fact that the axis of rotation is not rigidly fixed within it, but +its polar extremities wander in a circle of about 50 ft. diameter. This +oscillation brings about a variability in terrestrial latitudes, hence +the name. Euler showed mathematically that such an oscillation existed, +and, making certain assumptions as to the rigidity of the Earth, deduced +that its period was 305 days; S.C. Chandler, from 1890 onwards, deduced +from observations of the stars a period of 428 days; and Simon Newcomb +explained the deviation of these periods by pointing out that Euler's +assumption of a perfectly rigid Earth is not in accordance with fact. +For details of this intricate subject see the articles LATITUDE and +EARTH, FIGURE OF THE. + +4. _Evolution and Age._--In its earliest history the mass now +consolidated as the Earth and Moon was part of a vast nebulous +aggregate, which in the course of time formed a central nucleus--our +Sun--which shed its outer layers in such a manner as to form the solar +system (see NEBULAR THEORY). The moon may have been formed from the +Earth in a similar manner, but the theory of tidal friction suggests the +elongation of the Earth along an equatorial axis to form a pear-shaped +figure, and that in the course of time the protuberance shot off to form +the Moon (see TIDE). The age of the Earth has been investigated from +several directions, as have also associated questions related to +climatic changes, internal temperature, orientation of the land and +water (permanence of oceans and continents), &c. These problems are +treated in the articles GEOLOGY and GEOGRAPHY. + + +FOOTNOTE: + + [1] Aristotle regarded the Earth as having an upper inhabited half + and a lower uninhabited one, and the air on the lower half as tending + to flow upwards through the Earth. The obstruction of this passage + brought about an accumulation of air within the Earth, and the + increased pressure may occasion oscillations of the surface, which + may be so intense as to cause earthquakes. + + + + +EARTH, FIGURE OF THE. The determination of the figure of the earth is a +problem of the highest importance in astronomy, inasmuch as the diameter +of the earth is the unit to which all celestial distances must be +referred. + + +_Historical._ + +Reasoning from the uniform level appearance of the horizon, the +variations in altitude of the circumpolar stars as one travels towards +the north or south, the disappearance of a ship standing out to sea, and +perhaps other phenomena, the earliest astronomers regarded the earth as +a sphere, and they endeavoured to ascertain its dimensions. Aristotle +relates that the mathematicians had found the circumference to be +400,000 stadia (about 46,000 miles). But Eratosthenes (c. 250 B.C.) +appears to have been the first who entertained an accurate idea of the +principles on which the determination of the figure of the earth really +depends, and attempted to reduce them to practice. His results were very +inaccurate, but his method is the same as that which is followed at the +present day--depending, in fact, on the comparison of a line measured on +the earth's surface with the corresponding arc of the heavens. He +observed that at Syene in Upper Egypt, on the day of the summer +solstice, the sun was exactly vertical, whilst at Alexandria at the same +season of the year its zenith distance was 7 deg. 12', or one-fiftieth of +the circumference of a circle. He assumed that these places were on the +same meridian; and, reckoning their distance apart as 5000 stadia, he +inferred that the circumference of the earth was 250,000 stadia (about +29,000 miles). A similar attempt was made by Posidonius, who adopted a +method which differed from that of Eratosthenes only in using a star +instead of the sun. He obtained 240,000 stadia (about 27,600 miles) for +the circumference. Ptolemy in his _Geography_ assigns the length of the +degree as 500 stadia. + +The Arabs also investigated the question of the earth's magnitude. The +caliph Abdallah al Mamun (A.D. 814), having fixed on a spot in the +plains of Mesopotamia, despatched one company of astronomers northwards +and another southwards, measuring the journey by rods, until each found +the altitude of the pole to have changed one degree. But the result of +this measurement does not appear to have been very satisfactory. From +this time the subject seems to have attracted no attention until about +1500, when Jean Fernel (1497-1558), a Frenchman, measured a distance in +the direction of the meridian near Paris by counting the number of +revolutions of the wheel of a carriage. His astronomical observations +were made with a triangle used as a quadrant, and his resulting length +of a degree was very near the truth. + +Willebrord Snell[1] substituted a chain of triangles for actual linear +measurement. He measured his base line on the frozen surface of the +meadows near Leiden, and measured the angles of his triangles, which lay +between Alkmaar and Bergen-op-Zoom, with a quadrant and semicircles. He +took the precaution of comparing his standard with that of the French, +so that his result was expressed in toises (the length of the toise is +about 6.39 English ft.). The work was recomputed and reobserved by P. +von Musschenbroek in 1729. In 1637 an Englishman, Richard Norwood, +published a determination of the figure of the earth in a volume +entitled _The Seaman's Practice, contayning a Fundamentall Probleme in +Navigation experimentally verified, namely, touching the Compasse of the +Earth and Sea and the quantity of a Degree in our English Measures_. He +observed on the 11th of June 1633 the sun's meridian altitude in London +as 62 deg. 1', and on the 6th of June 1635, his meridian altitude in York as +59 deg. 33'. He measured the distance between these places partly with a +chain and partly by pacing. By this means, through compensation of +errors, he arrived at 367,176 ft. for the degree--a very fair result. + +The application of the telescope to angular instruments was the next +important step. Jean Picard was the first who in 1669, with the +telescope, using such precautions as the nature of the operation +requires, measured an arc of meridian. He measured with wooden rods a +base line of 5663 toises, and a second or base of verification of 3902 +toises; his triangulation extended from Malvoisine, near Paris, to +Sourdon, near Amiens. The angles of the triangles were measured with a +quadrant furnished with a telescope having cross-wires. The difference +of latitude of the terminal stations was determined by observations made +with a sector on a star in Cassiopeia, giving 1 deg. 22' 55" for the +amplitude. The terrestrial measurement gave 78,850 toises, whence he +inferred for the length of the degree 57,060 toises. + +Hitherto geodetic observations had been confined to the determination of +the magnitude of the earth considered as a sphere, but a discovery made +by Jean Richer (d. 1696) turned the attention of mathematicians to its +deviation from a spherical form. This astronomer, having been sent by +the Academy of Sciences of Paris to the island of Cayenne, in South +America, for the purpose of investigating the amount of astronomical +refraction and other astronomical objects, observed that his clock, +which had been regulated at Paris to beat seconds, lost about two +minutes and a half daily at Cayenne, and that in order to bring it to +measure mean solar time it was necessary to shorten the pendulum by more +than a line (about {1/12}th of an in.). This fact, which was scarcely +credited till it had been confirmed by the subsequent observations of +Varin and Deshayes on the coasts of Africa and America, was first +explained in the third book of Newton's _Principia_, who showed that it +could only be referred to a diminution of gravity arising either from a +protuberance of the equatorial parts of the earth and consequent +increase of the distance from the centre, or from the counteracting +effect of the centrifugal force. About the same time (1673) appeared +Christian Huygens' _De Horologio Oscillatorio_, in which for the first +time were found correct notions on the subject of centrifugal force. It +does not, however, appear that they were applied to the theoretical +investigation of the figure of the earth before the publication of +Newton's _Principia_. In 1690 Huygens published his _De Causa +Gravitatis_, which contains an investigation of the figure of the earth +on the supposition that the attraction of every particle is towards the +centre. + +Between 1684 and 1718 J. and D. Cassini, starting from Picard's base, +carried a triangulation northwards from Paris to Dunkirk and southwards +from Paris to Collioure. They measured a base of 7246 toises near +Perpignan, and a somewhat shorter base near Dunkirk; and from the +northern portion of the arc, which had an amplitude of 2 deg. 12' 9", +obtained for the length of a degree 56,960 toises; while from the +southern portion, of which the amplitude was 6 deg. 18' 57", they obtained +57,097 toises. The immediate inference from this was that, the degree +diminishing with increasing latitude, the earth must be a prolate +spheroid. This conclusion was totally opposed to the theoretical +investigations of Newton and Huygens, and accordingly the Academy of +Sciences of Paris determined to apply a decisive test by the measurement +of arcs at a great distance from each other--one in the neighbourhood of +the equator, the other in a high latitude. Thus arose the celebrated +expeditions of the French academicians. In May 1735 Louis Godin, Pierre +Bouguer and Charles Marie de la Condamine, under the auspices of Louis +XV., proceeded to Peru, where, assisted by two Spanish officers, after +ten years of laborious exertion, they measured an arc of 3 deg. 7', the +northern end near the equator. The second party consisted of Pierre +Louis Moreau de Maupertuis, Alexis Claude Clairault, Charles Etienne +Louis Camus, Pierre Charles Lemonnier, and Reginaud Outhier, who reached +the Gulf of Bothnia in July 1736; they were in some respects more +fortunate than the first party, inasmuch as they completed the +measurement of an arc near the polar circle of 57' amplitude and +returned within sixteen months from the date of their departure. + +The measurement of Bouguer and De la Condamine was executed with great +care, and on account of the locality, as well as the manner in which all +the details were conducted, it has always been regarded as a most +valuable determination. The southern limit was at Tarqui, the northern +at Cotchesqui. A base of 6272 toises was measured in the vicinity of +Quito, near the northern extremity of the arc, and a second base of 5260 +toises near the southern extremity. The mountainous nature of the +country made the work very laborious, in some cases the difference of +heights of two neighbouring stations exceeding 1 mile; and they had much +trouble with their instruments, those with which they were to determine +the latitudes proving untrustworthy. But they succeeded by simultaneous +observations of the same star at the two extremities of the arc in +obtaining very fair results. The whole length of the arc amounted to +176,945 toises, while the difference of latitudes was 3 deg. 7' 3". In +consequence of a misunderstanding that arose between De la Condamine and +Bouguer, their operations were conducted separately, and each wrote a +full account of the expedition. Bouguer's book was published in 1749; +that of De la Condamine in 1751. The toise used in this measure was +afterwards regarded as the standard toise, and is always referred to as +the _Toise of Peru_. + +The party of Maupertuis, though their work was quickly despatched, had +also to contend with great difficulties. Not being able to make use of +the small islands in the Gulf of Bothnia for the trigonometrical +stations, they were forced to penetrate into the forests of Lapland, +commencing operations at Tornea, a city situated on the mainland near +the extremity of the gulf. From this, the southern extremity of their +arc, they carried a chain of triangles northward to the mountain Kittis, +which they selected as the northern terminus. The latitudes were +determined by observations with a sector (made by George Graham) of the +zenith distance of [alpha] and [delta] Draconis. The base line was +measured on the frozen surface of the river Tornea about the middle of +the arc; two parties measured it separately, and they differed by about +4 in. The result of the whole was that the difference of latitudes of +the terminal stations was 57' 29" .6, and the length of the arc 55,023 +toises. In this expedition, as well as in that to Peru, observations +were made with a pendulum to determine the force of gravity; and these +observations coincided with the geodetic results in proving that the +earth was an oblate and not prolate spheroid. + +In 1740 was published in the Paris _Memoires_ an account, by Cassini de +Thury, of a remeasurement by himself and Nicolas Louis de Lacaille of +the meridian of Paris. With a view to determine more accurately the +variation of the degree along the meridian, they divided the distance +from Dunkirk to Collioure into four partial arcs of about two degrees +each, by observing the latitude at five stations. The results previously +obtained by J. and D. Cassini were not confirmed, but, on the contrary, +the length of the degree derived from these partial arcs showed on the +whole an increase with an increasing latitude. Cassini and Lacaille also +measured an arc of parallel across the mouth of the Rhone. The +difference of time of the extremities was determined by the observers at +either end noting the instant of a signal given by flashing gunpowder at +a point near the middle of the arc. + +While at the Cape of Good Hope in 1752, engaged in various astronomical +observations, Lacaille measured an arc of meridian of 1 deg. 13' 17", which +gave him for the length of the degree 57,037 toises--an unexpected +result, which has led to the remeasurement of the arc by Sir Thomas +Maclear (see GEODESY). + +Passing over the measurements made between Rome and Rimini and on the +plains of Piedmont by the Jesuits Ruggiero Giuseppe Boscovich and +Giovanni Battista Beccaria, and also the arc measured with deal rods in +North America by Charles Mason and Jeremiah Dixon, we come to the +commencement of the English triangulation. In 1783, in consequence of a +representation from Cassini de Thury on the advantages that would accrue +from the geodetic connexion of Paris and Greenwich, General William Roy +was, with the king's approval, appointed by the Royal Society to conduct +the operations on the part of England, Count Cassini, Mechain and +Delambre being appointed on the French side. A precision previously +unknown was attained by the use of Ramsden's theodolite, which was the +first to make the spherical excess of triangles measurable. The wooden +rods with which the first base was measured were replaced by glass rods, +which were afterwards rejected for the steel chain of Ramsden. (For +further details see _Account of the Trigonometrical Survey of England +and Wales_.) + +Shortly after this, the National Convention of France, having agreed to +remodel their system of weights and measures, chose for their unit of +length the ten-millionth part of the meridian quadrant. In order to +obtain this length precisely, the remeasurement of the French meridian +was resolved on, and deputed to J.B.J. Delambre and Pierre Francois +Andre Mechain. The details of this operation will be found in the _Base +du systeme metrique decimale_. The arc was subsequently extended by Jean +Baptiste Biot and Dominique Francois Jean Arago to the island of Iviza. +Operations for the connexion of England with the continent of Europe +were resumed in 1821 to 1823 by Henry Kater and Thomas Frederick Colby +on the English side, and F.J.D. Arago and Claude Louis Mathieu on the +French. + +The publication in 1838 of Friedrich Wilhelm Bessel's _Gradmessung in +Ostpreussen_ marks an era in the science of geodesy. Here we find the +method of least squares applied to the calculation of a network of +triangles and the reduction of the observations generally. The +systematic manner in which all the observations were taken with the view +of securing final results of extreme accuracy is admirable. The +triangulation, which was a small one, extended about a degree and a half +along the shores of the Baltic in a N.N.E. direction. The angles were +observed with theodolites of 12 and 15 in. diameter, and the latitudes +determined by means of the transit instrument in the prime vertical--a +method much used in Germany. (The base apparatus is described in the +article GEODESY.) + +The principal triangulation of Great Britain and Ireland, which was +commenced in 1783 under General Roy, for the more immediate purpose of +connecting the observatories of Greenwich and Paris, had been gradually +extended, under the successive direction of Colonel E. Williams, General +W. Mudge, General T.F. Colby, Colonel L.A. Hall, and Colonel Sir Henry +James; it was finished in 1851. The number of stations is about 250. At +32 of these the latitudes were determined with Ramsden's and Airy's +zenith sectors. The theodolites used for this work were, in addition to +the two great theodolites of Ramsden which were used by General Roy and +Captain Kater, a smaller theodolite of 18 in. diameter by the same +mechanician, and another of 24 in. diameter by Messrs Troughton and +Simms. Observations for determination of absolute azimuth were made with +those instruments at a large number of stations; the stars [alpha], +[delta], and [lambda] Ursae Minoris and 51 Cephei being those observed +always at the greatest azimuths. At six of these stations the probable +error of the result is under 0.4", at twelve under 0.5", at thirty-four +under 0.7": so that the absolute azimuth of the whole network is +determined with extreme accuracy. Of the seven base lines which have +been measured, five were by means of steel chains and two with Colby's +compensation bars (see GEODESY). The triangulation was computed by least +squares. The total number of equations of condition for the +triangulation is 920; if therefore the whole had been reduced in one +mass, as it should have been, the solution of an equation of 920 unknown +quantities would have occurred as a part of the work. To avoid this an +approximation was resorted to; the triangulation was divided into +twenty-one parts or figures; four of these, not adjacent, were first +adjusted by the method explained, and the corrections thus determined in +these figures carried into the equations of condition of the adjacent +figures. The average number of equations in a figure is 44; the largest +equation is one of 77 unknown quantities. The vertical limb of Airy's +zenith sector is read by four microscopes, and in the complete +observation of a star there are 10 micrometer readings and 12 level +readings. The instrument is portable; and a complete determination of +latitude, affected with the mean of the declination errors of two stars, +is effected by two micrometer readings and four level readings. The +observation consists in measuring with the telescope micrometer the +difference of zenith distances of two stars which cross the meridian, +one to the north and the other to the south of the observer at zenith +distances which differ by not much more than 10' or 15', the interval of +the times of transit being not less than one nor more than twenty +minutes. The advantages are that, with simplicity in the construction of +the instrument and facility in the manipulation, refraction is +eliminated (or nearly so, as the stars are generally selected within 25 deg. +of the zenith), and there is no large divided circle. The telescope, +which is counterpoised on one side of the vertical axis, has a small +circle for finding, and there is also a small horizontal circle. This +instrument is universally used in American geodesy. + + The principal work containing the methods and results of these + operations was published in 1858 with the title "Ordnance + Trigonometrical Survey of Great Britain and Ireland. Account of the + observations and calculations of the principal triangulation and of + the figure, dimensions and mean specific gravity of the earth as + derived therefrom. Drawn up by Captain Alexander Ross Clarke, R.E., + F.R.A.S., under the direction of Lieut.-Colonel H. James, R.E., + F.R.S., M.R.I.A., &c." A supplement appeared in 1862: "Extension of + the Triangulation of the Ordnance Survey into France and Belgium, with + the measurement of an arc of parallel in 52 deg. N. from Valentia in + Ireland to Mount Kemmel in Belgium. Published by ... Col. Sir Henry + James." + +Extensive operations for surveying India and determining the figure of +the earth were commenced in 1800. Colonel W. Lambton started the great +meridian arc at Punnae in latitude 8 deg. 9', and, following generally the +methods of the English survey, he carried his triangulation as far north +as 20 deg. 30'. The work was continued by Sir George (then Captain) Everest, +who carried it to the latitude of 29 deg. 30'. Two admirable volumes by Sir +George Everest, published in 1830 and in 1847, give the details of this +undertaking. The survey was afterwards prosecuted by Colonel T.T. +Walker, R.E., who made valuable contributions to geodesy. The working +out of the Indian chains of triangle by the method of least squares +presents peculiar difficulties, but, enormous in extent as the work was, +it has been thoroughly carried out. The ten base lines on which the +survey depends were measured with Colby's compensation bars. + + The survey is detailed in eighteen volumes, published at Dehra Dun, + and entitled _Account of the Operations of the Great Trigonometrical + Survey of India_. Of these the first nine were published under the + direction of Colonel Walker; and the remainder by Colonels Strahan and + St G.C. Gore, Major S.G. Burrard and others. Vol. i., 1870, treats of + the base lines; vol. ii., 1879, history and general descriptions of + the principal triangulation and of its reduction; vol. v., 1879, + pendulum operations (Captains T.P. Basevi and W.T. Heaviside); vols. + xi., 1890, and xviii., 1906, latitudes; vols. ix., 1883, x., 1887, + xv., 1893, longitudes; vol. xvii., 1901, the Indo-European + longitude-arcs from Karachi to Greenwich. The other volumes contain + the triangulations. + +In 1860 Friedrich Georg Wilhelm Struve published his _Arc du meridien de +25 deg. 20' entre le Danube et la Mer Glaciale mesure depuis 1816 jusqu'en +1855_. The latitudes of the thirteen astronomical stations of this arc +were determined partly with vertical circles and partly by means of the +transit instrument in the prime vertical. The triangulation, a great +part of which, however, is a simple chain of triangles, is reduced by +the method of least squares, and the probable errors of the resulting +distances of parallels is given; the probable error of the whole arc in +length is +- 6.2 toises. Ten base lines were measured. The sum of the +lengths of the ten measured bases is 29,863 toises, so that the average +length of a base line is 19,100 ft. The azimuths were observed at +fourteen stations. In high latitudes the determination of the meridian +is a matter of great difficulty; nevertheless the azimuths at all the +northern stations were successfully determined,--the probable error of +the result at Fuglenaes being +- 0".53. + +Before proceeding with the modern developments of geodetic measurements +and their application to the figure of the earth, we must discuss the +"mechanical theory," which is indispensable for a full understanding of +the subject. + + +_Mechanical Theory._ + +Newton, by applying his theory of gravitation, combined with the +so-called centrifugal force, to the earth, and assuming that an oblate +ellipsoid of rotation is a form of equilibrium for a homogeneous fluid +rotating with uniform angular velocity, obtained the ratio of the axes +229:230, and the law of variation of gravity on the surface. A few years +later Huygens published an investigation of the figure of the earth, +supposing the attraction of every particle to be towards the centre of +the earth, obtaining as a result that the proportion of the axes should +be 578 : 579. In 1740 Colin Maclaurin, in his _De causa physica fluxus +et refluxus maris_, demonstrated that the oblate ellipsoid of revolution +is a figure which satisfies the conditions of equilibrium in the case of +a revolving homogeneous fluid mass, whose particles attract one another +according to the law of the inverse square of the distance; he gave the +equation connecting the ellipticity with the proportion of the +centrifugal force at the equator to gravity, and determined the +attraction on a particle situated anywhere on the surface of such a +body. In 1743 Clairault published his _Theorie de la figure de la +terre_, which contains a remarkable theorem ("Clairault's Theorem"), +establishing a relation between the ellipticity of the earth and the +variation of gravity from the equator to the poles. Assuming that the +earth is composed of concentric ellipsoidal strata having a common axis +of rotation, each stratum homogeneous in itself, but the ellipticities +and densities of the successive strata varying according to any law, and +that the superficial stratum has the same form as if it were fluid, he +proved that + + g'- g 5 + ----- + e = -- m, + g 2 + +where g, g' are the amounts of gravity at the equator and at the pole +respectively, e the ellipticity of the meridian (or "flattening"), and m +the ratio of the centrifugal force at the equator to g. He also proved +that the increase of gravity in proceeding from the equator to the poles +is as the square of the sine of the latitude. This, taken with the +former theorem, gives the means of determining the earth's ellipticity +from observation of the relative force of gravity at any two places. +P.S. Laplace, who devoted much attention to the subject, remarks on +Clairault's work that "the importance of all his results and the +elegance with which they are presented place this work amongst the most +beautiful of mathematical productions" (Isaac Todhunter's _History of +the Mathematical Theories of Attraction and the Figure of the Earth_, +vol. i. p. 229). + +The problem of the figure of the earth treated as a question of +mechanics or hydrostatics is one of great difficulty, and it would be +quite impracticable but for the circumstance that the surface differs +but little from a sphere. In order to express the forces at any point of +the body arising from the attraction of its particles, the form of the +surface is required, but this form is the very one which it is the +object of the investigation to discover; hence the complexity of the +subject, and even with all the present resources of mathematicians only +a partial and imperfect solution can be obtained. + + We may here briefly indicate the line of reasoning by which some of + the most important results may be obtained. If X, Y, Z be the + components parallel to three rectangular axes of the forces acting on + a particle of a fluid mass at the point x, y, z, then, p being the + pressure there, and [rho] the density, + + dp = [rho](Xdx + Ydy + Zdz); + + and for equilibrium the necessary conditions are, that [rho](Xdx + Ydy + + Zdz) be a complete differential, and at the free surface Xdx + Ydy + + Zdz = 0. This equation implies that the resultant of the forces is + normal to the surface at every point, and in a homogeneous fluid it is + obviously the differential equation of all surfaces of equal pressure. + If the fluid be heterogeneous then it is to be remarked that for + forces of attraction according to the ordinary law of gravitation, if + X, Y, Z be the components of the attraction of a mass whose potential + is V, then + + dV dV dV + Xdx + Ydy + Zdz = --dx + --dy + --dz, + dx dy dz + + which is a complete differential. And in the case of a fluid rotating + with uniform velocity, in which the so-called centrifugal force enters + as a force acting on each particle proportional to its distance from + the axis of rotation, the corresponding part of Xdx + Ydy + Zdz is + obviously a complete differential. Therefore for the forces with which + we are now concerned Xdx + Ydy + Zdz = dU, where U is some function of + x, y, z, and it is necessary for equilibrium that dp = [rho]dU be a + complete differential; that is, [rho] must be a function of U or a + function of p, and so also p a function of U. So that dU = 0 is the + differential equation of surfaces of equal pressure and density. + + We may now show that a homogeneous fluid mass in the form of an oblate + ellipsoid of revolution having a uniform velocity of rotation can be + in equilibrium. It may be proved that the attraction of the ellipsoid + x squared + y squared + z squared(1 + [epsilon] squared) = c squared(1 + [epsilon] squared); upon a particle P + of its mass at x, y, z has for components + + X = -Ax, Y = -Ay, Z = -Cz, + + where + + /1 + [epsilon] squared 1 \ + A = 2[pi]k squared[rho]( ------------- tan^(-1) [epsilon] - -------- ), + \ [epsilon] cubed [epsilon] squared/ + + /1 + [epsilon] squared 1 + [epsilon] squared \ + C = 4[pi]k squared[rho]( -------------- - ------------- tan^(-1) [epsilon] ), + \ [epsilon] squared [epsilon] cubed / + + and k squared the constant of attraction. Besides the attraction of the mass + of the ellipsoid, the centrifugal force at P has for components + + x[omega] squared, + y[omega] squared, 0; then the condition of fluid equilibrium is + + (A - [omega] squared)xdx + (A - [omega] squared)ydy + Czdz = 0, + + which by integration gives + + (A - [omega] squared)(x squared + y squared) + Cz squared = constant. + + This is the equation of an ellipsoid of rotation, and therefore the + equilibrium is possible. The equation coincides with that of the + surface of the fluid mass if we make + + A - [omega] squared = C/(1 + [epsilon] squared), + + which gives + + [omega] squared 3 + [epsilon] squared 3 + ------------ = -------------- tan^(-1) [epsilon] - ---------- . + 2[pi]k squared[rho] [epsilon] cubed [epsilon] squared + + In the case of the earth, which is nearly spherical, we obtain by + expanding the expression for [omega] squared in powers of [epsilon] squared, + rejecting the higher powers, and remarking that the ellipticity e = + 1/2[epsilon] squared, + + [omega] squared/2[pi]k squared[rho] = 4[epsilon] squared/15 = 8e/15. + + Now if m be the ratio of the centrifugal force to the intensity of + gravity at the equator, and a = c(1 + e), then + + m = a[omega] squared,/(4/3)[pi]k squared[rho]a, :. [omega] squared/2[pi]k squared[rho] = (2/3)m. + + In the case of the earth it is a matter of observation that m = + 1/289, hence the ellipticity + + e = 5m/4 = 1/231, + + so that the ratio of the axes on the supposition of a homogeneous + fluid earth is 230:231, as stated by Newton. + + Now, to come to the case of a heterogeneous fluid, we shall assume + that its surfaces of equal density are spheroids, concentric and + having a common axis of rotation, and that the ellipticity of these + surfaces varies from the centre to the outer surface, the density also + varying. In other words, the body is composed of homogeneous + spheroidal shells of variable density and ellipticity. On this + supposition we shall express the attraction of the mass upon a + particle in its interior, and then, taking into account the + centrifugal force, form the equation expressing the condition of fluid + equilibrium. The attraction of the homogeneous spheroid x squared + y squared + z squared(1 + + 2e) = c squared(1 + 2e), where e is the ellipticity (of which the square is + neglected), on an internal particle, whose co-ordinates are x = f, y = + 0, z = h, has for its x and z components + + X' = -(4/3)[pi]k squared[rho]f(1 - (2/5)e), + Z' = -(4/3)[pi]k squared[rho]h(1 + (4/5)e), + + the Y component being of course zero. Hence we infer that the + attraction of a shell whose inner surface has an ellipticity e, and + its outer surface an ellipticity e + de, the density being [rho], is + expressed by + + dX' = (4/3).(2/5)[pi]k squared[rho]f de, dZ' = -(4/3).(4/5)[pi]k squared[rho]h de. + + To apply this to our heterogeneous spheroid; if we put c1 for the + semiaxis of that surface of equal density on which is situated the + attracted point P, and c0 for the semiaxis of the outer surface, the + attraction of that portion of the body which is exterior to P, namely, + of all the shells which enclose P, has for components + _ _ + 8 /c0 de 16 /c0 de + X0 = --[pi]k squaredf | [rho] --dc, Z0 = - -- [pi]k squaredh | [rho] --dc, + 15 _/c1 dc 15 _/c1 dc + + both e and [rho] being functions of c. Again the attraction of a + homogeneous spheroid of density [rho] on an _external_ point f, h has + the components + + X" = -(4/3)[pi]k squared[rho]fr^(-3) {c cubed(1 + 2e) - [lambda]ec^5}, + Z" = -(4/3)[pi]k squared[rho]hr^(-3) {c cubed(1 + 2e) - [lambda]'ec^5}, + + where [lambda] = (3/5)(4h squared - f squared)/r^4, + [lambda]' = (3/5)(2h squared - 3f squared)/r^4, and r squared = f squared + h squared. + + Now e being considered a function of c, we can at once express the + attraction of a shell (density [rho]) contained between the surface + defined by c + dc, e + de and that defined by c, e upon an external + point; the differentials with respect to c, viz. dX" dZ", must then + be integrated with [rho] under the integral sign as being a function + of c. The integration will extend from c = 0 to c = c1. Thus the + components of the attraction of the heterogeneous spheroid upon a + particle within its mass, whose co-ordinates are f, 0, h, are + _ _ + 4 | 1 /c1 + X = - -- [pi]k squaredf | -- | [rho] d{c cubed(1 + 2e)} + 3 |_r cubed _/0 + + _ _ _ + [lambda] /c1 2 /c1 | + - -------- | [rho] d(ec^5) - -- | [rho] de |, + r cubed _/0 5 _/0 _| + _ _ + 4 | 1 /c1 + Z = - -- [pi]k squaredh | -- | [rho] d{c cubed(1 + 2e)} + 3 |_r cubed _/0 + + _ _ _ + [lambda]'/c1 4 /c1 | + - -------- | [rho] d(ec^5) + -- | [rho] de |. + r cubed _/0 5 _/0 _| + + We take into account the rotation of the earth by adding the + centrifugal force f[omega] squared = F to X. Now, the surface of constant + density upon which the point f, 0, h is situated gives (1 - 2e) fdf + + hdh = 0; and the condition of equilibrium is that (X + F)df + Zdh = 0. + Therefore, + + (X + F)h = Zf(1 - 2e), + + which, neglecting small quantities of the order e squared and putting + [omega] squaredt squared = 4[pi] squaredk squared, gives + _ _ _ + 2e /c1 6 /c1 6 /c0 3[pi] + -- | [rho]d{c cubed(1 + 2e)} - ---- | [rho]d(ec^5) - -- | [rho]de = -----. + r cubed_/0 5r^5 _/0 5 _/c1 t squared + + Here we must now put c for c1, c for r; and 1 + 2e under the first + integral sign may be replaced by unity, since small quantities of the + second order are neglected. Two differentiations lead us to the + following very important differential equation (Clairault): + + d squarede 2[rho]c squared de / 2[rho]c 6 \ + --- + -------------- . -- + ( -------------- - -- ) e = 0. + dc squared [int][rho]c squareddc dc \[int][rho]c squareddc c squared/ + + When [rho] is expressed in terms of c, this equation can be + integrated. We infer then that a rotating spheroid of very small + ellipticity, composed of fluid homogeneous strata such as we have + specified, will be in equilibrium; and when the law of the density is + expressed, the law of the corresponding ellipticities will follow. + + If we put M for the mass of the spheroid, then + _ + 4[pi] /c c cubed 4[pi] squared + M = ----- | [rho]d{c cubed(1 + 2e)}; and m = --- . -----, + 3 _/0 M t squared + + and putting c = c0 in the equation expressing the condition of + equilibrium, we find + _ + 4 6 /c + M(2e - m) = -- [pi].--- | [rho]d(ec^5). + 3 5c squared_/0 + + Making these substitutions in the expressions for the forces at the + surface, and putting r/c = 1 + e - e(h/c) squared, we get + _ _ + Mk squared | 3 /5 \ h squared | f + G cos [phi] = --- | 1 - e - -- m + ( - m - 2e) -- | -- + ac |_ 2 \2 / c squared_| c + _ _ + Mk squared | 3 /5 \ h squared | h + G sin [phi] = --- | 1 + e - -- m + ( - m - 2e) -- | --. + ac |_ 2 \2 / c squared_| c + + Here G is gravity in the latitude [phi], and a the radius of the + equator. Since + + sec [phi] = (c/f){1 + e + (eh squared/c squared)}, + _ _ + Mk squared | 3 /5 \ | + G = --- | 1 - -- m + ( -- m - e) sin squared [phi] |, + ac |_ 2 \2 / _| + + an expression which contains the theorems we have referred to as + discovered by Clairault. + + The theory of the figure of the earth as a rotating ellipsoid has been + especially investigated by Laplace in his _Mecanique celeste_. The + principal English works are:--Sir George Airy, _Mathematical Tracts_, + a lucid treatment without the use of Laplace's coefficients; + Archdeacon Pratt's _Attractions and Figure of the Earth_; and + O'Brien's _Mathematical Tracts_; in the last two Laplace's + coefficients are used. + +In 1845 Sir G.G. Stokes (_Camb. Trans._ viii.; see also _Camb. Dub. +Math. Journ._, 1849, iv.) proved that if the external form of the +sea--imagined to percolate the land by canals--be a spheroid with small +ellipticity, then the law of gravity is that which we have shown above; +his proof required no assumption as to the ellipticity of the internal +strata, or as to the past or present fluidity of the earth. This +investigation admits of being regarded conversely, viz. as determining +the elliptical form of the earth from measurements of gravity; if G, the +observed value of gravity in latitude [phi], be expressed in the form G += g(1 + ss sin squared [phi]), where g is the value at the equator and ss a +coefficient. In this investigation, the square and higher powers of the +ellipticity are neglected; the solution was completed by F.R. Helmert +with regard to the square of the ellipticity, who showed that a term +with sin squared 2[phi] appeared (see Helmert, _Geodaesie_, ii. 83). For the +coefficient of this term, the gravity measurements give a small but not +sufficiently certain value; we therefore assume a value which agrees +best with the hypothesis of the fluid state of the entire earth; this +assumption is well supported, since even at a depth of only 50 km. the +pressure of the superincumbent crust is so great that rocks become +plastic, and behave approximately as fluids, and consequently the crust +of the earth floats, to some extent, on the interior (even though this +may not be fluid in the usual sense of the word). This is the geological +theory of "Isostasis" (cf. GEOLOGY); it agrees with the results of +measurements of gravity (_vide infra_), and was brought forward in the +middle of the 19th century by J.H. Pratt, who deduced it from +observations made in India. + +The sin squared 2[phi] term in the expression for G, and the corresponding +deviation of the meridian from an ellipse, have been analytically +established by Sir G.H. Darwin and E. Wiechert; earlier and less +complete investigations were made by Sir G.B. Airy and O. Callandreau. +In consequence of the sin squared 2[phi] term, two parameters of the level +surfaces in the interior of the earth are to be determined; for this +purpose, Darwin develops two differential equations in the place of the +one by Clairault. By assuming Roche's law for the variation of the +density in the interior of the Earth, viz. [rho] = [rho]1 - k(c/c1) squared, k +being a coefficient, it is shown that in latitude 45 deg., the meridian is +depressed about 31/4 metres from the ellipse, and the coefficient of the +term sin squared [phi] cos squared [phi] (= 1/4 sin squared 2[phi]) is -0.0000295. According to +Wiechert the earth is composed of a kernel and a shell, the kernel being +composed of material, chiefly metallic iron, of density near 8.2, and +the shell, about 900 miles thick, of silicates, &c., of density about +3.2. On this assumption the depression in latitude 45 deg. is 23/4 metres, and +the coefficient of sin squared [phi] cos squared [phi] is, in round numbers, +-0.0000280.[2] To this additional term in the formula for G, there +corresponds an extension of Clairault's formula for the calculation of +the flattening from ss with terms of the higher orders; this was first +accomplished by Helmert. + +For a long time the assumption of an ellipsoid with three unequal axes +has been held possible for the figure of the earth, in consequence of an +important theorem due to K.G. Jacobi, who proved that for a homogeneous +fluid in rotation a spheroid is not the only form of equilibrium; an +ellipsoid rotating round its least axis may with certain proportions of +the axes and a certain time of revolution be a form of equilibrium.[3] +It has been objected to the figure of three unequal axes that it does +not satisfy, in the proportions of the axes, the conditions brought out +in Jacobi's theorem (c: a < 1/[root]2). Admitting this, it has to be +noted, on the other hand, that Jacobi's theorem contemplates a +homogeneous fluid, and this is certainly far from the actual condition +of our globe; indeed the irregular distribution of continents and oceans +suggests the possibility of a sensible divergence from a perfect surface +of revolution. We may, however, assume the ellipsoid with three unequal +axes to be an interpolation form. More plausible forms are little +adapted for computation.[4] Consequently we now generally take the +ellipsoid of rotation as a basis, especially so because measurements of +gravity have shown that the deviation from it is but trifling. + + +_Local Attraction._ + +In speaking of the figure of the earth, we mean the surface of the sea +imagined to percolate the continents by canals. That this surface +should turn out, after precise measurements, to be exactly an ellipsoid +of revolution is _a priori_ improbable. Although it may be highly +probable that originally the earth was a fluid mass, yet in the cooling +whereby the present crust has resulted, the actual solid surface has +been left most irregular in form. It is clear that these irregularities +of the visible surface must be accompanied by irregularities in the +mathematical figure of the earth, and when we consider the general +surface of our globe, its irregular distribution of mountain masses, +continents, with oceans and islands, we are prepared to admit that the +earth may not be precisely any surface of revolution. Nevertheless, +there must exist some spheroid which agrees very closely with the +mathematical figure of the earth, and has the same axis of rotation. We +must conceive this figure as exhibiting slight departures from the +spheroid, the two surfaces cutting one another in various lines; thus a +point of the surface is defined by its latitude, longitude, and its +height above the "spheroid of reference." Calling this height N, then of +the actual magnitude of this quantity we can generally have no +information, it only obtrudes itself on our notice by its variations. In +the vicinity of mountains it may change sign in the space of a few +miles; N being regarded as a function of the latitude and longitude, if +its differential coefficient with respect to the former be zero at a +certain point, the normals to the two surfaces then will lie in the +prime vertical; if the differential coefficient of N with respect to the +longitude be zero, the two normals will lie in the meridian; if both +coefficients are zero, the normals will coincide. The comparisons of +terrestrial measurements with the corresponding astronomical +observations have always been accompanied with discrepancies. Suppose A +and B to be two trigonometrical stations, and that at A there is a +disturbing force drawing the vertical through an angle [delta], then it +is evident that the apparent zenith of A will be really that of some +other place A', whose distance from A is r[delta], when r is the earth's +radius; and similarly if there be a disturbance at B of the amount +[delta]', the apparent zenith of B will be really that of some other +place B', whose distance from B is r[delta]'. Hence we have the +discrepancy that, while the geodetic measurements deal with the points A +and B, the astronomical observations belong to the points A', B'. Should +[delta], [delta]' be equal and parallel, the displacements AA', BB' will +be equal and parallel, and no discrepancy will appear. The +non-recognition of this circumstance often led to much perplexity in the +early history of geodesy. Suppose that, through the unknown variations +of N, the probable error of an observed latitude (that is, the angle +between the normal to the mathematical surface of the earth at the given +point and that of the corresponding point on the spheroid of reference) +be [epsilon], then if we compare two arcs of a degree each in mean +latitudes, and near each other, say about five degrees of latitude +apart, the probable error of the resulting value of the ellipticity will +be approximately +- 1/500[epsilon], [epsilon] being expressed in +seconds, so that if [epsilon] be so great as 2" the probable error of +the resulting ellipticity will be greater than the ellipticity itself. + +It is necessary at times to calculate the attraction of a mountain, and +the consequent disturbance of the astronomical zenith, at any point +within its influence. The deflection of the plumb-line, caused by a +local attraction whose amount is k squaredA[delta], is measured by the ratio of +k squaredA[delta] to the force of gravity at the station. Expressed in seconds, +the deflection [Lambda] is + + [Lambda] = 12".447A[delta]/[rho], + +where [rho] is the mean density of the earth, [delta] that of the +attracting mass, and A = [f]s^(-3)xdv, in which dv is a volume element +of the attracting mass within the distance s from the point of +deflection, and x the projection of s on the horizontal plane through +this point, the linear unit in expressing A being a mile. Suppose, for +instance, a table-land whose form is a rectangle of 12 miles by 8 miles, +having a height of 500 ft. and density half that of the earth; let the +observer be 2 miles distant from the middle point of the longer side. +The deflection then is 1".472; but at 1 mile it increases to 2".20. + +At sixteen astronomical stations in the English survey the disturbance +of latitude due to the form of the ground has been computed, and the +following will give an idea of the results. At six stations the +deflection is under 2", at six others it is between 2" and 4", and at +four stations it exceeds 4". There is one very exceptional station on +the north coast of Banffshire, near the village of Portsoy, at which the +deflection amounts to 10", so that if that village were placed on a map +in a position to correspond with its astronomical latitude, it would be +1000 ft. out of position! There is the sea to the north and an +undulating country to the south, which, however, to a spectator at the +station does not suggest any great disturbance of gravity. A somewhat +rough estimate of the local attraction from external causes gives a +maximum limit of 5", therefore we have 5" which must arise from +unequal density in the underlying strata in the surrounding country. In +order to throw light on this remarkable phenomenon, the latitudes of a +number of stations between Nairn on the west, Fraserburgh on the east, +and the Grampians on the south, were observed, and the local deflections +determined. It is somewhat singular that the deflections diminish in all +directions, not _very_ regularly certainly, and most slowly in a +south-west direction, finally disappearing, and leaving the maximum at +the original station at Portsoy. + +The method employed by Dr C. Hutton for computing the attraction of +masses of ground is so simple and effectual that it can hardly be +improved on. Let a horizontal plane pass through the given station; let +r, [theta] be the polar co-ordinates of any point in this plane, and r, +[theta], z, the co-ordinates of a particle of the attracting mass; and +let it be required to find the attraction of a portion of the mass +contained between the horizontal planes z = 0, z = h, the cylindrical +surfaces r = r1, r = r2, and the vertical planes [theta] = [theta]1, +[theta] = [theta]2. The component of the attraction at the station or +origin along the line [theta] = 0 is + _ _ _ + /r2 /[theta]2 /h r squaredcos [theta] + k squared[delta] | | | ------------- dr d[theta] dz + _/r1 _/[theta]1 _/0 (r squared+z squared)^(3/2) + + = k squared[delta]h(sin[theta]2 - sin[theta]1) log{r2 + (r2 squared + h squared)^(1/2)/r1 + (r1 squared + h squared)^(1/2)}. + +By taking r2 - r1, sufficiently small, and supposing h also small +compared with r1 + r2 (as it usually is), the attraction is + + k squared[delta](r2 - r1)(sin [theta]2 - sin [theta]1)h/r, + +where r= 1/2(r1 + r2). This form suggests the following procedure. Draw on +the contoured map a series of equidistant circles, concentric with the +station, intersected by radial lines so disposed that the sines of their +azimuths are in arithmetical progression. Then, having estimated from +the map the mean heights of the various compartments, the calculation is +obvious. + +In mountainous countries, as near the Alps and in the Caucasus, +deflections have been observed to the amount of as much as 30", while +in the Himalayas deflections amounting to 60" were observed. On the +other hand, deflections have been observed in flat countries, such as +that noted by Professor K.G. Schweizer, who has shown that, at certain +stations in the vicinity of Moscow, within a distance of 16 miles the +plumb-line varies 16" in such a manner as to indicate a vast deficiency +of matter in the underlying strata; deflections of 10" were observed in +the level regions of north Germany. + +Since the attraction of a mountain mass is expressed as a numerical +multiple of [delta] : [rho] the ratio of the density of the mountain to +that of the earth, if we have any independent means of ascertaining the +amount of the deflection, we have at once the ratio [rho]:[delta], and +thus we obtain the mean density of the earth, as, for instance, at +Schiehallion, and afterwards at Arthur's Seat. Experiments of this kind +for determining the mean density of the earth have been made in greater +numbers; but they are not free from objection (see GRAVITATION). + +Let us now consider the perturbation attending a spherical subterranean +mass. A compact mass of great density at a small distance under the +surface of the earth will produce an elevation of the mathematical +surface which is expressed by the formula + + y = a mu((1 - 2u cos [theta] + u squared)^(-1/2) - 1), + +where a is the radius of the (spherical) earth, a(1 - u) the distance +of the disturbing mass below the surface, mu the ratio of the disturbing +mass to the mass of the earth, and a[theta] the distance of any point on +the surface from that point, say Q, which is vertically over the +disturbing mass. The maximum value of y is at Q, where it is y = a muu(1 +-u). The deflection at the distance a[theta] is [Lambda] = muu +sin[theta](1 - 2u cos[theta] + u squared)^(-3/2), or since [theta] is small, +putting h + u = 1, we have [Lambda] = mu[theta](h squared + [theta] squared)^(-3/2). +The maximum deflection takes place at a point whose distance from Q is +to the depth of the mass as 1:[root]2, and its amount is 2 mu/3 +[root](3h squared). If, for instance, the disturbing mass were a sphere a mile +in diameter, the excess of its density above that of the surrounding +country being equal to half the density of the earth, and the depth of +its centre half a mile, the greatest deflection would be 5", and the +greatest value of y only two inches. Thus a large disturbance of gravity +may arise from an irregularity in the mathematical surface whose actual +magnitude, as regards height at least, is extremely small. + +The effect of the disturbing mass mu on the vibrations of a pendulum +would be a maximum at Q; if v be the number of seconds of time gained +per diem by the pendulum at Q, and [sigma] the number of seconds of +angle in the maximum deflection, then it may be shown that v/[sigma] = +[pi][root]3/10. + +The great Indian survey, and the attendant measurements of the degree of +latitude, gave occasion to elaborate investigations of the deflection of +the plumb-line in the neighbourhood of the high plateaus and mountain +chains of Central Asia. Archdeacon Pratt (_Phil. Trans._, 1855 and +1857), in instituting these investigations, took into consideration the +influence of the apparent diminution of the mass of the earth's crust +occasioned by the neighbouring ocean-basins; he concluded that the +accumulated masses of mountain chains, &c., corresponded to subterranean +mass diminutions, so that over any level surface in a fixed depth +(perhaps 100 miles or more) the masses of prisms of equal section are +equal. This is supported by the gravity measurements at More in the +Himalayas at a height of 4696 metres, which showed no deflection due to +the mountain chain (_Phil. Trans._, 1871); more recently, H.A. Faye +(_Compt. rend._, 1880) arrived at the same conclusion for the entire +continent. + +This compensation, however, must only be regarded as a general +principle; in certain cases, the compensating masses show marked +horizontal displacements. Further investigations, especially of gravity +measurements, will undoubtedly establish other important facts. Colonel +S.G. Burrard has recently recalculated, with the aid of more exact data, +certain Indian deviations of the plumb-line, and has established that in +the region south of the Himalayas (lat. 24 deg.) there is a subterranean +perturbing mass. The extent of the compensation of the high mountain +chains is difficult to recognize from the latitude observations, since +the same effect may result from different causes; on the other hand, +observations of geographical longitude have established a strong +compensation.[5] + + +_Meridian Arcs._ + +The astronomical stations for the measurement of the degree of latitude +will generally lie not exactly on the same meridian; and it is therefore +necessary to calculate the arcs of meridian M which lie between the +latitude of neighbouring stations. If S be the geodetic line calculated +from the triangulation with the astronomically determined azimuths +[alpha]1 and [alpha]2, then + _ _ + cos [alpha] | 1 S squared | + M = S ------------------- | 1 + -- -------- sin squared [alpha] ... |, + cos 1/2[Delta][alpha] |_ 12 [alpha] squared _| + +in which 2[alpha] = [alpha]1 + [alpha]2 - 180 deg., [Delta][alpha] = +[alpha]2 - [alpha]1 - 180 deg.. + +The length of the arc of meridian between the latitudes [phi]1 and +[phi]2 is + + _[phi]2 _[phi]2 + / / (1 - e squared)d[phi] + M = | [rho]d[phi] = [alpha] | ----------------------- + _/ _/ (1 - e squaredsin squared[phi])^(3/2) + [phi]1 [phi]1 + +where a squarede squared = a squared - b squared; instead of using the eccentricity e, put the ratio +of the axes b:a = 1 - n:1 + n, then + + _[phi]2 + / b(1 + n)(1 - n squared)d[phi] + M = | ------------------------------. + _/ (1 + 2n cos 2[phi] + n squared)^(3/2) + [phi]1 + +This, after integration, gives + + / 5 5 \ / 21 \ + M/b = ( 1 + n + -n squared + -n cubed) [alpha]0 - ( 3n + 3n squared + --n cubed) [alpha]1 + \ 4 4 / \ 8 / + + /15 15 \ /35 \ + + ( --n squared + --n cubed) [alpha]2 - ( --n cubed ) [alpha]3, + \ 8 8 / \24 / + +where + + [alpha]0 = [phi]2 - [phi]1 + [alpha]1 = sin ([phi]2 - [phi]1) cos ([phi]2 + [phi]1) + [alpha]2 = sin 2([phi]2 - [phi]1) cos 2([phi]2 + [phi]1) + [alpha]3 = sin 3([phi]2 - [phi]1) cos 3([phi]2 + [phi]1). + +The part of M which depends on n cubed is very small; in fact, if we +calculate it for one of the longest arcs measured, the Russian arc, it +amounts to only an inch and a half, therefore we omit this term, and put +for M/b the value + + / 5 \ /15 \ + (l + n + --n squared) [alpha]0 - (3n + 3n squared) [alpha]1 + ( --n squared) [alpha]2. + \ 4 / \ 8 / + +Now, if we suppose the observed latitudes to be affected with errors, +and that the true latitudes are [phi]1 + x1, [phi]2 + x2; and if further +we suppose that n1 + dn is the true value of a - b:a + b, and that n1 +itself is merely a very approximate numerical value, we get, on making +these substitutions and neglecting the influence of the corrections x on +the _position_ of the arc in latitude, i.e. on [phi]1 + [phi]2, + + / 5 \ / \ /15 \ + M/b = ( 1 + n + --n1 squared)[alpha]0 - (3n1 + 3n1 squared)[alpha]1 + ( --n1 squared)[alpha]2 + \ 4 / \ / \8 / + _ _ + | / 5 \ / \ /15 \ | + + | ( 1 + -- n1 )a0 - ( 3 + 6n1 )a1 + ( -- n1 )a2 | dn + |_ \ 2 / \ / \4 / _| + _ _ + | da1 | + + | 1 + n1 - 3n --- | da0; + |_ da0_| + +here da0 = x2 - x1; and as b is only known approximately, put b = b1(1 + +u); then we get, after dividing through by the coefficient of da0, which +is = 1 + n1 - 3n1 cos([phi]2 - [phi]1) cos([phi]2 + [phi]1), an equation +of the form x2 = x1 + h + fu + gv, where for convenience we put v for +dn. + +Now in every measured arc there are not only the extreme stations +determined in latitude, but also a number of intermediate stations so +that if there be i + 1 stations there will be i equations + + x2 = x1 + f1u + g1v + h1 + x3 = x1 + f2u + g2v + h2 + : : : + : : : + x_i = x1 + f_iu + g_iv + h_i + +In combining a number of different arcs of meridian, with the view of +determining the figure of the earth, each arc will supply a number of +equations in u and v and the corrections to its observed latitudes. +Then, according to the method of least squares, those values of u and v +are the most probable which render the sum of the squares of _all_ the +errors x a minimum. The corrections x which are here applied arise not +from errors of observation only. The mere uncertainty of a latitude, as +determined with modern instruments, does not exceed a very small +fraction of a second as far as errors of observation go, but no accuracy +in observing will remove the error that may arise from local attraction. +This, as we have seen, may amount to some seconds, so that the +corrections x to the observed latitudes are attributable to local +attraction. Archdeacon Pratt objected to this mode of applying least +squares first used by Bessel; but Bessel was right, and the objection is +groundless. Bessel found, in 1841, from ten meridian arcs with a total +amplitude of 50 deg..6: + + a = 3272077 toises = 6377397 metres. + e (ellipticity) = (a - b)/a = 1/299.15 (prob. error +- 3.2). + +The probable error in the length of the earth's quadrant is +- 336 m. + +We now give a series of some meridian-arcs measurements, which were +utilized in 1866 by A.R. Clarke in the _Comparisons of the Standards of +Length_, pp. 280-287; details of the calculations are given by the same +author in his _Geodesy_ (1880), pp. 311 et seq. + +The data of the French arc from Formentera to Dunkirk are-- + + Stations. Astronomical Distance of + Latitudes. Parallels. + deg. ' " Ft. + Formentera 38 39 53.17 .. + Mountjouy 41 21 44.96 982671.04 + Barcelona 41 22 47.90 988701.92 + Carcassonne 43 12 54.30 1657287.93 + Pantheon 48 50 47.98 3710827.13 + Dunkirk 51 2 8.41 4509790.84 + +The distance of the parallels of Dunkirk and Greenwich, deduced from the +extension of the triangulation of England into France, in 1862, is +161407.3 ft., which is 3.9 ft. greater than that obtained from Captain +Kater's triangulation, and 3.2 ft. less than the distance calculated by +Delambre from General Roy's triangulation. The following table shows the +data of the English arc with the distances in standard feet from +Formentera. + + deg. ' " Ft. + Formentera .. .. + Greenwich 51 28 38.30 4671198.3 + Arbury 52 13 26.59 4943837.6 + Clifton 53 27 29.50 5394063.4 + Kellie Law 56 14 53.60 6413221.7 + Stirling 57 27 49.12 6857323.3 + Saxavord 60 49 37.21 8086820.7 + +The latitude assigned in this table to Saxavord is not the directly +observed latitude, which is 60 deg. 49' 38.58", for there are here a +cluster of three points, whose latitudes are astronomically determined; +and if we transfer, by means of the geodesic connexion, the latitude of +Gerth of Scaw to Saxavord, we get 60 deg. 49' 36.59"; and if we similarly +transfer the latitude of Balta, we get 60 deg. 49' 36.46". The mean of +these three is that entered in the above table. + +For the Indian arc in long. 77 deg. 40' we have the following data:-- + + deg. ' " Ft. + Punnea 8 9 31.132 .. + Putchapolliam 10 59 42.276 1029174.9 + Dodagunta 12 59 52.165 1756562.0 + Namthabad 15 5 53.562 2518376.3 + Daumergida 18 3 15.292 3591788.4 + Takalkhera 21 5 51.532 4697329.5 + Kalianpur 24 7 11.262 5794695.7 + Kaliana 29 30 48.322 7755835.9 + +The data of the Russian arc (long. 26 deg. 40') taken from Struve's work are +as below:-- + + deg. ' " Ft. + Staro Nekrasovsk 45 20 2.94 .. + Vodu-Luy 47 1 24.98 616529.81 + Suprunkovzy 48 45 3.04 1246762.17 + Kremenets 50 5 49.95 1737551.48 + Byelin 52 2 42.16 2448745.17 + Nemesh 54 39 4.16 3400312.63 + Jacobstadt 56 30 4.97 4076412.28 + Dorpat 58 22 47.56 4762421.43 + Hogland 60 5 9.84 5386135.39 + Kilpi-maki 62 38 5.25 6317905.67 + Tornea 65 49 44.57 7486789.97 + Stuor-oivi 68 40 58.40 8530517.90 + Fuglenaes 70 40 11.23 9257921.06 + +From the are measured in Cape Colony by Sir Thomas Maclear in long. 18 deg. +30', we have + + deg. ' " Ft. + North End 29 44 17.66 .. + Heerenlogement Berg 31 58 9.11 811507.7 + Royal Observatory 33 56 3.20 1526386.8 + Zwart Kop 34 13 32.13 1632583.3 + Cape Point 34 21 6.26 1678375.7 + +And, finally, for the Peruvian arc, in long. 281 deg. 0', + + deg. ' " Ft. + Tarqui 3 4 32.068 .. + Cotchesqui 0 2 31.387 1131036.3 + +Having now stated the data of the problem, we may seek that oblate +ellipsoid (spheroid) which best represents the observations. Whatever +the real figure may be, it is certain that if we suppose it an ellipsoid +with three unequal axes, the arithmetical process will bring out an +ellipsoid, which will agree better with all the observed latitudes than +any spheroid would, therefore we do not _prove_ that it is an ellipsoid; +to prove this, arcs of longitude would be required. The result for the +spheroid may be expressed thus:-- + + a = 20926062 ft. = 6378206.4 metres. + b = 20855121 ft. = 6356583.8 metres. + b : a = 293.98 : 294.98. + +As might be expected, the sum of the squares of the 40 latitude +corrections, viz. 153.99, is greater in this figure than in that of +three axes, where it amounts to 138.30. For this case, in the Indian arc +the largest corrections are at Dodagunta, + 3.87", and at Kalianpur, - +3.68". In the Russian arc the largest corrections are + 3.76", at +Tornea, and - 3.31", at Staro Nekrasovsk. Of the whole 40 corrections, +16 are under 1.0", 10 between 1.0" and 2.0", 10 between 2.0" and +3.0", and 4 over 3.0". The probable error of an observed latitude is +- +1.42"; for the spheroidal it would be very slightly larger. This +quantity may be taken therefore as approximately the probable amount of +local deflection. + +If [rho] be the radius of curvature of the meridian in latitude [phi], +[rho]' that perpendicular to the meridian, D the length of a degree of +the meridian, D' the length of a degree of longitude, r the radius drawn +from the centre of the earth, V the angle of the vertical with the +radius-vector, then + + Ft. + [rho] = 20890606.6 - 106411.5 cos 2[phi] + 225.8 cos 4[phi] + [rho]' = 20961607.3 - 35590.9 cos 2[phi] + 45.2 cos 4[phi] + D = 364609.87 - 1857.14 cos 2[phi] + 3.94 cos 4[phi] + D' = 365538.48 cos [phi] - 310.17 cos 3[phi] + 0.39 cos 5[phi] + Log r/a = 9.9992645 + .0007374 cos 2[phi] - .0000019 cos 4[phi] + V = 700.44" sin 2[phi] - 1.19" sin 4[phi]. + +A.R. Clarke has recalculated the elements of the ellipsoid of the earth; +his values, derived in 1880, in which he utilized the measurements of +parallel arcs in India, are particularly in practice. These values +are:-- + + a = 20926202 ft. = 6378249 metres, + b = 20854895 ft. = 6356515 metres, + b : a = 292.465 : 293.465. + + The calculation of the elements of the ellipsoid of rotation from + measurements of the curvature of arcs in any given azimuth by means of + geographical longitudes, latitudes and azimuths is indicated in the + article GEODESY; reference may be made to _Principal Triangulation_, + Helmert's _Geodasie_, and the publications of the Kgl. Preuss. Geod. + Inst.:--_Lotabweichungen_ (1886), and _Die europ. Laengengradmessung in + 52 deg. Br._ (1893). For the calculation of an ellipsoid with three + unequal axes see _Comparison of Standards_, preface; and for + non-elliptical meridians, _Principal Triangulation_, p. 733. + + +_Gravitation-Measurements._ + +According to Clairault's theorem (see above) the ellipticity e of the +mathematical surface of the earth is equal to the difference (5/2)m -ss, +where m is the ratio of the centrifugal force at the equator to gravity +at the equator, and ss is derived from the formula G = g(1 + ss +sin squared[phi]). Since the beginning of the 19th century many efforts have +been made to determine the constants of this formula, and numerous +expeditions undertaken to investigate the intensity of gravity in +different latitudes. If m be known, it is only necessary to determine ss +for the evaluation of e; consequently it is unnecessary to determine G +absolutely, for the relative values of G at two known latitudes suffice. +Such relative measurements are easier and more exact than absolute ones. +In some cases the ordinary thread pendulum, i.e. a spherical bob +suspended by a wire, has been employed; but more often a rigid metal +rod, bearing a weight and a knife-edge on which it may oscillate, has +been adopted. The main point is the constancy of the pendulum. From the +formula for the time of oscillation of the mathematically ideal +pendulum, t = 2 [pi] [root](l/G), l being the length, it follows that +for two points G1/G2 = t2 squared/t1 squared. + +In 1808 J.B. Biot commenced his pendulum observations at several +stations in western Europe; and in 1817-1825 Captain Louis de Freycinet +and L.I. Duperrey prosecuted similar observations far into the southern +hemisphere. Captain Henry Kater confined himself to British stations +(1818-1819); Captain E. Sabine, from 1819 to 1829, observed similarly, +with Kater's pendulum, at seventeen stations ranging from the West +Indies to Greenland and Spitsbergen; and in 1824-1831, Captain Henry +Foster (who met his death by drowning in Central America) experimented +at sixteen stations; his observations were completed by Francis Baily in +London. Of other workers in this field mention may be made of F.B. Luetke +(1826-1829), a Russian rear-admiral, and Captains J.B. Basevi and W.T. +Heaviside, who observed during 1865 to 1873 at Kew and at 29 Indian +stations, particularly at More in the Himalayas at a height of 4696 +metres. Of the earlier absolute determinations we may mention those of +Biot, Kater, and Bessel at Paris, London and Koenigsberg respectively. +The measurements were particularly difficult by reason of the length of +the pendulums employed, these generally being second-pendulums over 1 +metre long. In about 1880, Colonel Robert von Sterneck of Austria +introduced the half-second pendulum, which permitted far quicker and +more accurate work. The use of these pendulums spread in all countries, +and the number of gravity stations consequently increased: in 1880 there +were about 120, in 1900 there were about 1600, of which the greater +number were in Europe. Sir E. Sabine[6] calculated the ellipticity to be +1/288.5, a value shown to be too high by Helmert, who in 1884, with the +aid of 120 stations, gave the value 1/299.26,[7] and in 1901, with about +1400 stations, derived the value 1/298.3.[8] The reason for the +excessive estimate of Sabine is that he did not take into account the +systematic difference between the values of G for continents and +islands; it was found that in consequence of the constitution of the +earth's crust (Pratt) G is greater on small islands of the ocean than +on continents by an amount which may approach to 0.3 cm. Moreover, +stations in the neighbourhood of coasts shelving to deep seas have a +surplus, but a little smaller. Consequently, Helmert conducted his +calculations of 1901 for continents and coasts separately, and obtained +G for the coasts 0.036 cm. greater than for the continents, while the +value of ss remained the same. The mean value, reduced to continents, is + + G = 978.03(1 + 0.005302 sin squared[phi] - 0.000007 sin squared 2[phi])cm/sec squared. + +The small term involving sin squared 2[phi] could not be calculated with +sufficient exactness from the observations, and is therefore taken from +the theoretical views of Sir G.H. Darwin and E. Wiechert. For the +constant g = 978.03 cm. another correction has been suggested (1906) by +the absolute determinations made by F. Kuehnen and Ph. Furtwaengler at +Potsdam.[9] + + A report on the pendulum measurements of the 19th century has been + given by Helmert in the _Comptes rendus des seances de la 13^e + conference generale de l'Association Geod. Internationale a Paris_ + (1900), ii. 139-385. + +A difficulty presents itself in the case of the application of +measurements of gravity to the determination of the figure of the earth +by reason of the extrusion or standing out of the land-masses +(continents, &c.) above the sea-level. The potential of gravity has a +different mathematical expression outside the masses than inside. The +difficulty is removed by assuming (with Sir G.G. Stokes) the vertical +condensation of the masses on the sea-level, without its form being +considerably altered (scarcely 1 metre radially). Further, the value of +gravity (g) measured at the height H is corrected to sea-level by + +2gH/R, where R is the radius of the earth. Another correction, due to P. +Bouguer, is -(3/2)g[delta]H/[rho]R, where [delta] is the density of the +strata of height H, and [rho] the mean density of the earth. These two +corrections are represented in "Bouguer's Rule": g_H = g_s(1 - 2H/R + +3[delta]H/2[rho]R), where g_H is the gravity at height H, and g_s the +value at sea-level. This is supposed to take into account the attraction +of the elevated strata or plateau; but, from the analytical method, this +is not correct; it is also disadvantageous since, in general, the +land-masses are compensated subterraneously, by reason of the isostasis +of the earth's crust. + +In 1849 Stokes showed that the normal elevations N of the geoid towards +the ellipsoid are calculable from the deviations [Delta]g of the +acceleration of gravity, i.e. the differences between the observed g and +the value calculated from the normal G formula. The method assumes that +gravity is measured on the earth's surface at a sufficient number of +points, and that it is conformably reduced. In order to secure the +convergence of the expansions in spherical harmonics, it is necessary to +assume all masses outside a surface parallel to the surface of the sea +at a depth of 21 km. (= R x ellipticity) to be condensed on this surface +(Helmert, _Geod._ ii. 172). In addition to the reduction with 2gH/R, +there still result small reductions with mountain chains and coasts, and +somewhat larger ones for islands. The sea-surface generally varies but +very little by this condensation. The elevation (N) of the geoid is then +equal to + _ + /[pi] + N = R | FG^(-1) [Delta]g_[psi] d[psi], + _/ + +where [psi] is the spherical distance from the point N, and +[Delta]g_[psi] denotes the mean value of [Delta]g for all points in the +same distance [psi] around; F is a function of [psi], and has the +following values:-- + + +-------+-------+ + | [Psi]=| F= | + +-------+-------+ + | 0 deg. | 1 | + | 10 deg. | 1.22 | + | 20 deg. | 0.94 | + | 30 deg. | 0.47 | + | 40 deg. | -0.06 | + | 50 deg. | -0.54 | + | 60 deg. | -0.90 | + | 70 deg. | -1.08 | + | 80 deg. | -1.08 | + | 90 deg. | -0.91 | + | 100 deg. | -0.62 | + | 110 deg. | -0.27 | + | 120 deg. | +0.08 | + | 130 deg. | 0.36 | + | 140 deg. | 0.53 | + | 150 deg. | 0.56 | + | 160 deg. | 0.46 | + | 170 deg. | 0.26 | + | 180 deg. | 0 | + +-------+-------+ + +H. Poincare (_Bull. Astr._, 1901, p. 5) has exhibited N by means of +Lame's functions; in this case the condensation is effected on an +ellipsoidal surface, which approximates to the geoid. This condensation +is, in practice, the same as to the geoid itself. + +If we imagine the outer land-masses to be condensed on the sea-level, +and the inner masses (which, together with the outer masses, causes the +deviation of the geoid from the ellipsoid) to be compensated in the +sea-level by a disturbing stratum (which, according to Gauss, is +possible), and if these masses of both kinds correspond at the point N +to a stratum of thickness D and density [delta], then, according to +Helmert (_Geod._ ii. 260) we have approximately + + 3 g /[delta]D \ + [Delta]g = -- -- ( -------- - N ). + 2 R \ [rho] / + +Since N slowly varies empirically, it follows that in restricted regions +(of a few 100 km. in diameter) [Delta]g is a measure of the variation of +D. By applying the reduction of Bouguer to g, D is diminished by H and +only gives the thickness of the ideal disturbing mass which corresponds +to the perturbations due to subterranean masses. [Delta]g has positive +values on coasts, small islands, and high and medium mountain chains, +and occasionally in plains; while in valleys and at the foot of mountain +ranges it is negative (up to 0.2 cm.). We conclude from this that the +masses of smaller density existing under high mountain chains lie not +only vertically underneath but also spread out sideways. + + +_The European Arc of Parallel in 52 deg. Lat._ + +Many measurements of degrees of longitudes along central parallels in +Europe were projected and partly carried out as early as the first half +of the 19th century; these, however, only became of importance after the +introduction of the electric telegraph, through which calculations of +astronomical longitudes obtained a much higher degree of accuracy. Of +the greatest moment is the measurement near the parallel of 52 deg. lat., +which extended from Valentia in Ireland to Orsk in the southern Ural +mountains over 69 deg. long, (about 6750 km.). F.G.W. Struve, who is to be +regarded as the father of the Russo-Scandinavian latitude-degree +measurements, was the originator of this investigation. Having made the +requisite arrangements with the governments in 1857, he transferred +them to his son Otto, who, in 1860, secured the co-operation of England. +A new connexion of England with the continent, via the English Channel, +was accomplished in the next two years; whereas the requisite +triangulations in Prussia and Russia extended over several decennaries. +The number of longitude stations originally arranged for was 15; and the +determinations of the differences in longitude were uniformly commenced +by the Russian observers E.I. von Forsch, J.I. Zylinski, B. Tiele and +others; Feaghmain (Valentia) being reserved for English observers. With +the concluding calculation of these operations, newer determinations of +differences of longitudes were also applicable, by which the number of +stations was brought up to 29. Since local deflections of the plumb-line +were suspected at Feaghmain, the most westerly station, the longitude +(with respect to Greenwich) of the trigonometrical station Killorglin at +the head of Dingle Bay was shortly afterwards determined. + + The results (1891-1894) are given in volumes xlvii. and l. of the + memoirs (Zapiski) of the military topographical division of the + Russian general staff, volume li. contains a reconnexion of Orsk. The + observations made west of Warsaw are detailed in the _Die europ. + Laengengradmessung in 52 deg. Br._, i. and ii., 1893, 1896, published by + the Kgl. Preuss. Geod. Inst. + +The following figures are quoted from Helmert's report "Die Groesse der +Erde" (_Sitzb. d. Berl. Akad. d. Wiss._, 1906, p. 535):-- + + _Easterly Deviation of the Astronomical Zenith_. + + Name. Longitude. + deg. ' " + Feaghmain -10 21 -3.3 + Killorglin - 9 47 +2.8 + Haverfordwest - 4 58 +1.6 + Greenwich 0 0 +1.5 + Rosendael-Nieuport + 2 35 -1.7 + Bonn + 7 6 -4.4 + Goettingen + 9 57 -2.4 + Brocken +10 37 +2.3 + Leipzig +12 23 +2.7 + Rauenberg-Berlin +13 23 +1.7 + Grossenhain +13 33 -2.9 + Schneekoppe +15 45 +0.1 + Springberg +16 37 +0.8 + Breslau-Rosenthal +17 2 +3.5 + Trockenberg +18 53 -0.5 + Schoensee +18 54 -2.9 + Mirov +19 18 +2.2 + Warsaw +21 2 +1.9 + Grodno +23 50 -2.8 + Bobruisk +29 14 +0.5 + Orel +36 4 +4.4 + Lipetsk +39 36 +0.2 + Saratov +46 3 +6.4 + Samara +50 5 -2.6 + Orenburg +55 7 +1.7 + Orsk +58 34 -8.0 + +These deviations of the plumb-line correspond to an ellipsoid having an +equatorial radius (a) of nearly 6,378,000 metres (prob. error +- 70 +metres) and an ellipticity 1/299.15. The latter was taken for granted; +it is nearly equal to the result from the gravity-measurements; the +value for a then gives [Sigma][eta] squared a minimum (nearly). The +astronomical values of the geographical longitudes (with regard to +Greenwich) are assumed, according to the compensation of longitude +differences carried out by van de Sande Bakhuyzen (_Comp. rend, des +seances de la commission permanente de l'Association Geod. +Internationale a Geneve, 1893, annexe A.I._). Recent determinations +(Albrecht, _Astr. Nach._, 3993/4) have introduced only small alterations +in the deviations, a being slightly increased. + +Of considerable importance in the investigation of the great arc was +the representation of the linear lengths found in different countries, +in terms of the same unit. The necessity for this had previously +occurred in the computation of the figure of the earth from +latitude-degree-measurements. A.R. Clarke instituted an extensive +series of comparisons at Southampton (see _Comparisons of Standards of +Length of England, France, Belgium, Prussia, Russia, India and +Australia, made at the Ordnance Survey Office, Southampton, 1866_, and +a paper in the _Philosophical Transactions_ for 1873, by Lieut.