CONGREVE. 291 CONIBO. cal, Social, and ficlh/ious (1S74). He was early one of the foremost exponents of English Posi- tivism. CONGREVE, WiLLiAii (1670-1729). A bril- liant English dramatist. He was born at Banlsey, Yorkshire, and educated at Kilkenny, and at Trinity College, Dublin. He re- turned to England, and was entered at the Mid- dle Temple, but did not take kindly to law. His first publication was a novel, entitled Incognita, really a dramatic intrigue put into narrative. His first play. The Old Bachelor, was ])roduced at Drury Lane in January, 1093, and its suc- cess was remarkable. In Xovember he brought out The Double-Dealer, which was a compara- tive failure; but his comedy. Love for Lore, per- formed in 1095, was a great success, and brought to its author money and fame. The Mourning Bride, a blank-verse tragedy, was acted in 1097. Its success exceeded even that of his comedies, but it has long since been forgotten. Three years after, he jiroduced a comedy, entitled The Way of the World, which failed completely, and disgusted him with the theatre. In other re- spects C'ongreve was a fortunate man. He held various offices, which together yielded him an income of £1200. C'ongreve afTected to despise his theatrical triumphs, and cultivated the man- ners of the fine gentleman — an eccentricity which laid him open to rebuke when he was visited by Voltaire. In his later days he was afflicted with gout and l)lindness. He died in London, 1729, and was buried in Westminster Abbey. As a comic dramatist Congreve has been variously estimated. He was gross, but his age was gross. His plots are intricate, but they were so intend- ed. His world is composed of wives, gallants, and husbands — and the husbands are hoodwinked. The characters have no heart, no generosity, but they play their parts brilliantly. Indeed, the wit of C'ongreve's dialogue is unsurpassed in our later drama. Famous essays on Congreve and the art he represents are: Hazlitt, Lectures on Enalish Poets and Enqlish Comic Writers (London. 1840) : Lamb. "On the Artificial Com- edy of the Last Century," in Essui/s of Elia (London, 1875) ; Leigh Hunt, critical notice, prefixed to The Dramatic Works of Wi/ehcrley, Congreve, etc.. which he edited; Macaulay, re- view of Hunt, entitled Comic Dramatists or Leigh Hunt (London, 1848) ; and Swinburne, article on Congreve in Encyclopredia Britannica. Consult: Congreve 's Comedies, ed. Ewald (Lon- don, 1887) ; id., ed. Street (London, 1895) ; and Gosse, Life of Congreve (London, 1888). CONGREVE, Sir William (1772-1828). An English engineer, the inventor of the Congreve rocket. (See Ai!tillery. ) He was educated at the Royal Academy, Woolwich, received a com- luission in the artillery, and became controller of the Royal Laboratory at Woolwich. He was also a member of Parliament for Gatton. and later for Plymouth, and wrote various works on technological subjects, including: Description of the Hydro-Pneumatic Lock (1814) and A Treat- ise on. the General Principles, Poicers, and Fa- cility of A pplicntion of the Congreve Rocket System (1827). He received many honors for his invention, became prominent in scientific circles, and was a favorite with George IV. CON'GRTJENCE (Lat. congruentia. irom con- gruerc, to agree). In geometry, plane figures which can be su])erposed so as to coincide throughout are said to be congruent. This is the Euclidean definition of ecpiality, and indi- cates both quality of area and similarity of form. The symbol = for congruence signifies these two properties. In general it is not neces- sary actually to superpose the figures. If the eciuality of certain parts is known, the equality of the other parts can be established — e.g. if two sides and the included angle of one triangle are equal to the corresponding parts of another, the triangles are congruent, since the remaining parts are also equal and similarly placed. Con- gruence is related to axial and central sym- metry (q.v. ), and constitutes an important the- ory of geometry. Congruency, in modern geom- etry, signifies a system of elements satisfying a twofold condition. (Jf all possible lines, those- particular lines which satisfy a given conditioa are together called a comple.K, and those which satisfy two conditions are called a congruency — e.g. all lines which intersect a given circle form a complex, and all which intersect two given circles form a congruency. The order of a con- gruency is the number of its rays co-planar with a given plane; the class of a congruency is the- number of its lines concurrent in a given point. In the theory of numbers, two integers are said to be congruent with respect to a third, called the modulus, when their difTerencfr is exactly divisible by the modulus. Thus, 12 and 7, 27 and 12, are congruent with respect to 5 as a modulus, since (12 — 7) and (27 — 12) are divisible by 5. This relation is expressed thus: 12 = 7 ("mod 5), 27=12 (mod 5), and, in general, a =6 (mod c) . When two integers are congruent with respect to a third, either is called the residual of the other with respect to this modulus. A few fundamental theorems of congruences are: (1) If ai= a, (i2= a-',, . . . a„, r:?a'„ (to the same modulus), then Oj -f- a, + . . ._a„ = a', + a'- + . . . a'„. (2) If a ^ a', then na = na'. (3) If a=.a', b = b', then ab = a'b'. (4) If a^a', then a" So'". (5) If f(i = a',, a, = a'j, . . . , then G {a^, a^ ,...) = G («',, a'., ... ), G designating any rational integral func- tion of «-,, Oj, . . . In algebra, the congruence of functions is con- sidered in addition to the congruence of num- bers. When the elements considered are of the form ax -}- b the congruence is called linear. When the elements are of the form ax'-- bx -- c, the congruence is called quadratic, and so on. To solve a congruence is to find the values of the unknown quantity which satisfy the con- gruence. Tlius. to solve the quadratic congru- ence x' H .39 (mod 49) is to find the number whose square gives a remainder .39 when divided bj' 49. These numbers are 23. 20. As to geometry, consult: Henrici. Geometry of Congruent Figures (London. 1888) ; Bcman and Smith, Vcm Plane and Solid (leometry (Bos- ton, 1900) ; Plucker. Neue Geometric des Raumes gegriindet auf die lielrachtung der geraden Linie als Raumclement, edited by Clebsch (Leipzig, 1808) : and as to algebra. Salmon. Modern High- er Algebra (Dublin, 1876), and Pund. Algebra mit Einschluss der elementaren Zahlenthcorie (Leipzig. 1899). CONI, ko'ne. See CvsKO. CONIBO, kA-ne'bA. The most important tribe of Panoan stock (q.v.), ranging along the mid-