-Col. +A.R. Clarke, C.B., R.E., on the further comparisons of the standards +of Austria, Spain, the United States, Cape of Good Hope and Russia) and +found that 1 toise = 6.39453348 ft., 1 metre = 3.28086933 ft. + +In 1875 a number of European states concluded the metre convention, and +in 1877 an international weights-and-measures bureau was established at +Breteuil. Until this time the metre was determined by the end-surfaces +of a platinum rod (_metre des archives_); subsequently, rods of +platinum-iridium, of cross-section H, were constructed, having engraved +lines at both ends of the bridge, which determine the distance of a +metre. There were thirty of the rods which gave as accurately as +possible the length of the metre; and these were distributed among the +different states (see WEIGHTS AND MEASURES). Careful comparisons with +several standard toises showed that the metre was not exactly equal to +443,296 lines of the toise, but, in round numbers, 1/75000 of the length +smaller. The metre according to the older relation is called the "legal +metre," according to the new relation the "international metre." The +values are (see _Europ. Laengengradmessung_, i. p. 230):-- + + Legal metre = 3.28086933 ft., International metre = 3.2808257 ft. + +The values of a given above are in terms of the international metre; the +earlier ones in legal metres, while the gravity formulae are in +international metres. + + +_The International Geodetic Association (Internationale Erdmessung)._ + +On the proposition of the Prussian lieutenant-general, Johann Jacob +Baeyer, a conference of delegates of several European states met at +Berlin in 1862 to discuss the question of a "Central European +degree-measurement." The first general conference took place at Berlin +two years later; shortly afterwards other countries joined the movement, +which was then named "The European degree-measurement." From 1866 till +1886 Prussia had borne the expense incident to the central bureau at +Berlin; but when in 1886 the operations received further extension and +the title was altered to "The International Earth-measurement" or +"International Geodetic Association," the co-operating states made +financial contributions to this purpose. The central bureau is +affiliated with the Prussian Geodetic Institute, which, since 1892, has +been situated on the Telegraphenberg near Potsdam. After Baeyer's death +Prof. Friedrich Robert Helmert was appointed director. The funds are +devoted to the advancement of such scientific works as concern all +countries and deal with geodetic problems of a general or universal +nature. During the period 1897-1906 the following twenty-one countries +belonged to the association:--Austria, Belgium, Denmark, England, +France, Germany, Greece, Holland, Hungary, Italy, Japan, Mexico, Norway, +Portugal, Rumania, Russia, Servia, Spain, Sweden, Switzerland and the +United States of America. At the present time general conferences take +place every three years.[10] + +Baeyer projected the investigation of the curvature of the meridians and +the parallels of the mathematical surface of the earth stretching from +Christiania to Palermo for 12 degrees of longitude; he sought to +co-ordinate and complete the network of triangles in the countries +through which these meridians passed, and to represent his results by a +common unit of length. This proposition has been carried out, and +extended over the greater part of Europe; as a matter of fact, the +network has, with trifling gaps, been carried over the whole of western +and central Europe, and, by some chains of triangles, over European +Russia. Through the co-operation of France, the network has been +extended into north Africa as far as the geographical latitude of 32 deg.; +in Greece a network, united with those of Italy and Bosnia, has been +carried out by the Austrian colonel, Heinrich Hartl; Servia has +projected similar triangulations; Rumania has begun to make the triangle +measurements, and three base lines have been measured by French +officers with Brunner's apparatus. At present, in Rumania, there is +being worked a connexion between the arc of parallel in lat. 47 deg./48 deg. in +Russia (stretching from Astrakan to Kishinev) with Austria-Hungary. In +the latter country and in south Bavaria the connecting triangles for +this parallel have been recently revised, as well as the French chain on +the Paris parallel, which has been connected with the German net by the +co-operation of German and French geodesists. This will give a long arc +of parallel, really projected in the first half of the 19th century. The +calculation of the Russian section gives, with an assumed ellipticity of +1/299.15, the value a = 6377350 metres; this is rather uncertain, since +the arc embraces only 19 deg. in longitude. + +We may here recall that in France geodetic studies have recovered their +former expansion under the vigorous impulse of Colonel (afterwards +General) Francois Perrier. When occupied with the triangulation of +Algeria, Colonel Perrier had conceived the possibility of the geodetic +junction of Algeria to Spain, over the Mediterranean; therefore the +French meridian line, which was already connected with England, and was +thus produced to the 60th parallel, could further be linked to the +Spanish triangulation, cross thence into Algeria and extend to the +Sahara, so as to form an arc of about 30 deg. in length. But it then became +urgent to proceed to a new measurement of the French arc, between +Dunkirk and Perpignan. In 1869 Perrier was authorized to undertake that +revision. He devoted himself to that work till the end of his career, +closed by premature death in February 1888, at the very moment when the +_Depot de la guerre_ had just been transformed into the Geographical +Service of the Army, of which General F. Perrier was the first director. +His work was continued by his assistant, Colonel (afterwards General) +J.A.L. Bassot. The operations concerning the revision of the French arc +were completed only in 1896. Meanwhile the French geodesists had +accomplished the junction of Algeria to Spain, with the help of the +geodesists of the Madrid Institute under General Carlos Ibanez (1879), +and measured the meridian line between Algiers and El Aghuat (1881). +They have since been busy in prolonging the meridians of El Aghuat and +Biskra, so as to converge towards Wargla, through Ghardaia and Tuggurt. +The fundamental co-ordinates of the Pantheon have also been obtained +anew, by connecting the Pantheon and the Paris Observatory with the five +stations of Bry-sur-Marne, Morlu, Mont Valerien, Chatillon and +Montsouris, where the observations of latitude and azimuth have been +effected.[11] + +According to the calculations made at the central bureau of the +international association on the great meridian arc extending from the +Shetland Islands, through Great Britain, France and Spain to El Aghuat in +Algeria, a = 6377935 metres, the ellipticity being assumed as 1/299.15. +The following table gives the difference: astronomical-geodetic latitude. +The net does not follow the meridian exactly, but deviates both to the +west and to the east; actually, the meridian of Greenwich is nearer the +mean than that of Paris (Helmert, _Groesse d. Erde_). + + _West Europe-Africa Meridian-arc._[12] + + Name. Latitude. A.-G. + deg. ' " + Saxavord 60 49.6 -4.0 + Balta 60 45.0 -6.1 + Ben Hutig 58 33.1 +0.3 + Cowhythe 57 41.1 +7.3 + Great Stirling 57 27.8 -2.3 + Kellie Law 56 14.9 -3.7 + Calton Hill 55 57.4 +3.5 + Durham 54 46.1 -0.9 + Burleigh Moor 54 34.3 +2.1 + Clifton Beacon 53 27.5 +1.3 + Arbury Hill 52 13.4 -3.0 + Greenwich 51 28.6 -2.5 + Nieuport 51 7.8 -0.4 + Rosendael 51 2.7 -0.9 + Lihons 49 49.9 +0.5 + Pantheon 48 50.8 -0.0 + Chevry 48 0.5 +2.2 + Saligny le Vif 47 2.7 +3.0 + Arpheuille 46 13.7 +6.3 + Puy de Dome 45 46.5 +7.0 + Rodez 44 21.4 +1.7 + Carcassonne 43 13.3 +0.7 + Rivesaltes 42 45.2 -0.7 + Montolar 41 38.5 +3.6 + Lerida 41 37.0 -0.2 + Javalon 40 13.8 -0.2 + Desierto 40 5.0 -4.5 + Chinchilla 38 55.2 +2.2 + Mola de Formentera 38 39.9 -1.2 + Tetica 37 15.2 +3.5 + Roldan 36 56.6 -6.0 + Conjuros 36 44.4 -12.6 + Mt. Sabiha 35 39.6 +6.5 + Nemours 35 5.8 +7.4 + Bouzareah 36 48.0 +2.9 + Algiers (Voirol) 36 45.1 -9.1 + Guelt es Stel 35 7.8 -1.0 + El Aghuat 33 48.0 -2.8 + +[Illustration] + +While the radius of curvature of this arc is obviously not uniform +(being, in the mean, about 600 metres greater in the northern than in +the southern part), the Russo-Scandinavian meridian arc (from 45 deg. to +70 deg.), on the other hand, is very uniformly curved, and gives, with an +ellipticity of 1/299.15, a = 6378455 metres; this arc gives the +plausible value 1/298.6 for the ellipticity. But in the case of this arc +the orographical circumstances are more favourable. + +The west-European and the Russo-Scandinavian meridians indicate another +anomaly of the geoid. They were connected at the Central Bureau by means +of east-to-west triangle chains (principally by the arc of parallel +measurements in lat. 52 deg.); it was shown that, if one proceeds from the +west-European meridian arcs, the differences between the astronomical +and geodetic latitudes of the Russo-Scandinavian arc become some 4" +greater.[13] + +The central European meridian, which passes through Germany and the +countries adjacent on the north and south, is under review at Potsdam +(see the publications of the Kgl. Preuss. Geod. Inst., _Lotabweichungen_, +Nos. 1-3). Particular notice must be made of the Vienna meridian, now +carried southwards to Malta. The Italian triangulation is now complete, +and has been joined with the neighbouring countries on the north, and +with Tunis on the south. + +The United States Coast and Geodetic Survey has published an account of +the transcontinental triangulation and measurement of an arc of the +parallel of 39 deg., which extends from Cape May (New Jersey), on the +Atlantic coast, to Point Arena (California), on the Pacific coast, and +embraces 48 deg. 46' of longitude, with a linear development of about 4225 +km. (2625 miles). The triangulation depends upon ten base-lines, with an +aggregate length of 86 km. the longest exceeding 17 km. in length, which +have been measured with the utmost care. In crossing the Rocky +Mountains, many of its sides exceed 100 miles in length, and there is +one side reaching to a length of 294 km., or 183 miles; the altitude of +many of the stations is also considerable, reaching to 4300 metres, or +14,108 ft., in the case of Pike's Peak, and to 14,421 ft. at Elbert +Peak, Colo. All geometrical conditions subsisting in the triangulation +are satisfied by adjustment, inclusive of the required accord of the +base-lines, so that the same length for any given line is found, no +matter from what line one may start.[14] + +Over or near the arc were distributed 109 latitude stations, occupied +with zenith telescopes; 73 azimuth stations; and 29 telegraphically +determined longitudes. It has thus been possible to study in a very +complete manner the deviations of the vertical, which in the mountainous +regions sometimes amount to 25 seconds, and even to 29 seconds. + +With the ellipticity 1/299.15, a = 6377897 +- 65 metres (prob. error); in +this calculation, however, some exceedingly perturbed stations are +excluded; for the employed stations the mean perturbation in longitude +is +- 4.9" (zenith-deflection east-to-west +- 3.8"). + +The computations relative to another arc, the "eastern oblique arc of +the United States," are also finished.[15] It extends from Calais +(Maine) in the north-east, to the Gulf of Mexico, and terminates at New +Orleans (Louisiana), in the south. Its length is 2612 km. (1623 miles), +the difference of latitude 15 deg. 1', and of longitude 22 deg. 47'. In the +main, the triangulation follows the Appalachian chain of mountains, +bifurcating once, so as to leave an oval space between the two branches. +It includes among its stations Mount Washington (1920 metres) and Mount +Mitchell (2038 metres). It depends upon six base-lines, and the +adjustment is effected in the same manner as for the arc of the +parallel. The astronomical data have been afforded by 71 latitude +stations, 17 longitude stations, and 56 azimuth stations, distributed +over the whole extent of the arc. The resulting dimensions of an +osculating spheroid were found to be + + a = 6378157 metres +- 90 (prob. error), + e(ellipticity) = 1/304.5 +- 1.9 (prob. error). + +With the ellipticity 1/399.15, a = 6378041 metres +- 80 (prob. er.). + +During the years 1903-1906 the United States Coast and Geodetic Survey, +under the direction of O.H. Tittmann and the special management of John +F. Hayford, executed a calculation of the best ellipsoid of rotation for +the United States. There were 507 astronomical determinations employed, +all the stations being connected through the net-work of triangles. The +observed latitudes, longitude and azimuths were improved by the +attractions of the earth's crust on the hypothesis of isostasis for +three depths of the surface of 114, 121 and 162 km., where the isostasis +is complete. The land-masses, within the distance of 4126 km., were +taken into consideration. In the derivation of an ellipsoid of rotation, +the first case proved itself the most favourable, and there resulted:-- + + a = 6378283 metres +- 74 (prob. er.), ellipticity + = 1/297.8 +- 0.9 (prob. er.). + +The most favourable value for the depth of the isostatic surface is +approximately 114 km. + +The measurement of a great meridian arc, in long. 98 deg. W., has been +commenced; it has a range of latitude of 23 deg., and will extend over 50 deg. +when produced southwards and northwards by Mexico and Canada. It may +afterwards be connected with the arc of Quito. A new measurement of the +meridian arc of Quito was executed in the years 1901-1906 by the +_Service geographique_ of France under the direction of the Academie des +Sciences, the ground having been previously reconnoitred in 1899. The +new arc has an amplitude in latitude of 5 deg. 53' 33", and stretches from +Tulcan (lat. 0 deg. 48' 25") on the borders of Columbia and Ecuador, through +Columbia to Payta (lat. -5 deg. 5' 8") in Peru. The end-points, at which the +chain of triangles has a slight north-easterly trend, show a longitude +difference of 3 deg.. Of the 74 triangle points, 64 were latitude stations; +6 azimuths and 8 longitude-differences were measured, three base-lines +were laid down, and gravity was determined from six points, in order to +maintain indications over the general deformation of the geoid in that +region. Computations of the attraction of the mountains on the +plumb-line are also being considered. The work has been much delayed by +the hardships and difficulties encountered. It was conducted by +Lieut.-Colonel Robert Bourgeois, assisted by eleven officers and +twenty-four soldiers of the geodetic branch of the _Service +geographique_. Of these officers mention may be made of Commandant E. +Maurain, who retired in 1904 after suffering great hardships; Commandant +L. Massenet, who died in 1905; and Captains I. Lacombe, A. Lallemand, +and Lieut. Georges Perrier (son of General Perrier). It is conceivable +that the chain of triangles in longitude 98 deg. in North America may be +united with that of Ecuador and Peru: a continuous chain over the whole +of America is certainly but a question of time. During the years +1899-1902 the measurement of an arc of meridian was made in the extreme +north, in Spitzbergen, between the latitudes 76 deg. 38' and 80 deg. 50', +according to the project of P.G. Rosen. The southern part was determined +by the Russians--O. Baecklund, Captain D.D. Sergieffsky, F.N. +Tschernychev, A. Hansky and others--during 1899-1901, with the aid of 1 +base-line, 15 trigonometrical, 11 latitude and 5 gravity stations. The +northern part, which has one side in common with the southern part, has +been determined by Swedes (Professors Rosen, father and son, E. Jaederin, +T. Rubin and others), who utilized 1 base-line, 9 azimuth measurements, +18 trigonometrical, 17 latitude and 5 gravity stations. The party worked +under excessive difficulties, which were accentuated by the arctic +climate. Consequently, in the first year, little headway was made.[16] + +Sir David Gill, when director of the Royal Observatory, Cape Town, +instituted the magnificent project of working a latitude-degree +measurement along the meridian of 30 deg. long. This meridian passes through +Natal, the Transvaal, by Lake Tanganyika, and from thence to Cairo; +connexion with the Russo-Scandinavian meridian arc of the same longitude +should be made through Asia Minor, Turkey, Bulgaria and Rumania. With +the completion of this project a continuous arc of 105 deg. in latitude will +have been measured.[17] + +Extensive triangle chains, suitable for latitude-degree measurements, +have also been effected in Japan and Australia. + +Besides, the systematization of gravity measurements is of importance, +and for this purpose the association has instituted many reforms. It has +ensured that the relative measurements made at the stations in different +countries should be reduced conformably with the absolute determinations +made at Potsdam; the result was that, in 1906, the intensities of +gravitation at some 2000 stations had been co-ordinated. The intensity +of gravity on the sea has been determined by the comparison of +barometric and hypsometric observations (Mohn's method). The +association, at the proposal of Helmert, provided the necessary funds +for two expeditions:--English Channel--Rio de Janeiro, and the Red +Sea--Australia--San Francisco--Japan. Dr O. Hecker of the central bureau +was in charge; he successfully overcame the difficulties of the work, +and established the tenability of the isostatic hypothesis, which +necessitates that the intensity of gravity on the deep seas has, in +general, the same value as on the continents (without regard to the +proximity of coasts).[18] + +As the result of the more recent determinations, the ellipticity, +compression or flattening of the ellipsoid of the earth may be assumed +to be very nearly 1/298.3; a value determined in 1901 by Helmert from +the measurements of gravity. The semi-major axis, a, of the meridian +ellipse may exceed 6,378,000 inter. metres by about 200 metres. The +central bureau have adopted, for practical reasons, the value 1/299.15, +after Bessel, for which tables exist; and also the value a = +6377397.155(1 + 0.0001). + +The methods of theoretical astronomy also permit the evaluation of these +constants. The semi-axis a is calculable from the parallax of the moon +and the acceleration of gravity on the earth; but the results are +somewhat uncertain: the ellipticity deduced from lunar perturbations is +1/297.8 +- 2 (Helmert, _Geodaesie_, ii. pp. 460-473); William Harkness +(_The Solar Parallax and its related Constants_, 1891) from all possible +data derived the values: ellipticity = 1/300.2 +- 3, a = 6377972 +- 125 +metres. Harkness also considered in this investigation the relation of +the ellipticity to precession and nutation; newer investigations of the +latter lead to the limiting values 1/296, 1/298 (Wiechert). It was +clearly noticed in this method of determination that the influence of +the assumption as to the density of the strata in the interior of the +earth was but very slight (Radau, _Bull. astr._ ii. (1885) 157). The +deviations of the geoid from the flattened ellipsoid of rotation with +regard to the heights (the directions of normals being nearly the same) +will scarcely exceed +- 100 metres (Helmert).[19] + +The basis of the degree- and gravity-measurements is actually formed by +a stationary sea-surface, which is assumed to be level. However, by the +influence of winds and ocean currents the mean surface of the sea near +the coasts (which one assumes as the fundamental sea-surface) can +deviate somewhat from a level surface. According to the more recent +levelling it varies at the most by only some decimeters.[20] + +It is well known that the masses of the earth are continually undergoing +small changes; the earth's crust and sea-surface reciprocally oscillate, +and the axis of rotation vibrates relatively to the body of the earth. +The investigation of these problems falls in the programme of the +Association. By continued observations of the water-level on sea-coasts, +results have already been obtained as to the relative motions of the +land and sea (cf. GEOLOGY); more exact levelling will, in the course of +time, provide observations on countries remote from the sea-coast. Since +1900 an international service has been organized between some +astronomical stations distributed over the north parallel of 39 deg. 8', at +which geographical latitudes are observed whenever possible. The +association contributes to all these stations, supporting four entirely: +two in America, one in Italy, and one in Japan; the others partially +(Tschardjui in Russia, and Cincinnati observatory). Some observatories, +especially Pulkowa, Leiden and Tokyo, take part voluntarily. Since 1906 +another station for South America and one for Australia in latitude -31 deg. +55' have been added. According to the existing data, geographical +latitudes exhibit variations amounting to +-0.25", which, for the greater +part, proceed from a twelve- and a fourteen-month period.[21] + (A. R. C; F. R. H.) + + +FOOTNOTES: + + [1] _Eratosthenes Batavus, seu de terrae ambitus vera quantitate + suscitatus, a Willebrordo Snellio, Lugduni-Batavorum_ (1617). + + [2] O. Callandreau, "Memoire sur la theorie de la figure des + planetes," _Ann. obs. de Paris_ (1889); G.H. Darwin, "The Theory of + the Figure of the Earth carried to the Second Order of Small + Quantities," _Mon. Not. R.A.S._, 1899; E. Wiechert, "Ueber die + Massenverteilung im Innern der Erde," _Nach. d. koen. G. d. W. zu + Goett._, 1897. + + [3] See I. Todhunter, _Proc. Roy. Soc._, 1870. + + [4] J.H. Jeans, "On the Vibrations and Stability of a Gravitating + Planet," _Proc. Roy. Soc._ vol. 71; G.H. Darwin, "On the Figure and + Stability of a liquid Satellite," _Phil. Trans._ 206, p. 161; A.E.H. + Love, "The Gravitational Stability of the Earth," _Phil. Trans._ 207, + p. 237; _Proc. Roy. Soc._ vol. 80. + + [5] _Survey of India_, "The Attraction of the Himalaya Mountains upon + the Plumb Line in India" (1901), p. 98. + + [6] _Account of Experiments to Determine the Figure of the Earth by + means of a Pendulum vibrating Seconds in Different Latitudes_ (1825). + + [7] Helmert, _Theorien d. hoeheren Geod._ ii., Leipzig, 1884. + + [8] Helmert, _Sitzber. d. kgl. preuss. Ak. d. Wiss. zu Berlin_ + (1901), p. 336. + + [9] "Bestimmung der absoluten Groesse der Schwerkraft zu Potsdam mit + Reversionspendeln" (_Veroeffentlichung des kgl. preuss. Geod. Inst._, + N.F., No. 27). + + [10] _Die Koenigl. Observatorien fuer Astrophysik, Meteorologie und + Geodaesie bei Potsdam_ (Berlin, 1890); _Verhandlungen der I. + Allgemeinen Conferenz der Bevollmaechtigten zur mitteleurop. + Gradmessung_, October, 1864, in Berlin (Berlin, 1865); A. Hirsch, + _Verhandlungen der VIII. Allg. Conf. der Internationalen Erdmessung_, + October, 1886, in Berlin (Berlin, 1887); and _Verhandlungen der XI. + Allg. Conf. d. I. E._, October, 1895, in Berlin (1896). + + [11] Ibanez and Perrier, _Jonction geod. et astr. de l'Algerie avec + l'Espagne_ (Paris, 1886); _Memorial du depot general de la guerre_, + t. xii.: _Nouvelle meridienne de France_ (Paris, 1885, 1902, 1904); + _Comptes rendus des seances de la 12^e-19^e conference generale de + l'Assoc. Geod. Internat._, 1898 at Stuttgart, 1900 at Paris, 1903 at + Copenhagen, 1906 at Budapest (Berlin, 1899, 1901, 1904, 1908); A. + Ferrero, _Rapport sur les triangulations, pres. a la 12^e conf. gen. + 1898_. + + [12] R. Schumann, _C. r. de Budapest_, p. 244. + + [13] O. and A. Boersch, "Verbindung d. russ.-skandinav. mit der + franz.-engl. Breitengradmessung" (_Verhandlungen der 9. Allgem. Conf. + d. I. E. in Paris, 1889_, Ann. xi.). + + [14] U.S. Coast and Geodetic Survey; H.S. Pritchett, superintendent. + _The Transcontinental Triangulation and the American Arc of the + Parallel_, by C.A. Schott (Washington, 1900). + + [15] U.S. Coast and Geodetic Survey; O.H. Tittmann, superintendent. + _The Eastern Oblique Arc of the United States_, by C.A. Schott + (1902). + + [16] _Missions scientifiques pour la mesure d'un arc de meridien au + Spitzberg entreprises en 1899-1902 sous les auspices des + gouvernements russe et suedois._ _Mission russe_ (St Petersbourg, + 1904); _Mission suedoise_ (Stockholm, 1904). + + [17] Sir David Gill, _Report on the Geodetic Survey of South Africa, + 1833-1892_ (Cape Town, 1896), vol. ii. 1901, vol. iii. 1905. + + [18] O. Hecker, _Bestimmung der Schwerkraft a. d. Atlantischen Ozean_ + (Veroeffentl. d. Kgl. Preuss. Geod. Inst. No. 11), Berlin, 1903. + + [19] F.R. Helmert. "Neuere Fortschritte in der Erkenntnis der math. + Erdgestalt" (_Verhandl. des VII. Internationalen + Geographen-Kongresses, Berlin, 1899_), London, 1901. + + [20] C. Lallemand, "Rapport sur les travaux du service du nivellement + general de la France, de 1900 a 1906" (_Comp. rend. de la 14^e conf. + gen. de l'Assoc. Geod-Intern., 1903_, p. 178). + + [21] T. Albrecht, _Resultate des internat. Breitendienstes_, i. and + ii. (Berlin, 1903 and 1906); F. Klein and A. Sommerfeld, _Ueber die + Theorie des Kreisels_, iii. p. 672; R. Spitaler, "Die periodischen + Luftmassenverschiebungen und ihr Einfluss auf die Lagenaenderung der + Erdaxe" (_Petermanns Mitteilungen, Ergaenzungsheft_, 137); S. Newcomb, + "Statement of the Theoretical Laws of the Polar Motion" + (_Astronomical Journal_, 1898, xix. 158); F.R. Helmert, "Zur + Erklaerung der beobachteten Breitenaenderungen" (_Astr. Nachr._ No. + 3014); J. Weeder, "The 14-monthly period of the motion of the Pole + from determinations of the azimuth of the meridian marks of the + Leiden observatory" (_Kon. Ak. van Wetenschappen to Amsterdam_, + 1900); A. Sokolof, "Determination du mouvement du pole terr. au moyen + des mires meridiennes de Poulkovo" (_Mel. math. et astr._ vii., + 1894); J. Bonsdorff, "Beobachtungen von [delta] Cassiopejae mit dem + grossen Zenitteleskop" (_Mitteilungen der Nikolai-Hauptsternwarte zu + Pulkowo_, 1907); J. Larmor and E.H. Hills, "The irregular movement of + the Earth's axis of rotation: a contribution towards the analysis of + its causes" (_Monthly Notices R.A.S._, 1906, lxvii. 22); A.S. + Cristie, "The latitude variation Tide" (_Phil. Soc. of Wash._, 1895, + _Bull._ xiii. 103); H.G. van de Sande Bakhuysen, "Ueber die Aenderung + der Polhoehe" (_Astr. Nachr._ No. 3261); A.V. Baecklund, "Zur Frage + nach der Bewegung des Erdpoles" (_Astr. Nachr._ No. 3787); R. + Schumann, "Ueber die Polhoehenschwankung" (_Astr. Nachr._ No. 3873); + "Numerische Untersuchung" (_Ergaenzungshefte zu den Astr. Nachr._ No. + 11); _Weitere Untersuchungen_ (No. 4142); _Bull. astr._, 1900, June, + report of different theoretical memoirs. + + + + +EARTH CURRENTS. After the invention of telegraphy it was soon found that +telegraph lines in which the circuit is completed by the earth are +traversed by natural electric currents which occasionally interfere +seriously with their use, and which are known as "earth currents." + +1. Amongst the pioneers in investigating the subject were several English +telegraphists, e.g. W.H. Barlow (1) and C.V. Walker (2), who were in +charge respectively of the Midland and South-Eastern telegraph systems. +Barlow noticed the existence of a more or less regular diurnal variation, +and the result--confirmed by all subsequent investigators--that earth +currents proper occur in a line only when both ends are earthed. Walker, +as the result of general instructions issued to telegraph clerks, +collected numerous statistics as to the phenomena during times of large +earth currents. His results and those given by Barlow both indicate that +the lines to suffer most from earth currents in England have the general +direction N.E. to S.W. As Walker points out, it is the direction of the +terminal plates relative to one another that is the essential thing. At +the same time he noticed that whilst at any given instant the currents in +parallel lines have with rare exceptions the same direction, some lines +show normally stronger currents than others, and he suggested that +differences in the geological structure of the intervening ground might +be of importance. This is a point which seems still somewhat obscure. + +Our present knowledge of the subject owes much to practical men, but +even in the early days of telegraphy the fact that telegraph systems are +commercial undertakings, and cannot allow the public to wait the +convenience of science, was a serious obstacle to their employment for +research. Thus Walker feelingly says, when regretting his paucity of +data during a notable earth current disturbance: "Our clerks were at +their wits' end to clear off the telegrams.... At a time when +observations would have been very highly acceptable they were too much +occupied with their ordinary duties." Some valuable observations have, +however, been made on long telegraph lines where special facilities have +been given. + +Amongst these may be mentioned the observations on French lines in 1883 +described by E.E. Blavier (3), and those on two German lines +Berlin-Thorn and Berlin-Dresden during 1884 to 1888 discussed by B. +Weinstein (4). + +2. Of the experimental lines specially constructed perhaps the best +known are the Greenwich lines instituted by Sir G.B. Airy (5), the lines +at Pawlowsk due to H. Wild (6), and those at Parc Saint Maur, near Paris +(7). + +_Experimental Lines._--At Greenwich observations were commenced in 1865, +but there have been serious disturbances due to artificial currents from +electric railways for many years. There are two lines, one to Dartford +distant about 10 m., in a direction somewhat south of east, the other to +Croydon distant about 8 m., in a direction west of south. + +Information from a single line is incomplete, and unless this is clearly +understood erroneous ideas may be derived. The times at which the +current is largest and least, or when it vanishes, in an east-west line, +tell nothing directly as to the amplitude at the time of the resultant +current. The lines laid down at Pawlowsk in 1883 lay nearly in and +perpendicular to the geographical meridian, a distinct desideratum, but +were only about 1 km. long. The installation at Parc Saint Maur, +discussed by T. Moureaux, calls for fuller description. There are three +lines, one having terminal earth plates 14.8 km. apart in the +geographical meridian, a second having its earth plates due east and +west of one another, also 14.8 km. apart, and the third forming a closed +circuit wholly insulated from the ground. In each of the three lines is +a Deprez d'Arsonval galvanometer. Light reflected from the galvanometer +mirrors falls on photographic paper wound round a drum turned by +clockwork, and a continuous record is thus obtained. + +3. Each galvanometer has a resistance of about 200 ohms, but is shunted +by a resistance of only 2 ohms. The total effective resistances in the +N.-S. and E.-W. lines are 225 and 348 ohms respectively. If i is the +current recorded, L, g and s the resistances of the line, galvanometer +and shunt respectively, then E, the difference of potential between the +two earth plates, is given by + + E = i(1 + g/s) {L + gs/(g + s)}. + +To calibrate the record, a Daniell cell is put in a circuit including +1000 ohms and the three galvanometers as shunted. If i' be the current +recorded, e the E.M.F. of the cell, then e = i'(1 + g/s){1000 + 3gs/(g + +s)}. Under the conditions at Parc Saint Maur we may write 2 for gs/(g + +s), and 1.072 for e, and thence we have approximately E = 0.240(i/i') +for the N.-S. line, and E = -0.371(i/i') for the E.-W. line. + +The method of standardization assumes a potential difference between +earth plates which varies slowly enough to produce a practically steady +current. There are several causes producing currents in a telegraph wire +which do not satisfy this limitation. During thunderstorms surgings may +arise, at least in overhead wires, without these being actually struck. +Again, if the circuit includes a variable magnetic field, electric +currents will be produced independently of any direct source of +potential difference. In the third circuit at Parc Saint Maur, where no +earth plates exist, the current must be mainly due to changes in the +earth's vertical magnetic field, with superposed disturbances due to +atmospheric electricity or aerial waves. Even in the other circuits, +magnetic and atmospheric influences play some part, and when their +contribution is important, the galvanometer deflection has an uncertain +value. What a galvanometer records when traversed by a suddenly varying +current depends on other things than its mere resistance. + +Even when the current is fairly steady, its exact significance is not +easily stated. In the first place there is usually an appreciable E.M.F. +between a plate and the earth in contact with it, and this E.M.F. may +vary with the temperature and the dryness of the soil. Naturally one +employs similar plates buried to the same depth at the two ends, but +absolute identity and invariability of conditions can hardly be secured. +In some cases, in short lines (8), there is reason to fear that plate +E.M.F.'s have been responsible for a good deal that has been ascribed to +true earth currents. With deep earth plates, in dry ground, this source +of uncertainty can, however, enter but little into the diurnal +inequality. + +4. Another difficulty is the question of the resistance in the earth +itself. A given E.M.F. between plates 10 m. apart may mean very +different currents travelling through the earth, according to the +chemical constitution and condition of the surface strata. + +According to Professor A. Schuster (9), if [rho] and [rho]' be the +specific resistances of the material of the wire and of the soil, the +current i which would pass along an underground cable formed of actual +soil, equal in diameter to the wire connecting the plates, is given by i += i'[rho]/[rho]', where i' is the observed current in the wire. As +[rho]' will vary with the depth, and be different at different places +along the route, while discontinuities may arise from geological faults, +water channels and so on, it is clear that even the most careful +observations convey but a general idea as to the absolute intensity of +the currents in the earth itself. In Schuster's formula, as in the +formulae deduced for Parc Saint Maur, it is regarded as immaterial +whether the wire connecting the plates is above or below ground. This +view is in accordance with records obtained by Blavier (3) from two +lines between Paris and Nancy, the one an air line, the other +underground. + +5. The earliest quantitative results for the regular diurnal changes in +earth currents are probably those deduced by Airy (5) from the records +at Greenwich between 1865 and 1867. Airy resolved the observed currents +from the two Greenwich lines in and perpendicular to the _magnetic_ +meridian (then about 21 deg. to the west of astronomical north). The +information given by Airy as to the precise meaning of the quantities he +terms "magnetic tendency" to north and to west is somewhat scanty, but +we are unlikely to be much wrong in accepting his figures as +proportional to the earth currents from magnetic east to west and from +magnetic north to south respectively. Airy gives mean hourly values for +each month of the year. The corresponding mean diurnal inequality for +the whole year appears in Table 1., the unit being arbitrary. In every +month the algebraic mean of the 24 hourly values represented a current +from north to south in the magnetic meridian, and from east to west in +the perpendicular direction; in the same arbitrary units used in Table +I. the mean values of these two "constant" currents were respectively +777 and 559. + +6. _Diurnal Variation._--Probably the most complete records of diurnal +variation are those discussed by Weinstein (4), which depend on several +years' records on lines from Berlin to Dresden and to Thorn. Relative to +Berlin the geographical co-ordinates of the other two places are: + + Thorn 0 deg. 29' N. lat. 5 deg. 12' E. long. + Dresden 1 deg. 28' S. lat. 0 deg. 21' E. long. + +Thus the Berlin-Dresden line was directed about 81/2 deg. east of south, and +the Berlin-Thorn line somewhat more to the north of east. The latter +line had a length about 2.18 times that of the former. The resistances +in the two lines were made the same, so if we suppose the difference of +potential between earth plates along a given direction to vary as their +distance apart, the current observed in the Thorn-Berlin line has to be +divided by 2.18 to be comparable with the other. In this way, resolving +along and perpendicular to the geographical meridian, Weinstein gives as +proportional to the earth currents from east to west and from south to +north respectively + + J = 0.147i' + 0.435i, and J' = 0.989i' - 0.100i, + +where i and i' are the observed currents in the Thorn-Berlin and +Dresden-Berlin lines respectively, both being counted positive when +flowing towards Berlin. + +It is tacitly assumed that the average earth conductivity is the same +between Berlin and Thorn as between Berlin and Dresden. It should also +be noticed that local time at Berlin and Thorn differs by fully 20 +minutes, while the crests of the diurnal variations in _short_ lines at +the two places would probably occur about the same local time. The +result is probably a less sharp occurrence of maxima and minima, and a +relatively smaller range, than in a short line having the same +orientation. + + TABLE I. + + +-----------------------------------------------------+------------------------------+ + | Mean Diurnal Inequalities for the year. |Numerical Values of resultant | + | | current. | + +----------------------+------------------------------+------------------------------+ + | Greenwich. | Thorn-Berlin-Dresden. | Thorn-Berlin-Dresden. | + +--------+-------------+--------+-------+------+------+------------------------------+ + | |North | East | Berlin | Thorn |North | East | Mean hourly values from | + | Hour. | to | to | to | to | to | to +-----+-------+--------+-------+ + | |South | West |Dresden.|Berlin.|South | West |Year.|Winter.|Equinox.|Summer.| + | |(Mag.)|(Mag.)| | |(Ast.)|(Ast.)| | | | | + +--------+------+------+--------+-------+------+------+-----+-------+--------+-------+ + | 1 | -94 | -41 | -17 | -13 | -20 | -10 | 81 | 94 | 51 | 98 | + | 2 | -68 | -24 | -6 | -13 | -9 | -11 | 84 | 115 | 39 | 97 | + | 3 | -44 | -8 | -1 | -1 | -1 | -1 | 84 | 113 | 31 | 108 | + | 4 | -18 | +9 | -20 | +15 | -17 | +17 | 101 | 94 | 58 | 127 | + | 5 | -30 | -1 | -79 | +21 | -74 | +32 | 122 | 58 | 78 | 230 | + | 6 | -63 | -33 | -139 | +5 | -136 | +26 | 148 | 80 | 139 | 225 | + | 7 | -121 | -80 | -138 | -36 | -144 | -14 | 166 | 155 | 206 | 136 | + | 8 | -175 | -123 | -7 | -98 | -28 | -92 | 203 | 152 | 185 | 271 | + | 9 | -156 | -137 | +249 | -156 | +212 | -184 | 305 | 67 | 272 | 575 | + | 10 | -43 | -77 | +540 | -184 | +494 | -254 | 557 | 232 | 628 | 811 | + | 11 | +82 | +1 | +722 | -165 | +678 | -263 | 728 | 411 | 885 | 887 | + | Noon | +207 | +66 | +673 | -107 | +642 | -200 | 675 | 441 | 848 | 735 | + | 1 | +245 | +94 | +404 | -20 | +395 | -79 | 400 | 284 | 510 | 406 | + | 2 | +205 | +113 | +35 | +55 | +46 | +47 | 98 | 68 | 103 | 125 | + | 3 | +153 | +97 | -261 | +99 | -237 | +132 | 272 | 136 | 355 | 324 | + | 4 | +159 | +108 | -397 | +114 | -368 | +167 | 404 | 218 | 503 | 492 | + | 5 | +167 | +118 | -391 | +108 | -363 | +160 | 397 | 206 | 453 | 532 | + | 6 | +125 | +95 | -311 | +96 | -287 | +137 | 319 | 176 | 333 | 446 | + | 7 | +43 | +55 | -237 | +85 | -216 | +115 | 247 | 180 | 250 | 312 | + | 8 | -22 | +4 | -191 | +74 | -173 | +98 | 201 | 207 | 217 | 181 | + | 9 | -115 | -49 | -168 | +59 | -153 | +81 | 174 | 208 | 194 | 120 | + | 10 | -138 | -74 | -135 | +40 | -125 | +58 | 138 | 155 | 149 | 111 | + | 11 | -136 | -70 | -84 | +18 | -79 | +29 | 89 | 64 | 95 | 107 | + |Midnight| -147 | -80 | -43 | -2 | -43 | +4 | 91 | 42 | 119 | 111 | + +--------+------+------+--------+-------+------+------+-----+-------+--------+-------+ + +It was found that the average current derived from a number of +undisturbed days on either line might be regarded as made up of a +"constant part" plus a regular diurnal inequality, the constant part +representing the algebraic mean value of the 24 hourly readings. In both +lines the constant part showed a decided alteration during the third +year--changing sign in one line--in consequence, it is believed, of +alterations made in the earth plates. The constant part was regarded as +a plate effect, and was omitted from further consideration. Table I. +shows in terms of an arbitrary unit--whose relation to that employed for +Greenwich data is unknown--the diurnal inequality in the currents along +the two lines, and the inequalities thence calculated for ideal lines in +and perpendicular to the _geographical_ meridian. Currents are regarded +as positive when directed from Berlin to Dresden and from north to +south, the opposite point of view to that adopted by Weinstein. The +table also shows the mean _numerical_ value of the resultant current +(the "constant" part being omitted) for each hour of the day, for the +year as a whole, and for winter (November to February), equinox (March, +April, September, October) and summer (May to August). There is a marked +double period in both the N.-S. and E.-W. currents. In both cases the +numerically largest currents occur from 10 A.M. to noon, the directions +then being from north to south and from west to east. The currents tend +to die out and change sign about 2 P.M., the numerical magnitude then +rising again rapidly to 4 or 5 P.M. The current in the meridian is +notably the larger. The numerical values assigned to the resultant +current are arithmetic means from the several months composing the +season in question. + +7. The mean of the 24 hourly numerical values of the resultant current +for each month of the year a deducible from Weinstein's data--the unit +being the same as before--are given in Table II. + + TABLE II.--_Mean Numerical Value of Resultant Current._ + + Jan. Feb. March April May June July Aug. Sep. Oct. Nov. Dec. + 152 211 293 328 313 314 337 300 258 235 165 132 + +There is thus a conspicuous minimum at mid-winter, and but little +difference between the monthly means from April to August. This is +closely analogous to what is seen in the daily range of the magnetic +elements in similar latitudes (see MAGNETISM, TERRESTRIAL). There is +also considerable resemblance between the curve whose ordinates +represent the diurnal inequality in the current passing from north to +south, and the curve showing the hourly change in the westerly component +of the horizontal magnetic force in similar European latitudes. + +8. _Relations with Sun-spots, Auroras and Magnetic Storms._--Weinstein +gives curves representing the mean diurnal inequality for separate +years. In both lines the diurnal amplitudes were notably smaller in the +later years which were near sun-spot minimum. This raises a presumption +that the regular diurnal earth currents, like the ranges of the magnetic +elements, follow the 11-year sun-spot period. When we pass to the large +and irregular earth currents, which are of practical interest in +telegraphy, there is every reason to suppose that the sun-spot period +applies. These currents are always accompanied by magnetic disturbances, +and when specially striking by brilliant aurora. One most conspicuous +example of this occurred in the end of August and beginning of September +1859. The magnetic disturbances recorded were of almost unexampled size +and rapidity, the accompanying aurora was extraordinarily brilliant, and +E.M.F.'s of 700 and 800 volts are said to have been reached on telegraph +lines 500 to 600 km. long. It is doubtful whether the disturbances of +1859 have been equalled since, but earth current voltages of the order +of 0.5 volts per mile have been recorded by various authorities, e.g. +Sir W.H. Preece (10). + +It was the practice for several years to publish in the _Ann. du bureau +central meteorologique_ synchronous magnetic and earth current curves +from Parc Saint Maur corresponding to the chief disturbances of the +year. In most cases there is a marked similarity between the curve of +magnetic declination and that of the north-south earth current. At times +there is also a distinct resemblance between the horizontal force +magnetic curve and that of the east-west earth current, but exceptions +to this are not infrequent. Similar phenomena appear in synchronous +Greenwich records published by Airy in 1868; these show a close +accordance between the horizontal force curves and those of the currents +from magnetic east to west. Originally it was supposed by Airy that +whilst rapid movements in the declination and north-south current curves +sometimes occurred simultaneously, there was a distinct tendency for +the latter to precede the former. More recent examinations of the +Greenwich records by W. Ellis (11), and of the Parc St Maur curves by +Moureaux, have not confirmed this result, and it is now believed that +the two phenomena are practically simultaneous. + +There has also been a conflict of views as to the connexion between +magnetic and earth current disturbances. Airy's observations tended to +suggest that the earth current was the primary cause, and the magnetic +disturbance in considerable part at least its effect. Others, on the +contrary, have supposed earth currents to be a direct effect of changes +in the earth's magnetic field. The prevailing view now is that both the +magnetic and the earth current disturbances are due to electric currents +in the upper atmosphere, these upper currents becoming visible at times +as aurora. + +9. There seems some evidence that earth currents can be called into +existence by purely local causes, notably difference of level. Thus K.A. +Brander (12) has observed a current flowing constantly for a good many +days from Airolo (height 1160 metres) to the Hospice St Gotthard (height +2094 metres). In an 8-km. line from Resina to the top of Vesuvius L. +Palmieri (13)--observing in 1889 at three-hour intervals from 9 A.M. to +9 P.M.--always found a current running uphill so long as the mountain +was quiet. On a long line from Vienna to Graz A. Baumgartner (14) found +that the current generally flowed from both ends towards intervening +higher ground during the day, but in the opposite directions at night. +During a fortnight in September and October 1885 hourly readings were +taken of the current in the telegraph cable from Fort-William to Ben +Nevis Observatory, and the results were discussed by H.N. Dickson (15), +who found a marked preponderance of currents up the line to the summit. +The recorded mean data, otherwise regarded, represent a "constant" +current, equal to 29 in the arbitrary units employed by Dickson, flowing +up the line, together with the following diurnal inequality, + denoting +current towards Fort-William (i.e. down the hill, and nearly east to +west). + + Hour | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | + | | | | | | | | | | | | | + A.M. | -21 | -41 | +13 | +23 | +55 | -3 | +25 | -32 | -59 | -62 | -46 | +6 | + P.M. | +24 | +18 |+115 | +18 | +75 | -5 | +50 | -9 | -56 | -37 | -28 | -34 | + +There is thus a diurnal inequality, which is by no means very irregular +considering the limited number of days, and it bears at least a general +resemblance to that shown by Weinstein's figures for an east-west line +in Germany. This will serve to illustrate the uncertainties affecting +these and analogous observations. A constant current in one direction +may arise in whole or part from plate E.M.F.'s; a current showing a +diurnal inequality will naturally arise between _any_ two places some +distance apart whether they be at different levels or not. Finally, when +records are taken only for a short time, doubts must arise as to the +generality of the results. During the Ben Nevis observations, for +instance, we are told that the summit was almost constantly enveloped in +fog or mist. By having three earth plates in the same vertical plane, +one at the top of a mountain, the others at opposite sides of it, and +then observing the currents between the summit and each of the base +stations, as well as directly between the base stations--during an +adequate number of days representative of different seasons of the year +and different climatic conditions--many uncertainties would soon be +removed. + +10. _Artificial Currents._--The great extension in the applications of +electricity to lighting, traction and power transmission, characteristic +of the end of the 19th century, has led to the existence of large +artificial earth currents, which exert a disturbing influence on +galvanometers and magnetic instruments, and also tend to destroy metal +pipes. In the former case, whilst the disturbance is generally loosely +assigned to stray or "vagabond" earth currents, this is only partly +correct. The currents used for traction are large, and even if there +were a perfectly insulated return there would be a considerable +resultant magnetic field at distances from the track which were not +largely in excess of the distance apart of the direct and return +currents (16). At a distance of half a mile or more from an electric +tram line the disturbance is usually largest in magnetographs recording +the vertical component of the earth's field. The magnets are slightly +displaced from the position they would occupy if undisturbed, and are +kept in continuous oscillation whilst the trams are running (17). The +extent of the oscillation depends on the damping of the magnets. + +The distance from an electric tram line where the disturbance ceases to +be felt varies with the system adopted. It also depends on the length of +the line and its subdivision into sections, on the strength of the +currents supplied, the amount of leakage, the absence or presence of +"boosters," and finally on the sensitiveness of the magnetic +instruments. At the U.S. Coast and Geodetic Survey's observatory at +Cheltenham the effect of the Washington electric trams has been detected +by highly sensitive magnetographs, though the nearest point of the line +is 12 m. away (18). Amongst the magnetic observatories which have +suffered severely from this cause are those at Toronto, Washington +(Naval Observatory), Kew, Paris (Parc St Maur), Perpignan, Nice, Lisbon, +Vienna, Rome, Bombay (Colaba) and Batavia. In some cases magnetic +observations have been wholly suspended, in others new observatories +have been built on more remote sites. + +As regards damage to underground pipes, mainly gas and water pipes, +numerous observations have been made, especially in Germany and the +United States. When electric tramways have uninsulated returns, and the +potential of the rails is allowed to differ considerably from that of +the earth, very considerable currents are found in neighbouring pipes. +Under these conditions, if the joints between contiguous pipes forming a +main present appreciable resistance, whilst the surrounding earth +through moisture or any other cause is a fair conductor, current passes +locally from the pipes to the earth causing electrolytic corrosion of +the pipes. Owing to the diversity of interests concerned, the extent of +the damage thus caused has been very variously estimated. In some +instances it has been so considerable as to be the alleged cause of the +ultimate failure of water pipes to stand the pressure they are exposed +to. + + BIBLIOGRAPHY.--See Svante August Arrhenius, _Lehrbuch der kosmischen + Physik_ (Leipzig, 1903), pp. 984-990. For lists of references see J.E. + Burbank, _Terrestrial Magnetism_, vol. 10 (1905), p. 23, and P. + Bachmetjew (8). For papers descriptive of corrosion of pipes, &c., by + artificial currents see _Science Abstracts_ (in recent years in the + volumes devoted to engineering) under the heading "Traction, Electric; + Electrolysis." The following are the references in the text:--(1) + _Phil. Trans. R.S._ for 1849, pt. i. p. 61; (2) _Phil. Trans. R.S._ + vol. 151 (1861), p. 89, and vol. 152 (1862), p. 203; (3) _Etude des + courants telluriques_ (Paris, 1884); (4) _Die Erdstroeme im deutschen + Reichstelegraphengebiet_ (Braunschweig, 1900); (5) _Phil. Trans. R.S._ + vol. 158 (1868), p. 465, and vol. 160 (1870), p. 215; (6) _Mem. de + l'Academie St-Petersbourg_, t. 31, No. 12 (1883); (7) T. Moureaux, + _Ann. du Bureau Central Met._ (Annee 1893), 1 Mem. p. B 23; (8) P. + Bachmetjew, _Mem. de l'Academie St-Petersbourg_, vol. 12, No. 3 + (1901); (9) _Terrestrial Magnetism_, vol. 3 (1898), p. 130; (10) + _Journal Tel. Engineers_ (1881); (11) _Proc. R.S._ vol. 52 (1892), p. + 191; (12) _Akad. Abhandlung_ (Helsingfors, 1888); (13) _Acad. Napoli + Rend._ (1890), and _Atti_ (1894, 1895); (14) _Pogg. Ann._ vol. 76, p. + 135; (15) _Proc. R.S.E._ vol. 13, p. 530; (16) A. Ruecker, _Phil. Mag._ + 1 (1901), p. 423, and R.T. Glazebrook, ibid. p. 432; (17) J. Edler, + _Elektrotech. Zeit._ vol. 20 (1899); (18) L.A. Bauer, _Terrestrial + Magnetism_, vol. 11 (1906), p. 53. (C. Ch.) + + + + +EARTH-NUT, the English name for a plant known botanically as _Conopodium +denudatum_ (or _Bunium flexuosum_), a member of the natural order +Umbelliferae, which has a brown tuber-like root-stock the size of a +chestnut. It grows in woods and fields, has a slender flexuous smooth +stem 2 to 3 ft. high, much-divided leaves, and small white flowers in +many-rayed terminal compound umbels. Boswell Syme, in _English Botany_, +iv. 114, says: "The common names of this plant in England are various. +It is known as earth-nut, pig-nut, ar-nut, kipper-nut, hawk-nut, +jar-nut, earth-chestnut and ground-nut. Though really excellent in taste +and unobjectionable as food, it is disregarded in England by all but +pigs and children, both of whom appreciate it and seek eagerly for it." +Dr Withering describes the roots as little inferior to chestnuts. In +Holland and elsewhere on the continent of Europe they are more +generally eaten. + + + + +EARTH PILLAR, a pillar of soft rock, or earth, capped by some harder +material that has protected it from denudation. The "bad lands" of +western North America furnish numerous examples. Here "the formations +are often beds of sandstone or shale alternating with unindurated beds +of clay. A semi-arid climate where the precipitation is much +concentrated seems to be most favourable to the development of this type +of formation." The country round the Dead Sea, where loose friable sandy +clay is capped by harder rock, produces "bad-land" topography. The cap +of hard rock gives way at the joints, and the water making its way +downwards washes away the softer material directly under the cracks, +which become wider, leaving isolated columns of clay capped with hard +sandstone or limestone. These become smaller and fewer as denudation +proceeds, the pillars standing a great height at times, until finally +they all disappear. + + + + +EARTHQUAKE. Although the terrible effects which often accompany +earthquakes have in all ages forced themselves upon the attention of +man, the exact investigation of seismic phenomena dates only from the +middle of the 19th century. A new science has been thus established +under the name of _seismology_ (Gr. [Greek: seismos], an earthquake). + +_History._--Accounts of earthquakes are to be found scattered through +the writings of many ancient authors, but they are, for the most part, +of little value to the seismologist. There is a natural tendency to +exaggeration in describing such phenomena, sometimes indeed to the +extent of importing a supernatural element into the description. It is +true that attempts were made by some ancient writers on natural +philosophy to offer a rational explanation of earthquake phenomena, but +the hypotheses which their explanations involved are, as a rule, too +fanciful to be worth reproducing at the present day. It is therefore +unnecessary to dwell upon the references to seismic phenomena which have +come down to us in the writings of such historians and philosophers as +Thucydides, Aristotle and Strabo, Seneca, Livy and Pliny. Nor is much to +be gleaned from the pages of medieval and later writers on earthquakes, +of whom the most notable are Fromondi (1527), Maggio (1571) and +Travagini (1679). In England, the earliest work worthy of mention is +Robert Hooke's _Discourse on Earthquakes_, written in 1668, and read at +a later date before the Royal Society. This discourse, though containing +many passages of considerable merit, tended but little to a correct +interpretation of the phenomena in question. Equally unsatisfactory were +the attempts of Joseph Priestley and some other scientific writers of +the 18th century to connect the cause of earthquakes with electrical +phenomena. The great earthquake of Lisbon in 1755 led the Rev. John +Michell, professor of mineralogy at Cambridge, to turn his attention to +the subject; and in 1760 he published in the _Philosophical +Transactions_ a remarkable essay on the Cause and Phenomena of +Earthquakes. A suggestion of much scientific interest was made by Thomas +Young, when in his _Lectures on Natural Philosophy_, published in 1807, +he remarked that an earthquake "is probably propagated through the earth +nearly in the same manner as a noise is conveyed through the air." The +recognition of the fact that the seismologist has to deal with the +investigation of wave-motion in solids lies at the very base of his +science. In 1846 Robert Mallet communicated to the Royal Irish Academy +his first paper "On the Dynamics of Earthquakes"; and in the following +year W. Hopkins, of Cambridge, presented to the British Association a +valuable report in which earthquake phenomena were discussed in some +detail. Mallet's labours were continued for many years chiefly in the +form of Reports to the British Association, and culminated in his great +work on the Neapolitan earthquake of 1857. An entirely new impetus, +however, was given to the study of earthquakes by an energetic body of +observers in Japan, who commenced their investigations about the year +1880, mainly through the influence of Prof. John Milne, then of Tokyo. +Their work, carried on by means of new instruments of precision, and +since taken up by observers in many parts of the world, has so extended +our knowledge of earthquake-motion that seismology has now become +practically a new department of physical science. + +It is hardly too much to say, however, that the earliest systematic +application of scientific principles to the study of the effects of an +earthquake was made by Mallet in his investigation of the Neapolitan +earthquake mentioned above. It is true, the great Calabrian earthquake +of 1783 had been the subject of careful inquiry by the Royal Academy of +Naples, as also by Deodat Dolomieu and some other scientific +authorities; but in consequence of the misconception which at that time +prevailed with regard to the nature of seismic activity, the results of +the inquiry, though in many ways interesting, were of very limited +scientific value. It was reserved for Mallet to undertake for the first +time an extensive series of systematic observations in an area of great +seismic disturbance, with the view of explaining the phenomena by the +application of the laws of wave-motion. + + + Neapolitan earthquake, 1857. + +The "Great Neapolitan Earthquake," by which more than 12,300 lives were +lost, was felt in greater or less degree over all Italy south of the +parallel of 42 deg., and has been regarded as ranking third in order of +severity among the recorded earthquakes of Europe. The principal shock +occurred at about 10 P.M. on the 16th of December 1857; but, as is +usually the case, it had been preceded by minor disturbances and was +followed by numerous after-shocks which continued for many months. Early +in 1858, aided by a grant from the Royal Society, Mallet visited the +devastated districts, and spent more than two months in studying the +effects of the catastrophe, especially examining, with the eye of an +engineer, the cracks and ruins of the buildings. His voluminous report +was published in 1862, and though his methods of research and his +deductions have in many cases been superseded by the advance of +knowledge, the report still remains a memorable work in the history of +seismology. + +Much of Mallet's labour was directed to the determination of the +position and magnitude of the subterranean source from which the +vibratory impulses originated. This is known variously as the _seismic +centre_, _centrum_, _hypocentre_, _origin_ or _focus_. It is often +convenient to regard this centre theoretically as a point, but +practically it must be a locus or space of three dimensions, which in +different cases varies much in size and shape, and may be of great +magnitude. That part of the surface of the earth which is vertically +above the centre is called the _epicentre_; or, if of considerable area, +the epicentral or epifocal tract. A vertical line joining the epicentre +and the focus was termed by Mallet the _seismic vertical_. He calculated +that in the case of the Neapolitan earthquake the focal cavity was a +curved lamelliform fissure, having a length of about 10 m. and a height +of about 31/2 m., whilst its width was inconsiderable. The central point +of this fissure, the theoretical seismic centre, he estimated to have +been at a depth of about 61/2 m. from the surface. Dr C. Davison, in +discussing Mallet's data, was led to the conclusion that there were two +distinct foci, possibly situated on a fault, or plane of dislocation, +running in a north-west and south-east direction. Mallet located his +epicentre near the village of Caggiano, not far from Polla, while the +other seems to have been in the neighbourhood of Montemurro, about 25 m. +to the south-east. + +The intensity, or violence, of an earthquake is greatest in or near the +epicentre, whence it decreases in all directions. A line drawn through +points of equal intensity forms a curve round the epicentre known as an +_isoseist_, an _isoseismal_ or an _isoseismic line_. If the intensity +declined equally in all directions the isoseismals would be circles, but +as this is rarely if ever the case in nature they usually become +ellipses and other closed curves. The tract which is most violently +shaken was termed by Mallet the _meizoseismic area_, whilst the line of +maximum destruction is known as the _meizoseismic line_. That isoseismal +along which the decline of energy is most rapid was called by K. von +Seebach a _pleistoseist_. + +In order to determine the position of the seismic centre, Mallet made +much use of the cracks in damaged buildings, especially in walls of +masonry, holding that the direction of such fractures must generally be +at right angles to that in which the normal earthquake-wave reached +them. In this way he obtained the "angle of emergence" of the wave. He +also assumed that free-falling bodies would be overthrown and projected +in the direction of propagation of the wave, so that the epicentre might +immediately be found from the intersection of such directions. These +data are, however, subject to much error, especially through want of +homogeneity in the rocks, but Mallet's work was still of great value. + + + Charleston earthquake, 1886. + +A different method of ascertaining the depth of the focus was adopted by +Major C.E. Dutton in his investigation of the Charleston earthquake of +the 31st of August 1886 for the U.S. Geological Survey. This catastrophe +was heralded by shocks of greater or less severity a few days previously +at Summerville, a village 22 m. north-west of Charleston. The great +earthquake occurred at 9.51 P.M., standard time of the 75th meridian, +and in about 70 seconds almost every building in Charleston was more or +less seriously damaged, while many lives were lost. The epicentral tract +was mainly a forest region with but few buildings, and the principal +records of seismological value were afforded by the lines of railway +which traversed the disturbed area. In many places these rails were +flexured and dislocated. Numerous fissures opened in the ground, and +many of these discharged water, mixed sometimes with sand and silt, +which was thrown up in jets rising in some cases to a height of 20 ft. +Two epicentres were recognized--one near Woodstock station on the South +Carolina railway, and the other, being the centre of a much smaller +tract, about 14 m. south-west of the first and near the station of +Rantowles on the Charleston and Savannah line. Around these centres and +far away isoseismal lines were drawn, the relative intensity at +different places being roughly estimated by the effects of the +catastrophe on various structures and natural objects, or, where visible +records were wanting, by personal evidence, which is often vague and +variable. The Rossi-Forel scale was adopted. This is an arbitrary scale +formulated by Professor M.S. de Rossi, of Rome, and Dr F.A. Forel, of +Geneva, based mostly on the ordinary phenomena observed during an +earthquake, and consisting of ten degrees, of which the lowest is the +feeblest, viz. I. Microseismic shock; II. Extremely feeble shock; III. +Very feeble shock; IV. Feeble; V. Shock of moderate intensity; VI. +Fairly strong shock; VII. Strong shock; VIII. Very strong shock; IX. +Extremely strong shock; X. Shock of extreme intensity. Other +conventional scales, some being less detailed, have been drawn up by +observers in such earthquake-shaken countries as Italy and Japan. A +curve, or theoretical isoseismal, drawn through certain points where the +decline of intensity on receding from the epicentre seems to be greatest +was called by Dutton an "index-circle"; and it can be shown that the +radius of such a circle multiplied by the square root of 3 gives the +focal depth theoretically. In this way it was computed that in the +Charleston earthquake the origin under Woodstock must have had a depth +of about 12 m. and that near Rantowles a depth of nearly 8 m. The +determination of the index-circle presents much difficulty, and the +conclusions must be regarded as only approximate. + +It is probable, according to R.D. Oldham, that local earthquakes may +originate in the "outer skin" of the earth, whilst a large world-shaking +earthquake takes its origin in the deeper part of the "crust," whence +such a disturbance is termed a _bathyseism_. Large earthquakes may have +very extended origins, with no definite centre, or with several foci. + + + Great Indian earthquake, 1897. + +The gigantic disaster known as the "Great Indian Earthquake," which +occurred on the 12th of June 1897, was the subject of careful +investigation by the Geological Survey of India and was described in +detail by the superintendent, R.D. Oldham. It is sometimes termed the +Assam earthquake, since it was in that province that the effects were +most severe, but the shocks were felt over a large part of India, and +indeed far beyond its boundaries. Much of the area which suffered most +disturbance was a wild country, sparsely populated, with but few +buildings of brick or stone from which the violence of the shocks could +be estimated. The epicentral tract was of great size, having an +estimated area of about 6000 sq. m., but the mischief was most severe in +the neighbourhood of Shillong, where the stonework of bridges, churches +and other buildings was absolutely levelled to the ground. After the +main disturbance, shocks of greater or less severity continued at +intervals for many weeks. It is supposed that this earthquake was +connected with movement of subterranean rock-masses of enormous +magnitude along a great thrust-plane, or series of such planes, having a +length of about 200 m. and a maximum breadth of not less than 50 m. It +is pointed out by Oldham that this may be compared for size with the +great Faille du Midi in Belgium, which is known to extend for a distance +of 120 m. The depth of the principal focus, though not actually capable +of determination, was probably less than 5 m. from the surface. From the +focus many secondary faults and fractures proceeded, some reaching the +surface of the ground. Enormous landslips accompanied the earthquake, +and as an indirect effect of these slides the form of the water-courses +became in certain cases modified. Permanent changes of level were also +observed. + + + Kangra earthquake, 1905. + +Eight years after the great Assam earthquake India was visited by +another earthquake, which, though less intense, resulted in the loss of +about 20,000 lives. This catastrophe is known as the Kangra earthquake, +since its centre seems to have been located in the Kangra valley, in the +north-west Himalaya. It occurred on the 4th of April 1905, and the first +great shocks were felt in the chief epifocal district at about 6.9 a.m., +Madras time. Although the tract chiefly affected was around Kangra and +Dharmsala, there was a subordinate epifocal tract in Dehra Dun and the +neighbourhood of Mussoorie, whilst the effects of the earthquake +extended in slight measure to Lahore and other cities of the plain. It +is estimated that the earthquake was felt over an area of about +1,625,000 m. Immediately after the calamity a scientific examination of +its effects was made by the Geological Survey of India, and a report was +drawn up by the superintendent, C.S. Middlemiss. + + + California earthquake, 1906. + +The great earthquake, which, with the subsequent fire, wrought such +terrible destruction in and around San Francisco on the 18th of April +1906, was the most disastrous ever recorded in California. It occurred +between 10 and 15 minutes after 5 A.M., standard time of the 120th +meridian. The moment at which the disaster began and the duration of the +shock varied at different localities in the great area over which the +earthquake was felt. At San Francisco the main shock lasted rather more +than one minute. + +According to the official Report, the earthquake was due to rupture and +movement along the plane of the San Andreas fault, one of a series which +runs for several hundred miles approximately in a N.W. and S.E. +direction near the coast line. Evidence of fresh movement along this +plane of dislocation was traced for a distance of 190 m. from San Juan +on the south to Point Arena on the north. There the trace of the fault +is lost beneath the sea, but either the same fault or another appears 75 +m. to the north at Point Delgada. The belt of disturbed country is +notoriously unstable, and part of the fault had been known as the +"earthquake crack." The direction is marked by lines of straight cliffs, +long ponds and narrow depressions, forming a Rift, or old line of +seismic disturbance. According to Dr G.K. Gilbert the earthquake zone +has a length of 300 or 400 m. The principal displacement of rock, in +1906, was horizontal, amounting generally to about 10 ft. (maximum 21 +ft.), but there was also locally a slight vertical movement, which +towards the north end of the fault reached 3 ft. Movement was traced for +a distance of about 270 m., and it is estimated that at least 175,000 +sq. m. of country must have been disturbed. In estimating the intensity +of the earthquake in San Francisco a new scale was introduced by H.O. +Wood. The greatest structural damage occurred on soft alluvial soil and +"made ground." Most of the loss of property in San Francisco was due to +the terrible fire which followed the earthquake and was beyond control +owing to the destruction of the system of water-supply. + +Immediately after the catastrophe a California Earthquake Investigation +Committee was appointed by the governor of the state; and the American +Association for the Advancement of Science afterwards instituted a +Seismological Committee. The elaborate Report of the State Investigation +Committee, by the chairman, Professor A.C. Lawson, was published in +1908. + +On the 17th of August 1906 a disastrous earthquake occurred at +Valparaiso, and the year 1906 was marked generally by exceptional +seismic activity. + +The Jamaica earthquake of the 14th of January 1907 appears to have +accompanied movement of rock along an east and west fracture or series +of fractures under the sea a few miles from the city of Kingston. The +statue of Queen Victoria at Kingston was turned upon its pedestal the +eighth of a revolution. + + + Messina earthquake, 1908. + +A terrible earthquake occurred in Calabria and Sicily on December 28, +1908, practically destroying Messina and Reggio. According to the +official returns the total loss of life was 77,283. Whilst the principal +centre seems to have been in the Strait of Messina, whence the +disturbance is generally known as the Messina earthquake, there were +independent centres in the Calabrian peninsula, a country which had been +visited by severe earthquakes not long previously, namely on September +8, 1905, and October 23, 1907. The principal shock of the great Messina +earthquake of 1908 occurred at 5.21 A.M. (4.21 Greenwich time), and had +a duration of from 30 to 40 seconds. Neither during nor immediately +before the catastrophe was there any special volcanic disturbance at +Etna or at Stromboli, but it is believed that there must have been +movement along a great plane of weakness in the neighbourhood of the +Strait of Messina, which has been studied by E. Cortese. The sea-floor +in the strait probably suffered great disturbance, resulting in the +remarkable movement of water observed on the coast. At first the sea +retired, and then a great wave rolled in, followed by others generally +of decreasing amplitude, though at Catania the second was said to have +been greater than the first. At Messina the height of the great wave was +2.70 metres, whilst at Ali and Giardini it reached 8.40 metres and at +San Alessio as much as 11.7 metres. At Malta the tide-gauge recorded a +wave of 0.91 metre. The depth of the chief earthquake-centre was +estimated by Dr E. Oddone at about 9 kilometres. The earthquake and +accompanying phenomena were studied also by Professor A. Ricco, Dr M. +Baratta and Professor G. Platania and by Dr F. Omori of Tokyo. After the +great disturbance, shocks continued to affect the region intermittently +for several months. In certain respects the earthquake of 1908 presented +much resemblance to the great Calabrian catastrophe of 1783. + +It has been proposed by R.D. Oldham that the disturbance which causes +the fracture and permanent displacement of the rocks during an +earthquake should be called an "earthshake," leaving the term earthquake +especially for the vibratory motion. The movement of the earthquake is +molecular, whilst that of the earthshake is molar. Subsequently he +suggested the terms _mochleusis_ and _orchesis_ ([Greek: mochleuo], I +heave; [Greek: orcheomai], I dance), to denote respectively the molar +and the molecular movement, retaining the word earthquake for use in its +ordinary sense. + +In most earthquakes the proximate cause is generally regarded as the +fracture and sudden movement of underground rock-masses. Disturbances of +this type are known as "tectonic" earthquakes, since they are connected +with the folding and faulting of the rocks of the earth's crust. They +indicate a relief of the strain to which the rock-masses are subjected +by mountain-making and other crustal movements, and they are +consequently apt to occur along the steep face of a table-land or the +margin of a continent with a great slope from land to sea. In many cases +the immediate seat of the originating impulse is located beneath the +sea, giving rise to submarine disturbances which have been called +"seaquakes." Much attention has been given to these suboceanic +disturbances by Professor E. Rudolph. + +Professor J.H. Jeans has pointed out that the regions of the earth's +crust most affected by earthquakes lie on a great circle corresponding +with the equator of the slightly pear-shaped figure that he assigns to +the earth. This would represent a belt of weakness, subject to crushing, +from the tendency of the pear to pass into a spherical or spheroidal +form under the action of internal stresses. According to the comte de +Montessus de Ballore, the regions of maximum seismic instability appear +to be arranged on two great circles, inclined to each other at about +67 deg.. These are the Circumpacific and Mediterranean zones. + +Maps of the world, showing the origins of large earthquakes each year, +accompany the Annual Reports of the Seismological Committee of the +British Association, drawn up by Professor Milne. It is important to +note that Professor Milne has shown a relationship between +earthquake-frequency and the wandering of the earth's pole from its mean +position. Earthquakes seem to have been most frequent when the +displacement of the pole has been comparatively great, or when the +change in the direction of movement has been marked. Valuable earthquake +catalogues have been compiled at various times by Alexis Perrey, R. and +J.W. Mallet, John Milne, T. Oldham, C.W.C. Fuchs, F. de Montessus de +Ballore and others. + + + British earthquakes. + +Such earthquakes as are felt from time to time in Great Britain may +generally be traced to the formation of faults, or rather to incidents +in the growth of old faults. The East Anglian earthquake of the 22nd of +April 1884--the most disastrous that had occurred in the British Isles +for centuries--was investigated by Prof. R. Meldola and W. White on +behalf of the Essex Field Club. The shocks probably proceeded from two +foci--one near the villages of Peldon and Abberton, the other near +Wivenhoe and Rowhedge, in N.E. Essex. It is believed that the +superficial disturbance resulted from rupture of rocks along a deep +fault. An attempt has been made by H. Darwin, for the Seismological +Committee of the British Association, to detect and measure any gradual +movement of the strata along a fault, by observation at the Ridgeway +fault, near Upway, in Dorsetshire. Dr C. Davison in studying the +earthquakes which have originated in Britain since 1889 finds that +several have been "twins." A twin earthquake has two maxima of intensity +proceeding from two foci, whereas a double earthquake has its successive +impulses from what is practically a single focus. The Hereford +earthquake of December 1896, which resulted in great structural damage, +was a twin, having one epicentre near Hereford and the other near Ross. +Davison refers it to a slip along a fault-plane between the anticlinal +areas of Woolhope and May Hill; and according to the same authority the +Inverness earthquake of the 18th of September 1901 was referable to +movement along a fault between Loch Ness and Inverness. The South Wales +earthquake of June 27, 1906, was probably due to movement connected with +the Armorican system of folds, striking in an east and west direction. + +It may be noted that when a slip occurs along a fault, the displacement +underground may be but slight and may die out before reaching the +surface, so that no scarp is formed. In connexion, however, with a +seismic disturbance of the first magnitude the superficial features may +be markedly affected. Thus, the great Japan earthquake of October +1891--known often as the Mino-Owari earthquake--was connected with the +formation or development of a fault which, according to Professor B. +Koto, was traced on the surface for a distance of nearly 50 m. and +presented in places a scarp with a vertical throw of as much as 20 ft., +while probably the maximum displacement underground was very much +greater. + +Although most earthquakes seem to be of tectonic type, there are some +which are evidently connected, directly or indirectly, with volcanic +activity (see VOLCANO). Such, it is commonly believed, were the +earthquakes which disturbed the Isle of Ischia in 1881 and 1883, and +were studied by Professor J. Johnston-Lavis and G. Mercalli. In addition +to the tectonic and volcanic types, there are occasional earthquakes of +minor importance which may be referred to the collapse of the roof of +caverns, or other falls of rock in underground cavities at no great +depth. According to Prof. T.J.J. See most earthquakes are due, directly +or indirectly, to the explosive action of ste by the leakage of +sea-water through the ocean floor. + + + Earthquake waves. + +Whatever the nature of the impulse which originates the earthquake, it +gives rise to a series of waves which are propagated through the earth's +substance and also superficially. In one kind, known as normal or +condensational waves, or waves of elastic compression, the particles +vibrate to and from the centre of disturbance, moving in the direction +in which the wave travels, and therefore in a way analogous to the +movement of air in a sound-wave. Associated with this type are other +waves termed transverse waves, or waves of elastic distortion, in which +the particles vibrate across or around the direction in which the wave +is propagated. The normal waves result from a temporary change of volume +in the medium; the transverse from a change of shape. The distance +through which an earth-particle moves from its mean position of rest, +whether radially or transversely, is called the amplitude of the wave; +whilst the double amplitude, or total distance of movement, to and fro +or up and down, like the distance from crest to trough of a water wave, +may be regarded as the range of the wave. The period of a wave is the +time required for the vibrating particle to complete an oscillation. As +the rocks of the earth's crust are very heterogeneous, the +earthquake-waves suffer refraction and reflection as they pass from one +rock to another differing in density and elasticity. In this way the +waves break up and become much modified in course of transmission, thus +introducing great complexity into the phenomena. It is known that the +normal waves travel more rapidly than the transverse. + +Measurements of the surface speed at which earthquake-waves travel +require very accurate time-measurers, and these are not generally +available in earthquake-shaken regions. Observations during the +Charleston earthquake of 1886 were at that time of exceptional value, +since they were made over a large area where standard time was kept. +Lines drawn through places around the epicentre at which the shock +arrives at the same moment are called coseismal lines. The motion of the +wave is to be distinguished from the movement of the vibrating +particles. The velocity of the earth-particle is its rate of movement, +but this is constantly changing during the vibration, and the rate at +which the velocity changes is technically called the acceleration of the +particle. + +Unfelt movements of the ground are registered in the earthquake records, +or seismograms, obtained by the delicate instruments used by modern +seismologists. From the study of the records of a great earthquake from +a distant source, sometimes termed a teleseismic disturbance, some +interesting inferences have been drawn with respect to the constitution +of the interior of the earth. The complete record shows two phases of +"preliminary tremors" preceding the principal waves. It is believed that +while the preliminary tremors pass through the body of the earth, the +principal waves travel along or parallel to the surface. Probably the +first phase represents condensational, and the second phase +distortional, waves. Professor Milne concludes from the speed of the +waves at different depths that materials having similar physical +properties to those at the surface may extend to a depth of about 30 m., +below which they pass into a fairly homogeneous nucleus. From the +different rates of propagation of the precursors it has been inferred by +R.D. Oldham that below the outer crust, which is probably not everywhere +of the same thickness, the earth is of practically uniform character to +a depth of about six-tenths of the radius, but the remaining four-tenths +may represent a core differing physically and perhaps chemically from +the outer part. Oldham also suggests, from his study of oceanic and +continental wave-paths, that there is probably a difference in the +constitution of the earth beneath oceans and beneath continents. + +The surface waves, which are waves of great length and long period and +are propagated to great distances with practically a constant velocity, +have been regarded as quasi-elastic gravitational waves. Further, in a +great earthquake the surface of the ground is sometimes visibly agitated +in the epifocal district by undulations which may be responsible for +severe superficial damage. (See also for elastic waves ELASTICITY, Sec. +89.) + +An old classification of earthquake-shocks, traces of which still linger +in popular nomenclature, described them as "undulatory," when the +movement of the ground was mainly in a horizontal direction; +"subsultory," when the motion was vertical, like the effect of a normal +wave at the epicentre; and "vorticose," when the movement was rotatory, +apparently due to successive impulses in varying directions. + +The sounds which are associated with seismic phenomena, often described +as subterranean rumbling and roaring, are not without scientific +interest, and have been carefully studied by Davison. "Isacoustic lines" +are curves drawn through places where the sound is heard by the same +percentage of observers. The sound is always low and often inaudible to +many. + +The refined instruments which are now used by seismologists for +determining the elements of earthquake motion and for recording +earthquakes from distant origins are described in the article +SEISMOMETER. These instruments were developed as a consequence of the +attention given in modern times to the study of earthquakes in the Far +East. (F. W. R.*) + + + Seismology in Japan. + +Strange as it may appear, the advances that have been made in the study +of earthquakes and the world-wide interest shown in their phenomena were +initiated in work commenced in Japan. When the Japanese government, +desiring to adopt Western knowledge, invited to its shores bodies of men +to act as its instructors, the attention of the newcomers was naturally +attracted to the frequent shakings of the ground. Interest in these +phenomena increased more rapidly than their frequency, and at length it +was felt that something should be done for their systematic study. At +midnight on the 22nd of February 1880 movements more violent than usual +occurred; chimneys were shattered or rotated, tiles slid down from +roofs, and in the morning it was seen that Yokohama had the appearance +of a city that had suffered a bombardment. The excitement was intense, +and before the ruins had been removed a meeting was convened and the +Seismological Society of Japan established. The twenty volumes of +original papers published by this body summarize to a large extent the +results of the later study of seismology.[1] + +The attention of the students of earthquakes in Japan was at first +directed almost entirely to seismometry or earthquake measurement. Forms +of apparatus which then existed, as for example the seismographs, +seismometers and seismoscopes of Mallet, Palmieri and others, were +subjected to trial; but inasmuch as they did little more than indicate +that an earthquake had taken place--the more elaborate forms recording +also the time of its occurrence--they were rapidly discarded, and +instruments were constructed to _measure_ earthquake motion. Slightly +modified types of the new instruments devised in Japan were adopted +throughout the Italian peninsula, and it is fair to say that the +seismometry developed in Japan revolutionized the seismometry of the +world. The records obtained from the new instruments increased our +knowledge of the character of earthquake motion, and the engineer and +the architect were placed in a position to construct so that the effects +of known movements could be minimized. It was no doubt the marked +success, both practical and scientific, attending these investigations +that led the Japanese government to establish a chair of seismology at +its university, to organize a system of nearly 1000 observing stations +throughout the country, and in 1893 to appoint a committee of scientific +and practical men to carry out investigations which might palliate the +effects of seismic disturbances. In the first year this committee +received a grant of L5000, and as liberal sums for the same purpose +appear from time to time in the parliamentary estimates, it may be +assumed that the work has been fraught with good results. In their +publications we find not only records of experiences and experiments in +Japan, but descriptions and comments upon earthquake effects in other +countries. In two of the volumes there are long and extremely well +illustrated accounts of the earthquake which on the 12th of June 1897 +devastated Assam, to which country two members of the above-mentioned +committee were despatched to gather such information as might be of +value to the architect and builder in earthquake-shaken districts. + + + Seismological research. + +A great impetus to seismological investigation in Europe and America was +no doubt given by the realization of the fact that a large earthquake +originating in any one part of the world may be recorded in almost any +other. Italy for many years past has had its observatories for recording +earthquakes which can be felt, and which are of local origin, but at the +present time at all its first-class stations we find instruments to +record the unfelt movements due to earthquakes originating at great +distances, and as much attention is now paid to the large earthquakes of +the world as to the smaller ones originating within Italian +territory.[2] The _Kaiserliche Akademie der Wissenschaften_ of Vienna +established earthquake observatories in Austria,[3] and the Central +Observatorium of St Petersburg has carried out similar work in Russia. +Germany attached a seismological observatory to its university at +Strassburg, whilst provision has been made for a professorship of Earth +Physics (_Geophysik_) at Goettingen.[4] In accordance with the +recommendation of the British Association, seismographs of a similar +character have been installed at stations all over the world.[5] The +principal objects of this extended and still extending system of +stations are to determine the velocity with which motion is propagated +over the surface and through the interior of the earth, to locate the +positions of sub-oceanic earthquake origins, and generally to extend our +knowledge respecting the physical nature of the planet on which we live. + + + Frequency of earthquakes. + +We now know that earthquakes are many times more frequent than was +previously supposed. In Japan, for example, between 1885 and 1892 no +fewer than 8331 were recorded--that is to say, on the average there were +during that time more than 1000 disturbances per year. Although many of +these did not cause a sensible shaking over areas exceeding a few +hundred square miles, many of them were sufficiently intense to +propagate vibrations round and through the globe. If we pick out the +well-marked earthquake districts of the world, and give to each of them +a seismicity or earthquake frequency per unit area one-third of that in +Japan, the conclusion arrived at is that considerable areas of our +planet are on the average shaken every half-hour. + + + Volcanoes and earthquakes. + +The knowledge which we now possess respecting the localities where +earthquakes are frequent and the forms of the foci from which they have +spread, enables us to speak definitely respecting the originating causes +of many of these phenomena. It is found, for example, that although in +many countries there may be displays of volcanic and seismic activity +taking place almost side by side, it is only rarely that there is direct +relationship between the two. Now and then, however, before a volcano +breaks into eruption there may be a few ineffectual efforts to form a +vent, each of which is accompanied by no more than a slight local +shaking of the ground. This is true even for the largest and most +violent eruptions, when mountains have with practically a single effort +blown off their heads and shoulders. Thus the earthquake which +accompanied the eruption of Bandaisan, in central Japan, in 1888 was +felt only over a radius of 25 m. The analyses of the seismic registers +of Japan clearly indicate that comparatively few shakings originate near +to the volcanoes of the country, the majority of them, like those of +many other countries, coming from regions where volcanic rocks are +absent. The greatest number spread inland from the Pacific seaboard, the +movement becoming more and more feeble as it approaches the backbone of +the country, which is drilled with numerous volcanic vents. What is true +for Japan is generally true for the western coasts of North and South +America. + + + Origin of earthquakes. + +Speaking broadly, earthquakes are most frequent along the steeper +flexures in the earth's surface, and in those regions where there is +geological evidence to show that slow secular movements in the earth's +crust are possibly yet in progress. With a unit distance of 2 degrees, +or 120 geographical m., we find that the slopes running eastwards from +the highlands of Japan and westwards from the Andean ridges down into +the Pacific vary from 1 in 20 to 1 in 30, and it is on the faces or near +to the bottom of these slopes that seismic efforts are frequent. The +slopes running from Australia, eastern America and western Europe into +the neighbouring oceans vary between 1 in 70 and 1 in 250, and in these +regions earthquakes are of rare occurrence. The seismic activity met +with in the Himalayas and the Alps finds its best explanation in the +fact that these mountains are geologically recent, and there are no +reasons to doubt that the forces which brought their folds into +existence are yet in action. + +This peculiar association of earthquakes with pronounced topographical +configuration and certain geological conditions evidently indicates that +the origin of many of them is connected with rock folding. Inasmuch as +certain large earthquakes have been accompanied by rock fracture, as for +example in 1891, when in central Japan a fault some 50 m. in length was +created, whilst the origins of others have been distinctly traced to the +line of an existing fault or its continuation, we may conclude that the +majority of earthquakes are spasmodic accelerations in the secular +movements which are creating (and in some instances possibly +obliterating) the more prominent features of the earth's surface. These +secular movements, which include upheavals, subsidences, horizontal +displacements--all of which are explained on the assumption of a crust +seeking support on a nucleus gradually contracting by loss of heat, are +collectively referred to as bradyseismical ([Greek: bradys], slow) +movements. To these may be added movements directly attributable to the +influence of gravity. Sub-oceanic districts in a state of seismic strain +may be so far loaded by the accumulation of sediments that gentle +bending may be accompanied by sudden yieldings. This possibly accounts +for the frequency of earthquakes off the mouth of the Tonegawa on the +eastern side of Japan. The distortions so frequently observed in fossils +and pebbles, the varying thickness of contorted strata, and the "creep" +in coal-mines, together with other phenomena, indicate that rocks may +flow. Observations of this nature lead to the supposition that high +plateau-like regions may be gradually subsiding under the influence of +their own weight, and that the process of settlement may from time to +time be spasmodic in its character. Whether the earthquakes which +originate round the submerged basal frontiers of the continents bounding +the Pacific are ever attributable to such activities, it is impossible +to say. All that we know with certainty is that they are sometimes +accompanied by such a vast displacement of material that the ocean has +been set into a state of oscillation for periods of 24 hours, that in +some instances there have been marked changes in depth, and that +enormous sub-oceanic landslips have occurred. These phenomena are, +however, equally well explained on the assumption of sudden faulting +accompanied by violent shaking, which would dislodge steeply inclined +beds of material beneath the ocean as it does upon the land. + + + Two types of earthquake motion. + +Although the proximate cause of earthquake motion is traced to sudden +yieldings in the crust of the earth brought about by some form of +bradyseismical action, the existence of at least two distinct types of +seismic motion indicates that the mechanical conditions accompanying the +fracturing of rocks are not always identical. 90 or 95% of the +earthquakes which can be recorded consist of elastic or quasi-elastic +vibrations. The remainder, including the large earthquakes, not only +exhibit the elastic movements, but are accompanied by surface +undulations which are propagated most certainly for some hundreds of +miles round their origin, and then as horizontal movements sweep over +the whole surface of the globe. The former of these may accompany the +formation of a new fault or the sudden renewal of movement along an old +one; they are cracking or rending effects, without any great +displacement. The latter are probably fracturings accompanied by +vertical and horizontal displacements of masses of the earth's crust +sufficiently great to set up the observed surface undulations. These +shocks are so frequently followed a few minutes later by disturbances, +which from their similarity to the movements which have preceded them +may be called earthquake echoes, that we are led to the speculation that +we are here dealing with the caving-in of ill-supported portions of the +earth's crust, the waves from which are radiated to boundaries and then +returned to their origin to coalesce and give rise to a second impulse +not unlike the primary. Succeeding the first repetition of motion +recorded by the seismograph there is often a rhythmical repetition of +similar wave groups, suggesting the existence within our earth of +phenomena akin to multiple echoes. + + + Character of earthquake motion. + +The introduction of new methods into seismometry quickly revolutionized +our ideas respecting the character of earthquake motion. Although an +earthquake may be strongly felt within a distance of 50 m. from its +origin, and although the movements in the upper storeys of buildings +within the shaken area may be large, the actual range of the horizontal +motion of the ground is usually less than {1/10} of an inch. With such +earthquakes ordinary seismographs for recording vertical motion do not +show any disturbance. When the movement reaches 1/2 in. it becomes +dangerous, and a back-and-forth movement of an inch is usually +accompanied by destructive effects. In this latter case the amplitude of +the vertical record which indicates the existence of surface waves will +vary between 1/2 and {1/100} of an inch. In the earthquake which +devastated central Japan on the 26th of October 1891, nearly every +building within the epifocal district fell, the ground was fissured, +forests slipped down from mountain sides to dam up valleys, whilst the +valleys themselves were permanently compressed. The horizontal movements +seem to have reached 9 in. or 1 ft., and the surface undulations were +visible to the eye. + + + Period and duration. + +The rapidity with which the movements are performed varies throughout a +disturbance. A typical earthquake usually commences with minute elastic +vibrations, the periods of which vary between {1/5} and {1/20} of a +second. These are recorded by seismographs, and are noticed by certain +of the lower animals like pheasants, which before the occurrence of +movement perceptible to human beings scream as if alarmed. When an +earthquake is preceded by a sound we have evidence of preliminary +tremors even more rapid than those recorded by seismographs. Following +these precursors there is a shock or shocks, the period of which will be +1 or 2 seconds. From this climax the movements, although irregular in +character, become slower and smaller until finally they are +imperceptible. The duration of a small earthquake usually varies from a +few seconds to a minute, but large earthquakes, which are accompanied by +surface undulations, may be felt for 2 or 3 minutes, whilst an ordinary +seismograph indicates a duration of from 6 to 12 minutes. A free +horizontal pendulum tells us that with severe earthquakes the ground +comes to rest by a series of more or less rhythmical surgings, +continuing over 1 or 2 hours. Although the maximum displacement has a +definite direction, the successive vibrations are frequently performed +in many different azimuths. The predominating direction at a given +station in certain instances is apparently at right angles to the strike +of the neighbouring strata, this being the direction of easiest +yielding. + + + Velocity. + +Earthquake motion as recorded at stations several thousands of miles +distant from its origin exhibits characteristics strikingly different +from those just described. The precursors now show periods of from 1 to +5 seconds, whilst the largest movements corresponding to the shocks may +have periods of from 20 to 40 seconds. The interval of time by which the +first tremors have outraced the maximum movement has also become +greater. Within a few hundreds of miles from an origin this interval +increases steadily, the velocity of propagation of the first movements +being about 2 km. per second, whilst that of the latter may be taken at +about 1.6 km. per second. Beyond this distance the velocity of +transmission of the first movements rapidly increases, and for great +distances, as for example from Japan to England, it is higher than we +should expect for waves of compression passing through steel or glass. +This observation precludes the idea that these preliminary tremors have +travelled through the heterogeneous crust of the earth, and since the +average velocity of their transmission increases with the length of the +path along which they have travelled, and we but rarely obtain certain +evidence that a seismograph has been disturbed by waves which have +reached it by travelling in opposite directions round the world, we are +led to the conclusion that earthquake precursors pass through our earth +and not round its surface. The following table relating to earthquakes, +which originated off the coast of Borneo on the 20th and 27th of +September 1897, is illustrative of the velocities here considered:-- + + +---------------------------+-----------+-------------+---------------+ + | | | | _______ | + | | Distance | Velocity | /Average | + | Localities | from | in kms. | /depth of | + | | origin | per sec. if | \ / chord in | + | |in degrees.| on chord. | 1/4 V kms. | + +---------------------------+-----------+-------------+---------------+ + | Nicolaieff | 81 deg. | 8.1 | 8.0 | + | Potsdam | 92 deg. | 8.4 | 9.1 | + | Catania, Ischia, Rocca di | | | | + | Papa, Rome | 96 deg. | 9.0 | 9.5 | + | Isle of Wight | 103 deg. | 9.8 | 10.2 | + +---------------------------+-----------+-------------+---------------+ + +The chords referred to here are those joining the earthquake origins and +distant observing stations, and it will be noted that one-quarter of the +square root of the average depths at which these run closely corresponds +to observed average velocities if wave paths followed chords. This +increase of velocity with average depth shows that the paths followed +through the earth must be curved with their convexity towards the centre +of the earth. These observations do not directly tell us to what extent +a true wave path is deflected from the direction of a chord, but they +suggest as an extremely plausible assumption that the square of the +speed is a linear function of the depth below the surface of the earth. +With this assumption Dr C.G. Knott shows that the square of the speed +(v squared) can be expressed linearly in terms of the average depth of the +chord d, thus: v squared = 2.9 + .026 d, the units being miles and seconds. The +formula applies with fair accuracy to moderate and high values of d, but +it gives too high a value for short chords. It follows that the square +of the speed increases 0.9% per mile of descent in the earth. The +conclusion we arrive at is that the preliminary tremors which pass +through the earth do so in the vicinity of their origin at the rate of +almost 2.3 km. per second. This velocity increases as the wave path +plunges downwards, attaining in the central regions a velocity of 16 to +17 kms., whilst the highest average velocity which is across a diameter +lies between 10 and 12 kms. per second. + +The large surface waves radiating from an origin to a distant place have +velocities lying between 1.6 and 4 kms. per second, and it has been +observed that when the higher velocity has been noted this refers to an +observation at a station very remote from the origin. One explanation of +this is the assumption that only very large waves indicating a large +initial disturbance are capable of travelling to great distances, and as +pointed out by R.D. Oldham, large waves under the influence of gravity +will travel faster than small waves. These waves (which may be +gravitational or distortional) are recorded as slow tiltings of the +ground measured by angles of 0.5 to 10 or 15 seconds of arc, or as +horizontal displacements of 0.5 or several millimetres. Their calculated +lengths have reached 50 kms. (31 m.). + + + Frequency. + +In the section of this article relating to the cause of earthquakes a +little has been said about their frequency or the number of times these +phenomena are repeated during a given interval of time. It has been +shown that all countries are very often moved by earthquakes which have +originated at great distances. Great Britain, for example, is crossed +about 100 times a year by earthquake waves having durations of from 3 +minutes to 3 hours, whilst the vibratory motions which originate in that +country are not only small but of rare occurrence. In the earlier stages +of the world's history, because the contraction of its nucleus was more +rapid than it is at present, it is commonly inferred that phenomena +accompanying bradyseismical activity must have been more pronounced and +have shown themselves upon a grander scale than they do at the present +time. Now, although the records of our rocks only carry us back over a +certain portion of this history, they certainly represent an interval of +time sufficiently long to furnish some evidence of such enfeeblement if +it ever existed. So far from this being the case, however, we meet with +distinct evidences in the later chapters of geological history of +plutonic awakenings much more violent than those recorded at its +commencement. During Palaeozoic times many mountain ranges were formed, +and accompanying these orogenic processes there was marked volcanic +activity. In the succeeding Secondary period plutonic forces were +quiescent, but during the formation of the early Tertiaries, when some +of the largest mountain ranges were created, they awoke with a vigour +greater than had ever been previously exhibited. At this period it is +not improbable that Scotland was as remarkable for its volcanoes and its +earthquakes as Japan is at the present day. If the statement relating to +the general decrease in bradyseismical changes referred merely to their +frequency, and omitted reference to their magnitude, the views of the +geologist and physicist might harmonize. One explanation for this +divergence of opinion may rest on the fact that too little attention has +been directed to all the conditions which accompany the adaptation of +the earth's crust to its shrinking nucleus. As the latter grows smaller +the puckerings and foldings of the former should grow larger. Each +succeeding geological epoch should be characterized by mountain +formations more stupendous than those which preceded them, whilst the +fracturing, dislocation, caving-in of ill-supported regions, and +creation of lines of freedom for the exhibition of volcanic activity +which would accompany these changes, would grow in magnitude. The +written records of many countries reflect but on a smaller scale the +crystallized records in their hills. In 1844, at Comrie, in Perthshire, +as many as twelve earthquakes were recorded in a single month, whilst +now there are but one or two per year. Earthquake frequency varies with +time. A district under the influence of hypogenic activities reaches a +condition of seismic strain which usually is relieved rapidly at first, +but subsequently more slowly. + +The small shocks which follow an initial large disturbance are known as +after-shocks. The first shock which in 1891 devastated central Japan was +accompanied by the formation of a large fault, and the 3364 small shocks +which succeeded this during the following two years are regarded as due +to intermittent settlements of disjointed material. The decreasing +frequency with which after-shocks occur may be represented by a curve. +Dr F. Omori points out that the continuation of such a curve gives the +means of determining the length of time which will probably elapse +before the region to which it refers will return to the same seismic +quiescence that it had prior to the initial disturbance. + + + Periodicity. + +The positive results that we have respecting the periodicity of +earthquakes are but few. Generally earthquakes are somewhat more +frequent during winter than during summer, and this applies to both the +northern and southern hemispheres. The annual periodicity, which, +however, does not show itself if only destructive earthquakes are +considered, finds an explanation, according to Dr Knott, in the annual +periodicity of long-continued stresses, as for example those due to the +accumulation of snow and to barometric gradients. For certain earthquake +regions there appears to be a distinct semi-annual period for which no +satisfactory explanation has yet been adduced. Although the elaborate +registers of Japan, which have enabled us to group earthquakes according +to their respective origins and varying intensities, and to separate +after-shocks from initial disturbances, have been subjected by Dr Knott +to most careful analysis, with the object of discovering periodicities +connected with the ebb and flow of the tides, the lunar day or lunar +months, nothing of marked character has been found. Certainly there is +slight evidence of a periodicity connected with the times of conjunction +and opposition of the sun and moon, and a maximum frequency near the +time of perigee, but the effect of lunar stresses is comparatively +insignificant. Ordinary earthquakes, and especially after-shocks, show a +diurnal period, but we cannot say that there are more earthquakes during +the night than during the day. + + + Magnetic phenomena. + +Many experiments and investigations have been made to determine a +possible relationship between earthquakes and electrical phenomena, but +beyond drawing attention to the fact that luminous appearances may +accompany the friction of moving masses of rock, and that a temporary +current may be established in a line by the disturbance of an +earth-plate, these inquiries have yielded but little of importance. The +inquiries respecting a possible relationship between adjustments so +frequently taking place within and beneath that region called the crust +of the earth and magnetic phenomena are, however, of a more promising +nature. We have seen that at or near the origin of earthquakes which for +several hours disturb continents, and occasionally cause oceans to +oscillate for longer periods, we sometimes have direct evidence of the +bodily displacement of many cubic miles of material. When this material +is volcanic it is almost invariably magnetic, and we perceive in its +sudden rearrangement causes which should produce magnetic effects within +an epifocal district. In Japan, where attention is being directed to +phenomena of this description, not only have such effects been observed, +but unusual magnetic disturbances have been noted prior to the +occurrence of large earthquakes. These may, of course, be regarded as +mere coincidences, but when we consider volcanic and seismic activities +as evidences of physical and chemical changes, together with mechanical +displacements of a magnetic magma, it is reasonable to suppose that they +should have at least a local influence upon magnetic needles. Another +form of disturbance to which magnetic needles are subjected is that +which accompanies the passage of large earth-waves beneath certain +observatories situated at great distances from earthquake origins. At +Utrecht, Potsdam and Wilhelmshaven the magnetographs are frequently +disturbed by seismic waves, whilst at many other European observatories +such effects are absent or only barely appreciable. To explain these +marked differences in the behaviour of magnetic needles at different +stations we are at present only in a position to formulate hypotheses. +They may be due to the fact that different needles have different +periodic times of oscillation; it is possible that at one observatory +the mechanical movements of the ground are much greater than at others; +we may speculate on the existence of materials beneath and around +various observatories which are different in their magnetic characters; +and, lastly, we may picture a crust of varying thickness, which from +time to time is caused to rise and fall upon a magnetic magma, the +places nearest to this being the most disturbed. + + + Effects on the human mind. + +A subject to which but little attention has been directed is the effect +which displays of seismic and volcanic activities have had upon the +human mind. The effects are distinctly dual and opposite in character. +In countries like England, where earthquakes are seldom experienced, the +prevailing idea is that they are associated with all that is baneful. +For certain earthquakes, which fortunately are less than 1% of those +which are annually recorded, this is partially true. A disastrous shock +may unnerve a whole community. Effects of this nature, however, differ +in a marked manner with different nationalities. After the shock of +1891, when Japan lost 9960 of its inhabitants, amongst the wounded +indications of mental excitement were shown in spinal and other trouble. +Notwithstanding the lightheartedness of this particular nation, it is +difficult to imagine that the long series of seismic effects chronicled +in Japanese history, which culminated in 1896 in the loss of 29,000 +lives by sea-waves, has been without some effect upon its mental and +moral character. Several earthquakes are annually commemorated by +special services at temples. In bygone times governments have recognized +earthquakes as visitations of an angry deity, whom they have endeavoured +to appease by repealing stringent laws and taxes. In other countries the +sermons which have been preached to show that the tremblings of the +world were visitations consequent on impiety, and the prayers which have +been formulated to ward off disasters in the future, far exceed in +number the earthquakes which gave rise to them. In 1755 many of the +English clergy held the view that Lisbon was destroyed because its +inhabitants were Catholics, whilst the survivors from that disaster +attributed their misfortune to the fact that they had tolerated a few +Protestant heretics in their midst. To avoid a recurrence of disaster +certain of these were baptized by force. In the myths relating to +underground monsters and personages that are said to be the cause of +earthquakes we see the direct effects which exhibitions of seismic and +volcanic activity have produced upon the imagination. The beliefs, or +more properly, perhaps, the poetical fancies, thus engendered have +exhibited themselves in various forms. Beneath Japan there is said to be +a catfish, which in other countries is replaced by a mole, a hog, an +elephant or other living creature, which when it is restless shakes the +globe. The Kamchadales picture a subterranean deity called Tuil, who in +Scandinavian mythology is represented by the evil genius Loki. We have +only to think of the reference in the Decalogue forbidding the making of +graven images of that which is in the earth beneath, to see in early +Biblical history evidence of a subterranean mythology; and it seems +probable that the same causes which led to the creation of Pluto, Vulcan +and Poseidon gave rise to practices condemned by Moses. + + + Building to withstand earthquakes. + +Perhaps the greatest practical benefits derived from seismological +investigations relate to important changes and new principles which have +been introduced into the arts of the engineer and builder when +constructing in earthquake countries. The new rules and formulae, rather +than being theoretical deductions from hypotheses, are the outcome of +observation and experiment. True measures of earthquake motion have been +given to us by modern seismometers, with the result that seismic +destructivity can be accurately expressed in mechanical units. From +observation we now know the greatest acceleration and maximum velocity +of an earth particle likely to be encountered; and these are measures of +the destructivity. The engineer is therefore dealing with known forces, +and he has to bear in mind that these are chiefly applied in a +horizontal direction. A formula connecting the acceleration requisite to +overturn bodies of different dimensions has been given. The acceleration +which will fracture or shatter a column firmly fixed at its foundation +to the moving earth may be expressed as follows:-- + + 1 gFAB + a = -- ----, + 6 fw + +where + + a = the acceleration per sec. per sec. + F = the force of cohesion, or force per unit surface, which when + gradually applied produces fracture. + A = area of base fractured. + B = thickness of the column. + f = height of centre of gravity of column above the fractured base. + w = the weight of the portion broken off. + +With this formula and its derivatives we are enabled to state the height +to which a wall, for example, may be built capable of resisting any +assumed acceleration. Experience has shown that yielding first shows +itself at the base of a pier, a wall or a building, and it is therefore +clear that the lower portion of such structures should be of greater +dimensions or stronger than that above. Piers having these increased +dimensions below, and tapering upwards in a proper manner, so that every +horizontal section is sufficiently strong to resist the effects of the +inertia of its superstructure, are employed to carry railways in Japan. +In that country cast-iron piers are things of the past, whilst piers of +masonry, together with their foundations, no longer follow the rules of +ordinary engineering practice. + +After flood, fire, earthquake, or when opportunity presents itself, +changes are introduced in the construction of ordinary buildings. In a +so-called earthquake-proof house, although externally it is similar to +other dwellings, we find rafters running from the ridge pole to the +floor sills, an exceedingly light roof, iron straps and sockets +replacing mortices and tenons, and many other departures from ordinary +rules. Masonry arches for bridges or arched openings in walls (unless +protected by lintels), heavy gables, ornamental copings, cappings for +chimneys, have by their repeated failure shown that they are undesirable +features for construction in earthquake countries. As sites for +buildings it is well to avoid soft ground, on which the movement is +always greater than on hard ground. Excessive movement also takes place +along the face of unsupported openings, and for this reason the edges of +scarps, bluffs, cuttings and river-banks are localities to be avoided. +In short, the rules and precautions which have to be recognized so as to +avoid or mitigate the effects of earthquake movement are so numerous +that students of engineering and architecture in Japan receive a special +course of lectures on this subject. When it is remembered that a large +earthquake may entail a loss of life greater than that which takes place +in many wars, and that for the reconstruction of ordinary buildings, +factories and public works an expenditure of several million pounds +sterling is required, the importance of these studies cannot be +overrated. Severe earthquakes are fortunately unknown in the British +Isles, but we have simply to turn our eyes to earthquake-shaken colonies +and lands in close commercial touch with Great Britain to realize the +importance of mitigating such disasters as much as possible, and any +endeavour to obviate the wholesale destruction of life should appeal to +the civilized communities of the world. + + + Applications of seismometry. + +An unexpected application of seismometry has been to record the +vibration of railway trains, bridges and steamships. An instrument of +suitable construction will give records of the more or less violent +jolting and vibratory movements of a train, and so localize +irregularities due to changes in the character of ballast and sleepers, +to variation in gauge, &c. An instrument placed on a locomotive throws +considerable light upon the effects due to the methods of balancing the +wheels, and by alterations in this respect a saving of fuel of from 1 to +5 lb. of coal per mile per locomotive has sometimes been effected. + +By mapping the centres from which earthquakes originate off the coast of +Japan, we have not only determined districts where geological activity +is pronounced, but have placed before the cable engineer well-defined +localities which it is advisable to avoid; and in the records of unfelt +earthquakes which originate far from land similar information is being +collected for the deeper parts of the oceans. Occasionally these records +have almost immediately made clear the cause of a cable failure. From +lack of such information in 1888, when the cables connecting Australia +with the outer world were simultaneously broken, the sudden isolation +was regarded as a possible operation of war, and the colonists called +out their naval and military reserves. Records of earthquakes +originating at great distances have also frequently enabled us to +anticipate, to correct, to extend, or to disprove telegraphic accounts +of the disasters. Whatever information a seismogram may give is certain, +whilst the information gathered from telegrams may in the process of +transit become exaggerated or minimized. Otherwise unaccountable +disturbances in records from magnetographs, barographs and other +instruments employed in observatories are frequently explained by +reference to the traces yielded by seismometers. Perhaps the greatest +triumph in seismological investigation has been the determination of the +varying rates at which motion is propagated through the world. These +measurements have already thrown new light upon its effective rigidity, +and if we assume that the density of the earth increases uniformly from +its surface towards its centre, so that its mean density is 5.5, then, +according to Knott, the coefficient of elasticity which governs the +transmission of preliminary tremors of an earthquake increases at a rate +of nearly 1.2% per mile of descent. (J. Mi.) + + AUTHORITIES.--J. Milne, _Seismology_ (London, 1898), _Earthquakes_ + (London, 1898), Bakerian Lecture, "Recent Advances in Seismology," + _Proc. Roy. Soc._, 1906, 77, p. 365; J.A. Ewing, _Memoir on Earthquake + Measurement_ (Tokyo, 1883); C.E. Dutton, _Earthquakes in the Light of + the New Seismology_ (London, 1904); "The Charleston Earthquake of Aug. + 31, 1886," Ninth Annual _Report_ of the United States Geological + Survey, 1889; W.H. Hobbs, _Earthquakes, an Introduction to Seismic + Geology_ (London, 1908), "The San Francisco Earthquake and Fire, + 1906," _Bull. U.S. Geol. Surv._ No. 324; "The California Earthquake of + Ap. 18, 1906," _Rep. State Earthq. Com._ (Washington, D.C., 1908); + R.D. Oldham, "Report on the Great Earthquake of 12 June 1897," _Mem. + Geol. Surv. India_, xxix. 1899, "On the Propagation of Earthquake + Motion to great Distances," _Phil. Trans._, 1900, A, vol. 194, p. 135, + "The Constitution of the Interior of the Earth as revealed by + Earthquakes," _Quar. Jour. Geol. Soc._, 1906, 62, p. 456; 1907, 63, p. + 344; C. Davison, _A Study of Recent Earthquakes_ (London, 1905); _The + Hereford Earthquake of December 17, 1896_ (Birmingham, 1899), "The + Investigation of Earthquakes," _Beitraege z. Geophysik_, Bd. ix., 1908, + p. 201, and papers on British earthquakes in _Quart. Jour. Geol. + Soc._; T.J.J. See, "The Cause of Earthquakes, Mountain Formation and + Kindred Phenomena connected with the Physics of the Earth," _Proc. + Amer. Phil. Soc._, 1906, 45, p. 273; F. Frech, "Erdbeben und + Gebirgsbau," _Petermann's Mitteilungen_, Bd. 53, 1907, p. 245 (with + maps); C.G. Knott, _The Physics of Earthquake Phenomena_ (Oxford, + 1908); Comte F. de Montessus de Ballore, _Les Tremblements de terre: + geographie seismologique_ (Paris, 1906), _La Science seismologique_ + (1907); _Transactions of the Seismological Society of Japan; + Seismological Journal_ (Yokohama); _Bollettino della Societa + Sismologica Italiana_ (Rome); _Reports of the British Association_, + containing the annual reports of the Committee for Seismological + Investigations; papers in the _Beitraege zur Geophysik_ and the + _Ergaenzungsbaende_. + + +FOOTNOTES: + + [1] The publications for 1880-1892 were termed the _Transactions of + the Seismological Society of Japan_, and for 1893-1895 the + _Seismological Journal of Japan_. The observations are now published + by the Earthquake Investigation Committee of Japan, and edited by F. + Omori, professor of seismology at the university of Tokyo. + + [2] The chief Italian station is at Rocca di Papa near Rome. It is + equipped with delicate instruments designed by its director, Giovanni + Agamennone. The records since 1895 are published in the _Bollettino + della Societa Sismologica Italiana_, edited by Luigi Palazzo, + director of the Central Office for Meteorology and Geodynamics at + Rome. + + [3] The chief Austrian publications are:--_Mittheilungen der + Erdbebencommission der k. Akad. der Wissen. in Wien_ (since 1897); + _Die Erdbebenwarte_ (1901-1907); and the "Neueste + Erdbebennachrichten, _Beilage der Monatsschrift Die Erdbebenwarte_." + + [4] The "International Seismological Association" was founded at + Strassburg in 1903, and publishes the _Beitraege zur Geophysik_, + edited by George Gerland, director of the Strassburg station; the + papers are printed in several languages. + + [5] The records of the British Association stations are published + (since 1896) in the _Reports_. Chile has a national earthquake + service (founded after the Valparaiso earthquake of August 1906) + directed by comte de Montessus de Ballore. + + + + +EARTH-STAR (_Geaster_), in botany, a kind of puff-ball, with a distinct +outer coat which, on separating from the inner, splits into several +divisions, which become reflexed and spread like a star. The inner coat +enveloping the spores is supported, like a ball, either with or without +a stalk on the upper face of the star. The spores escape generally by +means of a distinct aperture which appears in the top of the ball. There +are several species in Britain found on the ground or on decaying +leaves. They are rare or local, but more common in the south or +south-east of England than in other parts of Britain. + +[Illustration: From Strasburger's _Lehrbuch der Botanik_, by permission +of Gustav Fischer. + +_Geaster Granulosus_, nat. size.] + + + + +EARTHWORM, the common name of a chaetopod worm found nearly all over the +world. Linnaeus recognized only one species of earthworm and named it +_Lumbricus terrestris_. There are now one thousand well-characterized +species known from different parts of the world, and the number +increases almost daily. The earthworms of England belong entirely to the +three genera _Lumbricus_, _Allolobophora_ and _Allurus_, which are +further subdivided by some systematists; and these genera form the +prevalent earthworm fauna of the Palaearctic region and are also very +numerous in the Nearctic region. Elsewhere they do not appear to be +indigenous, but are replaced by the numerous other genera of the +families enumerated in the article CHAETOPODA (q.v.). It is a remarkable +fact that these genera, comprizing a separate family _Lumbricidae_, when +introduced into tropical and other countries, thrive abundantly and oust +the indigenous forms. In gatherings of earthworms from various +extra-European countries it is always found that if the collections have +been made in cultivated ground and near the coast the worms are of +European species; farther inland the native forms are met with. Inasmuch +as in every case the _Lumbricidae_ from non-European countries are +identical with European species, since it has been shown that these +animals are very readily introduced accidentally with plants, &c., and +in view of the fact that they are impatient of sea water, it seems clear +that the presence of these _Lumbricidae_ in other continents is due to +accidental transportation. Most earthworms live in the soil, which they +devour as they burrow through it. A few, like their allies the river +worms (Limicolae), habitually frequent streams, lakes, &c. One genus, at +any rate, viz. _Pontodrilus_, seeks an unusual environment, and is found +in heaps of sea-weed cast up by the sea. The range of this genus is +therefore naturally wider than that of other genera which are confined +to land masses and cannot cross the sea by their own efforts. It might +be inferred, therefore, and the inference is proved by facts, that truly +oceanic islands have no indigenous fauna of earthworms, but are +inhabited by forms which are identical with those of neighbouring +continents, and doubtless, therefore, accidentally introduced. + +Like the leeches the earthworms produce cocoons which are a product of +the glandular epithelium of the clitellum. In these cocoons are +deposited the eggs together with a certain amount of albumen upon which +the developing embryos feed. So far as is known, the production of +cocoons is universal among earthworms and the remaining Oligochaeta of +aquatic habit. The young leave the cocoon as fully formed earthworms in +which, however, the genitalia are not fully developed. There is no free +living larval stage. Out of a single cocoon emerge a varying number of +young worms, the numbers being apparently characteristic of the species. +The work of earthworms in aiding in the production of the subsoil and in +levelling the surface was first studied by C. Darwin, and has since been +investigated by others. This work is partly carried out beneath the +surface and partly on the surface, upon which the worms wander at night +and eject the swallowed and triturated earth; frequently castings of +some height are formed of coiled ropes of agglutinated particles of +mould. The indigenous species of Great Britain, about twenty in number, +do not grow to a greater length than some 10 in.; but in several +tropical countries there are species which grow to a length of from 3 to +6 ft. Thus we have in Natal the gigantic _Microchaeta rappi_, in Ceylon +_Megascolex coeruleus_, in Australia _Megascolides australis_, and an +equally large form in South America. (F. E. B.) + + + + +EARWIG, an insect belonging to the _Forficulidae_, a family usually +referred to the Orthoptera, but sometimes regarded as typifying a +special order, to which the names Dermaptera, Dermatoptera and +Euplexoptera have been given, in allusion to certain peculiarities in +the structure of the wings in the species that possess them. The front +wings are short and horny and when at rest meet without overlapping in +the middle line, like the wing-cases of brachelytrous (cocktail) +beetles. The hind wings, on the contrary, are for the most part +membranous and, when extended, of large size; each consists of two +portions, the distal of which, in virtue of the arrangement and jointing +of its nervures, is capable of being both doubled up and folded fanwise +beneath the proximal, which is partly horny when the wing is tucked away +under the front wing-case of the same side. Apart from these +characteristics, the most distinctive feature of earwigs is the presence +at the end of the abdomen of a pair of pincers which are in reality +modified appendages, known as cercopods, and represent the similar limbs +of _Japyx_ and the caudal feelers of _Campodea_ and some other insects. + +The _Forficulidae_ are almost cosmopolitan; but the various species and +genera differ from each other both in structure and size to a +comparatively slight extent. The length and armature of the pincers and +the presence or absence of wings are perhaps the most important features +used by systematists in distinguishing the various kinds. Of particular +zoological interest in this connexion is a Ceylonese genus _Dyscritina_, +in which the cercopods are long, many-jointed and filiform during the +early stages of growth, and only assume at the last moult the forcipate +structure characteristic of the family. The best known earwig is the +common European species, _Forficula auricularia_. This insect is +gregarious and nocturnal. It hides by day under stones or the loosened +bark of trees or in any crevice or hole sheltered from the light. At +night it crawls about in search of food, which consists to a small +extent of dead animal or vegetable matter, but principally, as gardeners +are aware, of the petals and other parts of flowers of growing shoots +and soft ripe fruit. During the winter earwigs lie dormant; but in the +early months of the year females with their eggs may be found in the +soil, frequently in deserted earthworm burrows. Maternal instincts are +well developed, both the eggs, which number about fifty, and the young +being carefully brooded and watched over by the parent. Except for the +absence of wings, the young are miniature models of the adult. As growth +proceeds the integument is periodically cast; and at the final moult the +perfect winged insect appears. Males and females are like each other in +size, but may be distinguished by the difference in the number of +visible abdominal segments, the male having nine and the female seven. +In the male, moreover, the pincers are caliper-like and toothed at the +base, whereas in the female they are untoothed and only lightly curved +at the tip. These differences suggest that the pincers aid in the +pairing of the sexes. However that may be, they are known to be used in +the folding of the wings; and their importance as weapons of defence is +attested by the precision and effect with which they are wielded against +assailants like ants. (R. I. P.) + + + + +EASEMENT (Fr. _aise_; O. Fr. _aisement_; Anglo-Lat. _aisiamentum_, a +privilege or convenience), in English law, a species of "servitude" or +limited right of use over land belonging to another. It is distinguished +from _profits a prendre_--another species of servitude which involves a +right to participate in the profits of the soil of another--since an +easement confers merely a convenience (_aisiamentum_) to be exercised +over the land of another (without any participation in the profits of +it), i.e. a right to use the soil or produce of the soil in a way +tending to the more convenient enjoyment of another piece of land. Thus +a right of way is an easement, a right of common is a profit. An +easement is distinguishable also from a licence, which, unless it is +coupled with a grant, is personal to both grantor and grantee and is +neither binding on the licensor, nor, in general, assignable by the +licensee; while both the benefit and the burden of an easement are +annexed to land (Gale on _Easements_, 8th ed. p. 2). With easements are +sometimes classed certain closely allied "natural rights," such as a +landowner's right to lateral support for his soil in its natural state, +and a riparian owner's right to the natural flow of a stream. + +The essential features of an easement, in the strict sense of the term, +are therefore these: (i.) It is an incorporeal right; a right to the use +and enjoyment of land--not to the land itself; (ii.) it is imposed upon +corporeal property; (iii.) it is a right without profit; (iv.) it +requires for its constitution two distinct tenements--the "dominant +tenement" which enjoys the right, and the "servient tenement" which +submits to it. This last characteristic excludes from the category of +easements the so-called "easements _in gross_," such as a right of way +conferred by grant independently of the possession of any tenement by +the grantee. The true easement is an "appendant" or "appurtenant" right, +not a "right in gross." + +Further classifications of easements must be noted. They are divided +into (a) _affirmative_ or _positive_, those which authorize the +commission of an act by the dominant owner, e.g. rights of way, a right +to draw water from a spring, rights of aqueduct, and _negative_, when +the easement restricts the rights of the servient owner over his own +property, e.g. prevents him from building on land so as to obstruct +ancient lights (cf. also the right to the support of neighbouring soil); +(b) _continuous_, of which the enjoyment may be continual without the +interference of man, e.g. access to light, and _discontinuous_, where +there must be a fresh act on each occasion of the exercise of the right, +e.g. a right of way, or right to draw water; (c) _apparent_, where there +are visible external signs of the exercise of the right, e.g. a right to +dam up a watercourse, and _non-apparent_, where such signs are absent, +e.g. a right to lateral support from land, a prohibition to build above +a certain height. + +_Acquisition of Easements._--Easements may be acquired (a) by express +grant, either by statute, or by deed _inter vivos_, or by will; (b) by +an implied grant; (c) by express or implied reservation, e.g. by the +owner of land in selling the fee (as to implied reservation, see Gale on +_Easements_, 8th ed. pp. 137 et seq.); (d) by prescription, either at +common law or under the Prescription Act 1832. An express grant, or +express reservation, of an easement cannot be effected except by deed. +An easement arises by implied grant where a man makes one part of his +tenement dependent on another, or makes the parts mutually +interdependent, and grants any such part with the dependence attaching +to it to another person (Innes, _Law of Easements_, 7th ed. p. 10). For +example, a man builds two houses, each of which by the plan of +construction receives support from the other; this mutual right of +support is a _quasi_-easement, of which on severance of the tenements +the grantee of one will have the benefit; where the enjoyment of the +severed tenement could not be had at all without such a right, it is +said to be an "easement of necessity." + +Easements are acquired by prescription at common law by proof of +"immemorial user" by the dominant owner and those through whom he +claims. At one time it was thought that such proof must date back to the +first year (1189) of Richard I. (see preamble to Prescription Act 1832). +The ground, however, on which prescription was admitted as a means of +acquiring easements was the fiction of a "lost grant." Long enjoyment of +the right pointed to its having had a legal origin in a grant from the +servient owner, and so any period of reasonably long use came to be +accepted. A "lost grant" may be presumed to have been made (the question +is one of fact) if 20 years' uninterrupted enjoyment is shown. To avoid +the difficulties of proof of prescriptive right at common law, the +Prescription Act 1832 established shorter periods of user. In the case +of easements, other than light, the periods of prescription are 20 years +for a claim that may be defeated, and 40 years for an indefeasible claim +(s. 2). The right of access of light is dealt with under s. 3 (see +ANCIENT LIGHTS). The enjoyment to become prescriptive must be open, i.e. +of such a character that the owner of the tenement said to be servient +has a reasonable opportunity of becoming aware of the adverse claim +(_Union Lighterage Co._ v. _London Graving Dock Co._, 1902, 2 Ch. 557); +and it must be enjoyed as of right (_Gardner_ v. _Hodgson's Kingston +Brewery Co._, 1903, A.C. 229) as against the owner of the tenement +affected (_Kilgour_ v. _Gaddes_, 1904, 1 K.B. 457). The periods of +prescription are to be reckoned backwards from the time when some suit +or matter involving the claim of the dominant owner has arisen (s. 4). +Nothing is to be deemed an interruption unless the act of interruption +has been submitted to, or acquiesced in, for a year (s. 4). + +Easements may be extinguished (i.) by express release--here an +instrument under seal is necessary; (ii.) by "merger," i.e. where both +tenements become the property of the same owner; (iii.) by abandonment +through non-user. In the case of discontinuous easements, the shortest +period of non-user may suffice if there is direct evidence of an +intention to abandon. + +A word may be added here as to the right to air. It is an actionable +nuisance to cause pollution of the air entering a dwelling-house. The +owner of a dwelling-house may by prescription acquire a right to the +passage of air through it by a defined channel; and the enjoyment +without interruption of ventilation by means of air flowing in a +definite channel, with the knowledge of the owner and occupier of the +adjoining premises, creates a presumption of the grant of such an +easement (see Gale on _Easements_, 8th ed. p. 338). + +In _Scots Law_ the term "easement" is unknown. Both the name "servitude" +and the main species of servitudes existing in Roman law (q.v.) have +been adopted. The classification of servitudes into positive and +negative, &c., and the modes of their creation and extinction, are +similar to those of English law. The statutory period of prescription is +40 years (Scots Acts 1617, c. 12), or 20 years in the case of enjoyment +under any _ex facie_ valid irredeemable title duly recorded in the +appropriate register of sasines (Conveyancing [Scotland] Act 1874). +There are certain servitudes special to Scots law, e.g. "thirlage," by +which lands are "thirled" or bound to a particular mill, and the +possessors obliged to grind their grain there, for payment of certain +_multures_ (quantities of grain or meal, payable to the mill-owner) and +_sequels_ (small quantities given to the mill servants) as the customary +price of grinding. Statutory provision has been made for the commutation +of these duties (Thirlage Act 1799), and they have now almost +disappeared. + +The French Code Civil (Arts. 637 et seq.) and the other European codes +(e.g. Belgium, arts. 637 et seq.; Holland, arts. 721 et seq.; Italy, +arts. 531 et seq.; Spain, arts. 530 et seq.; Germany, arts. 1018 et +seq.) closely follow Roman law. French law is in force in Mauritius, and +has been followed in Quebec (Civil Code, arts. 499 et seq.) and St Lucia +(Civil Code, arts. 449 et seq.). In India the law is regulated, on +English lines, by the Easements Act 1882 (Act v. of 1882). The term +"easements," however, in India includes _profits a prendre_. In the +South African colonies the law of easements is based on the Roman Dutch +law (see Maasdorp, _Institutes of Cape Law_, 1904; Bk. ii. p. 166 et +seq.). In most of the other colonies the law of easements is similar to +English law. In some, however, it has been provided by statute that +rights to the access and use of light or water cannot be acquired by +prescription: e.g. Victoria (Water Act 1890, No. 1156, s. 3), Ontario +(Real Property Limitation Act, Revised Stats. Ontario, 1897; c. 133, s. +36, light). + +In the _United States_ the law of easements is founded upon, and +substantially identical with, English law. The English doctrine, +however, as to acquisition of right of light and air by prescription is +not accepted in most of the States. + + AUTHORITIES.--_English Law_: Gale, _Law of Easements_ (8th ed., + London, 1908); Goddard, _Law of Easements_ (6th ed., London, 1904); + Innes, _Digest of the Law of Easements_ (7th ed., London, 1903). + _Indian Law_: Peacock, _Easements in British India_ (Calcutta, 1904); + Hudson and Inman, _Law of Light and Air_ (2nd ed., London, 1905). + _Scots Law_: Erskine, _Principles of the Law of Scotland_ (20th ed., + Edinburgh, 1903). _American Law_: Jones, _Law of Easements_ (New York, + 1898); Bouvier, _Law Dict._ (Boston and London, 1897); _Ruling Cases_, + London and Boston, 1894-1901, tit. _Easement_ (American Notes). + (A. W. R.) + + + + +EAST, ALFRED (1849- ), English painter and etcher, was born at +Kettering on the 15th of December 1849. One of the most prominent among +modern English landscape painters, he received his art education first +at the Glasgow School of Art and then in Paris at the Ecole des +Beaux-Arts, and under Robert-Fleury and Bouguereau. His landscapes are +remarkable for the lyrical use of colour and for the pleasing rhythm of +line which is the result of careful selection and building up of the +elements that constitute the scene. Based on keen observation of the +colour of nature and on careful studies of the details, they are +arranged with a rare and by no means obvious sense of balance and +compositional beauty which summarily discards all disturbing accidents +of nature. He also achieved distinction as an etcher, and published an +instructive and useful volume on landscape painting (London, 1906). He +began to exhibit at the Royal Academy in 1882, and was elected an +associate. In 1906 he became president of the Royal Society of British +Artists. Many of his works are to be found in the English provincial +galleries; Manchester owns "The Silent Somme" and "Autumn"; Liverpool, +"Gibraltar from Algeciras"; Leeds, "The Golden Valley"; Birmingham, +"Hayle from Lelant"; Preston, "An Idyll of Spring"; and Hull, "Evening +on the Cotswolds." His "Passing Storm" is at the Luxembourg; "The Nene +Valley" at the Venice gallery; and "A Haunt of Ancient Peace" at the +National gallery in Budapest. In 1903 he received the order of the Crown +of Italy in connexion with his services to the Venice international +exhibition; and he was made an honorary member of the Japanese Meiji +Bijutsu Kai. + + + + +EAST ANGLIA, one of the kingdoms into which Anglo-Saxon Britain was +divided. Bede gives no information about its origin except that its +earliest settlers were Angles. The kingdom of East Anglia comprised the +two counties of Norfolk and Suffolk. With regard to the western boundary +we have no accurate information, but it was probably formed by the fens +of Cambridgeshire. + +This kingdom first appears in Bede's narrative early in the 7th century, +when its power was at its height. Towards the end of the reign of +AEthelberht, who died about 616, Raedwald of East Anglia, who had +apparently spent some time at the court of Kent, began to win for +himself the chief position among the Anglo-Saxon kings of his day. His +position was assured, at least temporarily, in 617, when he decided to +espouse the cause of the Northumbrian prince Edwin, then a fugitive at +his court, and defeated AEthelfrith of Northumbria on the banks of the +Idle, a tributary of the Trent, in Mercian territory. Raedwald had been +converted to Christianity in Kent, but after his return home he +relapsed, according to Bede, owing to the influence of his wife, and +there were to be seen in the same building a Christian and a pagan +altar. Bede states that Raedwald was the son of Tytili, the son of Wuffa, +from whom the East Anglian royal family derived their name Wuffingas. +According to the _Historia Brittonum_ Guffa (Wuffa) was the son of +(Guecha) Wehha, who first ruled the East Angles in Britain. This would +put the organization of the kingdom in the first or second quarter of +the 6th century. Eorpwald, the son of Raedwald, was converted to +Christianity by Edwin, but was soon afterwards slain by Ricberht (627 or +628), whereupon the kingdom again became pagan for three years, when +Sigeberht, the brother of Eorpwald, became king and founded a see for +Felix at Dunwich. Sigeberht also founded a school in East Anglia, and on +the arrival of an Irish missionary named Furseus he built him a +monastery at _Cnobheresburg_, perhaps to be identified with Burgh +Castle. Before 644, however, Sigeberht resigned the crown in favour of +his brother Ecgric and retired to a monastery. Shortly afterwards both +brothers were slain by Penda of Mercia in his invasion of East Anglia, +and Anna became king. This king was an enthusiastic Christian, and +converted Coenwalh, king of Wessex, who had fled to his court. Two of +his daughters, Saethryth and AEthelberg, took the veil; while another, +Sexburg, was married to Earconberht, king of Kent; and a fourth, +AEthelthryth, after two marriages, with Tondberht of the South Gyrwe and +Ecgfrith of Northumbria, became abbess of Ely. In 654 Anna was slain by +Penda of Mercia, and was succeeded by his brother AEthelhere, who was +killed in 655 at the Winwaed, fighting for the Mercian king against +Oswio of Northumbria. In 673 Archbishop Theodore divided the East +Anglian diocese into two, Elmham being the seat of the northern, Dunwich +that of the southern bishop. A long blank follows in the history of this +kingdom, until in 792 we find Offa of Mercia slaying AEthelberht, king of +East Anglia, who is said to have been his son-in-law. East Anglia was +subject to the supremacy of the Mercian kings until 825, when its people +slew Beornwulf of Mercia, and with their king acknowledged Ecgberht +(Egbert) of Wessex as their lord. In 870 Edmund, king of East Anglia, +was killed by the Danes under I'varr and Ubbi, the sons of Ragnar +Loethbrok. + +The following is a list of the kings of East Anglia of whom there is +record:--Wehha; Wuffa; Raedwald, son of Tytili and grandson of Wuffa +(reigning 617); Eorpwald, son of Raedwald (d. 627 or 628); Sigeberht, +brother of Eorpwald; Ecgric, brother of Sigeberht (both slain before +644); Anna, son of Ene and grandson of Tytili (d. 654); AEthelhere, +brother of Anna (d. 655); AEthelwald, a third brother; Aldwulf (succ. +663, d. 713), son of AEthelric and grandson of Ene; Elfwald, son of +Aldwulf (d. 749); Hun Beonna and Alberht; AEthelberht (792); Edmund +(870). + +After the death of Ragnar Loethbrok's sons East Anglia was occupied by the +Danish king Guthrum, who made a treaty with Alfred settling their +respective boundaries, probably about 880. Guthrum died in 890. A later +king named Eohric took up the cause of AEthelwald, the son of AEthelred +I., and was slain in the fight with the Kentish army at the Holm in 905. +A war broke out with King Edward the Elder in 913; in 921 a king whose +name is unknown was killed at the fall of Tempsford, and in the same +year the Danes of East Anglia submitted to Edward the Elder. From this +time, probably, East Anglia was governed by English earls, the most +famous of whom were AEthelstan, surnamed Half-King (932-956) and his +sons, AEthelwold (956-962), and AEthelwine, surnamed _Dei amicus_ +(962-992). + + See Bede, _Hist. Eccl._ (ed. C. Plummer, Oxford. 1896), ii. 5, 15, + iii. 7, 8, 18-20, 22, iv. 3, 5, 23; _Saxon Chronicle_ (ed. Earle and + Plummer, Oxford, 1899), s. a. 823, 838, 866, 870, 880, 885, 890, 894, + 905, 921; _Historia Brittonum_ (San-Marte, 1844), s. 59; H. Sweet, + _Oldest English Texts_, p. 171 (London, 1885). (F. G. M. B.) + + + + +EASTBOURNE, a municipal borough (1883) in the Eastbourne parliamentary +division of Sussex, England, 61 m. S.S.E. of London by the London, +Brighton & South Coast railway. Pop. (1891) 34,969; (1901) 43,344; +(local census, 1909) 49,286. It is situated 3 m. N.E. of Beachy Head, +the loftiest headland on the English Channel coast. It once consisted of +three parts--the village of East Bourne, a mile inland; South Bourne, +lying back from the shore; and Seahouses, facing the beach. The church +of St Mary, the ancient parish church of East Bourne, is a fine +transitional Norman building; and there are numerous modern churches and +chapels. The principal buildings and institutions are the town hall and +municipal buildings, the Princess Alice Memorial and other hospitals, a +free library and, among many high-class schools, Eastbourne College for +boys, founded in 1867. There is a fine pier with pavilion, and a marine +parade nearly 3 m. in extent, arranged in terraced promenades. +Devonshire Park of 13 acres is pleasantly laid out, and contains a +pavilion and a theatre. The duke of Devonshire is the principal +landowner. Golf links are laid out on the neighbouring downs. A Roman +villa was formerly seen close to the shore, but it is not now visible. +The corporation consists of a mayor, 8 aldermen and 24 councillors. In +1910 the corporation promoted a bill in parliament to add the Hampden +Park district in the parish of Willingdon to the borough and to make +Eastbourne, with this extension, a county borough. + + + + +EAST CHICAGO, a city of Lake county, Indiana, U.S.A., on Lake Michigan, +about 19 m. S.E. of the business centre of Chicago. Pop. (1890) 1255; +(1900) 3411 (1331 foreign-born); (1910) 19,098. It is served by several +railways, including the Pennsylvania, the Wabash, the Chicago Terminal +Transfer (whose shops are here), the Lake Shore & Michigan Southern, the +Chicago, Indiana & Southern, and the Indiana Harbor railways. East +Chicago covers an area whose greatest dimensions are 4 by 31/2 m. That +part of the city along the lake, known as Indiana Harbor, dates from +1901 and has grown very rapidly because of its position at the +southernmost part of the Calumet District, and because of the meeting +here of railway and lake commerce. A good harbour has been constructed, +a new ship canal connecting the harbour with the Calumet river. East +Chicago is industrially virtually a part of "Greater" Chicago; among its +manufactures are iron and steel, cement, lumber, boilers, hay presses, +chains, chemicals and foundry products. East Chicago was chartered as a +city in 1893. + + + + +EASTER, the annual festival observed throughout Christendom in +commemoration of the resurrection of Jesus Christ. The name Easter (Ger. +_Ostern_), like the names of the days of the week, is a survival from +the old Teutonic mythology. According to Bede (_De Temp. Rat._ c. xv.) +it is derived from _Eostre_, or _Ostara_, the Anglo-Saxon goddess of +spring, to whom the month answering to our April, and called +_Eostur-monath_, was dedicated. This month, Bede says, was the same as +the _mensis paschalis_, "when the old festival was observed with the +gladness of a new solemnity." + +The name of the festival in other languages (as Fr. _paques_; Ital. +_pasqua_; Span. _pascua_; Dan. _paaske_; Dutch _paasch_; Welsh _pasg_) +is derived from the Lat. _pascha_ and the Gr. [Greek: pascha]. These in +turn come from the Chaldee or Aramaean form [Hebrew: pascha] _pascha'_, +of the Hebrew name of the Passover festival [Hebrew: pesach] _pesach_, +from [Hebrew: pasach] "he passed over," in memory of the great +deliverance, when the destroying angel "passed over the houses, of the +children of Israel in Egypt when he smote the Egyptians" (Exod. xii. +27). + +An erroneous derivation of the word _pascha_ from the Greek [Greek: +paschein], "to suffer," thus connected with the sufferings or passion of +the Lord, is given by some of the Fathers of the Church, as Irenaeus, +Tertullian and others, who were ignorant of Hebrew. St Augustine (_In +Joann. Tract._ 55) notices this false etymology, shows how similarity of +sound had led to it, and gives the correct derivation. + +There is no indication of the observance of the Easter festival in the +New Testament, or in the writings of the apostolic Fathers. The sanctity +of special times was an idea absent from the minds of the first +Christians. "The whole of time is a festival unto Christians because of +the excellency of the good things which have been given" is the comment +of St Chrysostom on 1 Cor. v. 7, which has been erroneously supposed to +refer to an apostolic observance of Easter. The ecclesiastical historian +Socrates (_Hist. Eccl._ v. 22) states, with perfect truth, that neither +the Lord nor his apostles enjoined the keeping of this or any other +festival. He says: "The apostles had no thought of appointing festival +days, but of promoting a life of blamelessness and piety"; and he +attributes the observance of Easter by the church to the perpetuation of +an old usage, "just as many other customs have been established." + +This is doubtless the true statement of the case. The first Christians +continued to observe the Jewish festivals, though in a new spirit, as +commemorations of events which those festivals had foreshadowed. Thus +the Passover, with a new conception added to it of Christ as the true +Paschal Lamb and the first fruits from the dead, continued to be +observed, and became the Christian Easter. + +Although the observance of Easter was at a very early period the +practice of the Christian church, a serious difference as to the day for +its observance soon arose between the Christians of Jewish and those of +Gentile descent, which led to a long and bitter controversy. The point +at issue was when the Paschal fast was to be reckoned as ending. With +the Jewish Christians, whose leading thought was the death of Christ as +the Paschal Lamb, the fast ended at the same time as that of the Jews, +on the fourteenth day of the moon at evening, and the Easter festival +immediately followed, without regard to the day of the week. The Gentile +Christians, on the other hand, unfettered by Jewish traditions, +identified the first day of the week with the Resurrection, and kept the +preceding Friday as the commemoration of the crucifixion, irrespective +of the day of the month. With the one the observance of the day of the +month, with the other the observance of the day of the week, was the +guiding principle. + +Generally speaking, the Western churches kept Easter on the first day of +the week, while the Eastern churches followed the Jewish rule, and kept +Easter on the fourteenth day. St Polycarp, the disciple of St John the +Evangelist and bishop of Smyrna, visited Rome in 159 to confer with +Anicetus, the bishop of that see, on the subject; and urged the +tradition, which he had received from the apostle, of observing the +fourteenth day. Anicetus, however, declined to admit the Jewish custom +in the churches under his jurisdiction, but readily communicated with +Polycarp and those who followed it. About forty years later (197) the +question was discussed in a very different spirit between Victor, bishop +of Rome, and Polycrates, metropolitan of proconsular Asia. That province +was the only portion of Christendom which still adhered to the Jewish +usage, and Victor demanded that all should adopt the usage prevailing at +Rome. This Polycrates firmly refused to agree to, and urged many weighty +reasons to the contrary, whereupon Victor proceeded to excommunicate +Polycrates and the Christians who continued the Eastern usage. He was, +however, restrained from actually proceeding to enforce the decree of +excommunication, owing to the remonstrance of Irenaeus and the bishops +of Gaul. Peace was thus maintained, and the Asiatic churches retained +their usage unmolested (Euseb. _H.E._ v. 23-25). We find the Jewish +usage from time to time reasserting itself after this, but it never +prevailed to any large extent. + +A final settlement of the dispute was one among the other reasons which +led Constantine to summon the council of Nicaea in 325. At that time the +Syrians and Antiochenes were the solitary champions of the observance of +the fourteenth day. The decision of the council was unanimous that +Easter was to be kept on Sunday, and on the same Sunday throughout the +world, and "that none should hereafter follow the blindness of the +Jews" (Socrates, _H.E._ i. 9). The correct date of the Easter festival +was to be calculated at Alexandria, the home of astronomical science, +and the bishop of that see was to announce it yearly to the churches +under his jurisdiction, and also to the occupant of the Roman see, by +whom it was to be communicated to the Western churches. The few who +afterwards separated themselves from the unity of the church, and +continued to keep the fourteenth day, were named _Quartodecimani_, and +the dispute itself is known as the _Quarto-deciman_ controversy. +Although measures had thus been taken to secure uniformity of +observance, and to put an end to a controversy which had endangered +Christian unity, a new difficulty had to be encountered owing to the +absence of any authoritative rule by which the paschal moon was to be +ascertained. The subject is a very difficult and complex one (see also +CALENDAR). Briefly, it may be explained here that Easter day is the +first Sunday after the full moon following the vernal equinox. This, of +course, varies in different longitudes, while a further difficulty +occurred in the attempt to fix the correct time of Easter by means of +cycles of years, when the changes of the sun and moon more or less +exactly repeat themselves. At first an eight years' cycle was adopted, +but it was found to be faulty, then the Jewish cycle of 84 years was +used, and remained in force at Rome till the year 457, when a more +accurate calculation of a cycle of 532 years, invented by Victorius of +Acquitaine, took its place. Ultimately a cycle of 19 years was accepted, +and it is the use of this cycle which makes the Golden Number and Sunday +Letter, explained in the preface to the Book of Common Prayer, +necessary. Owing to this lack of decision as to the accurate finding of +Easter, St Augustine tells us (_Epist._ 23) that in the year 387 the +churches of Gaul kept Easter on the 21st of March, those of Italy on the +18th of April, and those of Egypt on the 25th of April; and it appears +from a letter of Leo the Great (_Epist._ 64, _ad Marcian._) that in 455 +there was a difference of eight days between the Roman and the +Alexandrine Easter. Gregory of Tours relates that in 577 "there was a +doubt about Easter. In Gaul we with many other cities kept Easter on the +fourteenth calends of May, others, as the Spaniards, on the twelfth +calends of April." + +The ancient British and Celtic churches followed the cycle of 84 years +which they had originally received from Rome, and their stubborn refusal +to abandon it caused much bitter controversy in the 8th century between +their representatives and St Augustine of Canterbury and the Latin +missionaries. These latter unfairly attempted to fix the stigma of the +Quartodeciman observance on the British and Celtic churches, and they +are even now sometimes ignorantly spoken of as having followed the +Asiatic practice as to Easter. This, however, is quite erroneous. The +British and Celtic churches always kept Easter according to the Nicene +decree on a Sunday. The difference between them and the Roman Church, at +this period, was that they still followed the 84 years' cycle in +computing Easter, which had been abandoned at Rome for the more accurate +cycle of 532 years. This difference of calculation led to Easter being +observed on different Sundays, in certain years, in England, by the +adherents of the two churches. Thus Bede records that in a certain year +(which must have been 645, 647, 648 or 651) Queen Eanfleda, who had +received her instruction from a Kentish priest of the Roman obedience, +was fasting and keeping Palm Sunday, while her husband, Oswy, king of +Northumbria, following the rule of the British church, was celebrating +the Easter festival. This diversity of usage was ended, so far as the +kingdom of Northumbria was concerned, by the council of Streaneshalch, +or Whitby, in 654. To Archbishop Theodore is usually ascribed the credit +of ending the difference in the rest of England in 669. + +The Gregorian correction of the calendar in 1582 has once more led to +different days being observed. So far as Western Christendom is +concerned the corrected calendar is now universally accepted, and Easter +is kept on the same day, but it was not until 1752 that the Gregorian +reformation of the calendar was adopted in Great Britain and Ireland. +Jealousy of everything emanating from Rome still keeps the Eastern +churches from correcting the calendar according to the Gregorian +reformation, and thus their Easter usually falls before, or after, that +of the Western churches, and only very rarely, as was the case in 1865, +do the two coincide. + +Easter, as commemorating the central fact of the Christian religion, has +always been regarded as the chief festival of the Christian year, and +according to a regulation of Constantine it was to be the first day of +the year. This reckoning of the year as beginning at Easter lingered in +France till 1565, when, by an ordinance of Charles IX., the 1st of +January finally took its place. + +Four different periods may be mentioned as connected with the observance +of Easter, viz. (1) the preparatory fast of the forty days of Lent; (2) +the fifteen days, beginning with the Sunday before and ending with the +Sunday after Easter, during which the ceremonies of Holy Week and the +services of the Octave of Easter were observed; this period, called by +the French the _Quinzaine de Paques_, was specially observed in that +country; (3) the Octave of Easter, during which the newly-baptized wore +their white garments, which they laid aside on the Sunday after Easter, +known as _Dominica in albis depositis_ from this custom; another name +for this Sunday was _Pascha clausum_, or the close of Easter, and from a +clipping of the word "close" the English name of "Low" Sunday is +believed to be derived; (4) Eastertide proper, or the paschal season +beginning at Easter and lasting till Whit Sunday, during the whole of +which time the festival character of the Easter season was maintained in +the services of the church. + +Many ecclesiastical ceremonies, growing up from early times, clustered +round the celebration of the Easter festival. One of the most notable of +these was the use of the paschal candle. This was a candle of very large +dimensions, set in a candlestick big enough to hold it, which was +usually placed on the north side, just below the first ascent to the +high altar. It was kept alight during each service till Whitsuntide. The +Paschal, as it was called at Durham cathedral, was one of the chief +sights of that church before the Reformation. It was an elaborate +construction of polished brass, and, contrary to the usual custom, seems +to have been placed in the centre of the altar-step, long branches +stretching out towards the four cardinal points, bearing smaller +candles. The central stem of the candlestick was about 38 ft. high, and +bore the paschal candle proper, and together they reached a combined +height of about 70 ft., the candle being lighted from an opening above. +Other paschal candles seem to have been of scarcely less size. At +Lincoln, c. 1300, the candle was to weigh three stones of wax; at +Salisbury in 1517 it was to be 36 ft. long; and at Westminster in 1558 +it weighed no less than 3 cwt. of wax. After Whitsuntide what remained +was made into smaller candles for the funerals of the poor. In the +ancient churches at Rome the paschal candlesticks were fixtures, but +elsewhere they were usually movable, and were brought into the church +and set up on the Thursday before Easter. At Winchester the paschal +candlestick was of silver, and was the gift of Canute. Others of more or +less importance are recorded as having been at Canterbury, Bury St +Edmunds, Hereford and York. The burning of the paschal candle still +forms part of the Easter ceremonial of the Roman Catholic Church (see +LIGHTS, CEREMONIAL). + +The liturgical colour for Easter was everywhere white, as the sign of +joy, light and purity, and the churches and altars were adorned with the +best ornaments that each possessed. Flowers and shrubs no doubt in early +times were also used for this purpose, but what evidence there is goes +against the medieval use of such decorations, which are so popular at +the present day. + +It is not the purpose of this article to enter on the wide subject of +the popular observances, such as the giving and sending of Pasch or +Easter eggs as presents. For such the reader may consult Brand's +_Popular Antiquities_, Hone's _Every-Day Book_, and Chambers's _Book of +Days_. + + AUTHORITIES.--Bingham, _Antiquities of the Christian Church_; Bede, + _Ecclesiastical History of England_; Procter and Frere, _A New History + of the Book of Common Prayer_ (London, 1901); Surtees Society, _Rites + of Durham_, ed. J.T. Fowler (1903); De Morgan, _Companion to the + Almanac_ (1845); De Moleon, _Voyages liturgiques_ (Paris, 1718). + (T. M. F.) + + + + +EASTER ISLAND (Rapanui, i.e. Great Rapa), an island in the eastern part +of the South Pacific ocean, belonging to Chile (since 1888), in 27 deg. 8' +S. and 109 deg. 28' W., 1400 m. E. of Pitcairn, and 2000 m. from the South +American coast. It is roughly triangular in shape, with its hypotenuse +12 m. long running north-east and south-west, and its three angles +marked by three volcanic peaks, of which the north-eastern reaches 1768 +ft. of altitude. The area of the island is 45 sq. m. The coast has no +good natural harbour, and landing is difficult. There is no lack of +fertile soil, and the climate is moist enough to make up for the absence +of running water. Formerly the island appears to have been wooded, but +it now presents only a few bushes (_Edwardsia_, _Broussonetia_, &c.), +ferns, grasses, sedges, &c. The natives grow bananas in the shelter of +artificial pits, also sugar-canes and sweet potatoes, and keep a few +goats and a large stock of domestic fowls, and a Tahitian commercial +house breeds cattle and sheep on the island. + +It is doubtful whether Rapanui was discovered by Davis in 1686, though +it is sometimes marked Davis Island on maps. Admiral Roggeveen reached +it on Easter day 1722; in 1774 Captain Cook discovered it anew and +called it Teapi or Waihu. It was subsequently visited by La Perouse +(1776), Kotzebue (1816), &c. At the time of Roggeveen's discovery the +island probably contained from 2000 to 3000 inhabitants of Polynesian +race, who, according to their own tradition, came from Rapa Iti (Little +Rapa) or Oparo, one of the Tubuai or Austral group. In 1863 a large +proportion of the inhabitants were kidnapped by the Peruvians and +transported to work at the guano diggings on the Chincha Islands. The +next year a Jesuit mission from Tahiti reached the island and succeeded +in the task of civilization. The natives, who number scarcely one +hundred, are all Christians. + +Easter Island is famous for its wonderful archaeological remains. Here +are found immense platforms built of large cut stones fitted together +without cement. They are generally built upon headlands, and on the +slope towards the sea. The walls on the seaside are, in some of the +platforms, nearly 30 ft. high and from 200 to 300 ft. long, by about 30 +ft. wide. Some of the squared stones are as much as 6 ft. long. On the +land side of the platforms there is a broad terrace with large stone +pedestals upon which once stood colossal stone images carved somewhat +into the shape of the human trunk. On some of the platforms there are +upwards of a dozen images, now thrown from their pedestals and lying in +all directions. Their usual height is from 14 to 16 ft., but the largest +are 37 ft., while some are only about 4 ft. They are formed from a grey +trachytic lava found at the east end of the island. The top of the heads +of the images is cut flat to receive round crowns made of a reddish +vesicular tuff found at a crater about 8 m. distant from the quarry +where the images were cut. A number of these crowns still lie at the +crater apparently ready for removal, some of the largest being over 10 +ft. in diameter. In the atlas illustrating the voyage of La Perouse a +plan of the island is given, with the position of several of the +platforms. Two of the images are also represented in a plate. One +statue, 8 ft. in height and weighing 4 tons, was brought to England, and +is now in the British Museum. In one part of the island are the remains +of stone houses nearly 100 ft. long by about 20 ft. wide. These are +built in courses of large flat stones fitted together without cement, +the walls being about 5 ft. thick and over 5 ft. high. They are lined on +the inside with upright slabs, on which are painted geometrical figures +and representations of animals. The roofs are formed by placing slabs so +that each course overlaps the lower one until the opening becomes about +5 ft. wide, when it is covered with flat slabs reaching from one side to +the other. The lava rocks near the houses are carved into the +resemblance of various animals and human faces, forming, probably, a +kind of picture writing. Wooden tablets covered with various signs and +figures have also been found. The only ancient implement discovered on +the island is a kind of stone chisel, but it seems impossible that such +large and numerous works could have been executed with such a tool. The +present inhabitants of Easter Island know nothing of the construction of +these remarkable works; and the entire subject of their existence in +this small and remote island is a mystery. + + + + +EASTERN BENGAL AND ASSAM, a province of British India, which was +constituted out of Assam and the eastern portion of Bengal on the 16th +of October 1905. Area 111,569 sq. m.; pop. (1901) 30,961,459. It is +situated between 20 deg. 45' and 28 deg. 17' N., and between 87 deg. 48' and 97 deg. 5' +E. The province, as thus reconstituted, consists of the Bengal districts +of Dacca, Mymensingh, Faridpur, Backergunje, Tippera, Noakhali, +Chittagong, Chittagong Hill Tracts, Rajshahi, Dinajpur, Jalpaiguri, +Rangpur, Bogra, Pabna, Malda, and the native states of Kuch Behar and +Hill Tippera; and the whole of the former area of Assam consisting of +the districts of Goalpara, Kamrup, Darrang, Nowgong, Sibsagar, +Lakhimpur, Sylhet, Cachar, Garo Hills, Khasi and Jaintia Hills, Naga +Hills and Lushai Hills. It is bounded on the N. by Bhutan, on the W. by +Burma, on the S. by Burma and the Bay of Bengal, and on the E. by +Bengal. The line of demarcation between Bengal and the new province +begins at the frontier of Bhutan, east of Darjeeling, runs south-west to +Sahibganj on the Ganges and thence follows the course of the Ganges down +to the deltaic branch, called the Haringhata, which leaves the main +stream above Goalanda, and the course of the latter, which runs south +into the Bay of Bengal. The capital of the province is Dacca, and its +chief port is Chittagong. + +The Bengal districts which were transferred to Eastern Bengal and Assam +comprised northern and eastern Bengal, the most prosperous and least +overcrowded portion of Bengal. The land there is less densely populated, +wages are higher and food cheaper, and the rainfall more copious and +more regular, while the staple crops of jute, tobacco and rice command a +higher price relative to the rent of the land than in Behar or other +parts of Bengal. The population are largely Mahommedans and of a more +virile stock than the Bengali proper. Northern Bengal corresponds almost +exactly with the Rajshahi division and lies within the boundaries of the +Ganges and Brahmaputra rivers. It contains much high land of a stiff red +clay, with an undulating surface covered for the most part with scrub +jungle. The inhabitants are Indo-Chinese, not Indo-Aryans as in Bengal +proper, and are Mahommedan by religion instead of Hindu. Eastern Bengal +consists of the Dacca and Chittagong divisions which are mainly Bengali +in race and Hindu in religion. For the Assamese districts see ASSAM. The +province as a whole contains 18,036,688 Mahommedans and 12,036,538 +Hindus. In language 27,272,895 of the inhabitants speak Bengali, +1,349,784 speak Assamese, and the remainder Hindi and various hill +dialects, Manipuri, Bodo, Khasi and Garo. The administration is in the +hands of a lieutenant-governor, assisted by a legislative council of +fifteen members. Under him are five commissioners, and financial matters +are regulated by a board of revenue consisting of two members. + +The constitution of the new province arose out of the fact that Bengal +had grown too unwieldy for the administration of a single +lieutenant-governor. In 1868 Sir Stafford Northcote drew attention to +the greatly augmented demands that the outlying portions of Bengal made +on the time and labour of the government. At that time the population of +the province was between 40 and 50 millions, and the question was left +in abeyance until 1903, when the population had risen to 781/2 millions. +In the meantime the importance of rendering Assam a self-contained and +independent administration with a service of its own, and of providing +for its future commercial expansion, had arisen. These two +considerations led Lord Curzon to propose that Bengal should be lopped +of territory both on its eastern and western borders, and that all the +districts east of the Brahmaputra should be constituted into a separate +province. This proposal was bitterly opposed by the Hindus of Bengal on +the ground that it would destroy the unity of the Bengali race; and +their agitation was associated with the _Swadeshi_ (own country) +movement for the boycott of British goods. + +After the constitution of the province in October 1905, the agitation in +Eastern Bengal increased. Public meetings of protest were held, +vernacular broadsheets containing scandalous attacks on the British +authorities were circulated, schoolboys and others were organized and +drilled as so-called "national volunteers," and employed as pickets to +prevent the sale of British goods. Such was the state of things when Sir +J. Bampfylde Fuller entered on his office as first lieutenant-governor +of Eastern Bengal in January 1906. His reception was ominous. +Representative bodies that were dominated by Hindus refused to vote the +usual addresses of welcome, and non-official Hindus abstained from +paying the customary calls. There were, however, no further overt signs +of objection to the lieutenant-governor personally, and after a month or +two--in spite of, or perhaps because of, his efforts to restrain +sedition and to keep discipline in the schools--there was a decided +change in the attitude of Hindu opinion. At Dacca, in July, for +instance, the reception at Government House was attended by large +numbers of Bengali gentlemen, who assured the lieutenant-governor that +"the trouble was nearly ended." The agitation was, in fact, largely +artificial, the work of Calcutta lawyers, journalists and schoolmasters; +the mass of the people, naturally law-abiding, was unmoved by it so long +as the government showed a firm hand; while the Mussulmans, who formed a +large proportion of the whole, saw in the maintenance of the partition +and of the prestige of the British government the guarantees of their +own security. + +All seemed to be going well when an unfortunate difference of opinion +occurred between the lieutenant-governor and the central government, +resulting in the resignation of Sir Bampfylde Fuller (August 1906) and +in ulterior consequences destined to be of far-reaching import. The +facts are briefly as follows. Acting on a report of Dr P. Chatterji, +inspector of schools, dated January 2, 1906, the lieutenant-governor, on +the 10th of February, addressed a letter to the registrar of Calcutta +University recommending that the privilege of affiliation to the +university should be withdrawn from the Banwarilal and Victoria high +schools at Sirajganj in Pabna, as a punishment for the seditious conduct +of both pupils and teachers. Apart from numerous cases of illegal +interference with trade and of disorder in the streets reported against +the students, two specific outrages of a serious character were +instanced as having occurred on the 15th of November: the raiding of a +cart laden with English cloth belonging to Marwari traders, and a +cowardly assault by some 40 or 50 lads on the English manager of the +Bank of Bengal. These outrages "were not the result of thoughtlessness +or sudden excitement, but were the outcome of a regularly organized +scheme, set on foot and guided by the masters of these schools, for +employing the students in enforcing a boycott." All attempts to discover +and punish the offenders had been frustrated by the refusal of the +school authorities to take action, and in the opinion of the +lieutenant-governor the only course open was to apply the remedy +suggested in the circular letter addressed to magistrates and collectors +(October 10, 1905) by Mr R.W. Carlyle, the officiating chief secretary +to the government of Bengal, directing them, in the event of students +taking any part in political agitation, boycotting and the like, to +inform the heads of schools or colleges concerned that, unless they +prevented such action being taken by the boys attending their +institutions, their grant-in-aid and the privilege of competing for +scholarships and of receiving scholarship-holders would be withdrawn, +and that the university would be asked to disaffiliate their +institutions. + +The reply, dated July 5th, from the secretary in the home department of +the government of India, was--to use Sir Bampfylde's own later +expression--to throw him over. It was likely that a difference of +opinion in the syndicate of the university would arise as to the degree +of culpability that attached to the proprietors of the schools; in the +event of the syndicate taking any "punitive action," the matter was +certain to be raised in the senate, and would lead to an acrimonious +public discussion, in which the partition of Bengal and the +administration of the new province would be violently attacked; and in +the actual state of public opinion in Bengal it seemed to the government +of India highly inexpedient that such a debate should take place. +"Collective punishment," too, "would be liable to be misconstrued in +England," and the government preferred to rely on the gradual effect of +the new university regulations, which aimed "at discouraging the +participation of students in political movements by enforcing the +responsibility of masters and the managing committees of schools for +maintaining discipline." + +On receipt of this communication Sir Bampfylde Fuller at once tendered +his resignation to the viceroy (July 15). He pointed out that to +withdraw from the position taken up would be "concession, not in the +interests of education, but to those people in Calcutta who have been +striving to render my government impossible, in order to discredit the +partition"; that previous concessions had had merely provocative +effects, and that were he to give way in this matter his authority would +be so weakened that he would be unable to maintain order in the country. +On the 3rd of August, after some days of deliberation, the viceroy +telegraphed saying that he was "unable to reconsider the orders sent," +and accepting Sir Bampfylde's resignation. By the Anglo-Indian press the +news was received with something like consternation, the _Times of +India_ describing the resignation as one of the gravest blunders ever +committed in the history of British rule in India, and as a direct +incentive to the forces of disquiet, disturbance and unrest. Equally +emphatic was the verdict of the Mussulman community forming two-thirds +of the population of Eastern Bengal. On the 7th of August, the day of +Sir Bampfylde Fuller's departure from Dacca, a mass-meeting of 30,000 +Mahommedans was held, which placed on record their disapproval of a +system of government "which maintains no continuity of policy," and +expressed its feeling that the lowering of British prestige must +"alienate the sympathy of a numerically important and loyal section of +His Majesty's subjects"; and many meetings of Mussulmans subsequently +passed resolutions to the same general effect. The _Akhbar-i-Islam_, the +organ of Bombay Mussulman opinion, deplored the "unwise step" taken by +the government, and ascribed it to Lord Minto's fear of the Babu press, +a display of weakness of which the Babus would not be slow to take +advantage. + +This latter prophecy was not slow in fulfilling itself. So early as the +8th of August Calcutta was the scene of several large demonstrations at +which the Swadeshi vow was renewed, and at which resolutions were passed +declining to accept the partition as a settled fact, and resolving on +the continuance of the agitation. The tone of the Babu press was openly +exultant: "We have read the familiar story of the Russian traveller and +the wolves," said a leading Indian newspaper in Calcutta. "The British +government follows a similar policy. First the little babies were +offered up in the shape of the _Bande Mataram_ circular and the Carlyle +circular. Now a bigger boy has gone in the person of our own Joseph. +Courage, therefore, O wolves! Press on and the horse will soon be yours +to devour! Afterwards the traveller himself will alone be left."[1] The +task before the new lieutenant-governor of Eastern Bengal, the Hon. L. +Hare, was obviously no easy one. The encouragement given to sedition by +the weakness of the government in this case was shown by later events in +Bengal and elsewhere (see INDIA: _History, ad fin._). + +For the early history of the various portions of the province see BENGAL +and ASSAM. + + See Sir James Bourdillon, _The Partition of Bengal_ (Society of Arts, + 1905); official blue-books on _The Reconstitution of the Provinces of + Bengal and Assam_ (Cd. 2658 and 2746), and _Resignation of Sir J. + Bampfylde Fuller_, lieutenant-governor, &c. (Cd. 3242). A long letter + from Sir J.B. Fuller, headed _J'accuse_, attacking the general policy + of the Indian government in regard to the seditious propaganda, + appeared in _The Times_ of June 6, 1908. + + +FOOTNOTE: + + [1] Quoted by Mr F.S.P. Lely in _The Times_ of November 22, 1906. + + + + +EASTERN QUESTION, THE, the expression used in diplomacy from about the +time of the congress of Verona (1822) to comprehend the international +problems involved in the decay of the Turkish empire and its supposed +impending dissolution. The essential questions that are involved are so +old that historians commonly speak of the "Eastern Question" in +reference to events that happened long before the actual phrase was +coined. But, wherever used, it is always the Turkish Question, the +generic term in which subsidiary issues, e.g. the Greek, Armenian or +Macedonian questions, are embraced. That a phrase of so wide and loose a +nature should have been stereotyped in so narrow a sense is simply the +outcome of the conditions under which it was invented. To the European +diplomatists of the first half of the 19th century the Ottoman empire +was still the only East with which they were collectively brought into +contact. The rivalry of Great Britain and Russia in Persia had not yet +raised the question of the Middle East; still less any ambitions of +Germany in the Euphrates valley. The immense and incalculable problems +involved in the rise of Japan, the awakening of China, and their +relations to the European powers and to America--known as the Far +Eastern Question--are comparatively but affairs of yesterday. + +The Eastern Question, though its roots are set far back in history--in +the ancient contest between the political and intellectual ideals of +Greece and Asia, and in the perennial rivalry of the powers for the +control of the great trade routes to the East--dates in its modern sense +from the treaty of Kuchuk Kainarji in 1774, which marked the definitive +establishment of Russia as a Black Sea power and formed the basis of her +special claims to interfere in the affairs of the Ottoman empire. The +compact between Napoleon and the emperor Alexander I. at Tilsit (1807) +marked a new phase, which culminated in 1812 in the treaty of Bucharest, +in which Russia definitely appeared as the protector of the Christian +nationalities subject to the Ottoman sultan. + +The attitude of the various powers in the Eastern Question was now +defined. Russia, apart from her desire to protect the Orthodox +nationalities subject to the Ottoman power, aimed at owning or +controlling the straits by which alone she could find an outlet to the +Mediterranean and the ocean beyond. Austria, once the champion of Europe +against the Turk, saw in the Russian advance on the Danube a greater +peril than any to be feared from the moribund Ottoman power, and made +the maintenance of the integrity of Turkey a prime object of her policy. +She was thus brought into line with Great Britain, whose traditional +friendship with Turkey was strengthened by the rise of a new power whose +rapid advance threatened the stability of British rule in India. But +though Austria, Great Britain and presently France, were all equally +interested in maintaining the Ottoman empire, the failure of the +congress of Vienna in 1815 to take action in the matter of a guarantee +of Turkey, and the exclusion of the Sultan from the Holy Alliance, +seemed to endorse the claim of Russia to regard the Eastern Question as +"her domestic concern" in which "Europe" had no right to interfere. The +revolt of the Greeks (1821) put this claim to the test; by the treaty of +Adrianople (1829) Russia stipulated for their autonomy as part of the +price of peace, but the powers assembled in conference at London refused +to recognize this settlement, and the establishment of Greece as an +independent kingdom (1832) was really aimed at the pretensions and the +influence of Russia. These reached their high-water mark in the treaty +of Unkiar Skelessi (July 8th, 1832). It was no longer a question of the +partition of Turkey or of a Russian conquest of Constantinople, but of +the deliberate degradation by Russia of the Ottoman empire into a weak +state wholly dependent upon herself. The ten years' crisis (1831-1841) +evoked by the revolt of Mehemet Ali, pasha of Egypt, thus resolved +itself into a diplomatic struggle between Russia and the other powers to +maintain or to recover influence at Constantinople. The Russian +experiment of maintaining the integrity of Turkey while practically +treating her as a vassal state, ended with the compromise of 1841; and +the emperor Nicholas I. reverted to the older idea of expelling the +Turks from Europe. The Eastern Question, however, slumbered until, in +1851, the matter of the Holy Places was raised by Napoleon III., +involving the whole question of the influence in Ottoman affairs of +France under the capitulations of 1740 and of Russia under the treaty of +1774. The Crimean War followed and in 1856 the treaty of Paris, by which +the powers hoped to stem the tide of Russian advance and establish the +integrity of a reformed Ottoman state. Turkey was now for the first +time solemnly admitted to the European concert. The next critical phase +was opened in 1871, when Russia took advantage of the collapse of France +to denounce the Black Sea clauses of the treaty of 1856. The renewal of +an aggressive policy thus announced to the world soon produced a new +crisis in the Eastern Question, which had meanwhile become complicated +by the growth of Pan-Slav ideals in eastern Europe. In 1875 a rising in +Herzegovina gave evidence of a state of feeling in the Balkan peninsula +which called for the intervention of Europe, if a disastrous war were to +be prevented. But this intervention, embodied in the "Andrassy Note" +(December 1875) and the Berlin memorandum (May 1876), met with the +stubborn opposition of Turkey, where the "young Turks" were beginning to +oppose a Pan-Islamic to the Pan-Slav ideal. The Russo-Turkish War of +1877-78 followed, concluded by the treaty of San Stefano, the terms of +which were modified in Turkey's favour by the congress of Berlin (1878), +which marks the beginning of the later phase of the Eastern Question. +Between Russia and Turkey it interposed, in effect, a barrier of +independent (Rumania, Servia) and quasi-independent (Bulgaria) states, +erected with the counsel and consent of collective Europe. It thus, +while ostensibly weakening, actually tended to strengthen the Ottoman +power of resistance. + +The period following the treaty of Berlin is coincident with the reign +of Sultan Abd-ul-Hamid II. The international position of the Ottoman +empire was strengthened by the able, if Machiavellian, statecraft of the +sultan; while the danger of disruption from within was lessened by the +more effective central control made possible by railways, telegraphs, +and the other mechanical improvements borrowed from western +civilization. With the spread of the Pan-Islamic movement, moreover, the +undefined authority of the sultan as caliph of Islam received a fresh +importance even in countries beyond the borders of the Ottoman empire, +while in countries formerly, or nominally still, subject to it, it +caused, and promised to cause, incalculable trouble. + +The Eastern Question thus developed, in the latter years of the 19th +century, from that of the problems raised by the impending break-up of a +moribund empire, into the even more complex question of how to deal with +an empire which showed vigorous evidence of life, but of a type of life +which, though on all sides in close touch with modern European +civilization, was incapable of being brought into harmony with it. The +belief in the imminent collapse of the Ottoman dominion was weakened +almost to extinction; so was the belief, which inspired the treaty of +1856, in the capacity of Turkey to reform and develop itself on European +lines. But the Ottoman empire remained, the mistress of vast undeveloped +wealth. The remaining phase of the Eastern Question, if we except the +concerted efforts to impose good government on Macedonia in the +interests of European peace, or the side issues in Egypt and Arabia, was +the rivalry of the progressive nations for the right to exploit this +wealth. In this rivalry Germany, whose interest in Turkey even so late +as the congress of Berlin had been wholly subordinate, took a leading +part, unhampered by the traditional policies or the humanitarian +considerations by which the interests of the older powers were +prejudiced. The motives of German intervention in the Eastern Question +were ostensibly commercial; but the Bagdad railway concession, +postulating for its ultimate success the control of the trade route by +way of the Euphrates valley, involved political issues of the highest +moment and opened up a new and perilous phase of the question of the +Middle East. + +This was the position when in 1908 an entirely new situation was created +by the Turkish revolution. As the result of the patient and masterly +organization of the "young Turks," combined with the universal +discontent with the rule of the sultan and the palace _camarilla_, the +impossible seemed to be achieved, and the heterogeneous elements +composing the Ottoman empire to be united in the desire to establish a +unified state on the constitutional model of the West. The result on the +international situation was profound. Great Britain hastened to re-knit +the bonds of her ancient friendship with Turkey; the powers, without +exception, professed their sympathy with the new regime. The +establishment of a united Turkey on a constitutional and nationalist +basis was, however, not slow in producing a fresh complication in the +Eastern Question. Sooner or later the issue was sure to be raised of the +status of those countries, still nominally part of the Ottoman empire, +but in effect independent, like Bulgaria, or subject to another state, +like Bosnia and Herzegovina. The cutting of the Gordian knot by +Austria's annexation of Bosnia and Herzegovina, and by the proclamation +of the independence of Bulgaria, and of Prince Ferdinand's assumption of +the old title of tsar (king), threatened to raise the Eastern Question +once more in its acutest form. The international concert defined in the +treaty of Berlin had been rudely shaken, if not destroyed; the +denunciation by Austria, without consulting her co-signatories, of the +clauses of the treaty affecting herself seemed to invalidate all the +rest; and in the absence of the restraining force of a united concert of +the great powers, free play seemed likely once more to be given to the +rival ambitions of the Balkan nationalities, the situation being +complicated by the necessity for the dominant party in the renovated +Turkish state to maintain its prestige. During the anxious months that +followed the Austrian _coup_, the efforts of diplomacy were directed to +calming the excitement of Servians, Montenegrins and the Young Turks, +and to considering a European conference in which the _fait accompli_ +should be regularized in accordance with the accepted canons of +international law. The long delay in announcing the assembly of the +conference proved the extreme difficulty of arriving at any satisfactory +basis of settlement; and though the efforts of the powers succeeded in +salving the wounded pride of the Turks, and restraining the impetuosity +of the Serbs and Montenegrins, warlike preparations on the part of +Austria continued during the winter of 1908-1909, being justified by the +agitation in Servia, Montenegro and the annexed provinces. It was not +till April 1909 (see EUROPE: ad fin.) that the crisis was ended, through +the effectual backing given by Germany to Austria; and Russia, followed +by England and France, gave way and assented to what had been done. + + See TURKEY: _History_, where cross-references to the articles on the + various phases of the Eastern Question will be found, together with a + bibliography. See also E. Driault, _La Question d'orient depuis son + origine_ (Paris, 1898), a comprehensive sketch of the whole subject, + including the Middle and Far East. (W. A. P.) + + + + +EAST GRINSTEAD, a market town in the East Grinstead parliamentary +division of Sussex, England, 30 m. S. by E. from London by the London, +Brighton & South Coast railway. Pop. of urban district (1901) 6094. St +Swithin's church contains, among numerous ancient memorials, one of the +iron memorial slabs (1507) peculiar to certain churches of Sussex, and +recalling the period when iron was extensively worked in the district. +There may be noticed Sackville College (an almshouse founded in 1608), +and St Margaret's home and orphanage, founded by the Rev. John Mason +Neale (1818-1866), warden of Sackville College. Brewing and brick and +tile making are carried on. In the vicinity (near Forest Row station) is +the golf course of the Royal Ashdown Forest Golf Club. + +The hundred of East Grinstead (Grenestede, Estgrensted) was in the +possession of the count of Mortain in 1086, but no mention of a vill or +manor of East Grinstead is made in the Domesday Survey. In the reign of +Henry III. the hundred was part of the honour of Aquila, then in the +king's hands. The honour was granted by him to Peter of Savoy, through +whom it passed to his niece Queen Eleanor. In the next reign the king's +mother held the borough of East Grinstead as parcel of the honour of +Aquila. East Grinstead was included in a grant by Edward III. to John of +Gaunt, duke of Lancaster, and it remained part of the duchy of Lancaster +until James I. granted the borough to Sir George Rivers, through whom it +was obtained by the Sackvilles, earls of Dorset. East Grinstead was a +borough by prescription. In the 16th century it was governed by an +alderman, bailiff and constable. It returned two members to parliament +from 1307 until 1832, but was disenfranchised by the Reform Act. In 1285 +the king ordered that his market at Grenestede should be held on +Saturday instead of Sunday, and in 1516 the inhabitants of the town were +granted a market each week on Saturday and a fair every year on the eve +of St Andrew and two days following. Charles I. granted the earl of +Dorset a market on Thursday instead of the Saturday market, and fairs on +the 16th of April and the 26th of September every year. Thursday is +still the market-day, and cattle-fairs are now held on the 21st of April +and the 11th of December. + + + + +EAST HAM, a municipal borough in the southern parliamentary division of +Essex, England, contiguous to West Ham, and thus forming geographically +part of the eastward extension of London. Pop. (1901) 96,018. Its modern +growth has been very rapid, the population being in the main of the +artisan class. There are some chemical and other factories. The ancient +parish church of St Mary Magdalen retains Norman work in the chancel, +which terminates in an eastern apse. There is a monument for Edmund +Neville who claimed the earldom of Westmorland in the 17th century, and +William Stukeley, the antiquary, was buried in the churchyard. East Ham +was incorporated in 1904, and among its municipal undertakings is a +technical college (1905). The corporation consists of a mayor, 6 +aldermen and 18 councillors. Area, 33201/2 acres. + + + + +EASTHAMPTON, a township of Hampshire county, Mass., U.S.A., in the +Connecticut Valley. Pop. (1900) 5603, of whom 1731 were foreign-born; +(1905) 6808; (1910) 8524. It is served by the Boston & Maine, and the +New York, New Haven & Hartford railways, and by interurban electric +railways. The township is generally level, and is surrounded by high +hills. In Easthampton are a free public library and Williston Seminary; +the latter, one of the oldest and largest preparatory schools in New +England, was founded in 1841 by the gifts of Samuel Williston +(1795-1874) and Emily Graves Williston (1797-1885). Mr and Mrs Williston +built up the industry of covering buttons with cloth, at first doing the +work by hand, then (1827) experimenting with machinery, and in 1848 +building a factory for making and covering buttons. As the soil was +fertile and well watered, the township had been agricultural up to this +time. It is now chiefly devoted to manufacturing. Among its products are +cotton goods, especially mercerised goods, for the manufacture of which +it has one of the largest plants in the country; rubber, thread, elastic +fabrics, suspenders and buttons. Parts of Northampton and Southampton +were incorporated as the "district" of Easthampton in 1785; it became a +township in 1809, and in 1841 and 1850 annexed parts of Southampton. + + + + +EAST HAMPTON, a township of Suffolk county, New York, in the extreme +S.E. part of Long Island, occupying the peninsula of Montauk, and +bounded on the S. and E. by the Atlantic Ocean, and on the N. by Block +Island Sound, Gardiner's Bay and Peconic Bay. Pop. (1900) 3746; (1905) +4303; (1910) 4722. The township, 25 m. long and 8 m. at its greatest +width from north to south, has an irregular north coast-line and a very +regular south coast-line. The surface is rougher to the west where there +are several large lakes, notably Great Pond, 2 m. long. The scenery is +picturesque and the township is much frequented by artists. Montauk +Lighthouse, on Turtle Hill, was first built in 1795. At Montauk, after +the Spanish-American War, was Camp Wikoff, a large U.S. military camp. +The township is served by the southern division of the Long Island +railway, the terminus of which is Montauk. Other villages of the +township, all summer resorts, are: Promised Land, Amagansett, East +Hampton and Sag Harbor; the last named, only partly in the township, was +incorporated in 1803 and had a population of 1969 in 1900, and 3084 in +1910. Silverware and watch cases are manufactured here. From Sag Harbor, +which is a port of entry, a daily steamer runs to New York city. The +village received many gifts in 1906-1908 from Mrs Russell Sage. Most of +the present township was bought from the Indians (Montauks, Corchaugs +and Shinnecocks) in 1648 for about L30, through the governors of +Connecticut and New Haven, by nine Massachusetts freemen, mostly +inhabitants of Lynn, Massachusetts. With twenty other families they +settled here in 1649, calling the place Maidstone, from the old home of +some of the settlers in Kent; but as early as 1650 the name East Hampton +was used in reference to the earlier settlement of South Hampton. Until +1664, when all Long Island passed to the duke of York, the government +was by town meeting, autonomous and independent except for occasional +appeals to Connecticut. In 1683 Gardiner's Island, settled by Lion +Gardiner in 1639 and so one of the first English settlements in what is +now New York state, was made a part of Long Island and of East Hampton +township. The English settlements in East Hampton were repeatedly +threatened by pirates and privateers, and there are many stories of +treasure buried by Captain Kidd on Gardiner's Island and on Montauk +Point. The Clinton Academy, opened in East Hampton village in 1785, was +long a famous school. Of the church built here in 1653 (first +Congregational and after 1747 Presbyterian in government), Lyman Beecher +was pastor in 1799-1810; and in East Hampton were born his elder +children. Whale fishing was begun in East Hampton in 1675, when four +Indians were engaged by whites in off-shore whaling; but Sag Harbor, +which was first settled in 1730 and was held by the British after the +battle of Long Island as a strategic naval and shipping point, became +the centre of the whaling business. The first successful whaling voyage +was made from Sag Harbor in 1785, and although the Embargo ruined the +fishing for a time, it revived during 1830-1850. Cod and menhaden +fishing, the latter for the manufacture of fish-oil and guano, were +important for a time, but in the second half of the 19th century Sag +Harbor lost its commercial importance. + + + + +EAST INDIA COMPANY, an incorporated company for exploiting the trade +with India and the Far East. In the 17th and 18th centuries East India +companies were established by England, Holland, France, Denmark, +Scotland, Spain, Austria and Sweden. By far the most important of these +was the English East India Company, which became the dominant power in +India, and only handed over its functions to the British Government in +1858 (see also DUTCH EAST INDIA COMPANY, OSTEND COMPANY). + + + English East India Co. + +The English East India Company was founded at the end of the 16th +century in order to compete with the Dutch merchants, who had obtained a +practical monopoly of the trade with the Spice Islands, and had raised +the price of pepper from 3s. to 8s. per lb. Queen Elizabeth incorporated +it by royal charter, dated December 31, 1600, under the title of "The +Governor and Company of Merchants of London, trading into the East +Indies." This charter conferred the sole right of trading with the East +Indies, i.e. with all countries lying beyond the Cape of Good Hope or +the Straits of Magellan, upon the company for a term of 15 years. +Unauthorized interlopers were liable to forfeiture of ships and cargo. +There were 125 shareholders in the original East India Company, with a +capital of L72,000: the first governor was Sir Thomas Smythe. The early +voyages of the company, from 1601 to 1612, are distinguished as the +"separate voyages," because the subscribers individually bore the cost +of each voyage and reaped the whole profits, which seldom fell below +100%. After 1612 the voyages were conducted on the joint stock system +for the benefit of the company as a whole. These early voyages, whose +own narratives may be read in Purchas, pushed as far as Japan, and +established friendly relations at the court of the Great Mogul. In +1610-1611 Captain Hippon planted the first English factories on the +mainland of India, at Masulipatam and at Pettapoli in the Bay of Bengal. +The profitable nature of the company's trade had induced James I. to +grant subsidiary licences to private traders; but in 1609 he renewed the +company's charter "for ever," though with a proviso that it might be +revoked on three years' notice if the trade should not prove profitable +to the realm. + + + English and Dutch disputes. + +Meanwhile friction was arising between the English and Dutch East India +Companies. The Dutch traders considered that they had prior rights in +the Far East, and their ascendancy in the Indian Archipelago was indeed +firmly established on the basis of territorial dominion and authority. +In 1613 they made advances to the English company with a suggestion for +co-operation, but the offer was declined, and the next few years were +fertile in disputes between the armed traders of both nations. In 1619 +was ratified a "treaty of defence" to prevent disputes between the +English and Dutch companies. When it was proclaimed in the East, +hostilities solemnly ceased for the space of an hour, while the Dutch +and English fleets, dressed out in all their flags and with yards +manned, saluted each other; but the treaty ended in the smoke of that +stately salutation, and perpetual and fruitless contentions between the +Dutch and English companies went on just as before. In 1623 these +disputes culminated in the "massacre of Amboyna," where the Dutch +governor tortured and executed the English residents on a charge of +conspiring to seize the fort. Great and lasting indignation was aroused +in England, but it was not until the time of Cromwell that some +pecuniary reparation was exacted for the heirs of the victims. The +immediate result was that the English company tacitly admitted the Dutch +claims to a monopoly of the trade in the Far East, and confined their +operations to the mainland of India and the adjoining countries. + + + The East Indiamen. + +The necessity of good ships for the East Indian trade had led the +company in 1609 to construct their dockyard at Deptford, from which, as +Monson observes, dates "the increase of great ships in England." Down to +the middle of the 19th century, the famous "East Indiamen" held +unquestioned pre-eminence among the merchant vessels of the world. +Throughout the 17th century they had to be prepared at any moment to +fight not merely Malay pirates, but the armed trading vessels of their +Dutch, French and Portuguese rivals. Many such battles are recorded in +the history of the East India Company, and usually with successful +results. + + + The acquisition of territory. + +It was not until it had been in existence for more than a century that +the English East India Company obtained a practical monopoly of the +Indian trade. In 1635, a year after the Great Mogul had granted it the +liberty of trading throughout Bengal, Charles I. issued a licence to +Courten's rival association, known as "the Assada Merchants," on the +ground that the company had neglected English interests. The piratical +methods of their rivals disgraced the company with the Mogul officials, +and a _modus vivendi_ was only reached in 1649. In 1657 Cromwell renewed +the charter of 1609, providing that the Indian trade should be in the +hands of a single joint stock company. The new company thus formed +bought up the factories, forts and privileges of the old one. It was +further consolidated by the fostering care of Charles II., who granted +it five important charters. From a simple trading company, it grew under +his reign into a great chartered company--to use the modern term--with +the right to acquire territory, coin money, command fortresses and +troops, form alliances, make war and peace, and exercise both civil and +criminal jurisdiction. It is accordingly in 1689, when the three +presidencies of Bengal, Madras and Bombay had lately been established, +that the ruling career of the East India Company begins, with the +passing by its directors of the following resolution for the guidance of +the local governments in India:--"The increase of our revenue is the +subject of our care, as much as our trade; 'tis that must maintain our +force when twenty accidents may interrupt our trade; 'tis that must make +us a nation in India; without that we are but a great number of +interlopers, united by His Majesty's royal charter, fit only to trade +where nobody of power thinks it their interest to prevent us; and upon +this account it is that the wise Dutch, in all their general advices +that we have seen, write ten paragraphs concerning their government, +their civil and military policy, warfare, and the increase of their +revenue, for one paragraph they write concerning trade." From this +moment the history of the transactions of the East India Company becomes +the history of British India (see INDIA: _History_). Here we shall only +trace the later changes in the constitution and powers of the ruling +body itself. + + + The interlopers. + +The great prosperity of the company under the Restoration, and the +immense profits of the Indian trade, attracted a number of private +traders, both outside merchants and dismissed or retired servants of the +company, who came to be known as "interlopers." In 1683 the case of +Thomas Sandys, an interloper, raised the whole question of the royal +prerogative to create a monopoly of the Indian trade. The case was tried +by Judge Jeffreys, who upheld the royal prerogative; but in spite of his +decision the custom of interloping continued and laid the foundation of +many great fortunes. By 1691 the interlopers had formed themselves into +a new society, meeting at Dowgate, and rivalling the old company; the +case was carried before the House of Commons, which declared in 1694 +that "all the subjects of England have equal right to trade to the East +Indies unless prohibited by act of parliament." This decision led up to +the act of 1698, which created a new East India Company in consideration +of a loan of two millions to the state. The old company subscribed +L315,000 and became the dominant factor in the new body; while at the +same time it retained its charter for three years, its factories, forts +and assured position in India. The rivalry between the two companies +continued both in England and in India, until they were finally +amalgamated by a tripartite indenture between the companies and Queen +Anne (1702), which was ratified under the Godolphin Award (1708). Under +this award the company was to lend the nation L3,200,000, and its +exclusive privileges were to cease at three years' notice after this +amount had been repaid. But by this time the need for permanence in the +Indian establishment began to be felt, while parliament would not +relinquish its privilege of "milking" the company from time to time. In +1712 an act was passed continuing the privileges of the company even +after their fund should be redeemed; in 1730 the charter was prolonged +until 1766, and in 1742 the term was extended until 1783 in return for +the loan of a million. This million was required for the war with +France, which extended to India and involved the English and French +companies there in long-drawn hostilities, in which the names of Dupleix +and Clive became prominent. + + + The company and the crown. + +So long as the company's chief business was that of trade, it was left +to manage its own affairs. The original charter of Elizabeth had placed +its control in the hands of a governor and a committee of twenty-four, +and this arrangement subsisted in essence down to the time of George +III. The chairman and court of directors in London exercised unchecked +control over their servants in India. But after Clive's brilliant +victory at Plassey (1757) had made the company a ruling power in India, +it was felt to be necessary that the British government should have some +control over the territories thus acquired. Lord North's Regulating Act +(1773) raised the governor of Bengal--Warren Hastings--to the rank of +governor-general, and provided that his nomination, though made by a +court of directors, should in future be subject to the approval of the +crown; in conjunction with a council of four, he was entrusted with the +power of peace and war; a supreme court of judicature was established, +to which the judges were appointed by the crown; and legislative power +was conferred on the governor-general and his council. Next followed +Pitt's India Bill (1784), which created the board of control, as a +department of the English government, to exercise political, military +and financial superintendence over the British possessions in India. +This bill first authorized the historic phrase "governor-general in +council." From this date the direction of Indian policy passed +definitely from the company to the governor-general in India and the +ministry in London. In 1813 Lord Liverpool passed a bill which further +gave the board of control authority over the company's commercial +transactions, and abolished its monopoly of Indian trade, whilst leaving +it the monopoly of the valuable trade with China, chiefly in tea. +Finally, under Earl Grey's act of 1833, the company was deprived of this +monopoly also. Its property was then secured on the Indian possessions, +and its annual dividends of ten guineas per L100 stock were made a +charge upon the Indian revenue. Henceforward the East India Company +ceased to be a trading concern and exercised only administrative +functions. Such a position could not, in the nature of things, be +permanent, and the great cataclysm of the Indian Mutiny was followed by +the entire transference of Indian administration from the company to the +crown, on the 2nd of August 1858. + + See _Purchas his Pilgrimes_ (ed. 1905), vols. 2, 3, 4, 5, for the + charter of Elizabeth and the early voyages; Sir W.W. Hunter, _History + of British India_ (1899); Beckles Willson, _Ledger and Sword_ (1903); + Sir George Birdwood, _Report on the Old Records of the India Office_ + (1879); _The East India Company's First Letter Book_ (1895), _Letters + Received by the East India Company from its Servants in the East_, ed. + Foster, (1896 ff.). See also the interesting memorial volume _Relics + of the Honourable East India Company_ (ed. Griggs, 1909), letterpress + by Sir G. Birdwood and W. Foster. + + + + +EAST INDIES, a name formerly applied vaguely, in its widest sense, to +the whole area of India, Further India and the Malay Archipelago, in +distinction from the West Indies, which, at the time of their discovery, +were taken to be the extreme parts of the Indian region. The term "East +Indies" is still sometimes applied to the Malay Archipelago (q.v.) +alone, and the phrase "Dutch East Indies" is commonly used to denote the +Dutch possessions which constitute the greater part of that archipelago. +The Dutch themselves use the term _Nederlandsch-Indie_. + + + + +EASTLAKE, SIR CHARLES LOCK (1793-1865), English painter, was born on the +17th of November 1793 at Plymouth, where his father, a man of uncommon +gifts but of indolent temperament, was solicitor to the admiralty and +judge advocate of the admiralty court. Charles was educated (like Sir +Joshua Reynolds) at the Plympton grammar-school, and in London at the +Charterhouse. Towards 1809, partly through the influence of his +fellow-Devonian Haydon, of whom he became a pupil, he determined to be a +painter; he also studied in the Royal Academy school. In 1813 he +exhibited in the British Institution his first picture, a work of +considerable size, "Christ restoring life to the Daughter of Jairus." In +1814 he was commissioned to copy some of the paintings collected by +Napoleon in the Louvre; he returned to England in 1815, and practised +portrait-painting at Plymouth. Here he saw Napoleon a captive on the +"Bellerophon"; from a boat he made some sketches of the emperor, and he +afterwards painted, from these sketches and from memory, a life-sized +full-length portrait of him (with some of his officers) which was +pronounced a good likeness; it belongs to the marquess of Lansdowne. In +1817 Eastlake went to Italy; in 1819 to Greece; in 1820 back to Italy, +where he remained altogether fourteen years, chiefly in Rome and in +Ferrara. + +In 1827 he exhibited at the Royal Academy his picture of the Spartan +Isidas, who (as narrated by Plutarch in the life of Agesilaus), rushing +naked out of his bath, performed prodigies of valour against the Theban +host. This was the first work that attracted much notice to the name of +Eastlake, who in consequence obtained his election as A.R.A.; in 1830, +when he returned to England, he was chosen R.A. In 1850 he succeeded +Shee as president of the Royal Academy, and was knighted. Prior to this, +in 1841, he had been appointed secretary to the royal commission for +decorating the Houses of Parliament, and he retained this post until the +commission was dissolved in 1862. In 1843 he was made keeper of the +National Gallery, a post which he resigned in 1847 in consequence of an +unfortunate purchase that roused much animadversion, a portrait +erroneously ascribed to Holbein; in 1855, director of the same +institution, with more extended powers. During his directorship he +purchased for the gallery 155 pictures, mostly of the Italian schools. +He became also a D.C.L. of Oxford, F.R.S., a chevalier of the Legion of +Honour, and member of various foreign academies. + +In 1849 he married Miss Elizabeth Rigby, who had already then become +known as a writer (_Letters from the Baltic_, 1841; _Livonian Tales_, +1846; _The Jewess_, 1848) and as a contributor to the _Quarterly +Review_. Lady Eastlake (1809-1893) had for some years been interested in +art subjects, and after her marriage she naturally devoted more +attention to them, translating Waagen's _Treasures of Art in Great +Britain_ (1854-1857), and completing Mrs Jameson's _History of our Lord +in Works of Art_. In 1865 Sir Charles Eastlake fell ill at Milan; and he +died at Pisa on the 24th of December in the same year. Lady Eastlake, +who survived him for many years, continued to play an active part as a +writer on art (_Five Great Painters_, 1883, &c.), and had a large circle +of friends among the most interesting men and women of the day. In 1880 +she published a volume of _Letters from France_ (describing events in +Paris during 1789), written by her father, Edward Rigby (1747-1821), a +distinguished Norwich doctor who was known also for his practical +interest in agriculture, and who is said to have made known the flying +shuttle to Norwich manufacturers. + +As a painter, Sir Charles Eastlake was gentle, harmonious, diligent and +correct; lacking fire of invention or of execution; eclectic, without +being exactly imitative; influenced rather by a love of ideal grace and +beauty than by any marked bent of individual power or vigorous +originality. Among his principal works (which were not numerous, 51 +being the total exhibited in the Academy) are: 1828, "Pilgrims arriving +in sight of Rome" (repeated in 1835 and 1836, and perhaps on the whole +his _chef-d'oeuvre_); 1829, "Byron's Dream" (in the Tate Gallery); 1834, +the "Escape of Francesco di Carrara" (a duplicate in the Tate Gallery); +1841, "Christ Lamenting over Jerusalem" (ditto); 1843, "Hagar and +Ishmael"; 1845, "Comus"; 1849, "Helena"; 1851, "Ippolita Torelli"; 1853, +"Violante"; 1855, "Beatrice." These female heads, of a refined +semi-ideal quality, with something of Venetian glow of tint, are the +most satisfactory specimens of Eastlake's work to an artist's eye. He +was an accomplished and judicious scholar in matters of art, and +published, in 1840, a translation of Goethe's _Theory of Colours_; in +1847 (his chief literary work) _Materials for a History of +Oil-Painting_, especially valuable as regards the Flemish school; in +1848, _Contributions to the Literature of the Fine Arts_ (a second +series was edited by Lady Eastlake in 1870, and accompanied by a Memoir +from her pen); in 1851 and 1855, translated editions of Kugler's +_History of the Italian School of Painting_, and _Handbook of Painting_ +(new edition, by Lady Eastlake, 1874). + + See W. Cosmo Monkhouse, _Pictures by Sir Charles Eastlake, with + biographical and critical Sketch_ (1875). (W. M. R.) + + + + +EAST LIVERPOOL, a city of Columbiana county, Ohio, U.S.A., on the Ohio +river, about 106 m. S.E. of Cleveland. Pop. (1890) 10,956; (1900) +16,485, of whom 2112 were foreign-born; (1910 census) 20,357. It is +served by the Pennsylvania railway, by river steamboats, and by +interurban electric lines. Next to Trenton, New Jersey, East Liverpool +is the most important place in the United States for the manufacture of +earthenware and pottery, 4859 out of its 5228 wage-earners, or 92.9%, +being employed in this industry in 1905, when $5,373,852 (83.5% of the +value of all its factory products) was the value of the earthenware and +pottery. No other city in the United States is so exclusively devoted to +the manufacture of pottery; in 1908 there were 32 potteries in the city +and its immediate vicinity. The manufacture of white ware, begun in +1872, is the most important branch of the industry--almost half of the +"cream-coloured," white granite ware and semivitreous porcelain produced +in the United States in 1905 (in value, $4,344,468 out of $9,195,703) +being manufactured in East Liverpool. Though there are large clay +deposits in the vicinity, very little of it can be used for crockery, +and most of the clay used in the city's potteries is obtained from other +states; some of it is imported from Europe. After 1872 a large number of +skilled English pottery-workers settled in the city. The city's product +of pottery, terra-cotta and fireclay increased from $2,137,063 to +$4,105,200 from 1890 to 1900, and in the latter year almost equalled +that of Trenton, N.J., the two cities together producing more than half +(50.9%) of the total pottery product of the United States; in 1905 East +Liverpool and Trenton together produced 42.1% of the total value of the +country's pottery product. The municipality owns and operates its +water-works. East Liverpool was settled in 1798, and was incorporated in +1834. + + + + +EAST LONDON, a town of the Cape province, South Africa, at the mouth of +the Buffalo river, in 33 deg. 1' S. 27 deg. 55' E., 543 m. E.N.E. of Cape Town +by sea and 666 m. S. of Johannesburg by rail. Pop. (1904) 25,220, of +whom 14,674 were whites. The town is picturesquely situated on both +sides of the river, which is spanned by a combined road and railway +bridge. The railway terminus and business quarter are on the east side +on the top of the cliffs, which rise 150 ft. above the river. In Oxford +Street, the chief thoroughfare, is the town hall, a handsome building +erected in 1898. Higher up a number of churches and a school are +grouped round Vincent Square, a large open space. In consequence of the +excellent sea bathing, and the beauty of the river banks above the town, +East London is the chief seaside holiday resort of the Cape province. +The town is the entrepot of a rich agricultural district, including the +Transkei, Basutoland and the south of Orange Free State, and the port of +the Cape nearest Johannesburg. It ranks third among the ports of the +province. The roadstead is exposed and insecure, but the inner harbour, +constructed at a cost of over L2,000,000, is protected from all winds. A +shifting sand bar lies at the mouth of the river, but the building of +training walls and dredging have increased the minimum depth of water to +22 ft. From the east bank of the Buffalo a pier and from the west bank a +breakwater project into the Indian Ocean, the entrance being 450 ft. +wide, reduced between the training walls to 250 ft. There is extensive +wharf accommodation on both sides of the river, and steamers of over +8000 tons can moor alongside. There is a patent slip capable of taking +vessels of 1000 tons dead weight. An aerial steel ropeway from the river +bank to the town greatly facilitates the delivery of cargo. The imports +are chiefly textiles, hardware and provisions, the exports mainly wool +and mohair. The rateable value of the town in 1908 was L4,108,000, and +the municipal rate 1-5/8 d. + +East London owes its foundation to the necessities of the Kaffir war of +1846-1847. The British, requiring a port nearer the scene of war than +those then existing, selected a site at the mouth of the Buffalo river, +and in 1847 the first cargo of military stores was landed. A fort, named +Glamorgan, was built, and the place permanently occupied. Around this +military post grew up the town, known at first as Port Rex. Numbers of +its inhabitants are descendants of German immigrants who settled in the +district in 1857. The prosperity of the town dates from the era of +railway and port development in the last decade of the 19th century. In +1875 the value of the exports was L131,803 and that of the imports +L552,033. In 1904 the value of the exports was L1,165,938 and that of +the imports L4,688,415. In 1907 the exports, notwithstanding a period of +severe trade depression, were valued at L1,475,355, but the imports had +fallen to L3,354,633. + + + + +EASTON, a city and the county-seat of Northampton county, Pennsylvania, +U.S.A., at the confluence of the Lehigh river and Bushkill Creek with +the Delaware, about 60 m. N. of Philadelphia. Pop. (1890) 14,481; (1900) +25,238, of whom 2135 were foreign-born; (1910 census) 28,523. Easton is +served by the Central of New Jersey, the Lehigh Valley, the Lehigh & +Hudson River and the Delaware, Lackawanna & Western railways, and is +connected by canals with the anthracite coal region to the north-west +and with Bristol, Pa. A bridge across the Delaware river connects it +with Phillipsburg, New Jersey, which is served by the Pennsylvania +railway. The city is built on rolling ground, commanding pleasant views +of hill and river scenery. Many fine residences overlook city and +country from the hillsides, and a Carnegie library is prominent among +the public buildings. Lafayette College, a Presbyterian institution +opened in 1832, is finely situated on a bluff north of the Bushkill and +Delaware. The college provides the following courses of instruction: +graduate, classical, Latin scientific, general scientific, civil +engineering, electrical engineering, mining engineering and chemical; in +1908 it had 38 instructors and 442 students, 256 of whom were enrolled +in the scientific and engineering courses. Overlooking the Bushkill is +the Easton Cemetery, in which is the grave of George Taylor (1716-1781), +a signer of the Declaration of Independence, with a monument of Italian +marble to his memory. Among the city's manufactures are silk, hosiery +and knit goods, flour, malt liquors, brick, tile, drills, lumber and +planing mill products and organs; in 1905 the value of all the factory +products was $5,654,594, of which $2,290,598, or 40.5%, was the value of +the silk manufactures. Easton is the commercial centre of an important +mining region, which produces, in particular, iron ore, soapstone, +cement, slate and building stone. The municipality owns and operates an +electric-lighting plant. Easton was a garden spot of the Indians, and +here, because they would not negotiate elsewhere, several important +treaties were made between 1756 and 1762 during the French and Indian +War. The place was laid out in 1752, and was made the county-seat of the +newly erected county. It was incorporated as a borough in 1789, received +a new borough charter in 1823, and in 1887 was chartered as a city. +South Easton was annexed in 1898. + + + + +EAST ORANGE, a city of Essex county, New Jersey, U.S.A., in the +north-eastern part of the state, adjoining the city of Newark, and about +12 m. W. of New York city. Pop. (1890) 13,282; (1900) 21,506, of whom +3950 were foreign-born and 1420 were negroes; (1910 census) 34,371. It +is served by the Morris & Essex division of the Delaware, Lackawanna & +Western railway and by the Orange branch of the Erie (the former having +four stations--Ampere, Grove Street, East Orange and Brick Church), and +is connected with Newark, Orange and West Orange by electric line. The +city covers an area of about 4 sq. m., and has broad, well-paved +streets, bordered with fine shade trees (under the jurisdiction of a +"Shade Tree Commission"). It is primarily a residential suburb of New +York and Newark, and has many beautiful homes; with Orange, West Orange +and South Orange it forms virtually one community, popularly known as +"the Oranges." The public school system is excellent, and the city has a +Carnegie library (1903), with more than 22,000 volumes in 1907. Among +the principal buildings are several attractive churches, the city hall, +and the club-house of the Woman's Club of Orange. The principal +manufactures of East Orange are electrical machinery, apparatus, and +supplies (the factory of the Crocker-Wheeler Co. being here--in a part +of the city known as "Ampere") and pharmaceutical materials. The total +value of the city's factory products in 1905 was $2,326,552. East Orange +has a fine water-works system, which it owns and operates; the water +supply is obtained from artesian wells at White Oaks Ridge, in the +township of Milburn (about 10 m. from the city hall); thence the water +is pumped to a steel reinforced reservoir (capacity 5,000,000 gallons) +on the mountain back of South Orange. In 1863 the township of East +Orange was separated from the township of Orange, which, in turn, had +been separated from the township of Newark in 1806. An act of the New +Jersey legislature in 1895 created the office of township president, +with power of appointment and veto. Four years later East Orange was +chartered as a city. + + See H. Whittemore, _The Founders and Builders of the Oranges_ (Newark, + 1896). + + + + +EASTPORT, a city and port of entry of Washington county, Maine, U.S.A., +co-extensive with Moose Island in Passamaquoddy Bay, about 190 m. E.N.E. +of Portland. Pop. (1890) 4908; (1900) 5311 (1554 foreign-born); (1910) +4961. It is served by the Washington County railway, and by steamboat +lines to Boston, Portland and Calais. It is the most eastern city of the +United States, and is separated from the mainland by a narrow channel, +which is spanned by a bridge. The harbour is well protected from the +winds, and the tide, which rises and falls here about 25 ft., prevents +it from being obstructed with ice. The city is built on ground sloping +gently to the water's edge, and commands delightful views of the bay, in +which there are several islands. Its principal industry is the canning +of sardines; there are also clam canneries. Shoes, mustard, decorated +tin, and shooks are manufactured, and fish and lobsters are shipped from +here in the season. The city is the port of entry for the customs +district of Passamaquoddy; in 1908 its imports were valued at $994,961, +and its exports at $1,155,791. Eastport was first settled about 1782 by +fishermen; it became a port of entry in 1790, was incorporated as a town +in 1798, and was chartered as a city in 1893. It was a notorious place +for smuggling under the Embargo Acts of 1807 and 1808. On the 11th of +July 1814, during the war of 1812, it was taken by the British. As the +British government claimed the islands of Passamaquoddy Bay under the +treaty of 1783, the British forces retained possession of Eastport after +the close of the war and held it under martial law until July 1818, when +it was surrendered in accordance with the decision rendered in November +1817 by commissioners appointed under Article IV. of the treaty of Ghent +(1814), this decision awarding Moose Island, Dudley Island and Frederick +Island to the United States and the other islands, including the Island +of Grand Manan in the Bay of Fundy, to Great Britain. + + + + +EAST PROVIDENCE, a township of Providence county, Rhode Island, U.S.A., +on the E. side of Providence river, opposite Providence. Pop. (1890) +8422; (1900) 12,138, of whom 2067 were foreign-born; (1910 census) +15,808. Area, 121/2 sq. m. It is served by the New York, New Haven & +Hartford railway. It has a rolling surface and contains several +villages, one of which, known as Rumford, has important manufactories of +chemicals and electrical supplies. South of this village, along the +river bank, are several attractive summer resorts, Hunt's Mills, Silver +Spring, Riverside, Vanity Fair, Kettle Point and Bullock's Point being +prominent among them. In 1905 the factory products of the township were +valued at $5,035,288. The oyster trade is important. It was within the +present limits of this township that Roger Williams established himself +in the spring of 1636, until he learned that the place was within the +jurisdiction of the Plymouth Colony. About 1644 it was settled by a +company from Weymouth as a part of a town of Rehoboth. In 1812 Rehoboth +was divided, and the west part was made the township of Seekonk. +Finally, in 1861, it was decided that the west part of Seekonk belonged +to Rhode Island, and in the following year that part was incorporated as +the township of East Providence. + + + + +EAST PRUSSIA (_Ost-Preussen_), the easternmost province of the kingdom +of Prussia, bounded on the N. by the Baltic, on the E. and S.W. by +Russia and Russian Poland, and on the W. by the Prussian province of +West Prussia. It has an area of 14,284 sq. m., and had, in 1905, a +population of 2,025,741. It shares in the general characteristics of the +great north German plain, but, though low, its surface is by no means +absolutely flat, as the southern half is traversed by a low ridge or +plateau, which attains a height of 1025 ft. at a point near the western +boundary of the province. This plateau, here named the Prussian +Seenplatte, is thickly sprinkled with small lakes, among which is the +Spirding See, 46 sq. m. in extent and the largest inland lake in the +Prussian monarchy. The coast is lined with low dunes or sandhills, in +front of which lie the large littoral lakes or lagoons named the +Frisches Haff and the Kurisches Haff. The first of these receives the +waters of the Nogat and the Pregel, and the other those of the Memel or +Niemen. East Prussia is the coldest part of Germany, its mean annual +temperature being about 44 deg. F., while the mean January temperature of +Tilsit is only 25 deg.. The rainfall is 24 in. per annum. About half the +province is under tillage; 18% is occupied by forests, and about 23% by +meadows and pastures. The most fertile soil is found in the valleys of +the Pregel and the Memel, but the southern slopes of the Baltic plateau +and the district to the north of the Memel consist in great part of +sterile moor, sand and bog. The chief crops are rye, oats and potatoes, +while flax is cultivated in the district of Ermeland, between the +Passarge and the upper Alle. East Prussia is the headquarters of the +horse-breeding of the country, and contains the principal government +stud of Trakehnen; numerous cattle are also fattened on the rich +pastures of the river-valleys. The extensive woods in the south part of +the province harbour a few wolves and lynxes, and the elk is still +preserved in the forest of Ibenhorst, near the Kurisches Haff. The +fisheries in the lakes and haffs are of some importance; but the only +mineral product of note is amber, which is found in the peninsula of +Samland in greater abundance than in any other part of the world. +Manufactures are almost confined to the principal towns, though +linen-weaving is practised as a domestic industry. Commerce is +facilitated by canals connecting the Memel and Pregel and also the +principal lakes, but is somewhat hampered by the heavy dues exacted at +the Russian frontier. A brisk foreign trade is carried on through the +seaports of Koenigsberg, the capital of the province, and Memel, the +exports consisting mainly of timber and grain. + +The population of the province was in 1900 1,996,626, and included +1,698,465 Protestants, 269,196 Roman Catholics and 13,877 Jews. The +Roman Catholics are mainly confined to the district of Ermeland, in +which the ordinary proportions of the confessions are completely +reversed. The bulk of the inhabitants are of German blood, but there are +above 400,000 Protestant Poles (Masurians or Masovians) in the south +part of the province, and 175,000 Lithuanians in the north. As in other +provinces where the Polish element is strong, East Prussia is somewhat +below the general average of the kingdom in education. There is a +university at Koenigsberg. + + See Lohmeyer, _Geschichte von Ost- und West-Preussen_ (Gotha, 1884); + Bruenneck, _Zur Geschichte des Kirchen-Patronats in Ost- und + West-Preussen_ (Berlin, 1902), and _Ost-Preussen, Land und Volk_ + (Stuttgart, 1901-1902). + + + + +EASTWICK, EDWARD BACKHOUSE (1814-1883), British Orientalist, was born in +1814, a member of an Anglo-Indian family. Educated at Charterhouse and +at Oxford, he joined the Bombay infantry in 1836, but, owing to his +talent for languages, was soon given a political post. In 1843 he +translated the Persian _Kessahi Sanjan_, or _History of the Arrival of +the Parsees in India_; and he wrote a _Life of Zoroaster_, a _Sindhi_ +vocabulary, and various papers in the transactions of the Bombay Asiatic +Society. Compelled by ill-health to return to Europe, he went to +Frankfort, where he learned German and translated Schiller's _Revolt of +the Netherlands_ and Bopp's _Comparative Grammar_. In 1845 he was +appointed professor of Hindustani at Haileybury College. Two years later +he published a Hindustani grammar, and, in subsequent years, a new +edition of the _Gulistan_, with a translation in prose and verse, also +an edition with vocabulary of the Hindi translation by Lallu Lal of +Chatur Chuj Misr's _Prem Sagar_, and translations of the _Bagh-o-Bahar_, +and of the _Anvar-i Suhaili_ of Bidpai. In 1851 he was elected a Fellow +of the Royal Society. In 1857-1858 he edited _The Autobiography of +Lutfullah_. He also edited for the Bible Society the Book of Genesis in +the Dakhani language. From 1860 to 1863 he was in Persia as secretary to +the British Legation, publishing on his return _The Journal of a +Diplomate_. In 1866 he became private secretary to the secretary of +state for India, Lord Cranborne (afterwards marquess of Salisbury), and +in 1867 went, as in 1864, on a government mission to Venezuela. On his +return he wrote, at the request of Charles Dickens, for _All the Year +Round_, "Sketches of Life in a South American Republic." From 1868 to +1874 he was M.P. for Penryn and Falmouth. In 1875 he received the degree +of M.A. with the franchise from the university of Oxford, "as a slight +recognition of distinguished services." At various times he wrote +several of Murray's Indian hand-books. His last work was the +_Kaisarnamah-i-Hind_ ("the lay of the empress"), in two volumes +(1878-1882). He died at Ventnor, Isle of Wight, on the 16th of July +1883. + + + + +EATON, DORMAN BRIDGMAN (1823-1899), American lawyer, was born at +Hardwick, Vermont, on the 27th of June 1823. He graduated at the +university of Vermont in 1848 and at the Harvard Law School in 1850, and +in the latter year was admitted to the bar in New York city. There he +became associated in practice with William Kent, the son of the great +chancellor, an edition of whose _Commentaries_ he assisted in editing. +Eaton early became interested in municipal and civil service reform. He +was conspicuous in the fight against Tweed and his followers, by one of +whom he was assaulted; he required a long period of rest, and went to +Europe, where he studied the workings of the civil service in various +countries. From 1873 to 1875 he was a member of the first United States +Civil Service Commission. In 1877, at the request of President Hayes, he +made a careful study of the British civil service, and three years later +published _Civil Service in Great Britain_. He drafted the Pendleton +Civil Service Act of 1883, and later became a member of the new +commission established by it. He resigned in 1885, but was almost +immediately reappointed by President Cleveland, and served until 1886, +editing the 3rd and 4th _Reports_ of the commission. He was an organizer +(1878) of the first society for the furtherance of civil service reform +in New York, of the National Civil Service Reform Association, and of +the National Conference of the Unitarian Church (1865). He died in New +York city on the 23rd of December 1899, leaving $100,000 each to Harvard +and Columbia universities for the establishments of professorships in +government. He was a legal writer and editor, and a frequent contributor +to the leading reviews. In addition to the works mentioned he published +_Should Judges be Elected?_ (1873), _The Independent Movement in New +York_ (1880), _Term and Tenure of Office_ (1882), _The Spoils System and +Civil Service Reform_ (1882), _Problems of Police Legislation_ (1895) +and _The Government of Municipalities_ (1899). + + See the privately printed memorial volume, _Dorman B. Eaton_, + 1823-1899 (New York, 1900). + + + + +EATON, MARGARET O'NEILL (1796-1879), better known as PEGGY O'NEILL, was +the daughter of the keeper of a popular Washington tavern, and was noted +for her beauty, wit and vivacity. About 1823, she married a purser in +the United States navy, John B. Timberlake, who committed suicide while +on service in the Mediterranean in 1828. In the following year she +married John Henry Eaton (1790-1856), a Tennessee politician, at the +time a member of the United States Senate. Senator Eaton was a close +personal friend of President Jackson, who in 1829 appointed him +secretary of war. This sudden elevation of Mrs Eaton into the cabinet +social circle was resented by the wives of several of Jackson's +secretaries, and charges were made against her of improper conduct with +Eaton previous to her marriage to him. The refusal of the wives of the +cabinet members to recognize the wife of his friend angered President +Jackson, and he tried in vain to coerce them. Eventually, and partly for +this reason, he almost completely reorganized his cabinet. The effect of +the incident on the political fortunes of the vice-president, John C. +Calhoun, whose wife was one of the recalcitrants, was perhaps most +important. Partly on this account, Jackson's favour was transferred from +Calhoun to Martin Van Buren, the secretary of state, who had taken +Jackson's side in the quarrel and had shown marked attention to Mrs +Eaton, and whose subsequent elevation to the vice-presidency and +presidency through Jackson's favour is no doubt partly attributable to +this incident. In 1836 Mrs Eaton accompanied her husband to Spain, where +he was United States minister in 1836-1840. After the death of her +husband she married a young Italian dancing-master, Antonio Buchignani, +but soon obtained a divorce from him. She died in Washington on the 8th +of November 1879. + + See James Parton's _Life of Andrew Jackson_ (New York, 1860). + + + + +EATON, THEOPHILUS (c. 1590-1658), English colonial governor in America, +was born at Stony Stratford, Buckinghamshire, about 1590. He was +educated in Coventry, became a successful merchant, travelled widely +throughout Europe, and for several years was the financial agent of +Charles I. in Denmark. He subsequently settled in London, where he +joined the Puritan congregation of the Rev. John Davenport, whom he had +known since boyhood. The pressure upon the Puritans increasing, Eaton, +who had been one of the original patentees of the Massachusetts Bay +colony in 1629, determined to use his influence and fortune to establish +an independent colony of which his pastor should be the head. In 1637 he +emigrated with Davenport to Massachusetts, and in the following year +(March 1638) he and Davenport founded New Haven. In October 1639 a form +of government was adopted, based on the Mosaic Law, and Eaton was +elected governor, a post which he continued to hold by annual +re-election, first over New Haven alone, and after 1643 over the New +Haven Colony or Jurisdiction, until his death at New Haven on the 7th of +January 1658. His administration was embarrassed by constantly recurring +disputes with the neighbouring Dutch settlements, especially after +Stamford (Conn.) and Southold (Long Island) had entered the New Haven +Jurisdiction, but his prudence and diplomacy prevented an actual +outbreak of hostilities. He was prominent in the affairs of the New +England Confederation, of which he was one of the founders (1643). In +1655 he and Davenport drew up the code of laws, popularly known as the +"Connecticut Blue Laws," which were published in London in 1656 under +the title _New Haven's Settling in New England and some Lawes for +Government published for the Use of that Colony_. + + A sketch of his life appears in Cotton Mather's _Magnalia_ (London, + 1702); see also J.B. Moore's "Memoir of Theophilus Eaton" in the + _Collections_ of the New York Historical Society, second series, vol. + ii. (New York, 1849). + + + + +EATON, WILLIAM (1764-1811), American soldier, was born in Woodstock, +Connecticut, on the 23rd of February 1764. As a boy he served for a +short time in the Continental army. He was a school teacher for several +years, graduated at Dartmouth College in 1790, was clerk of the lower +house of the Vermont legislature in 1791-1792, and in 1792 re-entered +the army as a captain, later serving against the Indians in Ohio and +Georgia. In 1797 he was appointed consul to Tunis, where he arrived in +February 1799. In March 1799, with the consuls to Tripoli and Algiers, +he negotiated alterations in the treaty of 1797 with Tunis. He rendered +great service to Danish merchantmen by buying on credit several Danish +prizes in Tunis and turning them over to their original owners for the +redemption of his notes. In 1803 he quarrelled with the Bey, was ordered +from the country, and returned to the United States to urge American +intervention for the restoration of Ahmet Karamanli to the throne of +Tripoli, arguing that this would impress the Barbary States with the +power of the United States. In 1804 he returned to the Mediterranean as +United States naval agent to the Barbary States with Barron's fleet. On +the 23rd of February 1805 he agreed with Ahmet that the United States +should undertake to re-establish him in Tripoli, that the expenses of +the expedition should be repaid to the United States by Ahmet, and that +Eaton should be general and commander-in-chief of the land forces in +Ahmet's campaign; as the secretary of the navy had given the entire +matter into the hands of Commodore Barron, and as Barron and Tobias Lear +(1762-1816), the United States consul-general at Algiers and a +diplomatic agent to conduct negotiations, had been instructed to +consider the advisability of making arrangements with the existing +government in Tripoli, Eaton far exceeded his authority. On the 8th of +March he started for Derna across the Libyan desert from the Arab's +Tower, 40 m. W. of Alexandria, with a force of about 500 men, including +a few Americans, about 40 Greeks and some Arab cavalry. In the march of +nearly 600 m. the camel-drivers and the Arab chiefs repeatedly mutinied, +and Ahmet Pasha once put himself at the head of the Arabs and ordered +them to attack Eaton. Ahmet more than once wished to give up the +expedition. There were practically no provisions for the latter part of +the march. On the 27th of April with the assistance of three bombarding +cruisers Eaton captured Derna--an exploit commemorated by Whittier's +poem _Derne_. On the 13th of May and on the 10th of June he successfully +withstood the attacks of Tripolitan forces sent to dislodge him. On the +12th of June he abandoned the town upon orders from Commodore Rodgers, +for Lear had made peace (4th June) with Yussuf, the _de facto_ Pasha of +Tripoli. Eaton returned to the United States, and received a grant of +10,000 acres in Maine from the Massachusetts legislature. According to a +deposition which he made in January 1807 he was approached by Aaron Burr +(q.v.), who attempted to enlist him in his "conspiracy," and wished him +to win over the marine corps and to sound Preble and Decatur. As he +received from the government, soon after making this deposition, about +$10,000 to liquidate claims for his expense in Tripoli, which he had +long pressed in vain, his good faith has been doubted. At Burr's trial +at Richmond in 1807 Eaton was one of the witnesses, but his testimony +was unimportant. In May 1807 he was elected a member of the +Massachusetts House of Representatives, and served for one term. He died +on the 1st of June 1811 in Brimfield, Massachusetts. + + See the anonymously published _Life of the Late Gen. William Eaton_ + (Brookfield, Massachusetts, 1813) by Charles Prentiss; C.C. Felton, + "Life of William Eaton" in Sparks's _Library of American Biography_, + vol. ix. (Boston, 1838); and Gardner W. Allen's _Our Navy and the + Barbary Corsairs_ (Boston, 1905). + + + + +EATON, WYATT (1849-1896), American portrait and figure painter, was born +at Philipsburg, Canada, on the 6th of May 1849. He was a pupil of the +schools of the National Academy of Design, New York, and in 1872 went to +Paris, where he studied in the Ecole des Beaux-Arts under J.L. Gerome. +He made the acquaintance of J.F. Millet at Barbizon, and was also +influenced by his friend Jules Bastien-Lepage. After his return to the +United States in 1876 he became a teacher in Cooper Institute and opened +a studio in New York city. He was one of the organizers (and the first +secretary) of the Society of American Artists. Among his portraits are +those of William Cullen Bryant and Timothy Cole, the wood engraver ("The +Man with the Violin"). Eaton died at Newport, Rhode Island, on the 7th +of June 1896. + + + + +EAU CLAIRE, a city and the county-seat of Eau Claire county, Wisconsin, +U.S.A., on the Chippewa river, at the mouth of the Eau Claire, about 87 +m. E. of St Paul. Pop. (1890) 17,415; (1900) 17,517, of whom 4996 were +foreign-born; (1910 census) 18,310. It is served by the Chicago & +North-Western, the Chicago, Milwaukee & St Paul, and the Wisconsin +Central railways, and is connected by an electric line with Chippewa +Falls (12 m. distant). The city has a Carnegie library with 17,200 +volumes in 1908, a Federal building, county court house, normal school +and insane asylum. It has abundant water-power, and is an important +lumber manufacturing centre; among its other manufactures are flour, +wooden-ware, agricultural machinery, saw-mill machinery, logging +locomotives, wood pulp, paper, linen, mattresses, shoes and trunks. The +total value of factory products in 1905 was $3,601,558. The city is the +principal wholesale and jobbing market for the prosperous Chippewa +Valley. Eau Claire was first settled about 1847, and was chartered as a +city in 1872; its growth dates from the development of the north-western +lumber trade in the decade 1870-1880. In 1881 a serious strike +necessitated the calling out of state militia for its suppression and +the protection of property. + + + + +EAU DE COLOGNE (Ger. _Koelnisches Wasser_, "Cologne water"), a perfume, +so named from the city of Cologne, where its manufacture was first +established by an Italian, Johann (or Giovanni) Maria Farina +(1685-1766), who settled at Cologne in 1709. The perfume gained a high +reputation by 1766, and Farina associated himself with his nephew, to +whose grandson the secret was ultimately imparted; the original perfume +is still manufactured by members of this family under the name of the +founder. The manufacture is, however, carried on at Cologne, and also in +Italy, by other firms bearing the name Farina, and the scent has become +part of the regular output of perfumers. The discovery has also been +ascribed to a Paul de Feminis, who is supposed to have brought his +recipe from Milan to Cologne, of which he became a citizen in 1690, and +sold the perfume under the name _Eau admirable_, leaving the secret at +his death to his nephew Johann Maria Farina. Certain of the Farinas +claim to use his process. It was originally prepared by making an +alcoholic infusion of certain flowers, pot-herbs, drugs and spices, +distilling and then adding definite quantities of several vegetable +essences. The purity and thorough blending of the ingredients are of the +greatest importance. The original perfume is simulated and even excelled +by artificial preparations. The oils of lemon, bergamot and orange are +employed, together with the oils of neroli and rosemary in the better +class. The common practice consists in dissolving the oils, in certain +definite proportions based on experience, in pure alcohol and +distilling, the distillate being diluted by rose-water. + + + + +EAUX-BONNES, a watering-place of south-western France, in the department +of Basses-Pyrenees, 31/2 m. S.E. of the small town of Laruns, the latter +being 24 m. S. of Pau by rail. Pop. (1906) 610. Eaux-Bonnes is situated +at a height of 2460 ft. at the entrance of a fine gorge, overlooking the +confluence of two torrents, the Valentin and the Sourde. The village is +well known for its sulphurous and saline mineral waters (first mentioned +in the middle of the 14th century), which are beneficial in affections +of the throat and lungs. They vary between 50 deg. and 90 deg. F. in +temperature, and are used for drinking and bathing. There are two +thermal establishments, a casino and fine promenades. + +The watering-place of LES EAUX-CHAUDES is 5 m. by road south-west of +Eaux-Bonnes, in a wild gorge on the Gave d'Ossau. The springs are +sulphurous, varying in temperature from 52 deg. to 97 deg. F., and are used in +cases of rheumatism, certain maladies of women, &c. The thermal +establishment is a handsome marble building. + +There is fine mountain scenery in the neighbourhood of both places, the +Pic de Ger near Eaux-Bonnes, commanding an extensive view. The valley of +Ossau, one of the most beautiful in the Pyrenees, before the Revolution +formed a community which, though dependent on Bearn, had its own legal +organization, manners and costumes, the last of which are still to be +seen on holidays. + + + + +EAVES (not a plural form as is sometimes supposed, but singular; O. Eng. +_efes_, in Mid. High Ger. _obse_, Gothic _ubizwa_, a porch; connected +with "over"), in architecture, the projecting edge of a sloping roof, +which overhangs the face of the wall so as to throw off the water. + + + + +EAVESDRIP, or EAVESDROP, that width of ground around a house or building +which receives the rain water dropping from the eaves. By an ancient +Saxon law, a landowner was forbidden to erect any building at less than +2 ft. from the boundary of his land, and was thus prevented from +injuring his neighbour's house or property by the dripping of water from +his eaves. The law of Eavesdrip has had its equivalent in the Roman +_stillicidium_, which prohibited building up to the very edge of an +estate. + +From the Saxon custom arose the term "eavesdropper," i.e. any one who +stands within "the eavesdrop" of a house, hence one who pries into +others' business or listens to secrets. At common law an eavesdropper +was regarded as a common nuisance, and was presentable at the court +leet, and indictable at the sheriff's tourn and punishable by fine and +finding sureties for good behaviour. Though the offence of eavesdropping +still exists at common law, there is no modern instance of a prosecution +or indictment. + + + + +EBBW VALE, an urban district in the western parliamentary division of +Monmouthshire, England, 21 m. N.W. of Newport on the Great Western, +London & North-Western and Rhymney railways. Pop. (1891) 17,312; (1901) +20,994. It lies near the head of the valley of the river Ebbw, at an +elevation of nearly 1000 ft., in a wild and mountainous mining district, +which contains large collieries and important iron and steel works. + + + + +EBEL, HERMANN WILHELM (1820-1875), German philologist, was born at +Berlin on the 10th of May 1820. He displayed in his early years a +remarkable capacity for the study of languages, and at the same time a +passionate fondness for music and poetry. At the age of sixteen he +became a student at the university of Berlin, applying himself +especially to philology, and attending the lectures of Boeckh. Music +continued to be the favourite occupation of his leisure hours, and he +pursued the study of it under the direction of Marx. In the spring of +1838 he passed to the university of Halle, and there began to apply +himself to comparative philology under Pott. Returning in the following +year to his native city, he continued this study as a disciple of Bopp. +He took his degree in 1842, and, after spending his year of probation at +the French Gymnasium of Berlin, he resumed with great earnestness his +language studies. About 1847 he began to study Old Persian. In 1852 he +accepted a professorship at the Beheim-Schwarzbach Institution at +Filehne, which post he held for six years. It was during this period +that his studies in the Old Slavic and Celtic languages began. In 1858 +he removed to Schneidemuehl, and there he discharged the duties of first +professor for ten years. He was afterwards called to the chair of +comparative philology at the university of Berlin. He died at Misdroy on +the 19th of August 1875. The most important work of Dr Ebel in the field +of Celtic philology is his revised edition of the _Grammatica Celtica_ +of Professor Zeuss, completed in 1871. This had been preceded by his +treatises--_De verbi Britannici futuro ac conjunctivo_ (1866), and _De +Zeussii curis positis in Grammatica Celtica_ (1869). He made many +learned contributions to Kuehn's _Zeitschrift fuer vergleichende +Sprachforschung_, and to A. Schleicher's _Beitraege zur vergleichenden +Sprachforschung_; and a selection of these contributions was translated +into English by Sullivan, and published under the title of _Celtic +Studies_ (1863). Ebel contributed the Old Irish section to Schleicher's +_Indogermanische Chrestomathie_ (1869). Among his other works must be +named _Die Lehnwoerter der deutschen Sprache_ (1856). + + + + +EBEL, JOHANN GOTTFRIED (1764-1830), the author of the first real +guide-book to Switzerland, was born at Zuellichau (Prussia). He became a +medical man, visited Switzerland for the first time in 1790, and became +so enamoured of it that he spent three years exploring the country and +collecting all kinds of information relating to it. The result was the +publication (Zuerich, 1793) of his _Anleitung auf die nuetzlichste und +genussvollste Art in der Schweitz zu reisen_ (2 vols.), in which he gave +a complete account of the country, the General Information sections +being followed by an alphabetically arranged list of places, with +descriptions. It at once superseded all other works of the kind, and was +the best Swiss guide-book till the appearance of "Murray" (1838). It was +particularly strong on the geological and historical sides. The second +(1804-1805) and third (1809-1810) editions filled four volumes, but the +following (the 8th appeared in 1843) were in a single volume. The work +was translated into French in 1795 (many later editions) and into +English (by 1818). Ebel also published a work (2 vols., Leipzig, +1798-1802) entitled _Schilderungen der Gebirgsvoelker der Schweiz_, which +deals mainly with the pastoral cantons of Glarus and Appenzell. In 1801 +he was naturalized a Swiss citizen, and settled down in Zuerich. In 1808 +he issued his chief geological work, _Ueber den Bau der Erde im +Alpengebirge_ (Zuerich, 2 vols.). He took an active share in promoting +all that could make his adopted country better known, e.g. Heinrich +Keller's map (1813), the building of a hotel on the Rigi (1816), and the +preparation of a panorama from that point (1823). From 1810 onwards he +lived at Zuerich, with the family of his friend, Conrad Escher von der +Linth (1767-1823), the celebrated engineer. (W. A. B. C.) + + + + +EBER, PAUL (1511-1569), German theologian, was born at Kitzingen in +Franconia, and was educated at Nuremberg and Wittenberg, where he became +the close friend of Philip Melanchthon. In 1541 he was appointed +professor of Latin grammar at Wittenberg, and in 1557 professor of the +Old Testament. His range of learning was wide, and he published a +handbook of Jewish history, a historical calendar intended to supersede +the Roman Saints' Calendar, and a revision of the Latin Old Testament. +In the theological conflict of the time he played a large part, doing +what he could to mediate between the extremists. From 1559 to the close +of his life he was superintendent-general of the electorate of Saxony. +He attained some fame as a hymn-writer, his best-known composition being +"Wenn wir in hoechsten Noethen sein." He died at Wittenberg on the 10th of +December 1569. + + + + +EBERBACH, a town of Germany, in the grand-duchy of Baden, romantically +situated on the Neckar, at the foot of the Katzenbuckel, 19 m. E. of +Heidelberg by the railway to Wuerzburg. Pop. (1900) 5857. It contains an +Evangelical and a Roman Catholic church, a commercial and a technical +school, and, in addition to manufacturing cigars, leather and cutlery, +carries on by water an active trade in timber and wine. Eberbach was +founded in 1227 by the German king Henry VII., who acquired the castle +(the ruins of which overhang the town) from the bishop of Worms. It +became an imperial town and passed later to the Palatinate. + + See Wirth, _Geschichte der Stadt Eberbach_ (Stuttgart, 1864). + + + + +EBERBACH, a famous Cistercian monastery of Germany, in the Prussian +province of Hesse-Nassau, situated near Hattenheim in the Rheingau, 10 +m. N.W. from Wiesbaden. Founded in 1116 by Archbishop Adalbert of Mainz, +as a house of Augustinian canons regular, it was bestowed by him in 1131 +upon the Benedictines, but was shortly afterwards repurchased and +conferred upon the Cistercian order. The Romanesque church (consecrated +in 1186) contains numerous interesting monuments and tombs, notable +among them being those of the archbishop of Mainz, Gerlach (d. 1371) +and Adolph II. of Nassau (d. 1475). It was despoiled during the Thirty +Years' War, was secularized in 1803, and now serves as a house of +correction. Its cellars contain some of the finest vintages of the Rhine +wines of the locality. + + See Baer, _Diplomatische Geschichte der Abtei Eberbach_ (Wiesb., + 1851-1858 and 1886, 3 vols.), and Schaefer, _Die Abtei Eberbach im + Mittelalter_ (Berlin, 1901). + + + + +EBERHARD, surnamed IM BART (_Barbatus_), count and afterwards duke of +Wuerttemberg (1445-1496), was the second son of Louis I., count of +Wuerttemberg-Urach (d. 1450), and succeeded his elder brother Louis II. +in 1457. His uncle Ulrich V., count of Wuerttemberg-Stuttgart (d. 1480), +acted as his guardian, but in 1459, assisted by Frederick I., elector +palatine, he threw off this restraint, and undertook the government of +the district of Urach as Count Eberhard V. He neglected his duties as a +ruler and lived a reckless life until 1468, when he made a pilgrimage to +Jerusalem. He visited Italy, became acquainted with some famous +scholars, and in 1474 married Barbara di Gonzaga, daughter of Lodovico +III., marquis of Mantua, a lady distinguished for her intellectual +qualities. In 1482 he brought about the treaty of Muensingen with his +cousin Eberhard VI., count of Wuerttemberg-Stuttgart. By this treaty the +districts of Urach and Stuttgart into which Wuerttemberg had been divided +in 1437 were again united, and for the future the county was declared +indivisible, and the right of primogeniture established. The treaty led +to some disturbances, but in 1492 the sanction of the nobles was secured +for its provisions. In return for this Eberhard agreed to some +limitations on the power of the count, and so in a sense founded the +constitution of Wuerttemberg. At the diet of Worms in 1495 the emperor +Maximilian I. guaranteed the treaty, confirmed the possessions and +prerogatives of the house of Wuerttemberg, and raised Eberhard to the +rank of duke. Eberhard, although a lover of peace, was one of the +founders of the Swabian League in 1488, and assisted to release +Maximilian, then king of the Romans, from his imprisonment at Bruges in +the same year. He gave charters to the towns of Stuttgart and Tuebingen, +and introduced order into the convents of his land, some of which he +secularized. He took a keen interest in the new learning, founded the +university of Tuebingen in 1476, befriended John Reuchlin, whom he made +his private secretary, welcomed scholars to his court, and is said to +have learned Latin in later life. In 1482 he again visited Italy and +received the Golden Rose from Pope Sixtus IV. He won the esteem of the +emperors Frederick III. and Maximilian I. on account of his wisdom and +fidelity, and his people held him in high regard. His later years were +mainly spent at Stuttgart, but he died at Tuebingen on the 25th of +February 1496, and in 1537 his ashes were placed in the choir of the +Stiftskirche there. Eberhard left no children, and the succession passed +to his cousin Eberhard, who became Duke Eberhard II. + + See Roesslin, _Leben Eberhards im Barte_ (Tuebingen, 1793); Bossert, + _Eberhard im Bart_ (Stuttgart, 1884). + + + + +EBERHARD, CHRISTIAN AUGUST GOTTLOB (1769-1845), German miscellaneous +writer, was born at Belzig, near Wittenberg, on the 12th of January +1769. He studied theology at Leipzig; but, a story he contributed to a +periodical having proved successful, he devoted himself to literature. +With the exception of _Hannchen und die Kuechlein_ (1822), a narrative +poem in ten parts, and an epic on the Creation, _Der erste Mensch und +die Erde_ (1828), Eberhard's work was ephemeral in character and is now +forgotten. He died at Dresden on the 13th of May 1845. + + His collected works (_Gesammelte Schriften_) appeared in 20 volumes in + 1830-1831. + + + + +EBERHARD, JOHANN AUGUSTUS (1739-1809), German theologian and +philosopher, was born at Halberstadt in Lower Saxony, where his father +was singing-master at the church of St Martin's, and teacher of the +school of the same name. He studied theology at the university of Halle, +and became tutor to the eldest son of the baron von der Horst, to whose +family he attached himself for a number of years. In 1763 he was +appointed con-rector of the school of St Martin's, and second preacher +in the hospital church of the Holy Ghost; but he soon afterwards +resigned these offices and followed his patron to Berlin. There he met +Nicolai and Moses Mendelssohn, with whom he formed a close friendship. +In 1768 he became preacher or chaplain to the workhouse at Berlin and +the neighbouring fishing village of Stralow. Here he wrote his _Neue +Apologie des Socrates_ (1772), a work occasioned by an attack on the +fifteenth chapter of Marmontel's _Belisarius_ made by Peter Hofstede, a +clergyman of Rotterdam, who maintained the patristic view that the +virtues of the noblest pagans were only _splendida peccata_. Eberhard +stated the arguments for the broader view with dignity, acuteness and +learning, but the liberality of the reasoning gave great offence to the +strictly orthodox divines, and is believed to have obstructed his +preferment in the church. + +In 1774 he was appointed to the living of Charlottenburg. A second +volume of his _Apologie_ appeared in 1778. In this he not only +endeavoured to obviate some objections which were taken to the former +part, but continued his inquiries into the doctrines of the Christian +religion, religious toleration and the proper rules for interpreting the +Scriptures. In 1778 he accepted the professorship of philosophy at +Halle. As an academical teacher, however, he was unsuccessful. His +powers as an original thinker were not equal to his learning and his +literary gifts, as was shown in his opposition to the philosophy of +Kant. In 1786 he was admitted a member of the Berlin Academy of +Sciences; in 1805 the king of Prussia conferred upon him the honorary +title of a privy-councillor. In 1808 he obtained the degree of doctor in +divinity, which was given him as a reward for his theological writings. +He died on the 6th of January 1809. He was master of the learned +languages, spoke and wrote French with facility and correctness, and +understood English, Italian and Dutch. He possessed a just and +discriminating taste for the fine arts, and was a great lover of music. + + Works:--_Neue Apologie des Socrates_, &c. (2 vols., 1772-1778); + _Allgemeine Theorie des Denkens und Empfindens_, &c. (Berlin, 1776), + an essay which gained the prize assigned by the Royal Society of + Berlin for that year; _Von dem Begriff der Philosophie und ihren + Theilen_ (Berlin, 1778)--a short essay, in which he announced the plan + of his lectures on being appointed to the professorship at Halle; + _Lobschrift auf Herrn Johann Thunmann Prof. der Weltweisheit und + Beredsamkeit auf der Universitaet zu Halle_ (Halle, 1779); _Amyntor, + eine Geschichte in Briefen_ (Berlin, 1782)--written with the view of + counteracting the influence of those sceptical and Epicurean + principles in religion and morals then so prevalent in France, and + rapidly spreading amongst the higher ranks in Germany; _Ueber die + Zeichen der Aufklaerung einer Nation_, &c. (Halle, 1783); _Theorie der + schoenen Kuenste und Wissenschaften_, &c. (Halle, 1783, 3rd ed. 1790); + _Vermischte Schriften_ (Halle, 1784); _Neue vermischte Schriften_ (ib. + 1786); _Allgemeine Geschichte der Philosophie_, &c. (Halle, 1788), 2nd + ed. with a continuation and chronological tables (1796); _Versuch + einer allgemeinen-deutschen Synonymik_ (Halle and Leipzig, 1795-1802, + 6 vols., 4th ed. 1852-1853), long reckoned the best work on the + synonyms of the German language (an abridgment of it was published by + the author in one large volume, Halle, 1802); _Handbuch der Aesthetik_ + (Halle, 1803-1805, 2nd ed. 1807-1820). He also edited the + _Philosophisches Magazin_ (1788-1792) and the _Philosophisches Archiv_ + (1792-1795). + + See F. Nicolai, _Gedaechtnisschrift auf J.A. Eberhard_ (Berlin and + Stettin, 1810); also K.H. Joerdens, _Lexicon deutscher Dichter und + Prosaisten_. + + + + +EBERLIN, JOHANN ERNST (1702-1762), German musician and composer, was +born in Bavaria, and became afterwards organist in the cathedral at +Salzburg, where he died. Most of his compositions were for the church +(oratorios, &c.), but he also wrote some important fugues, sonatas and +preludes; and his pieces were at one time highly valued by Mozart. + + + + +EBERS, GEORG MORITZ (1837-1898), German Egyptologist and novelist, was +born in Berlin on the 1st of March 1837. At Goettingen he studied +jurisprudence, and at Berlin oriental languages and archaeology. Having +made a special study of Egyptology, he became in 1865 _docent_ in +Egyptian language and antiquities at Jena, and in 1870 he was appointed +professor in these subjects at Leipzig. He had made two scientific +journeys to Egypt, and his first work of importance, _Aegypten und die +Buecher Moses_, appeared in 1867-1868. In 1874 he edited the celebrated +medical papyrus ("Papyrus Ebers") which he had discovered in Thebes +(translation by H. Joachim, 1890). Ebers early conceived the idea of +popularizing Egyptian lore by means of historical romances. _Eine +aegyptische Koenigstochter_ was published in 1864, and obtained great +success. His subsequent works of the same kind--_Uarda_ (1877), _Homo +sum_ (1878), _Die Schwestern_ (1880), _Der Kaiser_ (1881), of which the +scene is laid in Egypt at the time of Hadrian, _Serapis_ (1885), _Die +Nilbraut_ (1887), and _Kleopatra_ (1894), were also well received, and +did much to make the public familiar with the discoveries of +Egyptologists. Ebers also turned his attention to other fields of +historical fiction--especially the 16th century (_Die Frau +Buergermeisterin_, 1882; _Die Gred_, 1887)--without, however, attaining +the success of his Egyptian novels. Apart from their antiquarian and +historical interest, Ebers's books have not a very high literary value. +His other writings include a descriptive work on Egypt (_Aegypten in Wort +und Bild_, 2nd ed., 1880), a guide to Egypt (1886) and a life (1885) of +his old teacher, the Egyptologist Karl Richard Lepsius. The state of his +health led him in 1889 to retire from his chair at Leipzig on a pension. +He died at Tutzing in Bavaria, on the 7th of August 1898. + + Ebers's _Gesammelte Werke_ appeared in 25 vols. at Stuttgart + (1893-1895). Many of his books have been translated into English. For + his life see his _Die Geschichte meines Lebens_ (Stuttgart, 1893); + also R. Gosche, _G. Ebers, der Forscher und Dichter_ (2nd ed., + Leipzig, 1887). + + + + +EBERSWALDE, a town of Germany, in the kingdom of Prussia, 28 m. N.E. of +Berlin by rail; on the Finow canal. Pop. (1905) 23,876. The town has a +Roman Catholic and two Evangelical churches, a school of forestry, a +gymnasium, a higher-grade girls' school and two schools of domestic +economy. It possesses a mineral spring, which attracts numerous summer +visitors, and has various industries, which include iron-founding and +the making of horse-shoe nails, roofing material and bricks. A +considerable trade is carried on in grain, wood and coals. In the +immediate neighbourhood are one of the chief brass-foundries in Germany +and an extensive government paper-mill, in which the paper for the notes +of the imperial bank is manufactured. + +Eberswalde received its municipal charter in 1257. It was taken and +sacked during the Thirty Years' War. In 1747 Frederick the Great brought +a colony of Thuringian cutlers to the town, but this branch of industry +has entirely died out. About 4 m. to the north lies the old Cistercian +monastery of Chorin, the fine Gothic church of which contains the tombs +of several margraves of Brandenburg. + + + + +EBERT, FRIEDRICH ADOLF (1791-1834), German bibliographer, was born at +Taucha, near Leipzig, on the 9th of July 1791, the son of a Lutheran +pastor. At the age of fifteen he was appointed to a subordinate post in +the municipal library of Leipzig. He studied theology for a short time +at Leipzig, and afterwards philology at Wittenberg, where he graduated +doctor in philosophy in 1812. While still a student he had already +published, in 1811, a work on public libraries, and in 1812 another work +entitled _Hierarchiae in religionem ac literas commoda_. In 1813 he was +attached to the Leipzig University library, and in 1814 was appointed +secretary to the Royal library of Dresden. The same year he published +_F. Taubmanns Leben und Verdienste_, and in 1819 _Torquato Tasso_, a +translation from Pierre Louis Ginguene with annotations. The rich +resources open to him in the Dresden library enabled him to undertake +the work on which his reputation chiefly rests, the _Allgemeines +bibliographisches Lexikon_, the first volume of which appeared in 1821 +and the second in 1830. This was the first work of the kind produced in +Germany, and the most scientific published anywhere. From 1823 to 1825 +Ebert was librarian to the duke of Brunswick at Wolfenbuettel, but +returning to Dresden was made, in 1827, chief librarian of the Dresden +Royal library. Among his other works are--_Die Bildung des +Bibliothekars_ (1820), _Geschichte und Beschreibung der koeniglichen +oeffentlichen Bibliothek in Dresden_ (1822), _Zur Handschriftenkunde_ +(1825-1827), and _Culturperioden des obersaechsischen Mittelalters_ +(1825). Ebert was a contributor to various journals and took part in the +editing of Ersch and Gruber's great encyclopaedia. He died at Dresden on +the 13th of November 1834, in consequence of a fall from the ladder in +his library. + + See the article in _Ersch und Grubers Encyclopaedie_, and that in the + _Allg. deutsche Biog._ by his successor in the post of chief librarian + in Dresden, Schnorr von Carolsfeld. + + + + + +EBINGEN, a town of Germany, in the kingdom of Wuerttemberg, on the +Schmiecha, a left-hand tributary of the Danube, 22 m. S. of Tuebingen and +37 m. W. of Ulm by rail. It manufactures velvet and cotton-velvet +("Manchester") goods, stockings, stays, hats, needles, tools, &c. There +are also tanneries. Pop. 9000. + + + + +EBIONITES (Heb. [Hebrew: ebyonim], "poor men"), a name given to the +ultra-Jewish party in the early Christian church. It is first met with +in Irenaeus (_Adv. Haer._ i. 26. 2), who sheds no light on the origin of +the Ebionites, but says that while they admit the world to have been +made by the true God (in contrast to the Demiurge of the Gnostics), they +held Cerinthian views on the person of Christ, used only the Gospel of +Matthew (probably the Gospel according to the Hebrews--so Eusebius), and +rejected Paul as an apostate from the Mosaic Law, to the customs and +ordinances of which, including circumcision, they steadily adhered. A +similar account is given by Hippolytus (_Haer._ vii. 35), who invents a +founder named Ebion. Origen (_Contra Celsum_, v. 61; _In Matt._ tom. +xvi. 12) divides the Ebionites into two classes according to their +acceptance or rejection of the virgin birth of Jesus, but says that all +alike reject the Pauline epistles. This is confirmed by Eusebius, who +adds that even those who admitted the virgin birth did not accept the +pre-existence of Jesus as Logos and Sophia. They kept both the Jewish +Sabbath and the Christian Lord's day, and held extreme millenarian ideas +in which Jerusalem figured as the centre of the coming Messianic +kingdom. Epiphanius with his customary confusion makes two separate +sects, Ebionites and Nazarenes. Both names, however, refer to the same +people[1] (the Jewish Christians of Syria), the latter going back to the +designation of apostolic times (Acts xxiv. 5), and the former being the +term usually applied to them in the ecclesiastical literature of the 2nd +and 3rd centuries. + +The origin of the Nazarenes or Ebionites as a distinct sect is very +obscure, but may be dated with much likelihood from the edict of Hadrian +which in 135 finally scattered the old church of Jerusalem. While +Christians of the type of Aristo of Pella and Hegesippus, on the +snapping of the old ties, were gradually assimilated to the great church +outside, the more conservative section became more and more isolated and +exclusive. "It may have been then that they called themselves the Poor +Men, probably as claiming to be the true representatives of those who +had been blessed in the Sermon on the Mount, but possibly adding to the +name other associations." Out of touch with the main stream of the +church they developed a new kind of pharisaism. Doctrinally they stood +not so much for a theology as for a refusal of theology, and, rejecting +the practical liberalism of Paul, became the natural heirs of those +early Judaizers who had caused the apostle so much annoyance and +trouble. + +Though there is insufficient justification for dividing the Ebionites +into two separate and distinct communities, labelled respectively +Ebionites and Nazarenes, we have good evidence, not only that there were +grades of Christological thought among them, but that a considerable +section, at the end of the 2nd century and the beginning of the 3rd, +exchanged their simple Judaistic creed for a strange blend of Essenism +and Christianity. These are known as the Helxaites or Elchasaites, for +they accepted as a revelation the "book of Elchasai," and one Alcibiades +of Apamea undertook a mission to Rome about 220 to propagate its +teaching. It was claimed that Christ, as an angel 96 miles high, +accompanied by the Holy Spirit, as a female angel of the same stature, +had given the revelation to Elchasai in the 3rd year of Trajan (A.D. +100), but the book was probably quite new in Alcibiades' time. It taught +that Christ was an angel born of human parents, and had appeared both +before (e.g. in Adam and Moses) and after this birth in Judea. His +coming did not annul the Law, for he was merely a prophet and teacher; +Paul was wrong and circumcision still necessary. Baptism must be +repeated as a means of purification from sin, and proof against disease; +the sinner immerses himself "in the name of the mighty and most high +God," invoking the "seven witnesses" (sky, water, the holy spirits, the +angels of prayer, oil, salt and earth), and pledging himself to +amendment. Abstinence from flesh was also enjoined, and a good deal of +astrological fancy was interwoven with the doctrinal and practical +teaching. It is highly probable, too, that from these Essene Ebionites +there issued the fantastical and widely read "Clementine" literature +(_Homilies_ and _Recognitions_) of the 3rd century. Ebionite views +lingered especially in the country east of the Jordan until they were +absorbed by Islam in the 7th century. + + In addition to the literature cited see R.C. Ottley, _The Doctrine of + the Incarnation_, part iii. Sec. ii.; W. Moeller, _Hist. of the Christian + Church_, i. 99; art. in Herzog-Hauck, _Realencyklopaedie_, s.v. + "Ebioniten"; also CLEMENTINE LITERATURE. + + +FOOTNOTE: + + [1] So A. Harnack, _Hist. of Dogma_, i. 301, and F.J.A. Hort, + _Judaistic Christianity_, p. 199. Th. Zahn and J.B. Lightfoot ("St. + Paul and the Three," in _Commentary on Galatians_) maintain the + distinction. + + + + +EBNER-ESCHENBACH, MARIE, FREIFRAU VON (1830- ), Austrian novelist, was +born at Zdislavic in Moravia, on the 13th of September 1830, the daughter +of a Count Dubsky. She lost her mother in early infancy, but received a +careful intellectual training from two stepmothers. In 1848 she married +the Austrian captain, and subsequent field-marshal, Moritz von +Ebner-Eschenbach, and resided first at Vienna, then at Klosterbruck, where +her husband had a military charge, and after 1860 again at Vienna. The +marriage was childless, and the talented wife sought consolation in +literary work. In her endeavours she received assistance and encouragement +from Franz Grillparzer and Freiherr von Muench-Bellinghausen. Her first +essay was with the drama _Maria Stuart in Schottland_, which Philipp +Eduard Devrient produced at the Karlsruhe theatre in 1860. After some +other unsuccessful attempts in the field of drama, she found her true +sphere in narrative. Commencing with _Die Prinzessin von Banalien_ (1872), +she graphically depicts in _Bozena_ (Stuttgart, 1876, 4th ed. 1899) and +_Das Gemeindekind_ (Berlin, 1887, 4th ed. 1900) the surroundings of her +Moravian home, and in _Lotti, die Uhrmacherin_ (Berlin, 1883, 4th ed. +1900), _Zwei Comtessen_ (Berlin, 1885, 5th ed. 1898), _Unsuehnbar_ (1890, +5th ed. 1900) and _Glaubenslos?_ (1893) the life of the Austrian +aristocracy in town and country. She also published _Neue Erzaehlungen_ +(Berlin, 1881, 3rd ed. 1894), _Aphorismen_ (Berlin, 1880, 4th ed. 1895) +and _Parabeln, Maerchen und Gedichte_ (2nd ed., Berlin, 1892). Frau von +Ebner-Eschenbach's elegance of style, her incisive wit and masterly +depiction of character give her a foremost place among the German +women-writers of her time. On the occasion of her seventieth birthday the +university of Vienna conferred upon her the degree of doctor of +philosophy, _honoris causa_. + + An edition of Marie von Ebner-Eschenbach's _Gesammelte Schriften_ + began to appear in 1893 (Berlin). See A. Bettelheim, _Marie von + Ebner-Eschenbach: biographische Blaetter_ (Berlin, 1900), and M. + Necker, _Marie von Ebner-Eschenbach, nach ihren Werken geschildert_ + (Berlin, 1900). + + + + +EBOLI (anc. _Eburum_), a town of Campania, Italy, in the province of +Salerno, from which it is 16 m. E. by rail, situated 470 ft. above +sea-level, on the S. edge of the hills overlooking the valley of the +Sele. Pop. (1901) 9642 (town), 12,423 (commune). The sacristy of St +Francesco contains two 14th-century pictures, one by Roberto da Oderisio +of Naples. The ancient Eburum was a Lucanian city, mentioned only by +Pliny and in inscriptions, not far distant from the Campanian border. It +lay above the Via Popillia, which followed the line taken by the modern +railway. Some scanty remains of its ancient polygonal walls may still be +seen. (T. As.) + + + + +EBONY (Gr. [Greek: ebenos]), the wood of various species of trees of the +genus _Diospyros_ (natural order Ebenaceae), widely distributed in the +tropical parts of the world. The best kinds are very heavy, are of a +deep black, and consist of heart-wood only. On account of its colour, +durability, hardness and susceptibility of polish, ebony is much used +for cabinet work and inlaying, and for the manufacture of +pianoforte-keys, knife-handles and turned articles. The best Indian and +Ceylon ebony is furnished by _D. Ebenum_, a native of southern India and +Ceylon, which grows in great abundance throughout the flat country west +of Trincomalee. The tree is distinguished from others by the inferior +width of its trunk, and its jet-black, charred-looking bark, beneath +which the wood is perfectly white until the heart is reached. The wood +is stated to excel that obtained from _D. reticulata_ of the Mauritius +and all other varieties of ebony in the fineness and intensity of its +dark colour. Although the centre of the tree alone is employed, reduced +logs 1 to 3 ft. in diameter can readily be procured. Much of the East +Indian ebony is yielded by the species _D. Melanoxylon_ (Coromandel +ebony), a large tree attaining a height of 60 to 80 ft., and 8 to 10 ft. +in circumference, with irregular rigid branches, and oblong or +oblong-lanceolate leaves. The bark of the tree is astringent, and mixed +with pepper is used in dysentery by the natives of India. The wood of +_D. tomentosa_, a native of north Bengal, is black, hard and of great +weight. _D. montana_, another Indian species, produces a yellowish-grey +soft but durable wood. _D. quaesita_ is the tree from which is obtained +the wood known in Ceylon by the name _Calamander_, derived by Pridham +from the Sinhalee _kalumindrie_, black-flowing. Its closeness of grain, +great hardness and fine hazel-brown colour, mottled and striped with +black, render it a valuable material for veneering and furniture making. +_D. Dendo_, a native of Angola, is a valuable timber tree, 25 to 35 ft. +high, with a trunk 1 to 2 ft. in diameter. The heart-wood is very black +and hard and is known as black ebony, also as billet-wood, and Gabun, +Lagos, Calabar or Niger ebony. What is termed Jamaica or West Indian +ebony, and also the green ebony of commerce, are produced by _Brya +Ebenus_, a leguminous tree or shrub, having a trunk rarely more than 4 +in. in diameter, flexible spiny branches, and orange-yellow, +sweet-scented flowers. The heart-wood is rich dark brown in colour, +heavier than water, exceedingly hard and capable of receiving a high +polish. + +From the book of Ezekiel (xxvii. 15) we learn that ebony was among the +articles of merchandise brought to Tyre; and Herodotus states (iii. 97) +that the Ethiopians every three years sent a tribute of 200 logs of it +to Persia. Ebony was known to Virgil as a product of India (_Georg._ ii. +116), and was displayed by Pompey the Great in his Mithradatic triumph +at Rome. By the ancients it was esteemed of equal value for durability +with the cypress and cedar (see Pliny, _Nat. Hist._ xii. 9, xvi. 79). +According to Solinus (_Polyhistor_, cap. lv. p. 353, Paris, 1621), it +was employed by the kings of India for sceptres and images, also, on +account of its supposed antagonism to poison, for drinking-cups. The +hardness and black colour of the wood appear to have given rise to the +tradition related by Pausanias, and alluded to by Southey in _Thalaba_, +i. 22, that the ebony tree produced neither leaves nor fruit, and was +never seen exposed to the sun. + + + + +EBRARD, JOHANNES HEINRICH AUGUST (1818-1888), German theologian, was +born at Erlangen on the 18th of January 1818. He was educated in his +native town and at Berlin, and after teaching in a private family became +_Privatdocent_ at Erlangen (1841) and then professor of theology at +Zuerich (1844). In 1847 he was appointed professor of theology at +Erlangen, a chair which he resigned in 1861; in 1875 he became pastor of +the French reformed church in the same city. As a critic Ebrard occupied +a very moderate standpoint; as a writer his chief works were +_Christliche Dogmatik_ (2 vols., 1851), _Vorlesungen ueber praktische +Theologie_ (1864), _Apologetik_ (1874-1875, Eng. trans. 1886). He also +edited and completed H. Olshausen's commentary, himself writing the +volumes on the Epistle to the Hebrews, the Johannine Epistles, and +Revelation. In the department of belles-lettres he wrote a good deal +under such pseudonyms as Christian Deutsch, Gottfried Flammberg and +Sigmund Sturm. He died at Erlangen on the 23rd of July 1888. + + + + +EBRO (anc. _Iberus_ or _Hiberus_), the only one of the five great rivers +of the Iberian Peninsula (Tagus, Douro, Ebro, Guadalquivir, Guadiana) +which flows into the Mediterranean. The Ebro rises at Fuentibre, a +hamlet among the Cantabrian Mountains, in the province of Santander; at +Reinosa, 4 m. east, it is joined on the right by the Hijar, and thus +gains considerably in volume. It flows generally east by south through a +tortuous valley as far as Miranda de Ebro, passing through the +celebrated Roman bridge known as La Horadada ("the perforated"), near +Ona in Burgos. From Miranda it winds south-eastward through the wide +basin enclosed on the right by the highlands of Old Castile and western +Aragon, and on the left by the Pyrenees. The chief cities on its banks +are Logrono, Calahorra, Tudela, Saragossa and Caspe. Near Mora in +Catalonia it forces a way through the coastal mountains, and, passing +Tortosa, falls into the Mediterranean about 80 m. south-west of +Barcelona, after forming by its delta a conspicuous projection on the +otherwise regular coast line. In its length, approximately 465 m., the +Ebro is inferior to the Tagus, Guadiana and Douro; it drains an area of +nearly 32,000 sq. m. Its principal tributaries are--from the right hand +the Jalon with its affluent the Jiloca, the Huerva, Aguas, Martin, +Guadalope and Matarrana; from the left the Ega, Aragon, Arba, Gallego, +and the Segre with its intricate system of confluent rivers. The Ebro +and its tributaries have been utilized for irrigation since the Moorish +conquest; the main stream becomes navigable by small boats about Tudela; +but its value as a means of communication is almost neutralized by the +obstacles in its channel, and seafaring vessels cannot proceed farther +up than Tortosa. The great Imperial Canal, begun under the emperor +Charles V. (1500-1558), proceeds along the right bank of the river from +a point about 3 m. below Tudela, to El Burgo de Ebro, 5 m. below +Saragossa; the irrigation canal of Tauste skirts the opposite bank for a +shorter distance; and the San Carlos or New Canal affords direct +communication between Amposta at the head of the delta and the harbour +of Los Alfaques. From Miranda to Mora the Bilbao-Tarragona railway +follows the course of the Ebro along the right bank. + + + + +EBROIN (d. 681), Frankish "mayor of the palace," was a Neustrian, and +wished to impose the authority of Neustria over Burgundy and Austrasia. +In 656, at the moment of his accession to power, Sigebert III., the king +of Austrasia, had just died, and the Austrasian mayor of the palace, +Grimoald, was attempting to usurp the authority. The great nobles, +however, appealed to the king of Neustria, Clovis II., and unity was +re-established. But in spite of a very firm policy Ebroin was unable to +maintain this unity, and while Clotaire III., son of Clovis II., reigned +in Neustria and Burgundy, he was obliged in 660 to give the Austrasians +a special king, Childeric II., brother of Clotaire III., and a special +mayor of the palace, Wulfoald. He endeavoured to maintain at any rate +the union of Neustria and Burgundy, but the great Burgundian nobles +wished to remain independent, and rose under St Leger (Leodegar), bishop +of Autun, defeated Ebroin, and interned him in the monastery of Luxeuil +(670). A proclamation was then issued to the effect that each kingdom +should keep its own laws and customs, that there should be no further +interchange of functionaries between the kingdoms, and that no one +should again set up a tyranny like that of Ebroin. Soon, however, Leger +was defeated by Wulfoald and the Austrasians, and was himself confined +at Luxeuil in 673. In the same year, taking advantage of the general +anarchy, Ebroin and Leger left the cloister and soon found themselves +once more face to face. Each looked for support to a different +Merovingian king, Ebroin even proclaiming a false Merovingian as +sovereign. In this struggle Leger was vanquished; he was besieged in +Autun, was forced to surrender and had his eyes put out, and, on the +12th of October 678, he was put to death after undergoing prolonged +tortures. The church honours him as a saint. After his death Ebroin +became sole and absolute ruler of the Franks, imposing his authority +over Burgundy and subduing the Austrasians, whom he defeated in 678 at +Bois-du-Fay, near Laon. His triumph, however, was short-lived; he was +assassinated in 681, the victim of a combined attack of his numerous +enemies. He was a man of great energy, but all his actions seem to have +been dictated by no higher motives than ambition and lust of power. + + See _Liber historiae Francorum_, edited by B. Krusch, in _Mon. Germ. + hist. script. rer. Merov._ vol. ii.; _Vita sancti Leodegarii_, by + Ursinus, a monk of St Maixent (Migne, _Patr. Latina_, vol. xcvi.); + "Vita metrica" in _Poetae Latini aevi Carolini_, vol. iii. (_Mon. + Germ. hist._); J.B. Pitra, _Histoire de Saint Leger_ (Paris, 1846); + and J. Friedrich, "Zur Gesch. des Hausmeiers Ebroin," in the + _Proceedings of the Academy of Munich_ (1887, pp. 42-61). + (C. Pf.) + + + + +EBURACUM, or EBORACUM (probably a later variant), the Roman name of York +(q.v.) in England. Established about A.D. 75-80 as fortress of the +Ninth legion and garrisoned (after the annihilation of that legion about +A.D. 118) by the Sixth legion, it developed outside its walls a town of +civil life, which later obtained Roman municipal rank and in the 4th +century was the seat of a Christian bishop. The fortress and town were +separated by the Ouse. On the left bank, where the minster stands, was +the fortress, of which the walls can still be partly traced, and one +corner (the so-called Multangular Tower) survives. The municipality +occupied the right bank near the present railway station. The place was +important for its garrison and as an administrative centre, and the town +itself was prosperous, though probably never very large. The name is +preserved in the abbreviated form Ebor in the official name of the +archbishop of York, but the philological connexion between Eboracum and +the modern name York is doubtful and has probably been complicated by +Danish influence. (F. J. H.) + + + + +ECA DE QUEIROZ, JOSE MARIA (1843-1900), Portuguese writer, was born at +the northern fishing town of Povoa de Varzim, his father being a retired +judge. He went through the university of Coimbra, and on taking his +degree in law was appointed Administrador de Concelho at Leiria, but +soon tired of the narrow mental atmosphere of the old cathedral town and +left it. He accompanied the Conde de Rezende to Egypt, where he assisted +at the opening of the Suez Canal, and to Palestine, and on his return +settled down to journalism in Lisbon and began to evolve a style, at +once magical and unique, which was to renovate his country's prose. +Though he spent much of his days with the philosopher sonneteer Anthero +de Quental, and the critic Jayme Batalha Reis, afterwards consul-general +in London, he did not restrict his intimacy to men of letters, but +frequented all kinds of society, acquiring a complete acquaintance with +contemporary Portuguese life and manners. Entering the consular service +in 1872, he went to Havana, and, after a tour in the United States, was +transferred two years later to Newcastle-on-Tyne and in 1876 to Bristol. +In 1888 he became Portuguese consul-general in Paris, and there died in +1900. + +Queiroz made his literary debut in 1870 by a sensational story, _The +Mystery of the Cintra Road_, written in collaboration with the art +critic Ramalho Ortigao, but the first publication which brought him fame +was _The Farpas_, a series of satirical and humorous sketches of various +phases of social life, which, to quote the poet Guerra Junqueiro, +contain "the epilepsy of talent." These essays, the joint production of +the same partners, criticized and ridiculed the faults and foibles of +every class in turn, mainly by a comparison with the French, for the +education of Queiroz had made him a Frenchman in ideas and sympathies. +His Brazilian friend, Eduardo Prado, bears witness that at this period +French literature, especially Hugo's verse, and even French politics, +interested Queiroz profoundly, while he altogether ignored the +_belles-lettres_ of his own country and its public affairs. This phase +lasted for some years, and even when he travelled in the East he was +inclined to see it with the eyes of Flaubert, though the publication of +_The Relic_ and that delightful prose poem _Sweet Miracle_ afterwards +showed that he had been directly impressed and deeply penetrated by its +scenery, poetry and mysticism. The Franco-German War of 1870, however, +by lowering the prestige of France, proved the herald of a national +Portuguese revival, and had a great influence on Queiroz, as also had +his friend Oliveira Martins (q.v.), the biographer of the patriot kings +of the Aviz dynasty. He founded the Portuguese Realist-Naturalist +school, of which he remained for the rest of his life the chief +exponent, by a powerful romance, _The Crime of Father Amaro_, written in +1871 at Leiria but only issued in 1875. Its appearance then led to a +baseless charge that he had plagiarized _La Faute de l'Abbe Mouret_, and +ill-informed critics began to name Queiroz the Portuguese Zola, though +he clearly occupied an altogether different plane in the domain of art. +During his stay in England he produced two masterpieces, _Cousin Basil_ +and _The Maias_, but they show no traces of English influence, nor again +are they French in tone, for, living near to France, his disillusionment +progressed and was completed when he went to Paris and had to live under +the regime of the Third Republic. Settling at Neuilly, the novelist +became chronicler, critic, and letter-writer as well, and in all these +capacities Queiroz displayed a spontaneity, power and artistic finish +unequalled in the literature of his country since the death of Garrett. +A bold draughtsman, he excelled in freshness of imagination and careful +choice and collocation of words, while his warmth of colouring and +brilliance of language speak of the south. Many of his pages descriptive +of natural scenery, such for instance as the episode of the return to +Tormes in _The City and the Mountains_, have taken rank as classic +examples of Portuguese prose, while as a creator of characters he stood +unsurpassed by any writer of his generation in the same field. He +particularly loved to draw and judge the middle class, and he mocks at +and chastises its hypocrisy and narrowness, its veneer of religion and +culture, its triumphant lying, its self-satisfied propriety, its cruel +egotism. But though he manifested a predilection for middle-class types, +his portrait gallery comprises men and women of all social conditions. +_The Maias_, his longest book, treats of _fidalgos_, while perhaps his +most remarkable character study is of a servant, Juliana, in _Cousin +Basil_. At least two of his books, this latter and _The Crime of Father +Amaro_, are _chroniques scandaleuses_ in their plots and episodes; these +volumes, however, mark not only the high-water line of the +Realist-Naturalist school in Portugal, but are in themselves, leaving +aside all accidentals, creative achievements of a high order. + +Though Queiroz was a keen satirist of the ills of society, his pages +show hardly a trace of pessimism. _The City and the Mountains_, and in +part _The Relic_ also, reveal the apostle of Realism as an idealist and +dreamer, a true representative of that Celtic tradition which survives +in the race and has permeated the whole literature of Portugal. _The +Mandarin_, a fantastic variation on the old theme of a man self-sold to +Satan, and _The Illustrious House of Ramires_, are the only other +writings of his that require mention, except _The Correspondence of +Fradique Mendes_. In conjunction with Anthero de Quental and Jayme +Batalha Reis, Queiroz invented under that name a smart man of the world +who had something of himself and something of Eduardo Prado, and made +him correspond on all sorts of subjects with imaginary friends and +relatives to the delight of the public, many of whom saw in him a +mysterious new writer whose identity they were eager to discover. These +sparkling and humorous letters are an especial favourite with admirers +of Queiroz, because they reveal so much of his very attractive +personality, and perhaps the cleverest of the number, that on Pacheco, +has received an English dress. In addition to his longer and more +important works, Queiroz wrote a number of short stories, some of which +have been printed in a volume under the title of _Contos_. The gems of +this remarkable collection are perhaps _The Peculiarities of a +Fair-haired Girl_, _A Lyric Poet_, _Jose Matthias_, _The Corpse_, and +_Sweet Miracle_. + + Most of his books have gone through many editions, and they are even + more appreciated in the Brazils than in Portugal. It should be + mentioned that the fourth edition of _Father Amaro_ is entirely + different in form and action from the first, the whole story having + been rewritten. One of Queiroz's romances and two of his short stories + have been published in English. An unsatisfactory version of _Cousin + Basil_, under the title _Dragon's Teeth_, appeared at Boston, U.S.A., + in 1889, while _Sweet Miracle_ has had three editions in England and + one in America, and there is also a translation of _O Defunto_ (_The + Corpse_) under the name of _Our Lady of the Pillar_. + + An admirable critical study of the work of Queiroz will be found in _A + Geracao Nova--Os Novellistas_, by J. Pereira de Sampaio (_Bruno_), + (Oporto, 1886). The _Revista moderna_ of the 20th of November 1897 was + entirely devoted to him. Senhor Batalha Reis gives interesting + reminiscences of the novelist's early days in his preface to some + prose fragments edited by him and named _Prosas Barbaras_ (Oporto, + 1903). (E. Pr.) + + + + +ECARTE (Fr. for "separated," "discarded"), a game at cards, of modern +origin, probably first played in the Paris _salons_ in the first quarter +of the 19th century. It is a development of a very old card game called +_la triomphe_ or _French-ruff_. Ecarte is generally played by two +persons, but a pool of three may be formed, the player who is out taking +the place of the loser, and the winner of two consecutive games winning +the pool. At French ecarte (but not at English) bystanders who are +betting may advise the players, but only by pointing to the cards they +desire them to play, and the loser of the game goes out, one of the +_rentrants_ taking his place, unless the loser is playing _la chouette_, +i.e. playing single-handed against two, and taking all bets. + +The small cards (from the two to the six, both inclusive) are removed +from an ordinary pack. The players cut for deal, the highest having the +choice. The king is the highest card, the ace ranking after the knave. +The dealer gives five cards to his adversary, and five to himself, by +two at a time to each and by three at a time to each, or vice versa. The +eleventh card is turned up for trumps. If it is a king, the dealer +scores one, at any time before the next deal. The non-dealer then looks +at his cards. If satisfied with them he plays, and there is no +discarding; if not satisfied he "proposes." The dealer may either accept +or refuse. If he accepts, each player discards face downwards as many +cards as he thinks fit, and fresh ones are given from the undealt cards +or "stock," first to complete the non-dealer's hand to five, then to +complete the dealer's. To ask for "a book" is to ask for five cards. +Similarly a second proposal may be made, and so on, until one player is +satisfied with his hand. If the dealer refuses, the hand is played +without discarding. If the non-dealer announces that he holds the king +of trumps, he scores one; and similarly, if the dealer holds the king +and announces it, he scores one. The announcement must be made before +playing one's first card, or if that card be the king, on playing it. +The non-dealer, being satisfied with his hand, leads a card. The dealer +plays a card to it, the two cards thus played forming a trick. The +winner of the trick leads to the next, and so on. The second to play to +a trick must follow suit if able, and must win the trick if he can. + +The scores are for the king and for the majority of tricks. The player +who wins three tricks scores one for the "point"; if he wins all five +tricks, he scores two for the "vole." If the non-dealer plays without +proposing, or the dealer refuses the first proposal, and fails to win +three tricks, the adversary scores two, but no more even if he wins the +vole. The game is five up. The points are conveniently marked with a +three-card and a two-card, as at euchre. The three is put face upwards +with the two face downwards on the top of it. When one or two or three +points are scored the top card is moved so as to expose them. At four, +one pip of the two-card is put under the other card. Games may be +recorded similarly. + + _Hints to Players._--The following hints may be of service to + beginners:-- + + Shuffle thoroughly after every deal. + + Do not announce the king until in the act of playing your first card. + + The hands which should be played without proposing, called _jeux de + regle_ (standard hands), ought to be thoroughly known. They are as + follows:-- + + 1. All hands with three or more trumps, whatever the other cards. + + 2. Hands with _two trumps_ which contain also-- + + (a) Any three cards of one plain suit; + + (b) Two cards of one plain suit, one being as high as a queen; + + (c) Two small cards of one suit, the fifth card being a king of + another suit; + + (d) Three high cards of different suits. + + 3. Hands with _one trump_, which contain also-- + + (a) King, queen, knave of one suit, and a small card of another; + + (b) Four cards of one suit headed by king; + + (c) Three cards of one suit headed by queen, and queen of another + suit. + + 4. Hands with _no trump_, which contain three queens or cards of equal + value in different suits, e.g., four court cards. + + 5. Hands from which only two cards can be discarded without throwing a + king or a trump. + + Holding cards which make the point certain, propose. If you hold a + _jeu de regle_, and one of the trumps is the king, propose, as your + adversary cannot then take in the king. + + When discarding, throw out all cards except trumps and kings. + + If your adversary proposes you should accept, unless you are guarded + in three suits (a queen being a sufficient guard), or in two suits + with a trump, or in one suit with two trumps. Hence the rule not to + discard two cards, unless holding the king of trumps, applies to the + dealer. + + The hands with which to refuse are the same as those with which to + play without proposing, except as follows:-- + + 1. Two trumps and three cards of one plain suit should not be played + unless the plain suit is headed by a court card. + + 2. One trump and a tierce major is too weak, unless the fifth card is + a court card. With similar hands weaker in the tierce major suit, + accept unless the fifth card is a queen. + + 3. One trump and four cards of a plain suit is too weak to play. + + 4. One trump and two queens is too weak, unless both queens are singly + guarded. + + 5. One trump, queen of one suit, and knave guarded of another should + not be played unless the queen is also guarded, or the card of the + fourth suit is a court card. + + 6. One trump, a king and a queen, both unguarded, should not be + played, unless the fourth suit contains a card as high as an ace. + + 7. Four court cards without a trump are too weak to play, unless they + are of three different suits. + + Refuse with three queens, if two are singly guarded; otherwise, + accept. + + Lead from your guarded suit, and lead the highest. + + If the strong suit led is not trumped, persevere with it, unless with + king of trumps, or queen (king not having been announced), or knave + ace, when lead a trump before continuing your suit. + + You should not lead trumps at starting, unless you hold king or queen, + knave, or knave ace, with court cards out of trumps. + + The score has to be considered. If the dealer is at four, and the king + is not in your hand nor turned up, play any cards without proposing + which give an even chance of three tricks, e.g. a queen, a guarded + knave, and a guarded ten. The same rule applies to the dealer's + refusal. + + At the adverse score of four, and king not being in hand or turned up, + any hand with one trump should be played, unless the plain cards are + very small and of different suits. + + If the non-dealer plays without proposing when he is four to three, + and the dealer holds the king he ought not to mark it. The same rule + applies to the non-dealer after a refusal, if the dealer is four to + three. + + At the score of non-dealer three, dealer four, the dealer should + refuse on moderate cards, as the player proposing at this score must + have a very bad hand. + + At four a forward game should not be played in trumps, as there is no + advantage in winning the vole. + + _Laws of Ecarte._--The following laws are abridged from the revised + code adopted by the Turf Club:--A cut must consist of at least two + cards. Card exposed in cutting, fresh cut. Order of distribution of + cards, whether by three and two, or vice versa, once selected, dealer + must not change it during game. Player announcing king when he has not + got it, and playing a card without declaring error, adversary may + correct score and have hand played over again. If offender wins point + or vole that hand, he scores one less than he wins. Proposal, + acceptance, or refusal made cannot be retracted. Cards discarded must + not be looked at. Cards exposed in giving cards to non-dealer, he has + option of taking them or of having next cards; dealer exposing his own + cards, no penalty. Dealer turning up top card after giving cards, + cannot refuse second discard. Dealer accepting when too few cards in + stock to supply both, non-dealer may take cards, and dealer must play + his hand. Card led in turn cannot be taken up again. Card played to a + lead can only be taken up prior to another lead, to save revoke or to + correct error of not winning trick. Card led out of turn may be taken + up prior to its being played to. Player naming one suit and leading + another, adversary has option of requiring suit named to be led. If + offender has none, no penalty. Player abandoning hand, adversary is + deemed to win remaining tricks, and scores accordingly. If a player + revokes or does not win trick when he can do so, the adversary may + correct score and have hand replayed. + + See _Academie des jeux_ (various editions after the first quarter of + the 19th century); Hoyle's _Games_ (various editions about the same + dates); Ch. Van-Tenac et Louis Delanoue, _Traite du jeu de l'ecarte_ + (Paris, 1845; translated in Bohn's _Handbook of Games_, London, 1850); + "Cavendish," _The Laws of Ecarte, adopted by the Turf Club, with a + Treatise on the Game_ (London, 1878); _Pocket Guide to Ecarte_ + ("Cavendish," 1897); Foster's _Encyclopaedia of Indoor Games_ (1903). + + + + +ECBATANA (_Agbatana_ in Aeschylus, _Hangmatana_ in Old Persian, written +_Agamtanu_ by Nabonidos, and _Agamatanu_ at Behistun, mod. _Hamadan_), +the capital of Astyages (Istuvegu), which was taken by Cyrus in the +sixth year of Nabonidos (549 B.C.). The Greeks supposed it to be the +capital of Media, confusing the Manda, of whom Astyages was king, with +the Mada or Medes of Media Atropatene, and ascribed its foundation to +Deioces (the _Daiukku_ of the cuneiform inscriptions), who is said to +have surrounded his palace in it with seven concentric walls of +different colours. Under the Persian kings, Ecbatana, situated at the +foot of Mount Elvend, became a summer residence; and was afterwards the +capital of the Parthian kings. Sir H. Rawlinson attempted to prove that +there was a second and older Ecbatana in Media Atropatene, on the site +of the modern Takht-i-Suleiman, midway between Hamadan and Tabriz +(_J.R.G.S._ x. 1841), but the cuneiform texts imply that there was only +one city of the name, and Takht-i-Suleiman is the Gazaca of classical +geography. The Ecbatana at which Cambyses is said by Herodotus (iii. 64) +to have died is probably a blunder for Hamath. + + See Perrot and Chipiez, _History of Art in Persia_ (Eng. trans., + 1892); M. Dieulafoy, _L'Art antique de la Perse_, pt. i. (1884); J. de + Morgan, _Mission scientifique en Perse_, ii. (1894). See HAMADAN and + PERSIA: _Ancient History_, Sec. v. 2. (A. H. S.) + + + + +ECCARD, JOHANN (1553-1611), German composer of church music, was born at +Muehlhausen on the Unstrut, Prussia, in 1553. At the age of eighteen he +went to Munich, where he became the pupil of Orlando Lasso. In his +company Eccard is said to have visited Paris, but in 1574 we find him +again at Muehlhausen, where he resided for four years, and edited, +together with Johann von Burgk, his first master, a collection of sacred +songs, called _Crepundia sacra Helmboldi_ (1577). Soon afterwards he +obtained an appointment as musician in the house of Jacob Fugger, the +Augsburg banker. In 1583 he became assistant conductor, and in 1599 +conductor, at Koenigsberg, to Georg Friedrich, margrave of +Brandenburg-Anspach, the administrator of Prussia. In 1608 he was called +by the elector Joachim Friedrich to Berlin as chief conductor, but this +post he held only for three years, owing to his premature death at +Koenigsberg in 1611. Eccard's works consist exclusively of vocal +compositions, such as songs, sacred cantatas and chorales for four or +five, and sometimes for seven, eight, or even nine voices. Their +polyphonic structure is a marvel of art, and still excites the +admiration of musicians. At the same time his works are instinct with a +spirit of true religious feeling. His setting of the beautiful words +"Ein' feste Burg ist unser Gott" is still regarded by the Germans as +their representative national hymn. Eccard and his school are +inseparably connected with the history of the Reformation. + + Of Eccard's songs a great many collections are extant; see K.G.A. von + Winterfeld, _Der Evangelische Kirchengesang_ (1843); Doering + (_Choralkunde_, p. 47). + + + + +ECCELINO [or EZZELINO] DA ROMANO (1194-1259), Ghibelline leader, and +supporter of the emperor Frederick II., was born on the 25th of April +1194. He belonged to a family descended from a German knight named +Eccelin, who followed the emperor Conrad II. to Italy about 1036, and +received the fief of Romano near Padua. Eccelin's grandson was Eccelino +III., surnamed the Monk, who divided his lands between his two sons in +1223, and died in 1235. The elder of these two sons was Eccelino, who in +early life began to take part in family and other feuds, and in 1226, at +the head of a band of Ghibellines, seized Verona and became _podesta_ of +the city. He soon lost Verona, but regained it in 1230; and about this +time came into relations with Frederick II., who in 1232 issued a +charter confirming him in his possessions. In 1236 when besieged in +Verona he was saved by the advance of the emperor, who in November of +the same year took Vicenza and entrusted its government to Eccelino. In +1237 he obtained authority over Padua and Treviso; and on the 27th of +November in that year he shared in the victory gained by the emperor +over the Lombards at Cortenuova. In 1238 he married Frederick's natural +daughter, Selvaggia; in 1239 was appointed imperial vicar of the march +of Treviso; but in the same year was excommunicated by Pope Gregory IX. +He was constantly engaged in increasing his possessions; was present at +the siege of Parma in 1247, and after Frederick's death in 1250 he +supported his son, the German king Conrad IV. His cruelties had, +however, aroused general disgust, and in 1254 he was again +excommunicated. In 1256 Pope Alexander IV. proclaimed a crusade against +him, and a powerful league was soon formed under the leadership of +Philip, archbishop of Ravenna. Padua was taken from Eccelino, but on the +1st of September 1258 he defeated his enemies at Torricella. He then +made an attempt on Milan, and the rival forces met at Cassano on the +27th of September 1259, when Eccelino was wounded and taken prisoner. +Enraged at his capture, he tore the bandages from his wounds, refused to +take nourishment, and died at Soncino on the 7th of October 1259. In the +following year his brother Albert was put to death, and the Romano +family became extinct. Eccelino, who is sometimes called the _tyrant_, +acquired a terrible reputation on account of his cruelties, a reputation +that won for him the immortality of inclusion in Dante's _Inferno_; but +his unswerving loyalty to Frederick II. forms a marked contrast to the +attitude of many of his contemporaries. + +Eccelino is the subject of a novel by Cesare Cantu and of a drama by J. +Eichendorff. + + See J.M. Gittermann, _Ezzelino da Romano_ (Freiburg, 1890); S. Mitis, + _Storia d' Ezzelino IV. da Romano_ (Maddaloni, 1896); and F. Stieve, + _Ezzelino von Romano_ (Leipzig, 1909). + + + + +ECCENTRIC (from Gr. [Greek: ek], out of, and [Greek: kentron], centre), +literally "out from the centre," and thus used to connote generally any +deviation from the normal. In astronomy the word denotes a circle round +which a body revolves, but whose centre is displaced from the visible +centre of motion. In the ancient astronomy the ellipses in which it is +now known that the planets revolve around the sun could not be +distinguished from circles, but the unequal angular motion due to +ellipticity was observed. The theory of the eccentric was that the +centre of the epicycle of each planet moved uniformly in a circle, the +centre of which was displaced from that of the earth by an amount double +the eccentricity of the actual ellipse, as the case is now understood. +When measured around this imaginary centre, which is so situated on the +major axis of the ellipse that the focus, or place of the real sun, is +midway between it and the centre of the ellipse, the motion is +approximately uniform. In engineering, an eccentric is a mechanical +device for converting rotary into reciprocating motion (see +STEAM-ENGINE). For eccentric angle see ELLIPSE. + + + + +ECCHELLENSIS (or ECHELLENSIS), ABRAHAM (d. 1664), a learned Maronite, +whose surname is derived from Eckel in Syria, where he was born towards +the close of the 16th century. He was educated at the Maronite college +in Rome, and, after taking his doctor's degree in theology and +philosophy, returned for a time to his native land. He then became +professor of Arabic and Syriac in the college of the Propaganda at Rome. +Called to Paris in 1640 to assist Le Jay in the preparation of his +polyglot Bible, he contributed to that work the Arabic and Latin +versions of the book of Ruth and the Arabic version of the third book of +Maccabees. In 1646 he was appointed professor of Syriac and Arabic at +the College de France. Being invited by the Congregation of the +Propaganda to take part in the preparation of an Arabic version of the +Bible, Ecchellensis went again in 1652 or 1653 to Rome. He published +several Latin translations of Arabic works, of which the most important +was the _Chronicon Orientale_ of Ibnar-Rahib (Paris, 1653), a history of +the patriarchs of Alexandria. He was engaged in an interesting +controversy with John Selden as to the historical grounds of episcopacy, +in the course of which he published his _Eutychius vindicatus, sive +Responsio ad Seldeni Origines_ (Rome, 1661). Conjointly with Giovanni +Borelli he wrote a Latin translation of the 5th, 6th and 7th books of +the _Conics_ of Apollonius of Perga (1661). He died at Rome in 1664. + + + + +ECCLES, a municipal borough in the Eccles parliamentary division of +Lancashire, England, 4 m. W. of Manchester, of which it forms +practically a suburb. Pop. (1901) 34,369. It is served by the London & +North-Western railway and by the Birkenhead railway (North-Western and +Great Western joint). The Manchester Ship Canal passes through. The +church of St Mary is believed to date from the 12th century, but has +been enlarged and wholly restored in modern times. There are several +handsome modern churches and chapels, a town hall, and numerous cotton +mills, while silk-throwing and the manufacture of fustians and ginghams +are also among the industries, and there are also large engine works. A +peculiar form of cake is made here, taking name from the town, and has a +wide reputation. Eccles was incorporated in 1892, and the corporation +consists of a mayor, 6 aldermen and 18 councillors. The borough +maintains the tramway service, &c., but water and gas are supplied from +Manchester and Salford respectively. Area, 2057 acres. + +Before the Reformation the monks of Whalley Abbey had a grange here at +what is still called Monks' Hall; and in 1864 many thousands of silver +pennies of Henry III. and John of England and William I. of Scotland +were discovered near the spot. Robert Ainsworth, the author of the Latin +and English dictionary so long familiar to English students, was born at +Eccles in 1660; and it was at the vicarage that William Huskisson +expired on the 15th of September 1830 from injuries received at the +opening of the Liverpool & Manchester railway. From early times "wakes" +were held at Eccles, and bull-baiting, bear-baiting and cock-fighting +were carried on. Under Elizabeth these festivals, which had become +notoriously disorderly, were abolished, but were revived under James I., +and maintained until late in the 19th century on public ground. The +cockpit remained on the site of the present town hall. A celebration on +private property still recalls these wakes. + + + + +ECCLESFIELD, a township in the Hallamshire parliamentary division of the +West Riding of Yorkshire, England, 5 m. N. of Sheffield, on the Great +Central and Midland railways. The church of St Mary is Perpendicular, +with a central tower, and contains excellent woodwork. It formerly bore, +and must have deserved, the familiar title of the "Minster of the +Moors." Ecclesfield was the seat of a Benedictine priory, which passed +to the Carthusians in the 14th century. Cutlery and tools are largely +manufactured, and there are coal-mines, paper mills and iron and +fire-clay works. After the inclusion within the county borough of +Sheffield of part of the civil parish of Ecclesfield in 1901, the +population was 18,324. + + + + +ECCLESHALL, a market town in the north-western parliamentary division of +Staffordshire, England; 7 m. N.W. from Stafford, and 4 W. of Norton +Bridge station on the London & North-Western main line. Pop. (1901) +3799. The church of the Holy Trinity, one of the most noteworthy in +Staffordshire, is principally Early English, and has fine stained glass. +Several bishops of Lichfield are buried here, as Eccleshall Castle was +the episcopal residence from the 13th century until 1867. Of this the +ancient remains include a picturesque tower and bridge. To the west on +the borders of Shropshire is Blore Heath, the scene of a defeat of the +Lancastrians by the Yorkists in 1459. + + + + +ECCLESIA (Gr. [Greek: ekklesia], from [Greek: ek], out, and [Greek: +kalein], to call), in ancient Athens, the general assembly of all the +freemen of the state. In the primitive unorganized state the king was +theoretically absolute, though his great nobles meeting in the Council +(see BOULE) were no doubt able to influence him considerably. There is, +however, no doubt that in the earliest times the free people, i.e. the +fighting force of the state, were called together to ratify the +decisions of the king, and that they were gradually able to enforce +their wishes against those of the nobles. In Athens, as in Rome, where +the Plebs succeeded in their demand for the codification of the laws +(the Twelve Tables), it was no doubt owing to the growing power of the +people meeting in the Agora that Draco was entrusted with the task of +publishing a code of law and so putting an end to the arbitrary +judicature of the aristocratic party. But there is no evidence that the +Ecclesia had more than a _de facto_ existence before Solon's reforms. + +The precise powers which Solon gave the people are not known. It is +clear that the executive power in the state (see ARCHON) was still +vested in the Eupatrid class. It is obvious, therefore, that a moderate +reformer would endeavour to give to the people some control over the +magistracy. Now in speaking of the Thetes (the lowest of the four +Solonian classes; see SOLON), Aristotle's _Constitution of Athens_ says +that Solon gave them merely "a share in the Ecclesia and the Law +Courts," and in the _Politics_ we find that he gave them the right of +electing the magistrates and receiving their accounts at the end of the +official year. Thus it seems that the "mixed" character of Solon's +constitution consisted in the fact that though the officials of the +state were still necessarily Eupatrid, the Ecclesia elected those of the +Eupatrids whom they could trust, and further had the right of +criticizing their official actions. Secondly, all our accounts agree +that Solon admitted the Thetes to the Ecclesia, thus recognizing them as +citizens. Under Cleisthenes the Ecclesia remained the sovereign power, +but the Council seems to have become to some extent a separate +administrative body. The relation of Boule and Ecclesia in the +Cleisthenic democracy was of the greatest importance. The Ecclesia +alone, a heterogeneous body of untrained citizens, could not have +passed, nor even have drawn up intelligible measures; all the +preliminary drafting was done by the small committee of the Boule which +was in session at any particular time. In the 5th century the functions +of the Ecclesia and the popular courts of justice were vastly increased +by the exigencies of empire. At the beginning of the 4th century B.C. +the system of payment was introduced (see below). In 308 B.C. Demetrius +of Phalerum curtailed the power of the Ecclesia by the institution of +the _Nomophylaces_ (Guardians of the Law), who prevented the Ecclesia +from voting on an illegal or injurious motion. Under Roman rule the +powers of the Ecclesia and the popular courts were much diminished, and +after 48 B.C. (the franchise being frequently sold to any casual alien) +the Demos (people) was of no importance. They still assembled to pass +psephisms in the theatre and to elect strategi, and, under Hadrian, had +some small judicial duties, but as a governing body the Ecclesia died +when Athens became a _civitas libera_ under Roman protection. + +_Constitution and Functions._--Throughout the period of Athenian +greatness the Ecclesia was the sovereign power, not only in practice but +also in theory. The assembly met in early times near the sanctuary of +Aphrodite Pandemus (i.e. south of the Acropolis), but, in the 5th and +4th centuries, the regular place of meeting was the Pnyx. From the 5th +century it met sometimes in the theatre, which in the 3rd century was +the regular place. From Demosthenes we learn that in his time special +meetings were held at Peiraeus, and, in the last centuries B.C., +meetings were held at Athens and Peiraeus alternately. Certain meetings, +however, for voting ostracism (q.v.) and on questions affecting +individual status took place in the Agora. Meetings were (1) ordinary, +(2) extraordinary, and (3) convened by special messengers ([Greek: +kyriai], [Greek: synkletoi] and [Greek: katakletoi]), these last being +called when it was desirable that the country people should attend. At +ordinary meetings the attendance was practically confined to Athenian +residents. According to Aristotle there were four regular meetings in +each prytany (see BOULE); probably only the first of these was called +[Greek: kyria]. It is certain, however, that the four meetings did not +fall on regular days, owing to the occurrence of feast days on which no +meeting could take place. In the [Greek: kyria ekklesia] of each month +took place the _Epicheirotonia_ (monthly inquiry) of the state +officials, and if it proved unsatisfactory a trial before the Heliaea +was arranged; the council reported on the general security and the +corn-supply, and read out lists of vacant inheritances and unmarried +heiresses. In the sixth prytany of each year at the [Greek: kyria +ekklesia] the question whether ostracism should take place that year was +put to the vote. For all meetings it was usual that the Prytaneis should +give five days' notice in the form of a _programma_ (agenda). On +occasions of sudden importance the herald of the council summoned the +people with a trumpet, and sometimes special messengers were despatched +to "bring in" the country people ([Greek: katakalein]). + +After the archonship of Solon all Athenians over the age of eighteen +were eligible to attend the assembly, save those who for some reason had +suffered _atimia_ (loss of civil rights). To prevent the presence of any +disqualified persons, six _lexiarchs_ with thirty assistants were +present with the deme-rolls in their hands. These officers superintended +the payment in the 4th century and probably the _toxotae_ (police) also, +whose duty it was before the introduction of pay to drive the people out +of the Agora into the Ecclesia with a rope steeped in red dye which they +stretched out and used as a draw net (see Aristoph. _Acharn._ 22 and +_Eccles._ 378). The introduction of pay, which belongs to the early +years of the 4th century and by the _Constitution_ (c. 41 ad fin.) is +attributed to Agyrrhius, a statesman of the restored democracy, was a +device to secure a larger attendance. The rate rose from one to two +obols and then to three obols (Aristoph. _Eccles._ 300 sqq.), while at +the time of Aristotle it was one and a half drachmas for the [Greek: +kyria ekklesia] and one drachma for other meetings. Probably those who +were late did not receive payment. + +_Procedure._--The proceedings opened with formalities: the purification +by the _peristiarchs_, who carried round slain sucking pigs; the curse +against all who should deceive the people; the appointment (in the 4th +century) of the _proedri_ and their _epistates_ (see BOULE); the report +as to the weather-omens. The assembly was always dismissed if there were +thunder, rain or an eclipse. These formalities over, the Prytaneis +communicated the _probouleuma_ of the council, without which the +Ecclesia could not debate. This recommendation either submitted definite +proposals or merely brought the agenda before the assembly. Its +importance lay largely in the fact that it _explained_ the business in +hand, which otherwise must often have been beyond the grasp of a +miscellaneous assembly. After the reading, a preliminary vote was taken +as to whether the council's report should be accepted _en bloc_. If it +was decided to discuss, the herald called upon people to speak. Any +person, without distinction of age or position, might obtain leave to +speak, but it seems probable that the man who had moved the +recommendation previously in the council would advocate it in the +assembly. The council was, therefore, a check on the assembly, but its +powers were to some extent illusory, because any member of the assembly +(1) might propose an amendment, (2) might draw up a new resolution +founded on the principal motion, (3) might move the rejection of the +motion and the substitution of another, (4) might bring in a motion +asking the council for a recommendation on a particular matter, (5) +might petition the council for leave to speak on a given matter to the +assembly. Voting usually was by show of hands, but in special cases +(ostracism, &c.) by ballot (i.e. by casting pebbles into one of two +urns). The decision of the assembly was called a _psephism_ and had +absolute validity. These decisions were deposited in the Metrooen where +state documents were preserved; peculiarly important decrees were +inscribed also on a column (_stele_) erected on the Acropolis. It has +been shown that the power of the council was far from sufficient. The +real check on the vagaries of amateur legislators was the Graphe +Paranomon. Any man was at liberty to give notice that he would proceed +against the mover of a given resolution either before or after the +voting in the Ecclesia. A trial in a Heliastic court was then arranged, +and the plaintiff had to prove that the resolution in question +contravened an existing law. If this contention were upheld by the +court, when the case was brought to it by the Thesmothetae, the +resolution was annulled, and the defendant had to appear in a new trial +for the assessment of the penalty, which was usually a fine, rarely +death. Three convictions under this law, however, involved a certain +loss of rights; the loser could no longer move a resolution in the +Ecclesia. After the lapse of a year the mover of a resolution could not +be attacked. In the 4th century the Graphe Paranomon took the place of +Ostracism (q.v.). In the 5th century it was merely an arrangement +whereby the people sitting as sworn juries ratified or annulled their +own first decision in the Ecclesia. + +_Revision of Laws._--In the 4th century, the assembly annually, on the +eleventh day of Hecatombaeon (the first day of the official year), took +a general vote on the laws, to decide whether revision was necessary. If +the decision was in favour of alteration, it was open to any private +citizen to put up notice of amendments. The Nomothetae, a panel selected +by the Prytaneis from the Heliaea, heard arguments for and against the +changes proposed and voted accordingly. Against all new laws so passed, +there lay the Graphe; Paranomon. Thus the Nomothetae, not the Ecclesia, +finally passed the law. + +_Judicial Functions._--The Ecclesia heard cases of Probole and +Eisangelia (see GREEK LAW). The Probole was an action against sycophants +and persons who had not kept their promises to the people, or had +disturbed a public festival. The verdict went by show of hands, but no +legal consequences ensued; if the plaintiff demanded punishment he had +to go to the Heliaea which were not at all bound by the previous vote in +the Ecclesia. Cases of Eisangelia in which the penalty exceeded the +legal competence of the council came before the Ecclesia in the form of +a _probouleuma_. To prevent vexatious accusations, it was (at some date +unknown) decided that the accuser who failed to obtain one-fifth of the +votes should be fined 1000 drachmas (L40). (For the procedure in case of +OSTRACISM see that article.) + +_Summary._--Thus it will be seen that the Ecclesia, with no formal +organization, had absolute power save for the Graphe Paranomon (which, +therefore, constituted the dicasteries in one sense the sovereign power +in the state). It dealt with all matters home and foreign. Every member +could initiate legislation, and, as has been shown, the power of the +council was merely formal. As against this it must be pointed out that +it was by no means a representative assembly in practice. The phrase +used to describe a very special assembly ([Greek: katakletos ekklesia]) +shows that ordinarily the country members did not attend ([Greek: +katakalein] always involving the idea of motion from a distance towards +Athens), and Thucydides says that 5000 was the maximum attendance, +though it must be remembered that he is speaking of the time when the +number of citizens had been much reduced owing to the plague and the +Sicilian expedition. From this we understand the necessity of payment in +the 4th century, although in that period the Ecclesia was supreme +(_Constitution of Athens_, xli. 2). The functions of the Ecclesia thus +differed in two fundamental respects from those which are in modern +times associated with a popular assembly. (1) It did not exercise, at +least in the period as to which we are best instructed, the power of +law-making ([Greek: nomothesia]) in the strict sense. It must be +remembered, however, in qualification of this statement that it +possessed the power of passing _psephismata_ which would in many cases +be regarded as law in the modern sense. (2) The Ecclesia was principally +concerned with the supervision of administration. Much of what we regard +as executive functions were discharged by the Ecclesia. + + With this article compare those on SOLON; BOULE; AREOPAGUS; GREEK LAW, + and, for other ancient popular assemblies, APELLA; COMITIA. See also + A.H.J. Greenidge, _Handbook of Greek Constitutional History_ (1896); + Gilbert, _Greek Constitutional Antiquities_ (trans. Brooks and + Nicklin, 1895); Schoemann, _De comitiis Atheniensium_; L. Schmidt, "De + Atheniensis reipublicae indole democratica" in _Ind. Lect._ (Marburg, + 1865); J.W. Headlam, _Election by Lot at Athens_ (Cambridge, 1891). + See also the histories of Greece by Meyer, Busolt, Grote, Evelyn + Abbott, and J.E. Sandys' edition of the _Constitution of Athens_ + (1892); for a comparative study, E.A. Freeman, _Comparative Politics_. + (J. M. M.) + + + + +ECCLESIASTES (Heb. [Hebrew: Kohelet], _Kohelet_, "Koheleth"; Sept. +[Greek: ekklesiastes]; Jerome _concionator_), one of the Wisdom Books of +the Old Testament (see WISDOM LITERATURE). The book, as it stands, is a +collection of the discourses, observations and aphorisms of a sage +called Koheleth, a term the precise meaning of which is not certain. The +Greek _ecclesiastes_ means one who takes part in the deliberations of an +assembly (_ecclesia_), a debater or speaker in an assembly (Plato, +_Gorgias_, 452 E), and this is the general sense of the Hebrew word. Its +form (singular feminine) has been supposed to be the adoption or +imitation of the Arabic employment of a fem. sing. as the designation of +a high official person, as is the case in the title _caliph_ (whence the +rendering in the margin of the Revised Version, "Great orator"); but the +adoption of an Arabic idiom is not probable. This usage is not Hebrew; +it is not found either in the Old Testament or in the later (Mishnaic) +Hebrew. The form may have been suggested by that of the Hebrew word for +"wisdom." _Koheleth_, however, is employed in the book not as a title of +wisdom (for "wisdom" is never the speaker), but as the independent name +of the sage. It is intended to represent him as a member of an assembly +(_Kahal_)--not the Jewish congregation, but a body of students or +inquirers, such as is referred to in xii. 9-11, a sort of collegium, of +which he was the head; and as instructor of this body he gives his +criticism of life. The author begins, indeed, with identifying his sage +with King Solomon (i. 12-ii. 11, 12b); but he soon abandons this +literary device, and speaks in his own name. The rendering "preacher" +has a misleading connotation. + +In the book as we have it there is no orderly exposition of a theory; it +rather has the appearance of a collection of remarks jotted down by a +pupil (somewhat after the manner of Xenophon's _Memorabilia_), or of +extracts from a sage's notebook. It is, however, characterized +throughout (except in some scribal additions) by a definite thought, and +pervaded by a definite tone of feeling. The keynote is given in the +classic phrase with which the discussion opens and with which it closes: +"Vanity of vanities (i.e. absolute vanity), all[1] is vanity!" Life, +says the author, has nothing of permanent value to offer. His attitude +is one not of bitterness but of calm hopelessness, with an occasional +tinge of disgust or contempt. He fancies that he has tried or observed +everything in human experience, and his deliberate conclusion is that +nothing is worth doing. He believes in an all-powerful but indifferent +God, and is himself an observer of society, standing aloof from its +passions and ambitions, and interested only in pointing out their +emptiness. + +This general view is set forth in a number of particular observations. + +1. His fundamental proposition is that there is a fixed, unchangeable +order in the world, a reign of inflexible law (i. 4-11, iii. 1-11, 14, +15, vii. 13, viii. 5-9): natural phenomena, such as sunrise and sunset, +recur regularly; for everything in human experience a time has been set; +birth and death, building up and destroying, laughing and weeping, +silence and speech, love and hate, war and peace, are to be regarded not +as utterances of a living, self-directing world, but as incidents in the +work of a vast machine that rolls on for ever; there is an endless +repetition--nothing is new, nothing is lost; if one thinks he has found +something new, inquiry shows that it was in existence long ago; God, the +author of all, seeks out the past in order to make it once more present; +it is impossible to add to or take from the content of the world, +impossible to change the nature of things, to effect any radical +betterment of life; the result is unspeakable weariness--a depressing +series of sights and sounds. No goal or purpose is discoverable in this +eternal round; if the sun rises and goes on his journey through the sky, +it is merely to come back to the place where he rose; rivers flow for +ever into the sea without filling it. To what end was the world created? +It is impossible to say. Such is Koheleth's view of life, and it is +obvious that such a conception of an aimless cosmos is thoroughly +non-Jewish, if we may judge Jewish thought by the great body of the +extant literature. + +2. Further, says Koheleth, man is impelled to study the world, but under +the condition that he shall never comprehend it (iii. 11, vii. 23, 24, +viii. 16, 17). As to the meaning of the Hebrew term _olam_ in iii. 11, +there are various opinions, but "world" appears to be the rendering +favoured by the connexion: "God has made everything beautiful in its +time, and has put the _olam_ into men's minds, yet so that they cannot +understand His work": the _olam_, the sum of phenomena, is God's work. +The word is not found in this sense elsewhere in the Old Testament, but +it so occurs in the Mishna (_Pirke Aboth_, iv. 7), and the vocabulary of +Ecclesiastes is admittedly similar to that of the Mishna. Only here in +the Old Testament does it stand as a simple isolated noun; elsewhere it +is the definition of a noun (in "everlasting covenant," &c.), or it is +preceded by a preposition, in the phrases "for ever," "of old," or it +stands alone (sing. or plur.) in the same adverbial sense, "for ever." +The word means first a remote point in past or future, then a future +point without limit of time, then a period of history, and finally the +world considered as a mass of human experiences (cf. [Greek: aion]). The +renderings "eternity" and "future" in the present passage are +unsatisfactory; the former has an inappropriate metaphysical +connotation, and yields no distinct sense; the latter does not suit the +connexion, though there is reference to the future elsewhere (ix. 1). +God, the text here declares, has made the world an object of man's +thought, yet so that man can never find out the work that God has done +(iii. 11). The reference seems to be not so much to the variety and +complexity of phenomena as to the impossibility of construing them +rationally or in such a way that man may foresee and provide for his +future. Man is in the clutches of fate (ix. 11, 12): there is no +observable relation between exertion and result in life: the race is not +to the swift nor the battle to the strong; success does not attend +wisdom, knowledge and skill; men are like fish taken in a net or birds +caught in a snare. + +3. Human life, Koheleth declares, is unsatisfying. He inquired, he says, +into everything that is done by men under the sun (i. 12-16): God has +inflicted on men a restless desire for movement and work[2], yet life is +but a catalogue of fruitless struggles. He gives a number of +illustrations. In his character of king he tried all the bodily +pleasures of life (ii. 1-11): he had houses, vineyards, gardens, parks, +ponds, forests, servants, flocks and herds, treasures of gold and +silver, singers, wives; all these he set himself to enjoy in a rational +way--indeed, he found a certain pleasure in carrying out his designs, +but, when all was done, he surveyed it only to see that it was weary and +unprofitable. Dropping the role of Solomon and speaking as an observer +of life, the author declares (iv. 4) that the struggle for success is +the result of rivalry among men, which has no worthy outcome. The +securing of riches is a fallacious achievement, for often wealth +perishes by some accident (v. 13 f.), or its possessor is unable to +enjoy it (vi. 1-3a), or he has no one to whom to leave it, and he cannot +keep it--naked man comes into the world, naked he goes out. He does not +consider the possibility of deriving enjoyment from wealth by helping +the poor or encouraging learning (this latter, indeed, he looks on as +vanity), and in general he recognizes no obligation on the part of a man +to his fellows. A noteworthy survival of an old belief is found in vi. +3: though a man have the great good fortune to live long and to have +many children, yet, if he have not proper burial the blank darkness of +an untimely birth is better than he: this latter is merely the negation +of existence; the former, it appears to be held, is positive misfortune, +the loss of a desirable place in Sheol, though elsewhere (ix. 5) +existence in Sheol is represented as the negation of real life. It is +not necessary to suppose that the writer has here any particular case in +mind. + +If wealth be thus a vain thing, yet a sage might be supposed to find +satisfaction in wisdom, that is, practical good sense and sagacity; but +this also the author puts aside as bringing no lasting advantage, since +a wise man must finally give up the fruit of his wisdom to someone else, +who may be a fool, and in any case the final result for both fools and +wise men is the same--both are forgotten (ii. 12-23). A particular +instance is mentioned (ix. 13-15) of a beleaguered city saved by a wise +man; but the man happened to be poor, and no one remembered him. The +whole constitution of society, in fact, seems to the sage a lamentable +thing: the poor are oppressed, the earth is full of their cries, and +there is no helper (iv. 1); strange social upheavals may be seen: the +poor[3] set in high places, the rich cast down, slaves on horseback, +princes on foot (x. 5-7). He permits himself a sweeping generalization +(vii. 25-28): human beings as a rule are bad: one may occasionally find +a good man, never a good woman--woman is a snare and a curse. He (or an +editor) adds (vii. 29) that this condition of things is due to social +development: man was created upright (Gen. i. 27; Enoch lxix. 11), but +in the course of history has introduced corrupting complications into +life. + +4. The natural outcome of these experiences of the author is that he +cannot recognize a moral government of the world. He finds, like Job, +that there are good men who die prematurely notwithstanding their +goodness, and bad men who live long notwithstanding their badness (vii. +15), though long life, it is assumed, is one of the great blessings of +man's lot; and in general there is no moral discrimination in the +fortunes of men (viii. 14, ix. 2). + +5. There is no sacredness or dignity in man or in human life: man has no +pre-eminence over beasts, seeing that he and they have the same final +fate, die and pass into the dust, and no one knows what becomes of the +spirit, whether in man's case it goes up to heaven, and in the case of +beasts goes down into Sheol--death is practically the end-all; and so +poor a thing is life that the dead are to be considered more fortunate +than the living, and more to be envied than either class is he who never +came into existence (iv. 2, 3). It is a special grievance that the +wicked when they die are buried with pomp and ceremony, while men who +have acted well are forgotten[4] in the city (viii. 10). + +6. That the author does not believe in a happy or active future life +appears in the passage (iv. 2, 3) quoted above. The old Hebrew view of +the future excluded from Sheol the common activities of life and also +the worship of the national god (Isa. xxxviii. 18); he goes even beyond +this in his conception of the blankness of existence in the underworld. +The living, he says, at least know that they shall die, but the dead +know nothing--the memory of them, their love, hate and envy, perishes, +they have no reward, no part in earthly life (ix. 5, 6); there is +absolutely no knowledge and no work in Sheol (ix. 10). His conclusion is +that men should do now with all their might what they have to do; the +future of man's vital part, the spirit, is wholly uncertain. + +7. His conception of God is in accord with these views. God for him is +the creator and ruler of the world, but hardly more; he is the master of +a vast machine that grinds out human destinies without sympathy with man +and without visible regard for what man deems justice--a being to be +acknowledged as lord, not one to be loved. There can thus be no social +contact between man and God, no communion of soul, no enthusiasm of +service. Moral conduct is to be regulated not by divine law (of this +nothing is said) but by human experience. The author's theism is cold, +spiritless, without influence on life. + +If now the question be asked what purpose or aim a man can have, seeing +that there is nothing of permanent value in human work, an answer is +given which recurs, like a refrain, from the beginning to the end of the +book, and appears to be from the hand of the original author: after +every description of the vanity of things comes the injunction to enjoy +such pleasures as may fall to one's lot (ii. 24, 25, iii. 12, 13, 22, v. +18, 19, viii. 15, ix. 7-10, xi. 7-xii. 7). Elsewhere (ii.), it is true, +it is said that there is no lasting satisfaction in pleasure; but the +sage may mean to point out that, though there is no permanent outcome to +life, it is the part of common-sense to enjoy what one has. The +opportunity and the power to enjoy are represented as being the gift of +God; but this statement is not out of accord with the author's general +position, which is distinctly theistic. All the passages just cited, +except the last (xi. 7-xii. 7), are simple and plain, but the bearing of +the last is obscured by interpolations. Obviously the purpose of the +paragraph is to point out the wisdom of enjoying life in the time of +youth while the physical powers are fresh and strong, and the impotency +of old age has not yet crept in. Omitting xi. 8c, 9b, 10b, xii. 1a, the +passage will read: "Life is pleasant in the bright sunshine--however +long a man may live, he must be cheerful always, only remembering that +dark days will come. Let the young man enjoy all the pleasures of youth, +putting away everything painful, before the time comes when his bodily +powers decay and he can enjoy nothing." To relieve the apparent +Epicureanism of this passage, an editor has inserted reminders of the +vanity of youthful pleasures, and admonitions to remember God and His +judgment. The author, however, does not recommend dissipation, and does +not mean to introduce a religious motive--he offers simply a counsel of +prudence. The exhortation to remember the Creator in the days of youth, +though it is to be retained in the margin as a pious editorial addition, +here interrupts the line of thought. In xii. 1a some critics propose to +substitute for "remember thy Creator" the expression of xi. 9, "let thy +heart cheer thee"; but the repetition is improbable. Others would read: +"remember thy cistern" (Bickell), or "thy well" (Haupt), that is, thy +wife. The wife is so called in Prov. v. 15-19 in an elaborate poetical +figure (the wife as a source of bodily pleasure), in which the reference +is clear from the context; but there is no authority, in the Old +Testament or in other literature of this period, for taking the term as +a simple prose designation of a wife. Nor would this reference to the +wife be appropriate in the connexion, since the writer's purpose is +simply to urge men to enjoy life while they can. The paragraph (and the +original book) concludes with a sustained and impressive figure, in +which the failing body of the old man is compared to a house falling +into decay: first, the bodily organs (xii. 3, 4a): the keepers of the +house (the arms and hands) tremble, the strong men (the legs and perhaps +the backbone) are bent, the grinding women (the teeth) cease to work, +those that look out of the windows (the eyes) are darkened, the +street-doors are shut, the sound of the mill being low (apparently a +summary statement of the preceding details: communication with the outer +world through the senses is cut off, the performance of bodily functions +being feeble); the rest of v. 4 may refer to the old man's inability to +make or hear music: in the house there is no sound of birds[5] or of +singers, there are none of the artistic delights of a well-to-do +household; further (v. 5a) the inmates of the house fear dangers from +all powerful things and persons (the old man is afraid of everything), +the almond tree blossoms (perhaps the hair turns white). The two next +clauses are obscure.[6] Then comes the end: man goes to his everlasting +home; the dust (the body) returns to the earth whence it came (Gen. ii. +7), and the breath of life, breathed by God into the body, returns to +him who gave it. This last clause does not affirm the immortality of the +soul; it is simply an explanation of what becomes of the vital principle +(the "breath of life" of Gen. ii. 7); its positive assertion is not in +accord with the doubt expressed in iii. 21 ("who knows whether the +spirit of man goes upward?"), and it seems to be from another hand than +that of the author of the original book. + +There are other sayings in the book that appear to be at variance with +its fundamental thought. Wisdom is praised in a number of passages (iv. +13, vii. 5, 11, 12, 19, viii. 1, ix. 16, 17, x. 2, 3), though it is +elsewhere denounced as worthless. It may be said that the author, while +denying that wisdom (practical sagacity and level-headedness) can give +permanent satisfaction, yet admits its practical value in the conduct of +life. This may be so; but it would be strange if a writer who could say, +"in much wisdom is much grief," should deliberately laud wisdom. The +question is not of great importance and may be left undecided. It may be +added that there are in the book a number of aphorisms about fools (v. +3[4], vii. 5, 6, x. 1-3, 12-15) quite in the style of the book of +Proverbs, some of them contrasting the wise man and the fool; these +appear to be the insertions of an editor. Further, it may be concluded +with reasonable certainty that the passages that affirm a moral +government of the world are additions by pious editors who wished to +bring the book into harmony with the orthodox thought of the time. Such +assertions as those of ii. 26 (God gives joy to him who pleases him, and +makes the sinner toil to lay up for the latter), viii. 12 (it shall be +well with those that fear God, but not with the wicked), xii. 13 f. +(man's duty is simply to obey the commands of God, for God will bring +everything into judgment) are irreconcilable with the oft-repeated +statement that there is no difference in the earthly lots of the +righteous and the wicked, and no ethical life after death. + +Many practical admonitions and homely aphorisms are scattered through +the book: iv. 5, quiet is a blessing; iv. 9-12, two are better than one; +iv. 17 (Eng. v. 1), be reverent in visiting the house of God (the temple +and the connected buildings)--to listen (to the service of song or the +reading of Scripture) is better than to offer a foolish (thoughtless) +sacrifice; v. 1 (2), be sparing of words in addressing God; v. 1-5 +(2-6), pay your vows--do not say to the priest's messenger that you made +a mistake; vii. 2-4, sorrow is better than mirth; vii. 16-18, be not +over-righteous (over-attentive to details of ritual and convention) or +over-wicked (flagrantly neglectful of established beliefs and customs); +here "righteous" and "wicked" appear to be technical terms designating +two parties in the Jewish world of the 2nd and 1st centuries B.C., the +observers and the non-observers of the Jewish ritual law; these parties +represent in a general way the Pharisees and the Sadducees; viii. 2-4, +x. 20, it is well to obey kings and to be cautious in speaking about +them, for there are talebearers everywhere; vii. 20, no man is free from +sin; vii. 21, do not listen to all that you may overhear, lest you hear +yourself ill spoken of; ix. 4, a living dog is better than a dead lion; +xi. 1-6, show prudence and decision in business; do not set all your +goods on one venture; act promptly and hope for the best. At the close +of the book (xii. 9-12) there are two observations that appear to be +editorial recommendations and cautions. First, Koheleth is endorsed as +an industrious, discriminating and instructive writer. Possibly this is +in reply to objections that had been made to what he had written. There +follows an obscure passage (v. 11) which seems to be meant as a +commendation of the teaching of the sages in general: their words are +said to be like goads (inciting to action) and like nails driven in a +building (giving firmness to character); they issue from masters of +assemblies,[7] heads of academies (but not of the Sanhedrin). The +succeeding clause "they are given from one shepherd" may refer to a +collection or revision by one authoritative person, but its relevancy is +not obvious. The "shepherd" cannot be God (Gen. xlix. 24; Ps. xxiii. 1); +the poetical use of the word would not be appropriate here. The clause +is possibly a gloss, a comment on the preceding expression. A caution +against certain books is added (v. 12), probably works then considered +harmful (perhaps philosophic treatises), of which, however, nothing +further is known. + +_Composition of the Book._--If the analysis given above is correct, the +book is not a unit; it contains passages mutually contradictory and not +harmonizable. Various attempts have been made to establish its unity. +The hypothesis of "two voices" is now generally abandoned; there is no +indication of a debate, of affirmations and responses. A more plausible +theory is that the author is an honest thinker, a keen observer and +critic of life, who sees that the world is full of miseries and unsolved +problems, regards as futile the attempts of his time to demonstrate an +ethically active future life, and, recognizing a divine author of all, +holds that the only wise course for men is to abandon the attempt to get +full satisfaction out of the struggle for pleasure, riches and wisdom, +and to content themselves with making the best of what they have. This +conception of him is largely true, as is pointed out above, but it does +not harmonize the contradictions of the book, the discrepancies between +the piety of some passages and the emotional indifference toward God +shown in others. Other of the Biblical Wisdom books (Job, Proverbs) are +compilations--why not this? It is not necessary to multiply authors, as +is done, for example, by Siegfried, who supposes four principal writers +(a pessimistic philosopher, an Epicurean glossator, a sage who upholds +the value of wisdom, and an orthodox editor) besides a number of +annotators; it is sufficient to assume that several conservative scribes +have made short additions to the original work. Nor is it worth while to +attempt a logical or symmetrical arrangement of the material. It has +been surmised (by Bickell) that the sheets of the original codex became +disarranged and were rearranged incorrectly;[8] by other critics +portions of the book are transferred hither and thither; in all cases +the critic is guided in these changes by what he conceives to have been +the original form of the book. But it is more probable that we have it +in the form in which it grew up--a series of observations by the +original author with interspersed editorial remarks; and it is better to +preserve the existing form as giving a record of the process of growth. + +_Date._--As to the date of the book, though there are still differences +of opinion among scholars, there is a gradual approach to a consensus. +The Solomonic authorship has long since been given up: the historical +setting of the work and its atmosphere--the silent assumption of +monotheism and monogamy, the non-national tone, the attitude towards +kings and people, the picture of a complicated social life, the strain +of philosophic reflection--are wholly at variance with what is known of +the 10th century B.C. and with the Hebrew literature down to the 5th or +4th century B.C. The introduction of Solomon, the ideal of wisdom, is a +literary device of the later time, and probably deceived nobody. The +decisive considerations for the determination of the date are the +language, the historical background and the thought. The language +belongs to the post-classical period of Hebrew. The numerous Aramaisms +point to a time certainly not earlier than the 4th century B.C., and +probably (though the history of the penetration of Aramaic into Hebrew +speech is not definitely known) not earlier than the 3rd century. More +than this, there are many resemblances between the dialect of Koheleth +and that of Mishna. Not only are new words employed, and old words in +new significations, but the grammatical structure has a modern +stamp--some phrases have the appearance of having been translated out of +Aramaic into Hebrew. By about the beginning of our era the Jews had +given up Hebrew and wrote in Aramaic; the process of expulsion had been +going on, doubtless, for some time; but comparison with the later extant +literature (_Chronicles_, the Hebrew _Ecclesiasticus_ or _Ben-Sira_, +_Esther_) makes it improbable that such Hebrew as that of Koheleth would +have been written earlier than the 2nd century B.C. (for details see +Driver's _Introduction_). The general historical situation, also, +presupposed or referred to, is that of the period from the year 200 B.C. +to the beginning of our era; in particular, the familiar references to +kings as a part of the social system, and to social dislocations +(servants and princes changing places, x. 7), suggest the troublous time +of the later Greek and the Maccabean rulers, of which the history of +Josephus gives a good picture. + +The conception of the world and of human life as controlled by natural +law, a naturalistic cosmos, is alien not only to the prophetic and +liturgical Hebrew literature but also to Hebrew thought in general. +Whether borrowed or not, it must be late; and its resemblance to Greek +ideas suggests Greek influence. The supposition of such influence is +favoured by some critics (Tyler, Plumptre, Palm, Siegfried, Cheyne in +his _Jewish Religious Life after the Exile_, and others), rejected by +some (Zeller, Renan, Kleinert and others). This disagreement comes +largely from the attempts made to find definitely expressed Greek +philosophical dogmas in the book; such formulas it has not, but the +general air of Greek reflection seems unmistakable. The scepticism of +Koheleth differs from that of Job in quality and scope: it is deliberate +and calm, not wrung out by personal suffering; and it relates to the +whole course and constitution of nature, not merely to the injustices of +fortune. Such a conception has a Greek tinge, and would be found in +Jewish circles, probably, not before the 2nd century B.C. + +A precise indication of date has been sought in certain supposed +references or allusions to historical facts. The mention of persons who +do not sacrifice or take oaths (ix. 2) is held by some to point to the +Essenes; if this be so, it is not chronologically precise, since we have +not the means of determining the beginning of the movement of thought +that issued in Essenism. So also the coincidences of thought with +_Ben-Sira_ (_Ecclesiasticus_) are not decisive: cf. iii. 14 with _B.S._ +xviii. 6; v. 2-6 (3-7) with _B.S._ xxxiv. 1-7; vii. 19 with _B.S._ +xxxvii. 14; x. 8 with _B.S._ xxvii. 26a; xi. 10 with _B.S._ xxx. 21; +xii. 10, 11 with _B.S._ xxxix. 2 ff., xii. 13 with _B.S._ xliii. 27; if +there be borrowing in these passages, it is not clear on which side it +lies; and it is not certain that there is borrowing--the thoughts may +have been taken independently by the two authors from the same source. +In any case, since _Ben-Sira_ belongs to about 180 B.C., the date of +Koheleth, so far as these coincidences indicate it, would not be far +from 200 B.C. The contrast made in x. 16 f. between a king who is a boy +and one who is of noble birth may allude to historical persons. The +antithesis is not exact; we expect either "boy and mature man" or +"low-born and high-born." The "child" might be Antiochus V. (164 B.C.), +or Ptolemy V., Epiphanes (204 B.C.), but the reference is too general to +be decisive. The text of the obscure passage iv. 13-16 is in bad +condition, and it is only by considerable changes that a clear meaning +can be got from it. The two personages--the "old and foolish king" and +the "poor and wise youth"--have been supposed (by Winckler) to be +Antiochus Epiphanes (175-164 B.C.) and Demetrius (162-150 B.C.), or (by +Haupt) Antiochus and the impostor Alexander Balas (150-146 B.C.), or (by +others) Demetrius and Alexander; in favour of Alexander as the "youth" +it may be said that he was of obscure origin, was at first popular, and +was later abandoned by his friends. Such identifications, however, do +not fix the date of the book precisely; the author may have referred to +events that happened before his time. The reign of Herod, a period of +despotism and terror, and of strife between Jewish religious parties, is +preferred by some scholars (Graetz, Cheyne and others) as best answering +to the social situation depicted in the book, while still others (as +Renan) decide for the reign of Alexander Jannaeus (104-78 B.C.). The +data are not numerous and distinct enough to settle the question beyond +determining general limits: for reasons given above the book can hardly +have been composed before about 200 B.C., and if, as is probable, a +Septuagint translation of it was made (though the present Septuagint +text shows the influence of Aquila), it is to be put earlier than 50 +B.C. Probably also, its different parts are of different dates. + +Of the author nothing is known beyond the obvious fact that he was a man +of wide observation and philosophic thought, of the Sadducean type in +religion, but non-Jewish in his attitude toward life. He was, doubtless, +a man of high standing, but neither a king nor a high-priest, certainly +not the apostate priest Alcimus (1 Macc. vii. ix.); nor was he +necessarily a physician--there are no details in ch. xii. or elsewhere +that any man of good intelligence might not know. The book is written in +prose, some of which is rhythmical, with bits of verse here and there: +thus i. 2-11 is balanced prose, 12-14 plain prose, 15 a couplet, i. +16-ii. 25 simple prose, vii. contains a number of poetical aphorisms, +and so on. Some of the verses are apparently from the author, some from +editors. + +The fortunes of the book are not known in detail, but it is clear that +its merciless criticism of life and its literary charm made it popular, +while its scepticism excited the apprehensions of pious conservatives. +Possibly the _Wisdom of Solomon_ (c. 50 B.C.) was written partly as a +reply to it. The claim of sacredness made for it was warmly contested by +some Jewish scholars. In spite of the relief afforded by orthodox +additions, it was urged that its Epicurean sentiments contradicted the +Torah and favoured heresy. Finally, by some process of reasoning not +fully recorded, the difficulties were set aside and the book was +received into the sacred canon; Jerome (on Eccl. xii. 13, 14) declares +that the decisive fact was the orthodox statement at the end of the +book: the one important thing is to fear God and keep His commandments. +The probability is that the book had received the stamp of popular +approbation before the end of the 1st century of our era, and the +leading men did not dare to reject it. It is not certain that it is +quoted in the New Testament, but it appears to be included in Josephus' +list of sacred books. + + LITERATURE.--For the older works see Zoeckler (in Lange's _Comm._); for + Jewish commentaries see Zedner, _Cat. of Heb. books in Libry. of Brit. + Mus._ (1867), and for the history of the interpretations, C.D. + Ginsburg, _Coheleth_ (1861). _Introductions_ of A. Kuenen, S.R. + Driver, Cornhill, Koenig. Articles in Herzog-Hauck, _Realencykl._ (by + P. Kleinert); Hastings, _Dict. Bible_ (by A.S. Peake); T.K. Cheyne, + _Encycl. Bibl._ (by A.B. Davidson); _Jew. Encycl._ (by D.S. + Margoliouth). Commentaries: F. Hitzig (1847); C.D. Ginsburg (1861); H. + Graetz (1871); Tyler (1874); Delitzsch (1875); E.H. Plumptre (1881); + C.H.H. Wright (1883); Nowack, revision of Hitzig (1883); Volck (in + Strack u. Zoeckler's _Kurzgef. Komm._, 1889); Wildeboer (in Marti's + _Kurzer Hand-Comm._, 1898); C. Siegfried (in W. Nowack's _Handkomm._, + 1898); Oort (in _De Oude Test._, 1899). Other works: C. Taylor, _Dirge + of Koh._ (1874); Wuensche, _Midrash_ on Koh. (in his _Biblioth. + rabbin._, 1880); E. Renan, _L'Ecclesiaste_ (1882); Bickell, _Der + Prediger_ (1884) and _Kohel.-Untersuchungen_ (1886; Engl. by E.J. + Dillon, _Sceptics of Old Test._, 1895); Schiffer, _Das Buch Koh. nach + d. Auffass. d. Weisen d. Talmuds_, &c. (1884); A. Palm, _Qoh. u. d. + nach-aristotel. Philosophie_ (1885) and _Die Qoh.-Lit._ (1886); E. + Pfleiderer, _Die Phil. d. Heraklit_, &c. (1886); Cheyne, _Job and + Solomon_ (1887) and _Jew. Relig. Life_, &c. (1898); W. Euringer, _Der + Masorahtext d. Koh._ (1890); W.T. Davison, _Wisdom-Lit. of Old Test._ + (1894); H. Winckler, in his _Altorient. Forschungen_ (1898); J.F. + Genung, _Words of Koh._ (Boston, Mass., 1904); P. Haupt, + _Ecclesiastes_ (Baltimore, 1905). The rabbinical discussions of the + book are mentioned in _Shabbath_, 30b; _Megilla_, 7a; _Eduyoth_, v. 3; + _Mishna Yadaim_, iii. 5, iv. 6; _Midrash Koheleth_ (on xi. 9), _Aboth + d' Rab. Nathan_, i. (C. H. T.*) + + +FOOTNOTES: + + [1] The Hebrew has the definite article, "the whole," [Greek: to + pan]. + + [2] In fact, he suggests, a curse, as in Gen. iii. 17-19, though with + a wider sweep than that passage has in mind. + + [3] The text has "folly," but the parallelism and v. 7 point to + social, not intellectual, conditions, and a slight change ([Hebrew: + haskel] for [Hebrew: misken]) gives the sense "poor." + + [4] The Septuagint has less well: "They (the wicked) are praised in + the city." + + [5] The clause is obscure; literally "he (or, one) rises at (?) the + voice of the bird," usually understood to refer to the old man's + inability to sleep in the morning; but this is not a universal trait + of old age, and besides, a reference to affairs in the house is to be + expected; the Hebrew construction also is of doubtful correctness. A + change of the Hebrew text seems necessary; possibly we should read + [Hebrew: ishpal kol], "low is the voice," instead of [Hebrew: yakum + lekol] "he rises up at the voice." + + [6] The second is perhaps to be read: "the caper-berry blooms" (white + hair); usually "the caper-berry loses its appetizing power"; Eng. + Auth. Vers. "desire shall fail." For the meaning of the word _abyona_ + ("caper-berry," not "desire" or "poverty"), see art. by G.F. Moore in + _Journ. of Bibl. Lit._ x. 1 (Boston, Mass., 1891). + + [7] This is the Talmudic understanding of the Hebrew expression + (Jerus. Sanhed. 10, 28a, cf. Sanhed. 12a; see Ecclus. xxxix. 2). + There is no good authority for the renderings "collectors of maxims," + "collections of maxims." + + [8] It is not certain that the codex form was in use in Palestine or + in Egypt as early as the 2nd or the 1st century B.C. + + + + +ECCLESIASTICAL COMMISSIONERS, in England, a body corporate, whose full +title is "Ecclesiastical and Church Estates Commissioners for England," +invested with very important powers, under the operation of which +extensive changes have been made in the distribution of the revenues of +the Established Church. Their appointment was one of the results of the +vigorous movements for the reform of public institutions which followed +the Reform Act of 1832. In 1835 two commissions were appointed "to +consider the state of the several dioceses of England and Wales, with +reference to the amount of their revenues and the more equal +distribution of episcopal duties, and the prevention of the necessity of +attaching by commendam to bishoprics certain benefices with cure of +souls; and to consider also the state of the several cathedral and +collegiate churches in England and Wales, with a view to the suggestion +of such measures as might render them conducive to the efficiency of the +established church, and to provide for the best mode of providing for +the cure of souls, with special reference to the residence of the clergy +on their respective benefices." And it was enacted by an act of 1835 +that during the existence of the commission the profits of dignities and +benefices without cure of souls becoming vacant should be paid over to +the treasurer of Queen Anne's Bounty. In consequence of the +recommendation of these commissioners, a permanent commission was +appointed by the Ecclesiastical Commissioners Act 1836 for the purpose +of preparing and laying before the king in council such schemes as +should appear to them to be best adapted for carrying into effect the +alterations suggested in the report of the original commission and +recited in the act. The new commission was constituted a corporation +with power to purchase and hold lands for the purposes of the act, +notwithstanding the statutes of mortmain. The first members of the +commission were the two archbishops and three bishops, the lord +chancellor and the principal officers of state, and three laymen named +in the act. + +The constitution of the commission was amended by the Ecclesiastical +Commissioners Act 1840 and subsequent acts, and now consists of the two +archbishops, all the bishops, the deans of Canterbury, St Paul's and +Westminster, the lord chancellor, the lord president of the council, the +first lord of the treasury, the chancellor of the exchequer, the home +secretary, the lord chief justice, the master of the rolls, two judges +of the admiralty division, and certain laymen appointed by the crown and +by the archbishop of Canterbury. The lay commissioners are required to +be "members of the Church of England, and to subscribe a declaration to +that effect." The crown also appoints two laymen as church estates +commissioners, and the archbishop of Canterbury one. These three are the +joint treasurers of the commission, and constitute, along with two +members appointed by the commission, the church estates committee, +charged with all business relating to the sale, purchase, exchange, +letting or management of any lands, tithes or hereditaments. The +commission has power to make inquiries and examine witnesses on oath. +Five commissioners are a quorum for the transaction of business, +provided two of them are church estates commissioners; two +ecclesiastical commissioners at least must be present at any proceeding +under the common seal, and if only two are present they can demand its +postponement to a subsequent meeting. The schemes of the commission +having, after due notice to persons affected thereby, been laid before +the king in council, may be ratified by orders, specifying the times +when they shall take effect, and such orders when published in the +_London Gazette_ have the same force and effect as acts of parliament. + + The recommendations of the commission recited in the act of 1836 are + too numerous to be given here. They include an extensive rearrangement + of the dioceses, equalization of episcopal income, providing + residences, &c. By the act of 1840 the fourth report of the original + commissioners, dealing chiefly with cathedral and collegiate churches, + was carried into effect, a large number of canonries being suspended, + and sinecure benefices and dignities suppressed. + + The emoluments of these suppressed or suspended offices, and the + surplus income of the episcopal sees, constitute the fund at the + disposal of the commissioners. By an act of 1860, on the avoidance of + any bishopric or archbishopric, all the land and emoluments of the + see, except the patronage and lands attached to houses of residence, + become, by order in council, vested in the commissioners, who may, + however, reassign to the see so much of the land as may be sufficient + to secure the net annual income named for it by statute or order. All + the profits and emoluments of the suspended canonries, &c., pass over + to the commissioners, as well as the separate estates of those + deaneries and canonries which are not suspended. Out of this fund the + expenses of the commission are to be paid, and the residue is to be + devoted to increasing the efficiency of the church by the augmentation + of the smaller bishoprics and of poor livings, the endowment of new + churches, and employment of additional ministers. + + The substitution of one central corporation for the many local and + independent corporations of the church, so far at least as the + management of property is concerned, was a constitutional change of + great importance, and the effect of it undoubtedly was to correct the + anomalous distribution of ecclesiastical revenues by equalizing + incomes and abolishing sinecures. At the same time it was regarded as + having made a serious breach in the legal theory of ecclesiastical + property. "The important principle," says Cripps, "on which the + inviolability of the church establishment depends, that the church + generally possesses no property as a corporation, or which is + applicable to general purposes, but that such particular + ecclesiastical corporation, whether aggregate or sole, has its + property separate, distinct and inalienable, according to the + intention of the original endowment, was given up without an effort to + defend it" (_Law Relating to the Church and Clergy_, p. 46). + + + + +ECCLESIASTICAL JURISDICTION. This phrase in its primary sense imports +not jurisdiction over ecclesiastics, but jurisdiction exercised by +ecclesiastics over other ecclesiastics and over the laity. +"Jurisdiction" is a word borrowed from the jurists which has acquired a +wide extension in theology, wherein, for example, it is frequently used +in contradistinction to "order," to express the right to administer +sacraments as something superadded to the _power_ to celebrate them. So +it is used to express the territorial or other limits of ecclesiastical, +executive or legislative authority. Here it is used, in the limited +sense defined by an American Court, as "the authority by which judicial +officers take cognizance of and decide causes." + + + Origin of ecclesiastical jurisdiction. + +Such authority in the minds of lay Roman lawyers who first used this +word "jurisdiction" was essentially temporal in its origin and in its +sphere. The Christian Church transferred the notion to the spiritual +domain as part of the general idea of a Kingdom of God correlative, on +the spiritual side of man upon earth, to the powers, also ordained of +God, who had dominion over his temporal estate (see CANON LAW). As the +Church in the earliest ages had executive and legislative power in its +own spiritual sphere, so also it had "judicial officers," "taking +cognizance of and deciding causes." Only before its union with the +State, its power in this direction, as in others, was merely over the +spirits of men. Coercive temporal authority over their bodies or estates +could only be given by concession from the temporal prince. Moreover, +even spiritual authority over members of the Church, i.e. baptized +persons, could not be exclusively claimed as _of right_ by the Church +tribunals, if the subject matter of the cause were purely temporal. On +the other hand, it is clear that _all_ the faithful were subject to +these courts (when acting within their own sphere), and that, in the +earliest times, no distinction was made in this respect between clergy +and laity. + +The fundamental principle of ecclesiastical jurisdiction with its +"sanction" of excommunication will be found in Christ's words in Matt. +xviii. 15-18. A very early example of criminal spiritual jurisdiction +exercised by St Paul is found in the case of the incestuous Corinthian +(1 Cor. v.). We find later the same apostle exercising like jurisdiction +in the cause of Hymenaeus and Alexander (1 Tim. i. 20). After the time +of the Apostles, we find this criminal jurisdiction exercised by the +bishops individually over their respective "subjects"--doubtless with +the advice of their presbyters according to the precept of St Ignatius +(c. 110). As neighbouring dioceses coalesced into "provinces" and +provinces into larger districts (corresponding to the civil "dioceses" +of the later Roman Empire), the provincial synods of bishops and the +synods of the larger districts acquired a criminal jurisdiction, still +purely spiritual, of their own. At first this was "original" and mainly +(although not exclusively) over bishops (of the province or larger +district). The beginnings of an appellate jurisdiction in the cases of +clerics and laymen may be traced before the conversion of the Empire. +The bishop over whom the synod of neighbouring bishops had exercised +jurisdiction had no formal right of appeal; but sometimes bishops in +other parts of the Church would refuse to acknowledge the local +synodical sentence and would communicate with a bishop whom they deemed +unjustly deposed. The theory, as expressed in legal phrase by St Cyprian +in the 3rd century, was that the apostolic power of delegated +sovereignty from the Lord, alike legislative and judicial, was held in +joint-tenancy by the whole body of Catholic bishops. In both capacities, +however, a certain undefined pre-eminence was conceded to the occupants +of "Apostolic" sees, i.e. sees traditionally founded by Apostles, or of +sees with a special secular position. + +Even before the edict of Milan, at least as early as the latter half of +the 3rd century, the spiritual sentences of deposition from office had +sometimes indirect temporal consequences recognized by the secular +courts. The classical example is the case of Paul of Samosata, bishop of +Antioch. It would seem that, in the intervals of persecution, some +rights of property were recognized in the Christian Church and its +officers; although the Church was an illegal society. After some +previous abortive trials, Paul of Samosata was deposed and +excommunicated, in 269, by a great synod of the Antiochene district. +Paul, notwithstanding his deposition, kept possession of the episcopal +residence. The local church sought recovery of it before the tribunals +of the Empire. The judicial authorities requested a rescript from the +emperor Aurelian for the decision of the cause. Aurelian referred the +matter to the bishop of Rome and the bishops of Italy, who gave their +award in favour of the Antiochene Church. + + + Temporal Jurisdiction of the Church. + +Side by side with this which we may call criminal jurisdiction--none the +less real or coercive because its sanctions were purely spiritual--there +grew up a quasi-jurisdiction in causes entirely temporal, based upon the +free consent of the parties to accept the arbitration of the bishop. +This system had also its roots in the New Testament (see Matt, xviii. +15-17 and 1 Cor. vi. 1-8). In the matter of criminal jurisdiction we +paused for a moment at the edict of Milan; but we may at once trace this +second or civil branch of episcopal judicature or quasi-judicature down +as far as the reign of Charlemagne, when it underwent a fundamental +change, and became, if _either_ litigant once chose, no longer a matter +of consent but of right. + +Constantine decreed that judgment in causes might be passed by bishops +when litigants preferred their adjudication to that of the secular +courts (see his epistle to the Numidian bishops and _Cod. Theodos. Tit. +de Episcopis_). The episcopal judgment was to be equivalent to that of +the emperor and irreversible, and the civil authorities were to see to +its execution. Saints Ambrose and Augustine both spent days in deciding +temporal causes. Honorius, in the West, at the end of the 4th century, +made a constitution providing that if any desired to litigate before the +bishops they should not be forbidden, but that in civil matters the +prelates should render judgment in the manner of arbitrators by consent +(_Cod._ 1, _Tit._ iv.). Where the faithful had had recourse to the +bishop, no appeal was to be allowed, and the judges were to command +execution of the episcopal decree. A quarter of a century later, +however, Valentinian III. in the West expressly provided that bishops +were not to be permitted to be judges (that is, of course, in temporal +causes), save by the consent of the parties. This legislation was, +substantially, adopted by Justinian. + +On the revival of the Western Empire, however, Charlemagne, in the +beginning of the 9th century, under the mistaken belief that he was +following the authority of Constantine I. and Theodosius I., took a +great step forward, by which the bishop ceased to be a mere legally +indicated arbitrator by consent in secular causes, and became a real +judge. By a capitulary he provided that either litigant, without the +consent of the other party, and not only at the beginning of a suit but +at any time during its continuance, might take the cause from lay +cognizance and transfer it to the bishop's tribunal. He re-enacted the +prohibition of appeal. + +It should be remembered that, from the latter part of the 3rd century, +the leading bishops had generally been trained in secular learning. St +Cyprian, St Ambrose and St Augustine, St Paulinus of Nola and St John +Chrysostom had practised law as teachers or advocates. St Ambrose and St +Paulinus had even held high administrative and judicial offices. + + + Roman empire from Constantine. + +To return to the evolution of ecclesiastical jurisdiction from the time +of Constantine. With the "Nicene period" came a great development on the +criminal side. A system begins to be formed, and the secular arm +supports the decrees of the Church. The first trace of system is in the +limited right of appeal given by the first oecumenical council of Nicaea +and its provision that episcopal sentences or those of provincial synods +on appeal were to be recognized throughout the world. The fifth canon +provides that those, whether clerics or laymen, who are cut off from +communion in any particular province are not to be admitted thereto +elsewhere. Still examination must be had whether persons have been +expelled from the congregation by any episcopal small-mindedness +([Greek: mikropsychia]), or contentious spirit, or such-like harshness +([Greek: aedia]). That this may be conveniently inquired into, synods +are to be held, three in every year, in each province, and questions of +this kind examined. There is to be no "stay of execution"; the episcopal +sentence is to prevail until the provincial synod otherwise decide. It +will be noticed that as yet no provision is made for appeals by +_bishops_ from provincial synods sitting in first instance. + +The edicts of Milan had only admitted the Christian Church among the +number of lawful religions; but the tendency (except in the time of +Julian) was towards making it the only lawful religion. Hence the +practice, immediately after Nicaea I., of superadding banishment by the +emperor to synodical condemnation. The dogmatic decrees of Nicaea I. +were at once enforced in this temporal manner. On the other hand, the +Arian reaction at court worked its objects (see Pusey, _Councils of the +Church_) by using the criminal spiritual jurisdiction of synods against +the Catholics--often packing the synods for the purpose. The acts of +councils of this age are full of the trials of bishops not only for +heresy but for immorality and common law crimes. The accusations are +frequently unfounded; but the trials are already conducted in a certain +regular forensic form. The secular authorities follow the precedent of +Nicaea I. and intervene to supplement the spiritual sentence by +administrative penalties. Sometimes an imperial officer of high rank +(as, e.g. a "count") is present at the synod, as an assessor to maintain +order and advise upon points of procedure. Leading examples may be found +in the various prosecutions of St Athanasius, in whose case also there +is the germ of an appeal, _tanquam ab abusu_. It has been contended +that, according to later and more formulated jurisprudence, such an +appeal would have lain, since the trial at Tyre was not concerned with +purely spiritual matters (see the case in Hefele, _Councils_, in loc.). + +The trial of St Athanasius led to extensions of the right of appeal. +This was favoured by the development of the greater sees into positions +of great administrative dignity, shortly to be called "patriarchal." A +synod was held at Rome, attended by bishops from various regions, which +reversed the original judgment of the synod of Tyre which had condemned +Athanasius. A much larger synod at Antioch, gathered only from the East, +on the other hand, confirmed that judgment. This last synod did +something to systematize the criminal procedure of the Church, and its +legislation has been always received. + +This legislation marks another step forward. Deposition of a bishop by a +synod, or of a priest or deacon by his bishop, is to take effect even +pending an appeal, and a cleric continuing his functions after sentence +in first instance is to lose all right of appeal. The appeal given by +Nicaea I. to clerics and laymen from episcopal excommunications is +extended. The synod may restore them if convinced of the justice of +their cause (and not merely in cases of [Greek: aedia]). A bishop may +appeal to a great assembly of bishops. Any bishop, priest or deacon +"importuning" the emperor, instead of exerting his right of appeal to +synods, is to lose all right of appeal and never to be restored or +pardoned. If a provincial synod be divided as to the guilt of a bishop, +the metropolitan is to convene bishops from the neighbouring provinces +to decide the cause jointly with the bishops of the original province. + +A few years later, in 347, the council of Sardica, a council of +practically the whole West save Africa, reversed Tyre and acquitted St +Athanasius after a full judicial inquiry. This council endeavoured to +set up a system of appeals in the case of bishops, in which the see of +Rome was made to play a great part. "Out of honour to the memory of St +Peter," a condemned bishop may ask the intervention of Rome. If this be +done, the synod of first instance is to send letters to Julius, bishop +of Rome. If that prelate think the cause should be heard again, he is to +appoint judges; if otherwise, the original judgment is to be confirmed. +Pending appeal, the appellant's see is not to be filled up. The judges +appointed by the bishop of Rome to hear the appeal are to be from the +neighbouring provinces. The appellant may, however, request that bishop +to send priests from his side to sit with the synod of appeal. If such +priests are sent, they are to preside in the court of appeal. These +canons were always repudiated in the East, and when, sixty years +afterwards, they were, for the first time, heard of in Africa, they were +repudiated there also. + +A rescript of Gratian in 378 empowered the bishop of Rome to judge +bishops with the assistance of six or seven other bishops or, in the +case of a metropolitan, of fifteen comprovincial bishops. A bishop +refusing to come to Rome was to be brought there by the civil power. The +rescript, however, was not incorporated in the Codes and perhaps was +only a temporary measure. + +The tendency to give pre-eminence to Rome appears again in an imperial +letter to St Flavian, who, in the judgment of the East, was bishop of +Antioch, but who was rejected by the West and Egypt, summoning him to +Rome to be there judged by the bishops of the imperial city--a summons +which St Flavian did not obey (Tillemont, _Mem. Ecc._). In Africa in the +beginning of the 5th century Apiarius, a priest who had been deposed by +the bishop of Sicca for immorality, and whose deposition had been +affirmed by the "provincial synod," instead of further appealing to a +general synod of Africa, carried his appeal to Pope Zosimus. The pope +received the appeal, absolved him and restored him to the rank of +priest, and sent a bishop and two priests as legates to Africa with +instructions to them to hear the cause of Apiarius anew and for +execution of their sentence to crave the prefect's aid; moreover, they +were to summon the bishop of Sicca to Rome and to excommunicate him, +unless he should amend those things which the legates deemed wrong. The +upshot of a long conflict was that the papal claim to entertain appeals +from Africa by priests and deacons was rejected by the African bishops, +who in their final synodical epistle also repudiate in terms any right +of appeal by African _bishops_ to "parts beyond the seas" (see Hefele, +_Councils_, bk. viii.). + +The story of the administrative development of the Church in the 5th +century is mainly the story of the final emergence and constitution of +the great "patriarchates," as authorities superior to metropolitans and +provincial synods. In consequence of the occupants of the thrones of +Constantinople and Alexandria falling successively into opposite +heresies, the question arose how "patriarchs" were to be judged. In both +cases, as it seems, an attempt was made by the bishop of Rome to depose +the erring patriarch by his authority as primate of Christendom, acting +in concert with a Western synod. In both cases, apparently, an +oecumenical synod ignored the Roman deposition and judged the alleged +offences of the respective patriarchs in first and last instance. The +third and fourth oecumenical synods (Ephesus, 431; Chalcedon, 451) were +primarily tribunals for the trials of Nestorius and Dioscorus; it was +secondarily that they became organs of the universal episcopate for the +definition of the faith, or legislative assemblies for the enactment of +canons. Nothing is more remarkable than their minute care as to +observance of rules of procedure. In both cases, imperial assessors were +appointed. At Ephesus the Count Candidian was commissioned to maintain +order, but took little part in the proceedings. At Chalcedon, on the +other hand, the imperial commissioners decided points of order, kept the +synod to the question, took the votes and adjourned the court. But the +synod alone judged and pronounced sentence. No oecumenical synod has +tried a patriarch of Old Rome while yet in the flesh. The fifth +oecumenical council came nearest to so doing, in the case of Vigilius. +That pope, although in Constantinople, refused to attend the sittings of +the council. He was cited three times, in the canonical manner, and upon +not appearing was threatened in the third session with anathema (Hefele, +_Councils_, sect. 268 _ad fin._). He was not, however, charged with +direct heresy, as were Nestorius and Dioscorus, and the synod seems to +have hesitated to deal stringently with the primate of Christendom. In +the seventh session it accepted the suggestion of Justinian, merely to +order the name of Vigilius to be removed from the liturgical prayers, at +the same time expressing its desire to maintain unity with the see of +Old Rome (Hefele, sect. 273). After the council, Justinian banished the +pope to Egypt, and afterwards to an island, until he accepted the +council, which he ultimately did (ib. 276). The sixth oecumenical synod +decreed that the dead pope Honorius should be "cast out from the holy +Catholic Church of God" and anathematized, a sentence approved by the +reigning pope Leo II. and affirmed by the seventh oecumenical synod in +787. + +The constitution of the patriarchal system resulted in the recognition +of a certain right of appeal to Rome from the larger part of the West. +Britain remained outside that jurisdiction, the Celtic churches of the +British islands, after those islands were abandoned by the Empire, +pursuing a course of their own. In the East, Constantinople, from its +principality, acquired special administrative pre-eminence, naturally +followed, as in the case of "old Rome," by judicial pre-eminence. An +example of this is found in the ninth canon of Chalcedon, which also +illustrates the enforcement upon a clerical plaintiff in dispute with a +brother cleric of that recourse to the arbitration of their +ecclesiastical superior already mentioned. The canon provides that any +clerk having a complaint against another clerk must not pass by his own +bishop and turn to secular tribunals, but first lay bare his cause +before him, so that by the sentence of the bishop himself the dispute +may be settled by arbitrators acceptable to both parties. Any one acting +against these provisions shall be subject to canonical penalties. If any +clerk have a complaint against his own bishop, he shall have his cause +adjudicated upon by the synod of the province. But if a bishop or clerk +have a difference with the metropolitan of his province let him bring it +before the exarch of the "diocese" (i.e. the larger district answering +to the civil "diocese"), or before the royal see of Constantinople, who +shall do justice upon it. An "exarch" means properly a superior +metropolitan having several provinces under him. In the next century +Justinian (_Nov._ 123, c. 22) put the other patriarchates on the same +footing as Constantinople. In c. 21 he gives either plaintiff or +defendant an appeal within ten days to the secular judge of the locality +from the bishop's judgment. If there be no appeal, that judge is to give +execution to the episcopal award. The growth of a special "original" +jurisdiction at Constantinople, which perhaps developed earlier than +the corresponding institution at Rome, may be traced to the fact that +bishops from all parts were constantly in Constantinople. The bishop of +Constantinople, even before he became properly "patriarch," would often +assemble a synod from these visiting bishops, which acquired the +technical name of [Greek: synodos endemousa], the synod of sojourners. +This synod frequently decided questions belonging to other +patriarchates. + +The criminal jurisdiction thus exercised was generally speaking +unlimited. It must be remembered that the _forum externum_ of the +ecclesiastical jurisdiction, in the sense in which we now use the +phrase, of a judge deciding causes, was not then clearly marked off from +the _forum internum_, or what afterwards came to be called the "tribunal +of penance" (see Van Espen, _Jus ecc. univ._ pars iii. tit. iv. c. 1). +Ecclesiastical proceedings by way of prosecution are called "criminal," +but they are primarily _pro salute animae_; whereas temporal criminal +proceedings are primarily for the protection of the state and its +citizens. Hence a Christian might be first punished in the civil courts +and then put to public penance by the ecclesiastical jurisdiction, or +vice versa: an apparently double system of punishment which the medieval +Church, when the _forum externum_ had become quite separated from the +_forum internum_, sometimes repudiated (see Maitland, _English Canon +Law_, 138, 139, 144). + +Theodosius began the system of giving secular authority to Church +tribunals. Thus, in 376, L. 23 _Cod. Theodos. de. Episcopis_, &c., +subjected clerics for small offences pertaining to the observances of +religion to bishops and synods. In 399, L. 1 _Cod. de Religione_ +provides that, when it is a matter of religion, it beseems the bishop to +judge. A rescript of Constantius, in 355, inserted in _Cod. Theod._ +lxii. _de Epis. Ecc. et Cler._, excluded bishops from accusations before +secular judges and commanded such accusations to be speedily brought +before the tribunal of other bishops. This law was probably only +intended to be of a temporary character. Then comes the law of Gratian +already noticed. Then, in 399, a law of Honorius (_Cod. Theod._ L. 1 _de +Religione_): "As often as it concerns religion, it is meet that the +bishops should judge, but other causes which belong to ordinary +jurisdiction or to public law are to be heard in the ordinary courts +(_legibus oportet audiri_)." L. 3 _de Epis. Jud._, at the end of the +Theodosian Code, seems spurious (see the comment of Gothofredus in +loco). But a constitution of Honorius in 412 (_Cod. Theod._ L. xli. _de +Epis. Ecc. et Cler._) provides that clerks are not to be accused except +before the bishop. Bishops, priests, deacons, and every other "minister +of the Christian law" of inferior degree, are taken from secular +jurisdiction in criminal cases. The words are quite general; but it has +been contended that they apply only to crimes of an ecclesiastical +character (see Gothofredus in loc.; Van Espen, pars iii. tit. iii. c. 1, +10). In 425 a constitution of Theodosius II. provides that a recent +decree of the usurper John should be disregarded and that clerks whom he +had brought before secular judges should be reserved for the episcopal +jurisdictions, "since it is not lawful to subject the ministers of the +divine office to the arbitrament of temporal powers." Justinian has a +clearer perception of the demarcation between the spheres of spiritual +and temporal law. The 83rd Novell provides that if the offence be +ecclesiastical, needing ecclesiastical correction, the bishop shall take +cognizance of it. The 123rd Novell (c. 21) provides that if a clerk be +accused of a secular crime he shall be accused before his bishop, who +may depose him from his office and order, and then the competent judge +may take him and deal with him according to the laws. If the prosecutor +have first brought him before the civil judge, the evidence is to be +sent to the bishop, and the latter, if he thinks the crime has been +committed, may deprive him of his office and order, and the judge shall +apply to him the proper legal punishment. But if the bishop think the +evidence insufficient, the affair shall be referred to the emperor, by +way of appeal both from bishop and judge. If the cause be +ecclesiastical, the civil judges are to take no part in the inquiry. The +law includes with clerics, monks, deaconesses, nuns, ascetics; and the +word "clerics" covered persons in minor orders, down to doorkeepers. It +will be noticed that Justinian supposes that the prosecutor may begin +the proceedings before the civil judge. A constitution of Alexius +Comnenus I. seems to send him to the special forum of the accused. + + + Anglo-Saxon courts. + +Certain enactments of later Saxon times in England have been sometimes +spoken of as though they united together the temporal and spiritual +jurisdictions into one mixed tribunal deriving its authority from the +State. In the latter part of the 10th century, laws of Edgar provided +that the bishop should be at the county court and also the alderman, and +that there each of them should put in use both God's laws and the +world's law (Johnson's _English Canons_, i. 411). This probably was, as +Johnson suggests, that the bishop might enforce secular laws by +ecclesiastical censure and the alderman ecclesiastical laws with secular +punishment. But the two jurisdictions were kept separate; for by another +law of Edgar (_Leges Edg._ c. v.) it was provided that "in the most +august assembly the bishop and alderman should be present, and the one +should interpret to the people the law of God, the other the laws of +men." Edgar, in a speech to St Dunstan and the bishops in synod (in +969), said, "I hold in my hands the sword of Constantine, you that of +Peter. Let us join right hands and unite sword to sword" (Hardouin, +_Conc._ tom. vi. p. 1, col. 675). The juxtaposition of the judicatures +may, however, have led to some confusion between them. + +As to appeals the mixed council of Cliff at Hoo (747) said they should +go to the synod of the province. The only appeal to Rome in Saxon times +was that of St Wilfrid, bishop of York, who appealed from the division +of his see and his deposition for refusing to consent to it, and was +heard in a Roman synod under the presidency of Pope Agatho. The synod +found him unlawfully deposed and ordered his restoration. Upon his +return to England, the Roman judgment was refused recognition and he was +for a time imprisoned. Ten years later he was recalled to York, but +refusing to consent to the division of his see was again deposed and +again appealed to Rome. The appeal was heard at great length, in a synod +of 703 under John VI., deputies from the archbishop of Canterbury being +present. St Wilfrid was justified and was sent back to his see, with +papal letters to the kings of Northumbria and Mercia. The Roman decree +was again disregarded. At the council of "Nid" he was reconciled to the +other bishops of the province, but not restored. In the end he was +brought back to York, but not to the undivided see. The details of the +case will be found in Wilkins, _Concilia_, in Mansi, _Concilia_, under +the various councils named, and in Haddan & Stubbs, _Councils and Eccl. +Documents_, vol. iii. + + + Penalties inflicted by ecclesiastical courts. + +The penalties which the spiritual court could inflict, in the period +between the edict of Milan and c. 854, were properly excommunication +whether generally or as exclusion from the sacraments for a term of +months or years or till the day of death and (in the case of clerics) +suspension or deposition. Gradually, however, doubtless by way of +commutation of excommunication and of penance, temporal penalties were +added, as scourging, banishment, seclusion in a monastery, fines. It is +difficult to say how far some of these temporal penalties were +penitential only or how far they could be inflicted _in invitos_. But +the secular arm, from the time of Nicaea I., was in the habit of aiding +spiritual decrees, as by banishing deposed bishops, and gradually by +other ways, even with laymen. Scourging (although it had been a +well-known punishment of the synagogue) was at first forbidden. Can. 28 +(26) of the Apostolic Canons imposes deposition on any bishop, priest or +deacon striking the delinquent faithful. In Africa, however, a contrary +practice early sprang up (see St Augustine, _Epist._ clix. _ad Marcellum +al._ cxxxiii.). The small council of Vannes in Brittany in 465 made it +an alternative punishment for clerks convicted of drunkenness (Can. 13). +Canon 13 of the first council of Orleans, which has been cited in this +matter, seems to have no application. St Gregory the Great seems to +assume that scourging and seclusion in a monastery are in the discretion +of episcopal tribunals (see _Epistles_, lib. ii. ep. 11, 40, 42, 44, 45; +lib. vii. ep. 11, 67; lib. xii. ep. 31, c. 4). The 16th council of +Toledo (in 693) has been cited as if it visited certain very great +sinners with scourging as an ecclesiastical punishment. In fact, it only +approves the punishment as ordered by the Visigothic laws. An alleged +decree of a council of Autun in 670 is part of a code of discipline for +monasteries (see authorities cited by Hefele, _Councils_, sect. 290, +towards the end). Banishment does not seem to have been inflicted by the +spiritual court _in invitum_. Seclusion in a monastery seems first to +have been used by the civil power in aid of the spiritual. The fifth +canon of the council of Macon, in 584, forbids clergy to dress like +laymen and imposes a penalty of thirty days' imprisonment on bread and +water; but this may be merely penitential. There is little evidence of +the imposition of fines as ecclesiastical penalties; but there are +references to the practice in the epistles of St Gregory the Great, +notably in his instructions to St Augustine. Gregory III. copies from St +Gregory I. Probably these also were by way of penance. Isolated examples +in the early middle ages of metropolitans dealing with their suffragan +bishops by imprisonment in chains were extra-canonical abuses, connected +with the perversion of Church law which treated the metropolitan (who +originally was merely convener of the provincial synod and its +representative during the intervals of sessions) as the feudal "lord" of +his comprovincials. + +With the later 9th century we enter upon a new epoch, and by the time of +Gregory VII., in the 11th century, the tribunals have fallen into the +hands of a regular class of canonists who are in fact professional +church-lawyers in orders. The changes due to the adoption of the False +Decretals by Nicholas I. and the application of their principles by +Hildebrand (afterwards Gregory VII.) are discussed in the article CANON +LAW. The later medieval system, thus inaugurated, may be considered (1) +in its hierarchy, (2) in the subject matter of its jurisdiction, (3) in +its penalties. + + + Later medieval system. + +1. (a) It is a system of courts. Much that had been done by bishops, +_sine strepitu forensi et figura judicii_, is now done in the course of +regular judicial procedure. Again, the court takes the place of the +synod. The diocesan synod ceases to have judicial work. The court of the +metropolitan takes the place of the provincial synod, except possibly +for the trial of bishops, and even this becomes doubtful. + +(b) At first the bishop was the only judge in the diocesan court and he +always remains a judge. But just as the king appoints judges to hear +_placita coram rege ipso_, and the feudal lord appoints his seneschal or +steward, so the bishop appoints his official. + +(c) The archdeacon acquires a concurrent ordinary jurisdiction with the +bishop (see ARCHDEACON). For some time it was considered that he was a +mere office-holder dependent on the will of the bishop with a +jurisdiction merely "vicarial"; but by the 13th century it was settled +that he held a "benefice" and that his jurisdiction over causes was +ordinary and independent of the bishop (Van Espen, pars i. tit. xii. c. +1; Fournier, _Les Officialites au moyen age_, p. 134). It was partly in +order to counterpoise the power of archdeacons that bishops created +officials (Fournier, p. 8). Archdeacons in course of time created +officials who presided in court in their stead. The extent of +jurisdiction of archdeacons depended much upon local customs. In England +the custom was generally in their favour. Ordinarily, the appeal from an +archdeacon or his official lay to the court of the bishop; but by custom +the appeal might be to the court of the metropolitan: The Constitutions +of Clarendon, in 1164, made the appeal from the court of the archdeacon +lie to the court of the bishop. + +(d) The official of the bishop might be his official principal, who was +his _alter ego_, or a special officer for a particular locality +(_officialis foraneus_). The latter was treated as a mere delegate, from +whom an appeal could be made to the bishop. The former had one +consistory with the bishop, so that appeals from him had to be made to +the court of the metropolitan. How far the official principal had +jurisdiction in criminal matters by virtue of his office, how far it was +usual to add this jurisdiction by special commission, and what were the +respective limits of his office and that of the vicar-general, are +questions of some nicety. The emphasis in Italy was on the vicar-general +(_Sext. de officio Vicarii_). In the Low Countries, France and England +the jurisdiction of the official principal was wider (Van Espen, pars +i. tit. xii. cc. 4, 5; Fournier, p. 21). But he could not try criminal +matters unless specially committed to him (Lyndwood, _Provinciale_, lib. +ii. tit. 1). Later in England it became usual to appoint one man to the +two offices and to call him chancellor, a word perhaps borrowed from +cathedral chapters, and not in use for a diocesan officer till the time +of Henry VIII. or later (see CHANCELLOR). In Ireland the title, till the +church was disestablished, was vicar-general. + +The importance of distinguishing the normal functions of an official +principal and a vicar-general lies in this: that it was gradually +established that as a king should not hear causes but commit them to his +judges, so a bishop should not hear causes but appoint an official to +hear them (see Ridley, _View of the Civil and Eccl. Law_; Ayliffe, +_Parergon juris ecclesiastici_, p. 161; Godolphin, _Abridgement of the +Laws Ecclesiastical_, p. 8). The "parlements" of France were constantly +insisting on the independence and irremovability of the official +(Fournier, p. 219). But jurisdiction which was not necessarily incident +to the office of the official principal, that is to say voluntary +jurisdiction, such as the granting of licences and institution to +benefices, and criminal jurisdiction over clerks (and probably over +laymen), the bishop could reserve to himself. Reservations of this +nature are made in many English patents of chancellors and were held +good in _R._ v. _Tristram_, 1902, 1 K.B. 816. + +(e) The ecclesiastical and temporal courts are kept distinct. The +charter of William the Conqueror abrogated the laws of Edgar. No bishop +or archdeacon "shall any longer hold pleas in the Hundred concerning +episcopal law nor draw a cause which concerns the rule of such to the +judgment of men of the world" (Stubbs, _Select Charters_, part iii.). In +France, where the bishop was a temporal baron, his feudal and his +spiritual courts were kept by distinct officers (Fournier, p. 2). + +(f) From the bishop, or his official, appeal lay to the metropolitan, +who again could hear causes by his official. The Constitutions of +Clarendon recognize this appeal (c. viii.). + +(g) An appeal lay from the court of the metropolitan to that of the +primate. There were many disputes as to the existence of these primates +(see Maitland, _Canon Law in the Church of England_, p. 121). In England +the dispute between Canterbury and York was settled by making them both +primates, giving Canterbury the further honour of being primate of all +England. In France the primatial sees and the course of appeals to them +were well established (Fournier, p. 219). + +(h) Several attempts were made by metropolitans and their officials to +take causes arising in the dioceses of their comprovincials in the first +instance and not by way of appeal. The officials of primates in their +turn made similar attempts. After long struggles this was hindered, in +France by the bull _Romana_ (Fournier, p. 218), in England by the Bill +of Citations, 23 Henry VIII. c. 9, and Canon 94 of the Canons of 1603. +The preamble of the "Bill of Citations" is eloquent as to the mischief +which it is framed to prevent. There are, however, a few cases in which +the metropolitan is still allowed to cite in the first instance. One of +them was in cases of "perplexity." "Perplexity" arose where the +suffragans "could not owing to the geographical limitations of their +competence do full justice" (Maitland, pp. 118-119). Such was the case +of probate where notable goods of the deceased lay in more than one +diocese. Hence the origin of the "prerogative court" of Canterbury (cf. +Van Espen, pars i. tit. xix.; and for Spain, Covarruvias, _Pract. +Quaest._ c. 9). + +(i) Gradually there grew up a mass of peculiar and exempt jurisdictions +(Ayliffe, pp. 417, 418; Phillimore, Eccl. Law, pp. 214, 927; de +Maillane, _Dict. du droit canonique_, s.v. "Exemptions"). Exempt +jurisdictions began with the monasteries and were matter of vehement +discussion in the later middle ages. There were no true exemptions +before the 11th century (Van Espen, pars iii. tit. xii.). Peculiar or +special jurisdiction, equal to that of the bishop, was given to deans +and chapters over the cathedral precincts and in places where they had +corporate property (see _Parham_ v. _Templer_, 3 Phil. Ecc. R. 22). +Sometimes it was given to deans alone or to prebendaries in the parishes +whence they derived their prebends. Where the archdeacon had a +jurisdiction co-ordinate with the bishop, it was called a peculiar. The +metropolitans had peculiars within the dioceses of their comprovincials +wherever they had residences or manors, and some whose origin is +uncertain, e.g. that of the fifteen parishes in the deanery of the +Arches. The official administering justice for the metropolitan was +usually called a dean. From a peculiar jurisdiction ranking as episcopal +the appeal lay to the court of the metropolitan. As to metropolitan +peculiars, the metropolitan might give an appeal from the dean to his +regular official principal. Thus, in Canterbury there was an appeal from +the dean of Arches to the official principal of the Arches court. When +peculiars were abolished (_vide infra_) the dean of Arches disappeared, +and his title, in the 19th century, was erroneously given to the +official principal. On peculiars in Spain cf. Covarruvias, _Works_, tit. +i. p. 410. The French parlements, after the middle ages, discouraged +them. In exempt convents the head of the monastery or priory exercised +jurisdiction subject to an appeal to the pope. + +(j) It is said that originally a metropolitan had only one official +principal, who, like the metropolitan himself, acted both for the +diocese and province. Fournier (p. 219) says that in France it was not +till the 17th century that there grew up a custom of having different +officials for the metropolitan, one for him as bishop, a second as +metropolitan, and even a third as primate, with an appeal from one to +the other, and that it was an abuse due to the parlements which strove +to make the official independent of the bishop. In England there has +been, for a long time, a separate diocesan court of Canterbury held +before the "commissary." The word is significant as showing that there +was something special and restricted about the position. In York there +are two courts, one called the consistory for the diocese, the other +called the chancery for the province. But the same person was often +official of both courts. + +(k) In England the Constitutions of Clarendon added a provision for +appeal to the king, "and if the archbishop shall have failed in doing +justice recourse is to be had in the last resort (_postremo_) to our +lord the king, that by his writ the controversy may be ended in the +court of the archbishop; because there must be no further process +without the assent of our lord the king." The last words were an attempt +to limit further appeal to Rome. It will be observed that the king does +not hear the cause or adjudicate upon it. He merely corrects slackness +or lack of doing justice (_Si archiepiscopus defecerit in justitia +exhibenda_) and by his writ (_precepto_) directs the controversy to be +determined in the metropolitan's court. As bishop Stubbs says (_Report +of Eccl. Comm._ vol. i. _Hist. App._ i.): "The appeal to the king is +merely a provision for a rehearing before the archbishop, such failure +to do justice being not so much applicable to an unfair decision as to +the delays or refusal to proceed common at that time" (cf. Joyce, _The +Sword and the Keys_, 2nd ed. pp. 19-20). The _recursus ad principem_, in +some form or other of appeal or application to the sovereign or his lay +judges, was at the end of the middle ages well known over western +Europe. This recourse in England sometimes took the form of the appeal +to the king given by the Constitutions of Clarendon, just mentioned, and +later by the acts of Henry VIII.; sometimes that of suing for writs of +_prohibition_ or _mandamus_, which were granted by the king's judges, +either to restrain excess of jurisdiction, or to compel the spiritual +judge to exercise jurisdiction in cases where it seemed to the temporal +court that he was failing in his duty. The _appellatio tanquam ab abusu_ +(_appel comme d'abus_) in France was an application of a like nature. +Such an appeal lay even in cases where there was a refusal to exercise +voluntary jurisdiction (de Maillane, _Dictionnaire du droit canonique_, +tit. "Abus," cf. tit. "Appel"). This writer traces their origin to the +14th century; but the procedure does not seem to have become regularized +or common till the reigns of Louis XII. or Francis I. (cf. _Dict. +eccl._, Paris, 1765, titt. "Abus" and "Appel comme d'abus"). On the +_recursus ad principem_ and the practice of "cassation" in Belgium, +Germany and Spain, cf. Van Espen's treatise under this title (_Works_, +vol. iv.) and _Jus eccles. univ._ pars iii. tit. x. c. 4. Louis XIV. +forbad the parlements to give judgment themselves in causes upon an +_appel comme d'abus_. They had to declare the proceedings null and +abusive and command the court Christian to render right judgment (Edict +of 1695, arts. 34, 36, cited in Gaudry, _Traite de la legislation des +cultes_, Paris, 1854, tom. i. pp. 368, 369). + +In Catalonia "Pragmatics," letters from the prince, issued to restrain +jurisdiction assumed by ecclesiastical judges contrary to the customs of +the principality. Thus in 1368 Peter III. evoked to the royal court a +prosecution for abduction pending before the archbishop of Tarragona, +declaring that the archbishop and the official were incompetent to judge +noblemen. See this and other instances collected in _Usages y demas +derechos de Cataluna_, by Vives y Cebria (Barcelona, 1835), tom. iv. p. +137 et seq. + +(l) Lastly there was the appeal to the patriarchs, i.e. in the West to +Rome. The distinguishing feature of this appeal was that the rule of the +other appeals did not apply to it. In the regular course of those +appeals an appellant could not leap the intermediate stages; but he +could at any stage go to this final appeal, _omisso medio_, as it was +technically called (see _de appell. c. Dilect._ iii. for general rule, +and c. 3 _de appell._ in 6 for different rule in case of the pope, and +authorities cited in Van Espen, pars iii, tit. x. c. 2, 5). Van Espen +says: "The whole right of appeal to the Roman pontiff _omisso medio_ had +undoubtedly its origin in this principle, that the Roman pontiff is +ordinary of ordinaries, or, in other words, has immediate episcopal +authority in all particular churches, and this principle had its own +beginning from the False Decretals." + +Appeals to Rome lay from interlocutory as well as final judgments. +Causes could even be evoked to Rome before any judgment and there heard +in first instance (Van Espen, pars iii. tit. x. c. 1, 8). + +There was an alleged original jurisdiction of the pope, which he +exercised sometimes by permanent legates, whom Gregory VII. and his +successors established in the chief countries of Europe, and to whom +were committed the legislative executive and judicial powers of the +spiritual "prince" in the districts assigned to them. These Clement IV. +likened to "pro-consuls" and declared to have "ordinary" jurisdiction; +because they had jurisdiction over every kind of cause, without any +special delegation, in a certain defined area or province (c. ii. _de +Officio Legati_ in 6). They were expressed to have not merely appellate +but original jurisdiction over causes (iii. c. i. _de Officio Legati_). +The occupants of certain sees by a kind of prescription became legates +without special appointment, _legati nati_, as in the case of +Canterbury. In the 13th century Archbishop Peckham, says Maitland (p. +117), as archbishop "asserted for himself and his official (1) a general +right to entertain in the first instance complaints made against his +suffragans' subjects, and (2) a general right to hear appeals _omisso +medio_." It was, for the time, determined that the archbishop might +himself, in virtue of his legatine authority, entertain complaints from +other dioceses in first instance, but that this legatine jurisdiction +was not included in the ordinary jurisdiction of his official principal, +even if the archbishop had so willed it in his commission. In fact, +however, the official did before the end of the later medieval period +get the same power as the archbishop (Maitland, pp. 118-120; cf. +Lyndwood, lib. v. tit. 1), till it was taken from him by the Bill of +Citations. + +After legates came special delegates appointed by the pope to hear a +particular cause. It was the general practice to appoint two or three to +sit together (Van Espen, pars iii. tit. v. c. 2, 37). These might +sub-delegate the whole cause or any part of it as they pleased, ibid. +9-18. Dr Maitland (essay on "The Universal Ordinary") thinks, but +without very much foundation, that great numbers especially of the more +important causes were tried before these delegates; although the records +have largely perished, since they were the records of courts which were +dissolved as soon as their single cause had been decided. These courts +were convenient, since it was the custom to appoint delegates resident +in the neighbourhood, and the power of sub-delegation, general or +limited, simplified questions of distance. In Belgium causes appealed +to Rome had to be committed to local delegates (Van Espen, pars iii. +tit. v. c. 3, tit. x. c. 2). + +There could be an appeal from these delegates to the pope and from the +pope himself to the pope "better informed" (Van Espen, pars iii. tit. x. +c. 2, 12, 13). So personal had the system of jurisdiction become that +even the trials of bishops ceased to be necessarily conciliar. Generally +they were reserved to the pope (Van Espen, pars iii. tit. iii. c. 5, +17-19); but in England the archbishop, either in synod, or with some of +his comprovincial bishops concurring, tried and deposed bishops (see +case of Bishop Peacock and the other cases cited in _Read_ v. _Bishop of +Lincoln_, 14 P.D. 148, and Phillimore, _Eccl. Law_, pp. 66 et seq.). + +(m) The jurisdiction of a bishop _sede vacante_ passed, by general law, +to the dean and chapter; but in England the metropolitans became +"guardians" of the spiritualities and exercised original jurisdiction +through the vacant diocese (Phillimore, pp. 62-63), except in the case +of Durham, and with a peculiar arrangement as to Lincoln. + +If the metropolitan see were vacant the jurisdiction was exercised by +the dean and chapter through an official (Rothery, _Return of Cases +before Delegates_, Nos. 4, 5). As to France see Fournier, p. 294. + +(n) Officials, even of bishops and metropolitans, need not be in holy +orders, though Bishop Stubbs in his paper in the _Report of the +Commission on Ecclesiastical Courts_ seems to say so. They had to be +clerics, that is, to have received the tonsure. Even papal delegates +might be simple clerks (Van Espen, pars iii. tit. v. c. 2, 20). + +It came, however, to be the practice to impose some restrictions, as on +clerks twice married. Thus Archbishop Chichele provided that no clerk +married or bigamous (that is, having had two wives in succession) should +exercise spiritual jurisdiction (see Lyndwood, lib. iii. tit. 3). Abroad +unsuccessful attempts were made by local councils to enact that +officials and vicars-general should be in holy orders (Hefele on +Councils of Tortosa in 1429 and Sixth of Milan in 1582). These councils, +as will be seen, are late. + +(o) With or without the concurrence and goodwill of the national Church, +restrictions were imposed by the State on the papal jurisdiction, +whether original or appellate. In England the Constitutions of Clarendon +(by chap. viii.) prohibited appeals to the pope; but after the murder of +St Thomas of Canterbury Henry II. had to promise not to enforce them. +The statutes 38 Edw. III. st. 2, 13 Rich. II. st. 2, c. 2, and 16 Rich. +II. c. 5 forbid such appeals; but it is suggested that notwithstanding +the generality of their language they refer only to cases of temporal +cognizance. Cases upon the execution of these statutes are collected in +Stillingfleet, _On Ecclesiastical Jurisdiction_, p. 189; Gibson, +_Codex_, 83. Obstacles were placed in the way of appeals to the pope +_omisso medio_. Thus when a writ of _significavit_ issued on the mandate +of a bishop, an appeal to Rome availed not to stay execution; but if +there were an appeal to the archbishop it was otherwise. It therefore +became the custom to lodge a double appeal: one to the archbishop "for +defence," and the other to the pope as the real appeal ("Hostiensis," +_Super Decret._ ii. fol. 169; cf. Owen, _Institutes of Canon Law_, 1884, +pt. i. c. 19, 5). + +There seems to have been no machinery for assisting the original or +appellate jurisdiction of the pope by secular process,--by +_significavit_ or otherwise. + +The matrimonial cause between Henry VIII. and Catharine of Aragon was +the most famous English cause tried by delegates under the "original" +jurisdiction of the pope, and was ultimately "evoked" to Rome. The +foreseen adverse termination of this long-drawn cause led to Henry's +legislation. + +When the temporal courts interfered to prevent excess of jurisdiction, +they did so by prohibiting the ecclesiastical court from trying and the +suitor from suing in that court. The pope could not be effectively +prohibited, and no instance is recorded of a prohibition to papal +delegates. But suitors have been prohibited from appealing to the pope +(see per Willes, J., in _Mayor of London_ v. _Cox_, L.R. 2 H.L. 280). +Whatever may have been the law, it is certain that, notwithstanding the +statutes of Edw. III. and Rich. II., appeals to Rome and original trials +by papal delegates did go on, perhaps with the king's licence; for the +statute 24 Hen. VIII. c. 12 recites that the hearing of appeals was an +usurpation by the pope and a grievous abuse, and proceeds to take away +the appeal in matrimonial, testamentary and tithe causes, and to hinder +by forbidding citation and process from Rome, all original hearings +also. The statute 25 Hen. VIII. c. 19 follows this up by taking away +appeals in all other subjects of ecclesiastical jurisdiction. + +In 1438 the council of Basel took away all papal original jurisdiction +(save in certain reserved cases--of which _infra_), evocation of causes +to Rome, appeals to Rome _omisso medio_, and appeals to Rome altogether +in many causes. Such appeals when permissible, except the "greater," +were to be tried by delegates on the spot (31st Session; Mansi, +_Concilia, in loco_). These proceedings at Basel were regarded at Rome +as of no effect. Nevertheless this decree and others were adopted by a +French national council at Bourges and promulgated by the king as a +"Pragmatic Sanction" (Migne, _Dict. du droit canonique_, "Pragmatique +Sanction"). The parlements registered the Sanction and the effect was +permanent in France. Louis XI. and Charles VIII. sought to revoke it; +but both parlements and states-general refused to recognize the revoking +decrees. In 1499 Louis XII. ordered the Pragmatic to be inviolably +observed. The parlements thereupon condemned several private persons for +obtaining bulls from Rome. In 1516 a Concordat between Leo X. and +Francis I. settled all these questions in the sense of the Pragmatic, +substantially according to the Basel canon. All causes, except the +"greater," were to be terminated in the country where the proper +cognizance would lie (Migne, op. cit. "Concordat"). By this Concordat, +by an ordinance of Francis I. in 1539, by two or three other royal +edicts, and (above all) by the practice of the parlements, explanatory +of this legislation, and their _arrets_, the conflict of secular and +ecclesiastical jurisdictions was settled until the Revolution (Migne, +_ubi sup._). "Greater causes" came in France to be restricted to +criminal prosecutions of bishops. Even in these the original +jurisdiction of the pope was taken away. In first instance they were +tried by the provincial synod. Thence there was appeal to the pope (de +Maillane, op. cit. s.v. "Causes majeures"; _Dict. eccl._, Paris, 1765, +s.v. "Cause"). The only original jurisdiction left to the pope was in +the case of the matrimonial causes of princes. But they could only be +heard on the spot by judges delegate. Examples are the causes of Louis +XII. and Jeanne of France in 1498, and of Henry IV. and Marguerite of +Valois in 1599 (Migne, op. cit. s.v. "Causes"). The prohibition of papal +interference was enforced if necessary by the _appel comme d'abus_ +(_vide supra_). Out of respect for the pope this appeal was not brought +against his decrees but against their execution (_Dict. eccl._, Paris, +1765, s.v. "Abus"). + +Spain appears to have permitted and recognized appeals to the pope. A +royal writ of the 16th century cited by Covarruvias (c. xxxv.) prohibits +execution of the sentence of a Spanish court Christian pending an appeal +to the pope. + + + Civil jurisdiction. + +2. The subject matter over which the ecclesiastical courts had +jurisdiction was no longer purely "criminal" with a civil +quasi-jurisdiction by way of arbitration. In the later middle ages these +courts had jurisdiction over most questions, except indeed the then most +important ones, those relating to real property. This civil jurisdiction +was sometimes concurrent with that of the secular courts, sometimes +exclusive. For England it may be thus classified:-- + +(a) _Matrimonial._--This arose naturally from the sacred character of +Christian marriage. This jurisdiction was exclusive. From it followed +the right of the courts Christian to pronounce upon questions of +legitimacy. Upon this right an inroad was early made, in consequence of +the question of legitimation by subsequent marriage. In the 12th century +the Church's rule, that subsequent marriage did legitimize previous +issue, was settled (c. 6, x. 4, 17). The king's judges then began to ask +the ordinary the specific question whether A. B. was born before or +after his parents' marriage. After the inconclusive proceedings at the +realm-council of Merton (1236), when spiritual and temporal lords took +opposite views, the king's judges went a step further and thenceforward +submitted this particular question to a jury. All other questions of +legitimacy arising in the king's courts were still sent for trial to the +bishop and concluded by his certificate (see Pollock and Maitland, +_Hist. Eng. Law before Edward I._ vol. i. 105-106; Maitland, _ubi +supra_, pp. 53-56). + +(b) _Testamentary and in regard to succession from intestates._--Real +property was not the subject of will or testament in the medieval +period. But as to personal property, the jurisdiction of the courts +Christian became exclusive in England. The Church, East and West, had +long asserted a right to supervise those legacies which were devoted to +pious uses, a right recognized by Justinian (_Cod._ i. 3. 46). The +bishop or, failing him, the metropolitan, was to see such legacies +properly paid and applied and might appoint persons to administer the +funds (Pollock and Maitland, op. cit. ii. 330). This right and duty +became a jurisdiction in all testamentary causes. Intestacy was regarded +with the greatest horror, because of the danger to the intestate's soul +from a death without a fitting part given to pious uses (Maine, _Ancient +Law_, ed. 1906, note by Pollock, p. 230; cf. Pollock and Maitland, op. +cit. ii. 354). Hence came the jurisdiction of the ordinary in intestacy, +for the peace of the soul of the departed. This head of ecclesiastical +jurisdiction was in England not transferred to the secular court till +1857. + +(c) _Church Lands._--If undoubtedly held in _frankalmoign_ or "free +alms," by a "spiritual" tenure only, the claim of jurisdiction for the +ecclesiastical _forum_ seems to have been at first conceded. But the +Constitutions of Clarendon (c. 9) reserved the preliminary question, of +"frankalmoign" or not, for a jury in the king's court. Then, if the +tenure were found free alms, the plea was to be heard in the court +Christian. From the 13th century, however, inclusive, the king's courts +insisted on their exclusive jurisdiction in regard to all realty, +temporal or "spiritual" (Pollock and Maitland, op. cit. i. 106). + +(d) _Title to present to and possession of benefices._--As to the title +to present to benefices, the courts Christian at one time had concurrent +jurisdiction with the temporal courts. "Advowsons" were, however, looked +upon as a species of "real" property in England, and therefore the +king's court early claimed exclusive jurisdiction in disputes where the +title to present was involved. The Constitutions of Clarendon provided +that these causes should be heard only in the king's court (c. 1). This +rule was applied even where both litigants were "spiritual." In the 13th +century abbots sue each other in the royal court for advowsons (Selden +Soc. _Select Civil Pleas_, i. pl. 245). In 1231, in such a suit, the +bishop of London accepts wager of battle (Pollock and Maitland, op. cit. +i. 105). In cases, however, where the title to present was not in +question, but the fitness of the clerk presented, or, in cases of +election to benefices, the validity of the election, there was +jurisdiction in the courts Christian. + +(e) _The recovery of tithes and church dues,_ including in England +church rates levied to repair or improve churches and churchyards. + +(f) Questions concerning _fabrics, ornaments, ritual and ceremonial_ of +churches. + +(g) _Administration of pious gifts and revenues given to prelates or +convents._--Their right application could be effectively enforced only +in the courts Christian; until the rise in England of the equitable +jurisdiction of the court of chancery and the development of the +doctrine of "uses" at the end of the middle ages. + +(h) _Enforcement of contractual promises made by oath or pledge of +faith._--The breaking of such a promissory oath was called "perjury" (as +in classical Latin and in Shakespeare), contrary to modern usage which +confines the word to false evidence before a court of justice. In regard +to the execution of these promises, the jurisdiction of the +ecclesiastical courts was possibly traversed by c. 15 of the +Constitutions of Clarendon; but allowed by the statute 13 Edw. I. st. 4. +As just intimated, besides the enforcement of the promise, the +"perjury" was treated as an ecclesiastical crime. + +The _criminal jurisdiction of courts Christian over laymen_ included, +besides these "perjuries," (a) all _sexual offences_ not punishable on +indictment; (b) _Defamation of character_ (the king's courts came in +time to limit this to such defamation as could not be made the subject +of a temporal action); (c) _Offences by laymen against clerks_ (i.e. +against all "tonsured" persons, supra); (d) _Offences in regard to holy +places_--"brawling" and such like; (e) _Heresy, schism, apostasy, +witchcraft_. + +In regard to "clerks," there was (1) all the criminal jurisdiction which +existed over laymen, and (2) criminal jurisdiction in regard to +professional misconduct. Concerning "felonious" clerks the great +questions discussed were whether the courts Christian had exclusive +jurisdiction or the king's court, or whether there was a concurrent +jurisdiction. The subject was dealt with in the Constitutions of +Clarendon, formally revoked after the murder of St Thomas of Canterbury. +In the 13th century it was recognized that a "clerk" for felony was +subject only to ecclesiastical trial and punishment; punishment which +might involve lifelong imprisonment. For "misdemeanours," as yet +unimportant, he had no exemption from secular jurisdiction (Pollock and +Maitland, op. cit. ch. iv.). At some indeterminate later period, the +"clerk" was tried for felony by a jury in the king's court and then +"pleaded his clergy," after conviction there, and was remitted to the +ordinary for ecclesiastical punishment. "Clerks" for the purpose of +"benefit of clergy" included not only persons in minor orders, but all +"religious" persons, i.e. monks, friars, nuns, &c. Later the custom +arose of taking "clerk" to include any "literate," even if not in orders +or "religious" (cf. Stephen, _Hist. Crim. Law_, i. 461). The statute 4 +Hen. VII. c. 13 took away benefit of clergy, if claimed a second time, +from persons not "within orders," in certain bad cases. 4 Hen. VIII. c. +2 (a temporary act) took away "clergy," in certain heinous crimes, from +all persons not in "holy" orders. This statute was partly renewed by 22 +Hen. VIII. c. 13. Other changes were introduced by 23 Hen. VIII. c. 1 +and later acts. In time, "benefit of clergy" became entirely diverted +from its original objects. + +In _France_, till 1329, there seems to have been no clear line of +demarcation between secular and ecclesiastical jurisdictions. Beaumanoir +(_Coutume de Baulvoisis_, ch. xi., cited Gaudry, op. cit. i. 22) had +laid down the principle that spiritual justice should meddle only with +spiritual things. In the year named the secular courts complained to the +king, Philip of Valois, of the encroachments of the courts Christian. +The "cause" was solemnly argued before that monarch, who decided to +leave things as they were (Migne, _Dict. du droit canon._, s.v. +"Officialites"). In 1371 Charles V. forbade spiritual courts to take +cognizance of "real" and "possessory" actions even in regard to clerks +(Migne, loc. cit.; cf. Gaudry, _ubi sup._). From this period the +parlements began the procedure which, after the Pragmatic Sanction of +Charles VII., in 1438 took regular shape as the _appel comme d' abus_ +(_supra_; Migne, loc. cit.). Testamentary causes at first were subject +to the concurrent jurisdiction of the spiritual and secular courts. +After the 14th century, the latter had exclusive jurisdiction (Van +Espen, op. cit. lib. iii. tit. ii. cc. 2, 15, 16). In regard to +_marriage_ the secular jurists distinguished between the civil contract +and the sacrament, for purposes of separating the jurisdiction (_Dict. +eccl._, Paris, 1765, s.v. "Mariage"). The voluntary jurisdiction as +regards dispensations was kept for the Church. The contentious +jurisdiction of the courts Christian was confined to promises of +marriage, nullity of marriage caused by "diriment" impediments only, +validity or invalidity of the sacrament, divorce _a thoro_ (ibid.). +Questions in regard to the _property in a benefice_ were for the courts +Christian; in regard to its _possession_, for the king's courts. But if +a "possessory" action had been brought in the latter, a subsequent suit +in the courts spiritual for the property was deemed "abusive" and +restrained (ib., s.v. "Petitoire") _Breach of faith or of promise +confirmed by oath_ was matter for the court Christian (Fournier, pp. 95, +99, 109, 125). This branch of jurisdiction was larger and more freely +used than in England (cf. Pollock and Maitland, op. cit., as to +Normandy). The only other remaining civil jurisdiction of the +ecclesiastical courts was in _personal actions where clerks were +defendants_ (Migne, op. cit., s.v. "Officialites," Fournier, pp. +65-125); or, after the 14th century, where both parties were clerks. In +regard to crimes delicts (_delits_) were divided into classes for +purposes of jurisdiction. Clerks were punishable only in the court +Christian, except in cases of grave crimes such as murder, mutilation +(Fournier, p. 72), and cases called "royal cases" (_vide infra_). Laymen +were punishable in the court Christian for the _delits_ following: +injury to sacred or religious places, sacrilege, heresy (except where it +was a "royal case"), sorcery, magic, blasphemy (also punishable in the +secular court), adultery, simony, usury and infractions of the truce of +God (Fournier, pp. 90-93). What were called "privileged delicts" were +judged in the case of the clergy conjointly by the spiritual judge and +the king's judge. Bishops had no exemption (_Dict. ecc._, s.v. "Delits," +"Cas privilegie," "Causes majeures"). "Royal cases" included such crimes +as touched the prince, as all forms of treason; or the dignity of his +officers; or the public safety. In this class were also included such +heresies as troubled the state, as by forbidden assemblies, or by +teaching prohibited doctrine. Among these heresies were reckoned +idolatry, atheism, Protestantism, relapse (_ib. et_ "Cas royaux," +"Heresie"). These were of exclusive royal jurisdiction as against both +spiritual courts and the courts of feudal lords. A similar claim was +made by Pombal for Portugal (_vide infra_). + +The parlements, in order to have a ready means of enforcing all these +restrictions by _appel comme d'abus_, compelled the bishops to appoint +officials, Frenchmen, graduates, and (as it seems) "seculars" (_Dict. +eccl._, Paris, 1765, s.v. "Official"). This last qualification was +disputed (see Fevret, _Traite de l'abus_). + +3. _Punishments._--Ecclesiastical sanctions were divided into +_punishments_ (_poenae_), either purely temporal in character or else of +a mixed spiritual and temporal character, and _censures_ (_censurae_), +purely spiritual and remedial (see Van Espen, pars iii. tit. xl. cc. 1, +3; Phillimore, _Ecclesiastical Law_, p. 1064). In the book last cited +_censurae_ and _poenae_ are classed together as "censures" (which is the +modern use). + +_Poenae._--(a) Fines sprang from the older custom of directing alms by +way of penance in the internal forum (Van Espen, _ubi sup._ c. 1, 5-10). +They were to be applied to pious uses. (b) _Reclusion in a monastery_ +continued from former period, and might be either temporary or perpetual +(loc. cit. 17-19). (c) _Imprisonment_, in the bishop's prison, might be +in chains, or on bread and water, and temporary or perpetual. In its +severer forms it was only inflicted for more atrocious crimes which the +secular law would have punished with death (loc. cit. 21-27). The act 23 +Henry VIII. c. 11 made special provision for convicted clerks who broke +out of the prisons of the ordinary. (d) _Fustigation_, as in former +period, was hardly an ecclesiastical punishment. If given, it was to be +of a paternal character (loc. cit. 39-45). Punishments of a mixed nature +were: (e) _Suspension_ either from office alone or from office and +benefice; (f) _Deprivation_ of benefice; (g) _Deposition_ or +_Degradation_ (a more solemn and ceremonial form) from the ministry; (h) +_Irregularity_--not always a punishment--a state of incapacity to be +ordained, or, being ordained, to execute the ministry; this might result +from some defect of mind and body, but was also incurred by some grave +offences. + +_Censures_ were as follows: (i) _Suspension_ from attending divine +offices or _ab ingressu ecclesiae_, more appropriate for a layman. A +clerk in like case might be suspended from office. (j) _Interdict_ was +another form of partial or total suspension from the benefit of the +rites and sacraments of the Church. An interdict might be personal or +local (see INTERDICT). (k) _Excommunication_ was either greater or less. +The greater separated entirely from the Church. It might be pronounced +under anathema. The less deprived of participation in the sacraments, +and made a clerk incapable of taking a benefice. + +On the European continent the courts Christian often carried out their +decrees by their own apparitors who could levy pecuniary penalties on a +defendant's goods (Van Espen, pars iii. tit. ix. c. 4). They could +arrest and imprison. In England, except in the peculiar case of +imprisonment pending trial for heresy, or in the case of a clerk +convicted of crime, these things could not be. The sentence of the court +Christian had in all other cases to be enforced by the secular arm. +Early in Henry II.'s time it had become the custom of England for the +court Christian to "signify" its sentence of excommunication to the king +and to demand from him a writ of _significavit_ to the sheriff, to +imprison the person excommunicated. The writ apparently issued for no +court inferior to the bishop's, unless upon the bishop's request. In +some sense the king's writ of _significavit_ was discretionary; but its +issue could be enforced by excommunication or interdict. + +In the cases of heresy, apostasy and sorcery, the spiritual courts +sought the aid of the secular jurisdiction to superadd the punishment of +death. Incorrigible offenders on these matters were "left" to the +secular power, to be corrected with due "animadversion." This provision +of the fourth Lateran Council in 1215 was always interpreted to mean +death (see Van Espen, _Observ. in Conc. Lat. IV. Canones_, and the +decree in the _Sext. ut inquisitionis negotium_; and, as to English law +and practice, Maitland, op. cit., Essay vi., and pp. 161, 176; 2 Hen. +IV. c. 15; Fitzherbert, _Natura brevium_, 269; 2 Hen. V. st. 1, c. 7). +The "capital" punishment was generally (always in England) by burning. +Burning was an English punishment for some secular offences. + +The Concordat with Francis I. by which the pope gave up the right of +hearing appeals from France was not many years before the legislation of +Henry VIII. in England. Both monarchs proceeded on the same lines; but +Francis I. got the pope's consent: Henry VIII. acted _in invitum_, and +in time went rather further. + + + Ecclesiastical jurisdiction in England. + +The Statute of Appeals (24 Hen. VIII. c. 12) takes away appeals to Rome +in causes testamentary and matrimonial and in regard to right of tithes, +oblations and obventions. A final appeal is given to the archbishop of +the particular province; but in causes touching the king a final appeal +is given to the Upper House of Convocation of the province. The statute +is aimed at appeals; but the words used in it concerning "citations and +all other processes" are wide enough to take away also the "original" +jurisdiction of the pope. No appeal was yet given to the crown. +Canterbury, York, Armagh, Dublin, Cashel and Tuam are put in the place +of Rome. The English and Irish provinces are treated as self-contained. +All ends there. + +The "Act of Submission of the Clergy" (25 Hen. VIII. c. 19) took away +_all_ appeals to Rome and gave a further appeal, "for lack of justice," +from the several courts of the archbishops to the king in chancery. +Thence a commission was to issue to persons named therein to determine +the appeal definitely. This was copied from the then existent practice +in admiralty appeals and was the origin of the so-called court of +delegates. It is a moot question whether this statute took away the +appeal to the Upper Houses of the various convocations in causes wherein +the king was concerned (see _Gorham_ v. _Bishop of Exeter_, 15 Q.B. 52; +_Ex parte Bishop of Exeter_, 10 C.B. 102; _Re Gorham_ v. _Bishop of +Exeter_, 5 Exch. 630). 37 Hen. VIII. c. 17 provided that married laymen +might be judges of the courts Christian if they were doctors of civil +law, created in any university. This qualification even was considered +unnecessary in Charles I.'s time (_Cro. Car._ 258). Canon 127 of 1603 +provided that the judges must be learned in the civil and ecclesiastical +laws and at least masters of arts or bachelors of laws. Canon Law as a +study had been practically prohibited at the universities since 1536 +(Merriman, _Thomas Cromwell_, i. 142-143; _Cal. State Papers_, vol. ix. +p. xxix. 117; Owen, _Institutes of Canon Law_, viii.). The substitution +of "civilians," rather than common lawyers, for canonists (civilians, +hitherto, not an important body in England) had important consequences +(see Maitland, op. cit. 92 et seq.). + +Henry VIII. had exercised his jurisdiction as Supreme Head through a +vicar-general. Edward VI. exercised original jurisdiction in spiritual +causes by delegated commissions (see Archdeacon Hale, _Precedents in +Criminal Cases_, p. xlviii.). Unless the king was to be regarded as an +ecclesiastical person, they were not properly ecclesiastical courts; +although spiritual persons might sit in them, for they sat only as royal +commissioners. The same point has been taken by large bodies of clergy +and laity in regard to the court of final appeal created by 25 Hen. +VIII. c. 19 and its present successor the judicial committee of Privy +Council (_infra: Rep. Com. Ecc. Discipline_, pp. 9, 94 et seq.). At any +rate the "original" jurisdiction claimed for the monarch personally and +his delegates, under Henry VIII. and Edward VI., has not permanently +remained. In theory, Hooker's contentions have been conceded that "kings +cannot in their own proper persons decide questions about matters of +faith and Christian religion" and that "they have not ordinary spiritual +power" (_Ecc. Pol._ vii. 8, 1, 6; cf. _XXXIX. Articles_, Art. 37). + +Under Henry VIII. a system began of making certain crimes, which +previously had been only of spiritual cognizance, felonies (25 Hen. +VIII. c. 6), excluding thereby spiritual jurisdiction (Stephen, _Hist. +Crim. Law_, ii. 429). Bigamy (in its modern sense) was thus made felony +(1 Jac. I. c. 11). In this reign and the next, temporal courts were +sometimes given jurisdiction over purely spiritual offences. A trace of +this remains in 1 Edw. VI. c. 1 (still on the statute book; Stephen, +_Hist. Crim. Law_, ii. 439). Other traces occur in the Acts of +Uniformity, which make offences of depraving the Book of Common Prayer +triable at Assizes (between 23 Eliz. c. 1 and 7 & 8 Vict. c. 102--also +at Sessions) as well as in the courts Christian. + +During Edward VI.'s time the courts Christian seem practically to have +ceased to exercise criminal jurisdiction (Hale, _Precedents in Criminal +Cases_, p. xlix.). But they sat again for this purpose under Mary and +Elizabeth and (save between 1640 and 1661) continued regular criminal +sessions till towards the end of the 17th century as continuously and +constantly as the king's courts (op. cit.). + +The "ordinary" ecclesiastical tribunals of the later middle ages still +subsist in England, at least as regards the laity. This is hardly the +case elsewhere in the Western Church, though some exceptions are noted +below. Nevertheless, their exercise of criminal jurisdiction over the +laity is now in practice suspended; although in law it subsists (see +Stephen, _Hist. Crim. Law_; _Ray_ v. _Sherwood_, 1 Curt. R. 193; 1 Moore +P.C.R. 363; the observations of Kelly, C.B., in _Mordaunt_ v. +_Moncrieffe_, L.R. 2 Sc. & Div. 381, and of Lord Coleridge in _Martin_ +v. _Mackonochie_, L.R. 4 Q.B.D. 770, and, on the other hand, of Lord +Penzance in _Phillimore_ v. _Machon_, L.R. 1 P.D. 480). Theoretically +still, in cases of sexual immorality, penance may be imposed. Monitions +to amend may be decreed and be enforced by _significavit_ and writ _de +contumace capiendo_, or by excommunication with imprisonment not to +exceed six months (53 Geo. III. c. 127). The tribunals thus subsisting +are the courts of the bishop and archbishop, the latter sometimes called +the court of appeal of the province. Peculiar jurisdictions have been +gradually taken away under the operation of the acts establishing the +ecclesiastical commissioners. The appeal given to delegates appointed by +the crown has been transferred, first by 2 & 3 Will. IV. c. 92 to the +privy council, and then by 3 & 4 Will. IV. c. 41 to the judicial +committee of the privy council. Bishops may now be summoned as assessors +by 39 & 40 Vict. c. 59. + +There was in the time of Elizabeth, James I. and Charles I. a "Court of +High Commission" with jurisdiction over laity and clergy, based on 1 +Eliz. c. i. s. 15, which was reckoned as an ecclesiastical judicature (5 +R. 1, _Cawdrey's case_) concurrent with the ordinary court Christian. It +was created by virtue of the royal supremacy, and was taken away by 16 +Car. I. c. 11. As to its history see Stephen, _Hist. Crim. Law_, ii. +414-428. + +In regard to clerical offences, 3 & 4 Vict. c. 86 (the "Church +Discipline Act") creates new tribunals; and first a commission of +inquiry appointed by the bishop of five persons, of whom the +vicar-general, or an archdeacon, or a rural dean of the diocese must be +one. If they report a _prima facie_ case, the bishop may (with the +consent of parties) proceed to sentence. In the absence of such +consent, the bishop may hear the cause with three assessors, of whom one +shall be a barrister of seven years' standing and another the dean of +the cathedral, or one of the archdeacons, or the chancellor. This court +is called the "consistory" court, but is not the old consistory. Both +these tribunals are new. But the bishop may instead send the cause, in +first instance, to the old provincial court, to which appeal lies, if it +be not so sent. + +The Public Worship Regulation Act (37 & 38 Vict. c. 85) gave criminal +jurisdiction over beneficed clerks (concurrent with that of the tribunal +under 3 & 4 Vict. c. 86) to the judge under the act in matters of the +fabric, ornaments, furniture and decorations of churches, and the +conduct of divine service, rites and ceremonies. The "judge" under the +act is to be a barrister of ten years' standing, or an ex-judge of a +superior secular court, appointed by the archbishops of Canterbury and +York, with the approval of the crown, or, if they fail to appoint, by +the crown. Proceedings under this act are to be deemed to be taken in +the appropriate ancient ecclesiastical courts (_Green_ v. _Lord +Penzance_, 6 A. C. 657). The judge under this act became (upon vacancies +occurring) _ex officio_ official principal of the arches court of +Canterbury and of the chancery court of York. This provision caused +grave doubts to be entertained as to the canonical position of this +statutory official principal. + +Finally, the Clergy Discipline Act 1892 (55 & 56 Vict. c. 32) creates +yet a new court of first instance for the trial of clerical offences +against morality in the shape of a consistory court, which is not the +old court of that name, but is to comprehend the chancellor and five +assessors (three clergymen and two laymen chosen from a prescribed +list), with equal power with the chancellor on questions of fact. In +many instances the conviction of a temporal court is made conclusive on +the bishop without further trial. In regard to moral offences, +jurisdiction under this act is exclusive. But it only applies to clerks +holding preferment. Under all these three acts there is a final appeal +to the judicial committee of the privy council. + +None of these acts applies to the trial of bishops, who are left to the +old jurisdictions, or whatever may be held to be the old jurisdictions +(with that of the Roman See eliminated). As to suffragan bishops in the +province of Canterbury, see _Read_ v. _Bishop of Lincoln_, 13 P.D. 221, +14 P.D. 88. (On general questions see Phillimore, _Ecc. Law_, 65, 73.) +Despite the bishop of Lincoln's case, the law is in some uncertainty. + +Dilapidations are now not made matters of suit before the court, but of +administrative action by the bishop. + +The subject matter of ecclesiastical jurisdiction has been gradually +reduced in England, &c., by various causes. (1) The taking away of all +matrimonial, testamentary and _ab intestate_ jurisdiction by 20 & 21 +Vict. c. 77 (testamentary, &c., England), c. 79 (testamentary, &c., +Ireland), c. 85 (matrimonial, England); 33 & 34 Vict. c. 110 +(matrimonial, Ireland). Matrimonial jurisdiction was taken from the +bishop of Sodor and Man in 1884. (2) Since 6 & 7 Will. IV. c. 71, tithe +has become, except in a few rare cases, tithe rent charge, and its +recovery has been entirely an operation of secular law. Most kinds of +offerings are now recoverable in secular courts. (3) Administration of +pious gifts has passed to the court of chancery. (4) The enforcement of +contractual promises has long been abandoned by the courts Christian +themselves. (5) Church rates can no longer be enforced by suit (31 & 32 +Vict. c. 109). (6) _Defamation_ was taken away in England by 18 & 19 +Vict. c. 41, and in Ireland by 23 & 24 Vict. c. 32. (7) Laymen can no +longer be tried in the spiritual courts for offences against clerks. (8) +The jurisdiction for "brawling" in church, &c., is taken away by 23 & 24 +Vict. c. 32 in the case of the laity. In the case of persons in holy +orders there is a concurrent jurisdiction of the two tribunals +(_Valancy_ v. _Fletcher_, 1897, 1 Q.B. 265). This was an offence very +frequently prosecuted in the courts Christian (see A.J. Stephens, +_Ecclesiastical Statutes_, i. 336). + +The existing ecclesiastical jurisdiction in England is therefore now +confined to the following points. (1) Discipline of the clergy. (2) +Discipline of the laity in respect of sexual offences as already +stated. (3) Control of lay office-bearers, church-wardens, sidesmen, +organists, parish clerks, sextons. (4) Protection of the fabrics of +churches, of churchyards, ornaments, fittings, &c., sanctioning by +licence or faculty any additions or alterations, and preventing or +punishing unauthorized dealings by proceedings on the criminal side of +the courts. (5) Claims by individuals to particular seats in church or +special places of sepulture. (6) Rare cases of personal or special +tithes, offerings or pensions claimed by incumbents of benefices. In the +Isle of Man and the Channel Islands courts Christian have now +jurisdiction substantially as in England. In Jersey and in Guernsey +there are courts of first instance with appeal to the bishop of +Winchester. Ecclesiastical jurisdiction in Ireland was as in England +till the Irish Church was disestablished in 1869 by 32 & 33 Vict. c. 42. + + + Ecclesiastical jurisdiction in non-established churches. + +The position of a disestablished or an unestablished Church is +comparatively modern, and has given rise to new jural conceptions. These +Churches are _collegia licita_ and come within the liberty of +association so freely conceded in modern times. The relations of their +bishops, priests or other ministers and lay office-bearers _inter se_ +and to their lay folk depend upon contract; and these contracts will be +enforced by the ordinary courts of law. A consensual ecclesiastical +jurisdiction is thus created, which has to this extent temporal +sanction. _In foro conscientiae_ spiritual censures canonically imposed +are as binding and ecclesiastical jurisdiction is as powerful as ever. + +Into the British-settled colonies no bishops were sent till 1787; and +consequently there were no regular courts Christian. The bishop of +London was treated as the diocesan bishop of the colonists in North +America; and in order to provide for testamentary and matrimonial +jurisdiction it was usual in the letters patent appointing the governor +of a colony to name him ordinary. In New York state there is still a +court called the surrogates court, surrogate being the regular name for +a deputy ecclesiastical judge. In Lower Canada, by treaty, the Roman +Catholic Church remained established. + +Throughout the United States, whatever may have been the position in +some of them before their independence, the Church has now no position +recognized by the State, but is just a body of believers whose relations +are governed by contract and with whom ecclesiastical jurisdiction is +consensual. + +The position is the same now through all the British colonies (except, +as already mentioned, Lower Canada or Quebec). From 1787 onwards, +colonial bishops and metropolitans were appointed by letters patent +which purported to give them jurisdiction for disciplinary purposes. But +a series of cases, of which the most remarkable was that _Re the Bishop +of Natal_ (3 Moore P.C. N.S. A.D. 1864), decided that in colonies +possessing self-governing legislatures such letters patent were of no +value; and soon after the crown ceased to issue them, even for crown +colonies. + +In India the metropolitan of Calcutta and the bishops of Madras and +Bombay have some very limited jurisdiction which is conferred by letters +patent under the authority of the statutes 53 Geo. III. c. 155 and 3 & 4 +Will. IV. c. 85. But the other Indian bishops have no position +recognized by the State and no jurisdiction, except consensual. + + + Ecclesiastical jurisdiction in Scotland. + +The Church had the same jurisdiction in Scotland, and exercised it +through similar courts to those which she had in England and France, +till about 1570. As late as 1566 Archbishop Hamilton of Glasgow, upon +his appointment, had restitution of his jurisdiction in the probate of +testaments and other matters (Keith, _History of the Scottish Bishops_, +Edinburgh, 1824, p. 38). There was an interval of uncertainty, with at +any rate titular bishops, till 1592. Then parliament enacted a new +system of Church courts which, though to some extent in its turn +superseded by the revival of episcopacy under James VI., was revived or +ratified by the act of 1690, c. 7, and stands to this day. It is a +Presbyterian system, and the Scottish Episcopal Church is a +disestablished and voluntary body since 1690. + +The Presbyterian courts thus created are arranged in ascending order:-- + +(a) _Kirk Session_ consists of the minister of the parish and the +"ruling elders" (who are elected by the session). It has cognizance of +scandalous offences by laymen and punishes them by deprivation of +religious privileges. It does not judge ministers (Brodie-Innes, +_Comparative Principles of the Laws of England and Scotland_, 1903, p. +144). + +(b) The _Presbytery_ has jurisdiction, partly appellate and partly +original, over a number of parishes. There are now eighty-four +presbyteries. These courts consist of every parochial minister or +professor of divinity of any university within the limits, and of an +elder commissioned from every kirk session. A minister is elected to +preside as moderator. These courts judge ministers in first instance for +scandalous conduct. As civil courts they judge in first instance all +questions connected with glebes and the erection and repair of churches +and manses. They regulate matters concerning public worship and +ordinances, and have appellate jurisdiction from the kirk session. + +(c) The _Provincial Synod_ consists of a union of three or more +presbyteries with the same members. There are now sixteen. They meet +twice a year to hear appeals from presbyteries. No appeal can go direct +to the General Assembly, _omisso medio_, unless the presbytery have so +expressly directed, or unless there be no meeting of synod after the +decision of the presbytery before the meeting of General Assembly. + +(d) The _General Assembly_ is the supreme ecclesiastical court of this +system. It meets annually. The king's "lord high commissioner" attends +the sittings; but does not intervene or take part in the court's +decisions. The court consists of ministers and elders, elected from the +presbyteries in specified proportions, and of commissioners from the +four universities, the city of Edinburgh and the royal burghs. The +Presbyterian Church in India sends one minister and one elder. The whole +Assembly consists of 371 ministers and 333 elders. The jurisdiction is +entirely appellate. The Assembly appoints a commission to exercise some +of its functions during the intervals of its session. To this commission +may be referred the cognizance of particular matters. + +Questions of _patronage_ now (by 37 & 38 Vict. c. 82) belong to the +Church courts; but not questions of _lapse_ or _stipend_. Seats, seat +rents, pews, the union and disjunction of parishes and formation of +district parishes are of secular jurisdiction. Questions of tithes (or +"teinds") and ministers' stipends were referred to commissioners by acts +of the Scots parliaments beginning in 1607. The commissioners of teinds +became a species of ecclesiastical court. By Scots act of 1707, c. 9, +their powers were transferred to the judges of the court of session, who +now constitute a "teind court" (Brodie-Innes, op. cit. pp. 138, 139). +Matrimonial matters and those relating to wills and succession (called +in Scotland "consistorial" causes) were in 1563 taken from the old +bishops' courts and given to "commissaries" appointed by the crown with +an appeal to the court of session, which by act 1609, c. 6, was declared +the king's great consistory. They have remained matters of secular +jurisdiction. + +The Scots ecclesiastical courts are entitled to the assistance of the +secular courts to carry out their jurisdiction by "due assistance." +Within the limits of their jurisdiction they are supreme. But if a court +go outside its jurisdiction, or refuse to exercise powers conferred on +it by law, the civil court may "reduce" (i.e. set aside) the sentence +and award damages to the party aggrieved. + + + Protestant continental European states. + +With the Reformation in the 16th century, Church courts properly +speaking disappeared from the non-episcopal religious communities which +were established in Holland, in the Protestant states of Switzerland and +of Germany, and in the then non-episcopal countries of Denmark and +Norway. + +Discipline over ministers and other office-bearers was exercised by +administrative methods in the form of trials before consistories or +synods. To this extent ecclesiastical jurisdiction is still exercised in +these countries. Consistories and synods have exercised discipline of a +penitential kind over their lay members; but in later times their +censures have generally ceased to carry temporal consequences. +Ecclesiastical jurisdiction on the civil side for the trial of causes +soon disappeared. Heresy has been treated as a crime to be tried in and +punished by the ordinary courts of the country, as in the cases of +Servetus (q.v.) and Grotius (q.v.). + +For the episcopal churches of Sweden and Finland the first constitution +or "Church order" was formed in 1571. It provided for the visitation of +the clergy by the bishop, and for the power of the clergy to exclude +their lay folk from the Holy Communion, subject to appeal to the bishop. +Both minor and major excommunication had been in use, and for a long +time public penance was required. The procedure underwent great +modification in 1686; but public penance was not taken away till 1855, +and then confession to and absolution by the priest in the presence of +witnesses was still required. Civil jurisdiction in causes appears to +have been given up early (Cornelius, _Svenska Kirkaus Historia_, Upsala, +1875, pp. 146, 186, 189, 285). + + + Roman Catholic countries. + +Over the rest of western continental Europe and in the colonies of +Spain, Portugal and France, ecclesiastical jurisdiction remained +generally in the state which we have already described till near the end +of the 18th century. The council of Trent took away the jurisdiction of +archdeacons in marriage questions. The testamentary jurisdiction +disappeared (as already stated) in France. Disputed cases of contract +were more often tried in the secular courts. Recourse to the secular +prince by way of _appel comme d'abus_, or otherwise, became more +frequent and met with greater encouragement. Kings began to insist upon +trying ecclesiastics for treason or other political crimes in secular +courts. So under the advice of his minister (the marquis of Pombal), +King Joseph of Portugal in 1759-1760 claimed that the pope should give +him permission to try in all cases clerics accused of treason, and was +not content with the limited permission given to try and execute, if +guilty, the Jesuits then accused of conspiring his death (_Life of +Pombal_, by Count da Carnota, 1871, pp. 128, 141). But there was no +sudden change in the position of the courts Christian till the French +Revolution. + +In France a law of the Revolution (September 1790) purported to suppress +all ecclesiastical jurisdictions. On the re-establishing of the Catholic +religion on the basis of the new Concordat, promulgated 18 Germinal, +year X. (April 8, 1802), no express provision was made for +ecclesiastical jurisdictions; but several bishops did create new +ecclesiastical tribunals, "officialities" (Migne, _Dict. de droit +canon._, s.v.). The government in some cases recognized these tribunals +as capable of judging ecclesiastical causes (Migne, _ubi sup._). In 1810 +the diocesan official of Paris entertained the cause between Napoleon +and Josephine, and pronounced a decree of nullity (Migne, _ubi sup._ +s.v. "Causes"). Such litigation as still continued before the spiritual +forum was, however, confined (save in the case of the matrimonial +questions of princes) to the professional conduct of the clergy. + +Such neighbouring countries as were conquered by France or +revolutionized after her pattern took the same course of suppressing +their ecclesiastical jurisdictions. After 1814, some of these +jurisdictions were revived. But the matter is now determined for all +countries which have adopted codes, whether after the pattern of the +Code Napoleon or otherwise. These countries have created a hierarchy of +temporal courts competent to deal with every matter of which law takes +cognizance, and a penal code which embraces and deals with all crimes or +delicts which the state recognizes as offences. Hence, even in countries +where the Roman Church is established, such as Belgium, Italy, the +Catholic states of Germany and cantons of Switzerland, most of the Latin +republics of America, and the province of Quebec, and _a fortiori_ where +this Church is not established, there is now no discipline over the +laity, except penitential, and no jurisdiction exercised in civil suits, +except possibly the matrimonial questions of princes (of which there was +an example in the case of the reigning prince of Monaco). In Spain +causes of nullity and divorce _a thoro_, in Portugal causes of nullity +between Catholics, are still for the court Christian. In Peru, the old +ecclesiastical matrimonial jurisdiction substantially remains (Lehr, _Le +Mariage dans les principaux pays_, 1899, arts. 362, 797, 772, 781). +Otherwise these three countries are Code countries. In Austria, the +ancient ecclesiastical jurisdiction was taken away by various acts of +legislation from 1781 to 1856; even voluntary jurisdiction as to +dispensations. The Concordat of 1856 and consequent legislation restored +matrimonial jurisdiction to the courts Christian over marriages between +Roman Catholics. In 1868 this was taken away. The Austrian bishops, +however, maintain their tribunals for spiritual purposes, and insist +that such things as divorce _a vinculo_ must be granted by their +authority (Aichner, _Compendium juris ecclesiastici_, pp. 551-553). + +By consent and submission of her members, the Roman Church decides _in +foro conscientiae_ questions of marriage, betrothal and legitimacy +everywhere; but no temporal consequences follow except in Spain, +Portugal and Peru. + +The position in France was the same as that in Belgium, Italy, &c., till +1906, when the Church ceased to be established. The only Latin countries +in which conflict has not arisen appear to be the principality of +Andorra and the republic of San Marino (Giron y Areas, _Situacion +juridica de la Iglesia Catolica_, Madrid, 1905, p. 173 et seq.). + +Even as to the discipline of the Roman clergy it is only in certain +limited cases that one can speak of ecclesiastical jurisdiction. Bishops +and beneficed incumbents (_cures_) must be regularly tried; and where +the Church is established the canonical courts are recognized. But the +majority of parishes are served by mere _desservants_ or _vicaires_, who +have no rights and can be recalled and dismissed by mere administrative +order without trial (Migne, _ubi sup._ s.v. "Inamovibilite," +"Desservants"). + +The Napoleonic legislation re-established the _appel comme d'abus_ +("_Articles organiques_," art. 6). The recourse was now to the council +of state (see Migne, _ubi supra_, "Officialite"). But the revocation of +a _desservant_, and the forbidding him the execution of his ministry in +the diocese, was not a case in which the council of state would +interfere (Migne, _ubi sup._ "Appel comme d'abus," "Conseil d'etat"). + + + Jurisdiction in Anglican communion. + +In those provinces of the Anglican communion where the Church is not +established by the state, the tendency is not to attempt any external +discipline over the laity; but on the other hand to exercise consensual +jurisdiction over the clergy and office-bearers through courts nearly +modelled on the old canonical patterns. + + + Modern jurisdiction of Church of Rome. + +In the Roman communion, on the other hand, both where the Church is +established and where it is not, the tendency is to reduce the status of +_cure_ to that of _desservant_, and to deal with all members of the +priestly or lower orders by administrative methods. This practice +obtains in all missionary countries, e.g. Ireland and also in Belgium +(S.B. Smith, _Elements of Ecclesiastical Law_, New York, i. 197 et seq.; +p. 403 et seq.; Tauber, _Manuale juris canonici_, Sabariae, 1904, p. +277). In the United States, the 3rd plenary council of Baltimore in 1884 +provided that one rector out of ten should be irremovable (Smith, op. +cit. i. 197, 419). In England there are few Roman "benefices" (E. +Taunton, _Law of the Church_, London, 1906, s.v. "Benefice"). A +_desservant_ has an informal appeal, by way of recourse, to the +metropolitan and ultimately to the pope (Smith, op. cit. p. 201). The +bishop's "official" is now universally called his vicar-general (except +in France, where sometimes an _official_ is appointed _eo nomine_), and +generally exercises both voluntary and contentious jurisdiction (op. +cit. i. 377). As of old, he must be at least tonsured and without a wife +living. At the Vatican Council, a desire was expressed that he should be +a priest (ib.). He should be a doctor in theology or a licentiate in +canon law (ib. p. 378). Whether a bishop is bound to appoint a +vicar-general is still disputed (ib. p. 380; cf. _supra_; _contra_, +Bouix, _Inst. Juris Canon. De Judic._ i. 405). In 1831 the pope enacted +that in all the dioceses of the then Pontifical States, the court of +first instance for the criminal causes of ecclesiastics should consist +of the ordinary and four other judges. In the diocese of Rome, the +court of the cardinal vicar-general consists of such vicar-general and +four other prelates (Smith, _ubi supra_). In the Roman communion in +England and the United States, there are commissions of investigation +appointed to hear in first instance the criminal causes of clerks. They +consist of five, or at least three, priests nominated by the bishop in +and with the advice of the diocesan synod. In the United States, since +1884, the bishop presides on these commissions. They report their +opinions to the bishop, who passes final sentence (ib. ii. 129-131). + +"Exemptions" now include all the regular religious orders, i.e. those +orders which have solemn vows. Over the members of these orders their +superiors have jurisdiction and not the bishop. Otherwise if they live +out of their monastery, or even within that enclosure so notoriously +offend as to cause scandal. In the first case, they may be punished by +the ordinary of the place, acting as delegate of the pope without +special appointment (_Conc. Trid. Sess._ vi. c. 3). In the second case, +the bishop may require the superior to punish within a certain time and +to certify the punishment to him; in default he himself may punish +(_Conc. Trid. Sess._ xxv. c. 14, cf. Smith, op. cit. i. 204-206). So, +regulars having cure of souls are subject to the jurisdiction of the +bishop in matters pertaining thereto (ib. p. 206). The exemption of +regular religious orders may be extended to religious societies without +solemn vows by special concession of the pope, as in the case of the +Passionists and Redemptorists (ib. p. 205; Sanguineti, _Juris ecc. +inst._, Rome, 1800, pp. 393, 394). + +Appeal lies, in nearly all cases, to the metropolitan (Smith, op. cit. +pp. 219-223). Metropolitans usually now have a metropolitan tribunal +distinct from their diocesan court (ib. ii. 141), but constructed on the +same lines, with the metropolitan as judge and his vicar-general as +vice-judge. In some "missionary" dioceses, the metropolitan, _qua_ +metropolitan, has a separate commission of investigation, to try the +criminal causes of clerks, sentence being passed by himself or his +vicar-general (ib. p. 142). + +The next step in the hierarchy, that of "primates" (_supra_), has "in +the present state of the Church" ceased to exist for our purpose +(Sanguineti, op. cit. p. 334), as a result of Tridentine legislation. +The only appellate jurisdiction from the metropolitans is the Roman See. +To it also lies a direct appeal from the court of first instance, +_omisso medio_ (Smith, op. cit. i. 224). The pope's immediate and +original jurisdiction in every diocese is now expressly affirmed by the +Vatican Council (ib. p. 239). That original jurisdiction he reserves +exclusively to himself in _causis majoribus_ (ib. pp. 249-250). These +are (1) causes relating to elections, translations and deprivations of, +and criminal prosecutions against, bishops, and (2) the matrimonial +cases of princes (Taunton, op. cit. s.v. "Cause"). + + + Eastern Church. + +In the Eastern Church, the early system of ecclesiastical judicature +long continued. But a sacred character was ascribed to the emperors. +They are "anointed lords like the bishops" (Balsamon, in _Conc. Ancyr. +Can._ xii., representing the view of the 12th and 13th centuries). +Bishops were often deposed by administrative order of the emperor; +synods being expected afterwards to confirm, or rather accept, such +order. The germ of this dealing with a _major causa_ may be found in the +practice of the Arian emperors in the 4th century. The cause of Ignatius +and Photius was dealt with in the 9th century by various synods; those +in the East agreeing with the emperor's view for the time being, while +those in the West acted with the pope. (The details are in Mansi, _Conc. +in locis_, and in Hefele, _Conc. in locis_, more briefly. They are +summarized in Landon, _Manual of Councils_, s.v. "Constantinople," +"Rome," and in E.S. Foulkes, _Manual of Ecclesiastical History_, s.v. +"Century IX.") Since these transactions patriarchs have been deposed by +the Byzantine emperors; and the Turkish sultans since the 15th century +have assumed to exercise the same prerogative. + +The spiritual courts in the East have permanently acquired jurisdiction +in the matrimonial causes of baptized persons; the Mahommedan +governments allowing to Christians a personal law of their own. The +patriarch of Constantinople is enabled to exercise an extensive +criminal jurisdiction over Christians (Neale, _Hist. of the Eastern +Church_, i. 30, 31). + +The empire of Russia has in the matter of ecclesiastical jurisdiction +partly developed into other forms, partly systematized 4th century and +later Byzantine rules. The provincial system does not exist; or it may +be said that all Russia is one province. An exception should be made in +the case of Georgia, which is governed by an "exarch," with three +suffragans under him. In the remainder of the empire the titles of +metropolitan, save in the case of the metropolitan of all Russia, and of +archbishop, were and are purely honorary, and their holders have merely +a diocesan jurisdiction (see Mouravieff, _History of the Russian +Church_, translated Blackmore, 1842, translator's notes at pp. 370, 390, +416 et seq.). So in Egypt the bishop or "pope" (afterwards patriarch) of +Alexandria was the only true metropolitan (Neale, _History of the +Eastern Church_, Gen. Introd. vol. i. p. 111). The metropolitan of +Russia from the time of the conversion (A.D. 988) settled at Kiev, and +his province was part of the patriarchate of Constantinople, and appeals +lay to Constantinople. Many such appeals were taken, notably in the case +of Leon, bishop of Rostov (Mouravieff, op. cit. p. 38). The +metropolitical see was for a short time transferred to Vladimir and then +finally to Moscow (Mouravieff, chs. iv., v.). After the taking of +Constantinople in 1452, the Russian metropolitans were always chosen and +consecrated in Russia, appeals ceased, and Moscow became _de facto_ +autocephalous (Joyce, ubi sup. p. 379; Mouravieff, op. cit. p. 126). The +tsar Theodore in 1587 exercised the power of the Byzantine emperors by +deposing the metropolitan, Dionysius Grammaticus (Mouravieff, p. 125). +In 1587 the see of Moscow was raised to patriarchal rank with the +consent of Constantinople, and the subsequent concurrence of Alexandria, +Antioch and Jerusalem (ib. c. vi.). Moscow became the final court, in +theory, as it had long been in practice. Certain religious houses, +however, had their own final tribunals and were "peculiars," exempt from +any diocesan or patriarchal jurisdiction for at least all causes +relating to Church property (ib. p. 131). + +The subject matter of ecclesiastical jurisdiction in Russia during the +whole patriarchal period included matrimonial and testamentary causes, +inheritance and sacrilege, and many questions concerning the Church +domains and Church property, as well as spiritual offences of clergy and +laity (ib.). The bishops had consistorial courts; the patriarchs, +chanceries and consistories (ib.). Bishops were judged in synod (see, +e.g. the case of the archbishop of Polotsk in 1622, ib. p. 179) and only +lawfully judged in synod (ib. p. 215). + +Clerks and the dependants of the metropolitan (afterwards the patriarch) +appear to have been immune from secular jurisdiction, except in the case +of crimes against life, from the time of Ivan the Terrible (ib. pp. +180-181). The tsar Michael, in the earlier 17th century, confirmed these +immunities in the case of the clergy of the patriarch's own diocese, but +provided that in country places belonging to his diocese, monasteries, +churches and lands should be judged in secular matters by the Court of +the Great Palace, theoretically held before the tsar himself (ib. p. +181). This tsar limited the "peculiar" monasteries to three, and gave +the patriarch jurisdiction over them (ib.). The next tsar, Alexis, +however, by his code instituted a "Monastery Court," which was a secular +tribunal composed of laymen, to judge in civil suits against spiritual +persons, and in matters arising out of their manors and properties (ib. +p. 193). This court was not in operation during the time when the +patriarch Nikon was also in effect first minister; but upon his decline +exercised its full jurisdiction (ib. p. 216). Nikon was himself tried +for abdicating his see, causing disorder in the realm, oppression and +violence, first before a synod of Moscow composed of his suffragans and +some Greek bishops, and afterwards before another synod in which sat the +patriarchs of Alexandria and Antioch, the metropolitans of Servia and +Georgia, the archbishops of Sinai and Wallachia, and the metropolitans +of Nice, Amasis, Iconium, Trebizond, Varna and Scio, besides the Russian +bishops. This synod in 1667 deposed Nikon, degraded him from holy +orders, and sentenced him to perpetual penance in a monastery (ib. pp. +220-232). The next tsar, Theodore, suppressed the secular "monastery +court," and directed that all suits against spiritual persons should +proceed only in the patriarchal "court of requests" (ib. p. 264). There +was, however, a species of _appel comme d'abus_. Causes could be evoked +to the tsar himself, "when any partiality of the judges in any affair in +which they themselves were interested was discovered" (ib.). + +The old system was swept away by Peter the Great, who settled +ecclesiastical jurisdiction substantially on its present basis. The +patriarchate was abolished and its jurisdiction transferred by a council +at St Petersburg in 1721 to a Holy Governing Synod. The change was +approved by the four patriarchs of the East in 1723 (ib. chs. +xv.-xvii.). Peter permanently transferred to the secular _forum_ the +testamentary jurisdiction and that concerning inheritance, as also +questions of "sacrilege" (ib. p. 264). As the result of a long series of +legislation, beginning with him and ending with Catherine II., all +church property of every kind was transferred to secular administration, +allowances, according to fixed scales, being made for ministers, monks +and fabrics (op. cit. translator's appendix i. p. 413 et seq.). There +remain to the spiritual courts in Russia the purely ecclesiastical +discipline of clerks and laity and matrimonial causes. + +The court of first instance is the "consistorial court" of the bishop. +This consists of a small body of ecclesiastics. Its decisions must be +confirmed by the bishop (op. cit. translator's appendix ii. pp. +422-423). In the more important causes, as divorce (i.e. _a vinculo_), +it only gives a provisional decision, which is reported by the bishop, +with his own opinion, for final judgment, to the Most Holy Governing +Synod. + +The governing synod is the final court of appeal. It consists of a small +number of bishops and priests nominated by the tsar, and is assisted by +a "procurator," who is a layman, who explains to it the limits of its +jurisdiction and serves as the medium of communication between it and +the autocrat and secular authorities. It deals with the secular crimes +of spiritual persons, if of importance and if not capital (these last +being reserved for the secular forum), and with heresy and schism. It is +the only court which can try bishops or decree divorce. The tsar +formally confirms its judgments; but sometimes reduces penalties in the +exercise of the prerogative of mercy (see Mouravieff, op. cit. ch. xvii. +translator's app. ii.). + +The governing synod now sits at St Petersburg, but appoints delegated +commissions, with a portion of its jurisdiction, in Moscow and Georgia. +The latter commission is presided over by the "exarch" (_supra_). + +Since the War of Independence, the kingdom of Greece has been +ecclesiastically organized after the model of Russia, as one +autocephalous "province," separated from its old patriarchate of +Constantinople, with an honorary metropolitan and honorary archbishops +(Neale, op. cit. Gen. Introd. vol. i.). The Holy Synod possesses the +metropolitical jurisdiction. It sits at Athens. The metropolitan of +Athens is president, and there are four other members appointed by the +government in annual rotation from the senior bishops. There is attached +to it a government commissioner, with no vote, but affixing his +signature to the synodical judgments (Joyce, op. cit. p. 35). + +The subject matter of the jurisdiction of Hellenic courts Christian +seems to be confined to strictly spiritual discipline, mainly in regard +to the professional misconduct of the clergy. Imprisonment may be +inflicted in these last cases (ib.). All matrimonial causes are heard by +the secular tribunals (Lehr, op. cit. sec. 587). + +The bishop's consistorial court, consisting of himself and four priests, +has a limited jurisdiction in first instance. Such a court can only +suspend for seven days unless with the sanction of the Holy Synod +(Joyce, op. cit.). + +The Holy Synod can only inflict temporary suspension, or imprisonment +for fifteen days, unless with the sanction of the King's ministry. +Deprivation, or imprisonment for more than two months, requires the +approval of the king (ib.). The king or the ministry do not, however, +rehear the cause by way of appeal, but merely restrain severity of +sentence (ib.). + +The Church of Cyprus has been autocephalous since at any rate the +oecumenical synod of Ephesus in 431. The episcopate now consists of an +archbishop and three suffragans (Hackett, _Orthodox Church in Cyprus_, +1901, ch. v. _et passim_). The final court is the island synod, which +consists of the archbishop, his suffragans and four dignified priests. +It has original and exclusive cognizance of causes of deposition of +bishops (op. cit. pp. 260, 262). + +Each bishop is assisted by at least two officers with judicial or +quasi-judicial powers, the "archimandrite" who adjudicates upon causes +of revenue and the archdeacon who adjudicates on questions between +deacons (op. cit. pp. 272-273). The "exarch" of the archbishop, who is a +dignitary but not a bishop, has a seat in the provincial synod. + +In the Balkan States, the system--inherited from Byzantine and Turkish +times--of ecclesiastical jurisdictions prevails, except that they are +now autocephalous, and independent of the patriarch of Constantinople. +Matrimonial causes in Servia are of ecclesiastical cognizance (Lehr, op. +cit. sect. 901). + + AUTHORITIES.--St Augustine, _Epistles_; _Codex Theodosianus_, edited + by Th. Mommsen and P.M. Meyer (1905); _Code and Novells of Emperor + Justinian_, ed. J. Gothofredus (1665); T. Balsamon, "In Conc. Ancyr." + in the _Corpus juris canonici_ (1879-1881); "_Hostiensis_" _Super + Decretum_; W. Lyndwood, _Provinciale_ (Oxford, 1679); Sir A. + Fitzherbert, _Natura brevium_ (1534); Sir T. Ridley, _View of the + Civile and Ecclesiastical Law_ (1607); J. Ayliffe, _Parergon juris + ecclesiastici_ (1726); J. Godolphin, _Abridgement of the Laws + Ecclesiastical_ (London, 1687); E. Gibson, _Codex juris ecclesiastici_ + (Oxford, 1761); D. Covarruvias, _Opera omnia_ (Antwerp, 1638); Jean + Hardouin, _Concilia_ (1715); J.D. Mansi, _Concilia_ (1759-1798); E. + Stillingfleet, _Ecclesiastical Jurisdiction_ (1704); L.S. le Nain de + Tillemont, _Memoires pour servir a l'histoire ecclesiastique_ + (1701-1712); P.T. Durand de Maillane, _Dictionnaire du droit + canonique_ (1761); _Dictionnaire ecclesiastique et canonique_, par une + societe de religieux (Paris, 1765); Z.B. van Espen, _Jus + ecclesiasticum universum_ (Louvain, 1720), _De recursu ad Principem, + observationes in Concilium Lateranense iv._; L. Thomassin, _Vetus et + nova disciplina ecc._ (1705-1706); W. Beveridge, _Synodicon_ (Oxford, + 1672); J.A.S. da Carnota, _Life of Pombal_ (1843); J.P. Migne, + _Dictionnaire de droit canon._ (Paris, 1844); R. Keith, _History of + the Scottish Bishops_ (Edinburgh, 1824); P.N. Vives y Cebria, _Usages + y demas derechos de Cataluna_ (1832); C.A. Cornelius, _Svenska Kyrkaus + Historia_ (Upsala, 1875); Mouravieff, _History of the Russian Church_ + (trans. Blackmore, 1842); Ffoulkes, _Manual of Ecclesiastical History_ + (1851); E.H. Landon, _Manual of Councils of the Church_ (1893); W.H. + Hale, _Precedents in Criminal Cases_ (London, 1847); E.B. Pusey, + _Councils of the Church_ (Oxford, 1857); C.J. von Hefele, + _Conciliengeschichte_ (Freiburg, 1855-1890); M. Gaudry, _Traite de la + legislation des cultes_ (Paris, 1854); W. Stubbs, _Select Charters_ + (Oxford, 1895); A.W. Haddan and W. Stubbs, _Councils and + Ecclesiastical Documents_ (Oxford, 1869); A.J. Stephens, + _Ecclesiastical Statutes_ (1845); H.C. Rothery, _Return of Cases + before Delegates_ (1864); J.W. Joyce, _The Sword and the Keys_ (2nd + ed., 1881); _Report of Ecclesiastical Courts Commission_ (1888); P. + Fournier, _Les Officialites au moyen age_ (1880); S.B. Smith, + _Elements of Ecclesiastical Law_ (New York, 1889-1890); S. Sanguineti, + _Juris ecc. inst._ (Rome, 1890); J.F. Stephen, _History of the + Criminal Law of England_ (London, 1883); Pollock and Maitland, + _History of English Law before Edward I._ (1898); F.W. Maitland, + _Roman Canon Law in the Church of England_ (1898); R. Owen, _Canon + Law_ (1884); Sir R.J. Phillimore, _Ecclesiastical Law_ (2nd ed., + 1895); J.W. Brodie-Innes, _Comparative Principles of the Laws of + England and Scotland_ (1903); R.B. Merriman, _Life and Letters of + Thomas Cromwell_ (1902); S. Aichner, _Compendium juris ecclesiast._ + (8th ed., Brixen, 1905, especially in regard to Austro-Hungarian + Empire); J. Hackett, _History of the Orthodox Church in Cyprus_ + (1901); Tauber, _Manuale juris canonici_ (1906); E.L. Taunton, _Law of + the Church_ (London, 1906); _Report of Royal Commission on + Ecclesiastical Discipline_ (1906). (W. G. F. P.) + + + + +ECCLESIASTICAL LAW, in its broadest sense, the sum of the authoritative +rules governing the Christian Church, whether in its internal polity or +in its relations with the secular power. Since there are various +churches, widely differing alike in their principles and practice, it +follows that a like difference exists in their ecclesiastical law, which +is the outcome of their corporate consciousness as modified by their +several relations to the secular authority. At the outset a distinction +must be made between churches which are "established" and those that are +"free." The ecclesiastical laws of the latter are, like the rules of a +private society or club, the concern of the members of the church only, +and come under the purview of the state only in so far as they come in +conflict with the secular law (e.g. polygamy among the Mormons, or +violation of the trust-deeds under which the property of a church is +held). In the case of "established" Churches, on the other hand, +whatever the varying principle on which the system is based, or the +difference in its practical application, the essential conditions are +that the ecclesiastical law is also the law of the land, the decisions +of the church courts being enforced by the civil power. This holds good +both of the Roman Catholic Church, wherever this is recognized as the +"state religion," of the Oriental Churches, whether closely identified +with the state itself (as in Russia), or endowed with powers over +particular nationalities within the state (as in the Ottoman empire), +and of the various Protestant Churches established in Great Britain and +on the continent of Europe. + +Writers on the theory of ecclesiastical law, moreover, draw a fundamental +distinction between that of the Church of Rome and that of the Protestant +national or territorial Churches. This distinction is due to the claim of +the Roman Catholic Church to be the _only_ Church, her laws being thus of +universal obligation; whereas the laws of the various established +Protestant Churches are valid--at least so far as legal obligation is +concerned--only within the limits of the countries in which they are +established. The practical effects of this distinction have been, and +still are, of enormous importance. The Roman Catholic Church, even when +recognized as the state religion, is nowhere "established" in the sense +of being identified with the state, but is rather an _imperium in +imperio_ which negotiates on equal terms with the state, the results +being embodied in concordats (q.v.) between the state and the pope as +head of the Church. The concordats are of the nature of truces in the +perennial conflict between the spiritual and secular powers, and imply in +principle no surrender of the claims of the one to those of the other. +Where the Roman Catholic Church is not recognized as a state religion, as +in the United States or in the British Islands, she is in the position of +a "free Church," her jurisdiction is only _in foro conscientiae_, and her +ecclesiastical laws have no validity from the point of view of the state. +On the other hand, the root principle of the ecclesiastical law of the +established Protestant Churches is the rejection of alien jurisdiction +and the assertion of the supremacy of the state. The theory underlying +this may vary. The sovereign may be regarded, as in the case of the +Russian emperor or of the English kings from the Reformation to the +Revolution, as the vicar of God in all causes spiritual as well as +temporal within his realm. As the first fervent belief in the divine +right of kings faded, however, a new basis had to be discovered for a +relation between the spiritual and temporal powers against which Rome had +never ceased to protest. This was found in the so-called "collegial" +theory of Church government (_Kollegialsystem_), which assumed a sort of +tacit concordat between the state and the religious community, by which +the latter vests in the former the right to exercise a certain part of +the _jus in sacra_ properly inherent in the Church (see PUFENDORF, +SAMUEL). This had great and lasting effects on the development of the +theory of Protestant ecclesiastical law on the continent of Europe. In +England, on the other hand, owing to the peculiar character of the +Reformation there and of the Church that was its outcome, no theory of +the ecclesiastical law is conceivable that would be satisfactory at once +to lawyers and to all schools of opinion within the Church. This has been +abundantly proved by the attitude of increasing opposition assumed by the +clergy, under the influence of the Tractarian movement, towards the civil +power in matters ecclesiastical, an attitude impossible to justify on any +accepted theory of the Establishment (see below). + +Protestant ecclesiastical law, then, is distinguished from that of the +Roman Catholic Church (1) by being more limited in its scope, (2) by +having for its authoritative source, not the Church only or even mainly, +but the Church in more or less complete union with or subordination to +the State, the latter being considered, equally with the Church, as an +organ of the will of God. The ecclesiastical law of the Church of Rome, +on the other hand, whatever its origin, is now valid only in so far as +it has the sanction of the authority of the Holy See. And here it must +be noted that the "canon law" is not identical with the "ecclesiastical +law" of the Roman Catholic Church. By the canon law is meant, +substantially, the contents of the _Corpus juris canonici_, which have +been largely superseded or added to by, e.g. the canons of the council +of Trent and the Vatican decrees. The long projected codification of the +whole of the ecclesiastical law of the Church of Rome, a work of +gigantic labour, was not taken in hand until the pontificate of Pius X. +(See also CANON LAW and ECCLESIASTICAL JURISDICTION.) + +The ecclesiastical law of England is in complete dependence upon the +authority of the state. The Church of England cannot be said, from a +legal point of view, to have a corporate existence or even a +representative assembly. The Convocation of York and the Convocation of +Canterbury are provincial assemblies possessing no legislative or +judicial authority; even such purely ecclesiastical questions as may be +formally commended to their attention by "letters of business" from the +crown can only be finally settled by act of parliament. The +ecclesiastical courts are for the most part officered by laymen, whose +subordination to the archbishops and bishops is purely formal, and the +final court of appeal is the Judicial Committee of the Privy Council. In +like manner changes in the ecclesiastical law are made directly by +parliament in the ordinary course of legislation, and in point of fact a +very large portion of the existing ecclesiastical law consists of acts +of parliament. + +The sources of the ecclesiastical law of England are thus described by +Dr. Richard Burn (_The Ecclesiastical Law_, 9th ed., 1842):--"The +ecclesiastical law of England is compounded of these four main +ingredients--the civil law, the canon law, the common law, and the +statute law. And from these, digested in their proper rank and +subordination, to draw out one uniform law of the church is the purport +of this book. When these laws do interfere and cross each other, the +order of preference is this:--'The civil law submitteth to the canon +law; both of these to the common law; and all three to the statute law. +So that from any one or more of these, without all of them together, or +from all of them together without attending to their comparative +obligation, it is not possible to exhibit any distinct prospect of the +English ecclesiastical constitution.' Under the head of statute law Burn +includes 'the Thirty-nine Articles of Religion, agreed upon in +Convocation in the year 1562; and in like manner the Rubric of the Book +of Common Prayer, which, being both of them established by Acts of +Parliament, are to be esteemed as part of the statute law.'" + +The first principle of the ecclesiastical law in England is the +assertion of the supremacy of the crown, which in the present state of +the constitution means the same thing as the supremacy of parliament. +This principle has been maintained ever since the Reformation. Before +the Reformation the ecclesiastical supremacy of the pope was recognized, +with certain limitations, in England, and the Church itself had some +pretensions to ecclesiastical freedom. The freedom of the Church is, in +fact, one of the standing provisions of those charters on which the +English constitution was based. The first provision of Magna Carta is +_quod ecclesia Anglicana libera sit_. By the various enactments of the +period of the Reformation the whole constitutional position of the +Church, not merely with reference to the pope but with reference to the +state, was definitely fixed. The legislative power of convocation was +held to extend to the clergy only, and even to that extent required the +sanction and assent of the crown. The common law courts controlled the +jurisdiction of the ecclesiastical courts, claiming to have "the +exposition of such statutes or acts of parliament as concern either the +extent of the jurisdiction of these courts or the matters depending +before them. And therefore if these courts either refuse to allow these +acts of parliament, or expound them in any other sense than is truly and +properly the exposition of them, the king's great courts of common law +may prohibit and control them." + +The design of constructing a code of ecclesiastical laws was entertained +during the period of the Reformation, but never carried into effect. It +is alluded to in various statutes of the reign of Henry VIII., who +obtained power to appoint a commission to examine the old ecclesiastical +laws, with a view of deciding which ought to be kept and which ought to +be abolished; and in the meantime it was enacted that "such canons, +institutions, ordinances, synodal or provincial or other ecclesiastical +laws or jurisdictions spiritual as be yet accustomed and used here in +the Church of England, which necessarily and conveniently are requisite +to be put in ure and execution for the time, not being repugnant, +contrarient, or derogatory to the laws or statutes of the realm, nor to +the prerogatives of the royal crown of the same, or any of them, shall +be occupied, exercised, and put in ure for the time with this realm" (35 +Henry VIII. c. 16, 25 c. 19, 27 c. 8). + +The work was actually undertaken and finished in the reign of Edward VI. +by a sub-committee of eight persons, under the name of the _Reformatio +legum ecclesiasticarum_, which, however, never obtained the royal +assent. Although the powers of the 25 Henry VIII. c. 1 were revived by +the 1 Elizabeth c. 1, the scheme was never executed, and the +ecclesiastical laws remained on the footing assigned to them in that +statute--so much of the old ecclesiastical laws might be used as had +been actually in use, and was not repugnant to the laws of the realm. + +The statement is, indeed, made by Sir R. Phillimore (_Ecclesiastical +Law_, 2nd ed., 1895) that the "Church of England has at all times, +before and since the Reformation, claimed the right of an independent +Church in an independent kingdom, to be governed by the laws which she +has deemed it expedient to adopt." This position can only be accepted if +it is confined, as the authorities cited for it are confined, to the +resistance of interference from abroad. If it mean that the Church, as +distinguished from the kingdom, has claimed to be governed by laws of +her own making, all that can be said is that the claim has been +singularly unsuccessful. From the time of the Reformation no change has +been made in the law of the Church which has not been made by the king +and parliament, sometimes indirectly, as by confirming the resolutions +of convocation, but for the most part by statute. The list of statutes +cited in Sir R. Phillimore's _Ecclesiastical Law_ fills eleven pages. It +is only by a kind of legal fiction akin to the "collegial" theory +mentioned above, that the Church can be said to have deemed it expedient +to adopt these laws. + +The terms on which the Church Establishment of Ireland was abolished, by +the Irish Council Act of 1869, may be mentioned. By sect. 20 the present +ecclesiastical law was made binding on the members for the time being of +the Church, "as if they had mutually contracted and agreed to abide by +and observe the same"; and by section 21 it was enacted that the +ecclesiastical courts should cease after the 1st of January 1871, and +that the ecclesiastical laws of Ireland, except so far as relates to +matrimonial causes and matters, should cease to exist as law. (See also +ENGLAND, CHURCH OF; ESTABLISHMENT; &c.) + + AUTHORITIES.--The number of works on ecclesiastical law is very great, + and it must suffice here to mention a few of the more conspicuous + modern ones: Ferdinand Walter, _Lehrbuch des Kirchenrechts aller + christlichen Konfessionen_ (14th ed., Bonn, 1871); G. Phillips, + _Kirchenrecht_, Bde. i.-vii. (Regensburg, 1845-1872) incomplete; the + text-book by Cardinal Hergenroether (q.v.); P. Hinschius, _Kirchenrecht + der Katholiken und Protestanten in Deutschland_, 6 Bde. (Berlin, 1869 + sqq.), only the Catholic part, a masterly and detailed survey of the + ecclesiastical law, finished; Sir Robert Phillimore, _Eccl. Law of the + Church of England_ (2nd ed., edited by Sir Walter Phillimore, 2 vols., + London, 1895). For further references see CANON LAW, and the article + "Kirchenrecht" in Herzog-Hauck, _Realencyklopaedie_ (ed. Leipzig, + 1901). + + + + +ECCLESIASTICUS (abbreviated to _Ecclus._), the alternative title given +in the English Bible to the apocryphal book otherwise called "The Wisdom +of Jesus the son of Sirach." The Latin word _ecclesiasticus_ is, +properly speaking, not a name, but an epithet meaning "churchly," so +that it would serve as a designation of any book which was read in +church or received ecclesiastical sanction, but in practice +Ecclesiasticus has become a by-name for the Wisdom of Sirach. The true +name of the book appears in the authorities in a variety of forms, the +variation affecting both the author's name and the description of his +book. The writer's full name is given in 1. 27 (Heb. text) as "Simeon +the son of Jeshua (i.e. Jesus) the son of Eleazar the son of Sira." In +the Greek text this name appears as "Jesus son of Sirach Eleazar" +(probably a corruption of the Hebrew reading), and the epithet "of +Jerusalem" is added, the translator himself being resident in Egypt. The +whole name is shortened sometimes to "Son of Sira," _Ben Sira_ in +Hebrew, _Bar Sira_ in Aramaic, and sometimes (as in the title prefixed +in the Greek cod. B) to _Sirach_. The work is variously described as the +_Words_ (Heb. text), the _Book_ (Talmud), the _Proverbs_ (Jerome), or +the _Wisdom_ of the son of Sira (or Sirach). + +Of the date of the book we have only one certain indication. It was +translated by a person who says that he "came into Egypt in the 38th +year of Euergetes the king" (Ptolemy VII.), i.e. in 132 B.C., and that +he executed the work some time later. The translator believed that the +writer of the original was his own grandfather (or ancestor, [Greek: +pappos]). It is therefore reasonable to suppose that the book was +composed not later than the first half of the 2nd century B.C., or (if +we give the looser meaning to [Greek: pappos]) even before the beginning +of the century. Arguments for a pre-Maccabean date may be derived (a) +from the fact that the book contains apparently no reference to the +Maccabean struggles, (b) from the eulogy of the priestly house of Zadok +which fell into disrepute during these wars for independence. + +In the Jewish Church Ecclesiasticus hovered on the border of the canon; +in the Christian Church it crossed and recrossed the border. The book +contains much which attracted and also much which repelled Jewish +feeling, and it appears that it was necessary to pronounce against its +canonicity. In the Talmud (Sanhedrin 100 b) Rabbi Joseph says that it is +forbidden to read (i.e. in the synagogue) the book of ben Sira, and +further that "if our masters had not hidden the book (i.e. declared it +uncanonical), we might interpret the good things which are in it" +(Schechter, _J. Q. Review_, iii. 691-692). In the Christian Church it +was largely used by Clement of Alexandria (c. A.D. 200) and by St +Augustine. The lists of the Hebrew canon, however, given by Melito (c. +A.D. 180) and by Origen (c. A.D. 230) rightly exclude Ecclesiasticus, +and Jerome (c. A.D. 390-400) writes: "Let the Church read these two +volumes (Wisdom of Solomon and Ecclesiasticus) for the instruction of +the people, not for establishing the authority of the dogmas of the +Church" (_Praefatio in libros Salomonis_). In the chief MS. of the +Septuagint, cod. B, Ecclesiasticus comes between Wisdom and Esther, no +distinction being drawn between canonical and uncanonical. In the +Vulgate it immediately precedes Isaiah. The council of Trent declared +this book and the rest of the books reckoned in the Thirty-nine Articles +as apocryphal to be canonical. + +The text of the book raises intricate problems which are still far from +solution. The original Hebrew (rediscovered in fragments and published +between 1896 and 1900) has come down to us in a mutilated and corrupt +form. The beginning as far as iii. 7 is lost. There is a gap from xvi. +26 to xxx. 11. There are marginal readings which show that two different +recensions existed once in Hebrew. The Greek version exists in two +forms--(a) that preserved in cod. B and in the other uncial MSS., (b) +that preserved in the cursive codex 248 (Holmes and Parsons). The former +has a somewhat briefer text, the latter agrees more closely with the +Hebrew text. The majority of Greek cursives agree generally with the +Latin Vulgate, and offer the fuller text in a corrupt form. The Syriac +(Peshitta) version is paraphrastic, but on the whole it follows the +Hebrew text. Owing to the mutilation of the Hebrew by the accidents of +time the Greek version retains its place as the chief authority for the +text, and references by chapter and verse are usually made to it. + +Bickell and D.S. Margoliouth have supposed that the Hebrew text +preserved in the fragments is not original, but a retranslation from the +Greek or the Syriac or both. This view has not commended itself to the +majority of scholars, but there is at least a residuum of truth in it. +The Hebrew text, as we have it, has a history of progressive corruption +behind it, and its readings can often be emended from the Septuagint, +e.g. xxxvii. 11 (read [Hebrew: umira] for the meaningless [Hebrew: +umerer]). The Hebrew marginal readings occasionally seem to be +translations from the Greek or Syriac, e.g. xxxviii. 4 ([Hebrew: bara +shamaym] for [Greek: ektisen pharmaka]). More frequently, however, +strange readings of the Greek and Syriac are to be explained as +corruptions of our present Hebrew. Substantially our Hebrew must be +pronounced original. + +The restoration of a satisfactory text is beyond our hopes. Even before +the Christian era the book existed in two recensions, for we cannot +doubt, after reading the Greek translator's preface, that the translator +amplified and paraphrased the text before him. It is probable that at +least one considerable omission must be laid to his charge, for the hymn +preserved in the Hebrew text after ch. li. 12 is almost certainly +original. Ancient translators allowed themselves much liberty in their +work, and Ecclesiasticus possessed no reputation for canonicity in the +2nd century B.C. to serve as a protection for its text. Much, however, +may be done towards improving two of the recensions which now lie before +us. The incomplete Hebrew text exists in four different MSS., and the +study of the peculiarities of these had already proved fruitful. The +Syriac text, made without doubt from the Hebrew, though often +paraphrastic is often suggestive. The Greek translation, made within a +century or half-century of the writing of the book, must possess great +value for the criticism of the Hebrew text. The work of restoring true +Hebrew readings may proceed with more confidence now that we have +considerable portions of the Hebrew text to serve as a model. For the +restoration of the Greek text we have, besides many Greek MSS., uncial +and cursive, the old Latin, the Syro-Hexaplar, the Armenian, Sahidic and +Ethiopic versions, as well as a considerable number of quotations in the +Greek and Latin Fathers. Each of the two recensions of the Greek must, +however, be separately studied, before any restoration of the original +Greek text can be attempted. + +The uncertainty of the text has affected both English versions +unfavourably. The Authorized Version, following the corrupt cursives, is +often wrong. The Revised Version, on the other hand, in following the +uncial MSS. sometimes departs from the Hebrew, while the Authorized +Version with the cursives agrees with it. Thus the Revised Version (with +codd. [Hebrew: alef]*, A, B, C) omits the whole of iii. 19, which the +Authorized Version retains, but for the clause, "Mysteries are revealed +unto the meek," the Authorized Version has the support of the Hebrew, +Syriac and cod. 248. Sometimes both versions go astray in places in +which the Hebrew text recommends itself as original by its vigour; e.g. +in vii. 26, where the Hebrew is, + + Hast thou a wife? abominate her not. + Hast thou a hated wife? trust not in her. + +Again in ch. xxxviii. the Hebrew text in at least two interesting +passages shows its superiority over the text which underlies both +English versions. + + _Hebrew._ _Revised Version (similarly + Authorized Version)._ + + ver. 1. Acquaint thyself with a Honour a physician according + physician before thou have to thy need of him with the + need of him. honours due unto him. + + ver. 15. He that sinneth against his He that sinneth before his + Maker will behave himself Maker, let him fall into the + proudly against a physician. hands of the physician. + +In the second instance, while the Hebrew says that the man who rebels +against his Heavenly Benefactor will _a fortiori_ rebel against a human +benefactor, the Greek text gives a cynical turn to the verse, "Let the +man who rebels against his true benefactor be punished through the +tender mercies of a quack." The Hebrew text is probably superior also in +xliv. 1, the opening words of the eulogy of the Fathers: "Let me now +praise favoured men," i.e. men in whom God's grace was shown. The Hebrew +phrase is "men of grace," as in v. 10. The Greek text of v. 1, "famous +men," seems to be nothing but a loose paraphrase, suggested by v. 2, +"The Lord manifested in them great glory." + +In character and contents Ecclesiasticus resembles the book of Proverbs. +It consists mainly of maxims which may be described in turn as moral, +utilitarian and secular. Occasionally the author attacks prevalent +religious opinions, e.g. the denial of free-will (xv. 11-20), or the +assertion of God's indifference towards men's actions (xxxv. 12-19). +Occasionally, again, Ben Sira touches the highest themes, and speaks of +the nature of God: "He is All" (xliii. 27); "He is One from everlasting" +(xlii. 21, Heb. text); "The mercy of the Lord is upon all flesh" (xviii. +13). Though the book is imitative and secondary in character it contains +several passages of force and beauty, e.g. ch. ii. (how to fear the +Lord); xv. 11-20 (on free-will); xxiv. 1-22 (the song of wisdom); xlii. +15-25 (praise of the works of the Lord); xliv. 1-15 (the well-known +praise of famous men). Many detached sayings scattered throughout the +book show a depth of insight, or a practical shrewdness, or again a +power of concise speech, which stamps them on the memory. A few examples +out of many may be cited. "Call no man blessed before his death" (xi. +28); "He that toucheth pitch shall be defiled" (xiii. 1); "He hath not +given any man licence to sin" (xv. 20); "Man cherisheth anger against +man; and doth he seek healing from the Lord?" (xxviii. 3); "Mercy is +seasonable ... as clouds of rain" (xxxv. 20); "All things are double one +against another: and he hath made nothing imperfect" (xlii. 24, the +motto of Butler's _Analogy_); "Work your work before the time cometh, +and in his time he will give you your reward" (li. 30). In spite, +however, of the words just quoted it cannot be said that Ben Sira +preaches a hopeful religion. Though he prays, "Renew thy signs, and +repeat thy wonders ... Fill Sion with thy majesty and thy Temple with +thy glory" (xxxvi. 6, 14 [19], Heb. text), he does not look for a +Messiah. Of the resurrection of the dead or of the immortality of the +soul there is no word, not even in xli. 1-4, where the author exhorts +men not to fear death. Like the Psalmist (Ps. lxxxviii. 10, 11) he asks, +"Who shall give praise to the Most High in the grave?" In his maxims of +life he shows a somewhat frigid and narrow mind. He is a pessimist as +regards women; "From a woman was the beginning of sin; and because of +her we all die" (xxv. 24). He does not believe in home-spun wisdom; "How +shall he become wise that holdeth the plough?" (xxxviii. 25). Artificers +are not expected to pray like the wise man; "In the handywork of their +craft is their prayer" (v. 34). Merchants are expected to cheat; "Sin +will thrust itself in between buying and selling" (xxvii. 2). + + BIBLIOGRAPHY.--The literature of Ecclesiaticus has grown very + considerably since the discovery of the first Hebrew fragment in 1896. + A useful summary of it is found at the end of Israel Levi's article, + "Sirach," in the _Jewish Encyclopedia_. Eberhard Nestle's article in + Hastings's _Dictionary of the Bible_ is important for its + bibliographical information as well as in other respects. A complete + edition of the Hebrew fragments in collotype facsimile was published + jointly by the Oxford and Cambridge Presses in 1901. J.H.A. Hart's + edition of cod. 248 throws much light on some of the problems of this + book. It contains a fresh collation of all the chief authorities + (Heb., Syr., Syr.-Hex., Lat. and Gr.) for the text, together with a + complete textual commentary. + + The account given in the _Synopsis_ attributed to Athanasius (Migne, + _P.G._, iv. 375-384) has an interest of its own. The beginning is + given in the Authorized Version as "A prologue made by an uncertain + author." (W. E. B.) + + + + +ECGBERT, or ECGBERHT (d. 839), king of the West Saxons, succeeded to the +throne in 802 on the death of Beorhtric. It is said that at an earlier +period in his life he had been driven out for three years by Offa and +Beorhtric. The accession of Ecgbert seems to have brought about an +invasion by AEthelmund, earl of the Hwicce, who was defeated by Weoxtan, +earl of Wiltshire. In 815 Ecgbert ravaged the whole of the territories +of the West Welsh, which probably at this time did not include much more +than Cornwall. The next important occurrence in the reign was the defeat +of Beornwulf of Mercia at a place called Ellandun in 825. After this +victory Kent, Surrey, Sussex and Essex submitted to Wessex; while the +East Anglians, who slew Beornwulf shortly afterwards, acknowledged +Ecgbert as overlord. In 829 the king conquered Mercia, and Northumbria +accepted him as overlord. In 830 he led a successful expedition against +the Welsh. In 836 he was defeated by the Danes, but in 838 he won a +battle against them and their allies the West Welsh at Hingston Down in +Cornwall. Ecgbert died in 839, after a reign of thirty-seven years, and +was succeeded by his son AEthelwulf. A somewhat difficult question has +arisen as to the parentage of Ecgbert. Under the year 825 the Chronicle +states that in his eastern conquests Ecgbert recovered what had been +the rightful property of his kin. The father of Ecgbert was called +Ealhmund, and we find an Ealhmund, king in Kent, mentioned in a charter +dated 784, who is identified with Ecgbert's father in a late addition to +the Chronicle under the date 784. It is possible, however, that the +Chronicle in 825 refers to some claim through Ine of Wessex from whose +brother Ingeld Ecgbert was descended. + + See _Anglo-Saxon Chronicle_, edited by Earle and Plummer (Oxford, + 1899); W. de G. Birch, _Cartularium Saxonicum_ (London, 1885-1893). + Also a paper by Sir H.H. Howorth in _Numismatic Chronicle_, third + series, vol. xx. pp. 66-87 (reprinted separately, London, 1900), where + attention is called to the peculiar dating of several of Ecgbert's + charters, and the view is put forward that he remained abroad + considerably later than the date given by the Chronicle for his + accession. On the other hand a charter in Birch, _Cart. Sax._, + purporting to date from 799, contains the curious statement that peace + was made between Coenwulf and Ecgbert in that year. + + + + +ECGBERT, or ECGBERHT (d. 766), archbishop of York, was made bishop of +that see in 734 by Ceolwulf, king of Northumbria, succeeding Wilfrid II. +on the latter's resignation. The pall was sent him in 735 and he became +the first northern archbishop after Paulinus. He was the brother of +Eadberht, who ruled Northumbria 737-758. He was the recipient of the +famous letter of Bede, dealing with the evils arising from spurious +monasteries. Ecgberht himself wrote a _Dialogus Ecclesiasticae +Institutionis_, a _Penitentiale_ and a _Pontificale_. He was a +correspondent of St Boniface, who asks him to support his censure of +AEthelbald of Mercia. + + See Bede, _Continuatio_, sub. ann. 732, 735, 766, and _Epistola ad + Ecgberctum_ (Plummer, Oxford, 1896); _Chronicle_, sub ann. 734, 735, + 738, 766 (Earle and Plummer, Oxford, 1899); Haddan and Stubbs, + _Councils and Ecclesiastical Documents_ (Oxford, 1869-1878), iii. + 403-431; _Proceedings of Surtees Society_ (Durham, 1853). + + + + +ECGFRITH (d. 685), king of Northumbria, succeeded his father Oswio in +671. He was married to AEthelthryth, daughter of Anna of East Anglia, +who, however, took the veil shortly after Ecgfrith's accession, a step +which possibly led to his long quarrel with Wilfrid archbishop of York. +Ecgfrith married a second wife, Eormenburg, before 678, the year in +which he expelled Wilfrid from his kingdom. Early in his reign he +defeated the Picts who had risen in revolt. Between 671 and 675 Ecgfrith +defeated Wulfhere of Mercia and seized Lindsey. In 679, however, he was +defeated by AEthelred of Mercia, who had married his sister Osthryth, on +the river Trent. Ecgfrith's brother AElfwine was killed in the battle, +and the province of Lindsey was given up when peace was restored at the +intervention of Theodore of Canterbury. In 684 Ecgfrith sent an +expedition to Ireland under his general Berht, which seems to have been +unsuccessful. In 685, against the advice of Cuthbert, he led a force +against the Picts under his cousin Burde, son of Bile, was lured by a +feigned flight into their mountain fastnesses, and slain at +Nechtanesmere (now Dunnichen) in Forfarshire. Bede dates the beginning +of the decline of Northumbria from his death. He was succeeded by his +brother Aldfrith. + + See Eddius, _Vita Wilfridi_ (Raine, _Historians of Church of York_, + Rolls, Series, London, 1879-1894), 19, 20, 24, 34, 39, 44; Bede, + _Hist. Eccl._ (Plummer, Oxford, 1896), iii. 24, iv. 5, 12, 13, 18, 19, + 21, 26. + + + + +ECGONINE, in chemistry, C9H15NO3, a cycloheptane derivative with a +nitrogen bridge. It is obtained by hydrolysing cocaine with acids or +alkalis, and crystallizes with one molecule of water, the crystals +melting at 198 deg. to 199 deg. C. It is laevo-rotatory, and on warming with +alkalis gives iso-ecgonine, which is dextro-rotatory. It is a tertiary +base, and has also the properties of an acid and an alcohol. When boiled +with caustic baryta it gives methylamine. It is the carboxylic acid +corresponding to tropine, for it yields the same products on oxidation, +and by treatment with phosphorus pentachloride is converted into +anhydroecgonine, C9H13NO2, which, when heated to 280 deg. C. with +hydrochloric acid, splits out carbon dioxide and yields tropidine, +C8H13N. Anhydroecgonine melts at 235 deg. C., and has an acid and a basic +character. It is an unsaturated compound, and on oxidation with +potassium permanganate gives succinic acid. It is apparently a tropidine +monocarboxylic acid, for on exhaustive methylation it yields +cycloheptatriene-1.3.5-carboxylic acid-7. Sodium in amyl alcohol +solution reduces it to hydroecgonidine C9H15NO2, while moderate +oxidation by potassium permanganate converts it into _norecgonine_. The +presence of the heptamethylene ring in these compounds is shown by the +production of suberone by the exhaustive methylation, &c., of +hydroecgonidine ethyl ester (see POLYMETHYLENES and TROPINE). The above +compounds may be represented as: + + CH2--CH----CH COOH CH2--CH----CH COOH CH2--CH------CH COOH + | | | | | | | | | + | N CH3 CH OH | N CH3 CH | N CH3 CH2 + | | | | | || | | | + CH2--CH----CH2 CH2--CH----CH CH2--CH------CH2 + Ecgonine Anhydroecgonine Hydroecgonine + + + + +ECHEGARAY Y EIZAGUIRRE, JOSE (1833- ), Spanish mathematician, +statesman and dramatist, was born at Madrid in March 1833, and was +educated at the grammar school of Murcia, whence he proceeded to the +Escuela de Caminos at the capital. His exemplary diligence and unusual +mathematical capacity were soon noticed. In 1853 he passed out at the +head of the list of engineers, and, after a brief practical experience +at Almeria and Granada, was appointed professor of pure and applied +mathematics in the school where he had lately been a pupil. His +_Problemas de geometria analitica_ (1865) and _Teorias modernas de la +fisica unidad de las fuerzas materiales_ (1867) are said to be esteemed +by competent judges. He became a member of the Society of Political +Economy, helped to found _La Revista_, and took a prominent part in +propagating Free Trade doctrines in the press and on the platform. He +was clearly marked out for office, and when the popular movement of 1868 +overthrew the monarchy, he resigned his post for a place in the +revolutionary cabinet. Between 1867 and 1874 he acted as minister of +education and of finance; upon the restoration of the Bourbon dynasty he +withdrew from politics, and won a new reputation as a dramatist. + +As early as 1867 he wrote _La Hija natural_, which was rejected, and +remained unknown till 1877, when it appeared with the title of _Para tal +culpa tal pena_. Another play, _La Ultima Noche_, also written in 1867, +was produced in 1875; but in the latter year Echegaray was already +accepted as the successful author of _El Libro talonario_, played at the +Teatro de Apolo on the 18th of February 1874, under the transparent +pseudonym of Jorge Hayaseca. Later in the same year Echegaray won a +popular triumph with _La Esposa del vengador_, in which the good and bad +qualities--the clever stagecraft and unbridled extravagance--of his +later work are clearly noticeable. From 1874 onwards he wrote, with +varying success, a prodigious number of plays. Among the most favourable +specimens of his talent may be mentioned _En el puno de la espada_ +(1875); _O locura o santidad_ (1877), which has been translated into +Swedish and Italian; _En el seno de la muerte_ (1879), of which there +exists an admirable German version by Fastenrath. _El gran Galeoto_ +(1881), perhaps the best of Echegaray's plays in conception and +execution, has been translated into several languages, and still holds +the stage. The humorous proverb, _?Piensa mal y acertaras?_ exemplifies +the author's limitations, but the attempt is interesting as an instance +of ambitious versatility. His susceptibility to new ideas is illustrated +in such pieces as _Mariana_ (1892), _Mancha que limpia_ (1895), _El Hijo +de Don Juan_ (1892), and _El Loco Dios_ (1900): these indicate a close +study of Ibsen, and _El Loco Dios_ more especially might be taken for an +unintentional parody of Ibsen's symbolism. + +Echegaray succeeded to the literary inheritance of Lopez de Ayala and of +Tamayo y Baus; and though he possesses neither the poetic imagination of +the first nor the instinctive tact of the second, it is impossible to +deny that he has reached a larger audience than either. Not merely in +Spain, but in every land where Spanish is spoken, and in cities as +remote from Madrid as Munich and Stockholm, he has met with an +appreciation incomparably beyond that accorded to any other Spanish +dramatist of recent years. But it would be more than usually rash to +prophesy that this exceptional popularity will endure. There have been +signs of a reaction in Spain itself, and Echegaray's return to politics +in 1905 was significant enough. He applies his mathematics to the +drama; no writer excels him in artful construction, in the arrangement +of dramatic scenes, in mere theatrical technique, in the focusing of +attention on his chief personages. These are valuable gifts in their +way, and Echegaray has, moreover, a powerful, gloomy imagination, which +is momentarily impressive. In the drawing of character, in the invention +of felicitous phrase, in the contrivance of verbal music, he is +deficient. He alternates between the use of verse and prose; and his +hesitancy in choosing a medium of expression is amply justified, for the +writer's prose is not more distinguished than his verse. These serious +shortcomings may explain the diminution of his vogue in Spain; they will +certainly tell against him in the estimate of posterity. (J. F.-K.) + + + + +ECHELON (Fr. from _echelle_, ladder), in military tactics, a formation +of troops in which each body of troops is retired on, but not behind, +the flank of the next in front, the position of the whole thus +resembling the steps of a staircase. To form echelon from line, the +parts of the line move off, each direct to its front, in succession, so +that when the formation is completed the rightmost body, for example, is +farthest advanced, the one originally next on its left is to the left +rear, a third is to the left rear of the second, and so on. The word is +also used more loosely to express successive lines, irrespective of +distances and relative positions, e.g. the "second echelon of ammunition +supply," which is fully a day's march behind the first. + + + + +ECHIDNA, or PORCUPINE ANT-EATER (_Echidna aculeata_), one of the few +species of Monotremata, the lowest subclass of Mammalia, forming the +family Echidnidae. It is a native of Australia, where it chiefly abounds +in New South Wales, inhabiting rocky and mountainous districts, where it +burrows among the loose sand, or hides itself in crevices of rocks. In +size and appearance it bears a considerable resemblance to the hedgehog, +its upper surface being covered over with strong spines directed +backwards, and on the back inwards, so as to cross each other on the +middle line. The spines in the neighbourhood of the tail form a tuft +sufficient to hide that almost rudimentary organ. The head is produced +into a long tubular snout, covered with skin for the greater part of its +length. The opening of the mouth is small, and from it the echidna puts +forth its long slender tongue, lubricated with a viscous secretion, by +means of which it seizes the ants and other insects on which it feeds. +It has no teeth. Its legs are short and strong, and form, with its broad +feet and large solid nails, powerful burrowing organs. In common with +the other monotremes, the male echidna has its heel provided with a +sharp hollow spur, connected with a secreting gland, and with muscles +capable of pressing the secretion from the gland into the spur. It is a +nocturnal or crepuscular animal, generally sleeping during the day, but +showing considerable activity by night. When attacked it seeks to escape +either by rolling itself into a ball, its erect spines proving a +formidable barrier to its capture, or by burrowing into the sand, which +its powerful limbs enable it to do with great celerity. "The only mode +of carrying the creature," writes G. Bennett (_Gatherings of a +Naturalist in Australasia_), "is by one of the hind legs; its powerful +resistance and the sharpness of the spines will soon oblige the captor, +attempting to seize it by any other part of the body, to relinquish his +hold." In a younger stage of their development, however, the young are +carried in a temporary abdominal pouch, to which they are transferred +after hatching, and into which open the mammary glands. The echidnas are +exceedingly restless in confinement, and constantly endeavour by +burrowing to effect their escape. From the quantity of sand and mud +always found in the alimentary canal of these animals, it is supposed +that these ingredients must be necessary to the proper digestion of +their insect food. + +There are two varieties of this species, the Port Moresby echidna and +the hairy echidna. The last-mentioned is found in south-eastern New +Guinea, Australia and Tasmania. In all the spines are mixed with hair; +in the Tasmanian race they are nearly hidden by the long harsh fur. Of +the three-clawed echidnas (_Proechidna_) confined to New Guinea there +are two species, Bruijn's echidna (_P. bruijnii_), discovered in 1877 in +the mountains on the north-east coast at an elevation of 3500 ft., and +the black-spined echidna (_P. nigroaculeata_) of larger size--the type +specimen measuring 31 in., as against 24 in.--with shorter +claws. + + + + + + + + +End of the Project Gutenberg EBook of Encyclopaedia Britannica, 11th +Edition, Volume 8, Slice 9, by Various + +*** END OF THIS PROJECT GUTENBERG EBOOK ENCYCLOPAEDIA BRITANNICA *** + +***** This file should be named 34878.txt or 34878.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/3/4/8/7/34878/ + +Produced by Marius Masi, Don Kretz and the Online +Distributed Proofreading Team at http://www.pgdp.net + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +http://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need, are critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at http://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +http://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at http://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit http://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including checks, online payments and credit card donations. +To donate, please visit: http://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart is the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + http://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. |