« PrécédentContinuer »
compressed air has also been found to be the most thus compressed, the mercury column ascends in convenient power (see BRAKES). Air compressed the stem, and when the pressure is relieved the and stored in a reservoir under the vehicle has also index is left at that point to which the mercury been proposed as a motive power for tramway cars. rose under the highest pressure applied. The In a different direction the agency of compressed | actual amount of compression, and the original air is important in the artificial production of volume, as well as the pressure, being known, the cold for chilling-houses for meat-preservation on compressibility can be thereby calculated, a correcland, and for frozen-meat chambers for preserving tion being finally added for the compression of the fresh meat on board vessels (see REFRIGERATION). glass piezometer itself. From experiments made
Compression and Compressibility. When with such apparatus, the following conclusions (see a body is subjected to the action of any force which Report on some of the Physical Properties of Fresh causes it to occupy less volume, it is said to be Water and Sea-water, by Professor P. G. Tait; compressed, and the diminution of volume is termed Challenger Escpedition Coinmission Reports, Physics compression. The term compressibility is fre. and Chemistry, part iv.) seem now to be well estabquently used to signify that property of bodies lished regarding the compressibility of liquids, more whereby they yield to that particular form of stress especially of water. The compressibility of water known as pressure ; but more strictly it is employed
decreases as both the temperature and pressure are to denote the measure of this property as possessed raised ; under moderate pressures (e.g. one or two by different substances. Under the same pressure atmospheres) it has a point of minimum value about it is obvious that the same volume of various 60° C., while its actual value at 10° C. and at a substances will diminish by different amounts; pressure of one ton per square inch is very nearly and, to measure this change, the compressibility goo7. Sea-water is less compressible than fresh is defined to be the ratio of the amount of
water; the ratio of the compressibility of the compression per unit volume to the compressing former to the latter being .915. “Solutions of comforce applied. It thus may be determined by mon salt are less compressible as they are stronger ; measuring the amount of compression of a known the compressibility falling off uniformly with involume when under a certain pressure; dividing creased strength. Both sea-water and salt solutions this by the product of the original volume and the diminish in compressibility with temperature and pressure gives the average compressibility (per pressure in the same manner as fresh water. It unit pressure) of the substance throughout the has also been proved that the maximum-density range of pressure employed. The unit of pressure point of water is lowered by pressure ; the actual generally used is one atmosphere, which is defined amount of this lowering being 3o.1 C. per tonin this country as being the weight of a column of -i.e. water under a pressure of one ton per mercury, one square inch in section, 29.905 inches sq. in. has its maximum density point at 0*9, in height, at the temperature of 0° C., and weighed instead of at 4°, as under ordinary atmospheric at sea-level in the latitude of London. Its actual pressure. value in pounds-weight per square inch is nearly
The compressibility of solids is generally very 14:7; so that 152:3 atmospheres of pressure is much smaller than that of either liquids or gases. equivalent to a pressure of one ton per square inch. It is best measured by noting the shortening
In gases the relation between pressure and volume of a rod or fibre of the material tested while is given by Boyle's Law (see GASES)-viz. the subjected to hydrostatic pressure; the linear comvolume of a given mass of gas is inversely pro- pressibility thus obtained is, to a sufficient degree portional to its pressure. From this it follows that of approximation, one-third the cubical compresthe compressibility is inversely proportional to the sibility. For glass it is '00000265 per atmo. pressure-i.e. the diminution of volume due to a sphere. given increment of pressure is correspondingly Compulsion. The effect of compulsion on the small as the pressure is great. The behaviour of validity of obligations and payments, and on a gas under pressure is closely related to the criminal responsibility, is noticed under CONTRACT, proximity of its temperature to the critical point | CRIME, FORCE AND FEAR, and DURESS. (see CRITICAL TEMPERATURE); for if below this temperature the gas can, and if above
Compurgators were twelve persons whom it, cannot be liquefied by pressure
Anglo-Saxon law permitted the accused to call in alone. It is only since 1877 that
proof of his innocency, and who joined their oaths liquefaction has been effected in those
to his. They were persons taken from the neighgases formerly termed permanent.
bourhood, or otherwise known to the accused. It From the first attempts to compress
was rather in the character of witnesses than of liquids it was concluded that they
jurymen that they acted, though the institution has were incompressible, but Canton in
been spoken of as the Anglo-Saxon jury; what 1762, by a comparatively simple experi.
they swore to was not so much their knowledge, as ment, showed that the compressibility
their belief. The number of compurgators varied of water though small is quite appre
with the rank of the parties and the nature of the ciable, and that it is less at higher
accusation, but was usually twelve. The system than at lower temperatures. The
of compurgators was adopted even in civil actions measurement of the compressibility of
for debt. Compurgation, which was a custom liquids is usually made in a glass vessel
common to most of the Teutonic races, fell into (see fig.) termed a piezometer. A tube,
disuse after the conquest; but the ceremony of ABCD, open at one end, D, is bent
what was called canonical purgation of clerks-conupon itself between C and D, widened
vict, was not abolished in England till the reign of at one end into a cylindrical bulb, AB,
Elizabeth. See (under Jury) JURY TRIAL. and at the other into a cistern, D. The Comrie, a pleasant and sheltered village of liquid experimented on fills the bulb Perthshire, on the Earn, 7 miles W. of Crieff. It and stem to C, from which point to has often been visited by earthquakes, notably in D, mercury fills the tube. On the sur-| the October of 1839 and January of 1876. These
face of the mercury at Can index are apparently due to its geological position on the floats. The instrument is placed in a larger and great line of fault between the Highlands and the much stronger vessel containing water to which | Lowlands. Here George Gilfillan was born in 1813. pressure (measured by an attached gauge) is The Free church, built in 1879-81, cost over £10,000. applied. The contents of the piezometer being | The railway hither was opened in 1893. Pop. 870.
Comstock Lode, a ledge of silver, to which Comus, in later antiquity, a divinity of festive Virginia City, Nevada, largely owes its prosperity. mirth and joy, represented as a winged youth, Discovered in 1859, the lode has since yielded at sometimes drunk and languid as after a debauch, or times over ten million dollars annually. The shaft slumbering in a standing posture with legs crossed. is 2300 feet deep, but work is now confined to the Comus thus became the representative deity of upper levels, the workmen having been driven from riotous merry-making, of tipsy dance and jollity, the depths by the heat (120° F.) and by the steam and as such figures in Milton's noble poetic tribute generated through the action of the air on the | to chastity, the mask of Comus; though here the sulphurous rock penetrated by the different poet, as elsewhere, has devised his own mythology, levels.
and made him the child of Bacchus and of Circe, Comte, AUGUSTE, the founder of Positivism ‘much like his father, but his mother more.' (9.v.), was born 19th January 1798, at Montpellier, | Comyn, CUMMING, or CUMyn, a family which where his father was treasurer of taxes. At the | rose to great power and eminence in England Lycée of his native place he was distinguished and Scotland. It took its name from the town equally for his aptitude for mathematics and his | of Comines, near Lille, on the frontier between resistance to official authority, characteristics which | France and Belgium. While one branch remained did not desert him on his entering the École Poly. there, and in 1445 gave birth to the historian technique at Paris in his seventeenth year. Here Philippe de Comines (9.v.), another followed the he took the lead in a protest of the students against banners of William of Normandy to the conquest the manners of one of the tutors, and was expelled, of England. In 1069 the Conqueror sent Robert after a residence of two years had obtained recog- of Comines, or Comyn, whom he created Earl nition of his abilities from the professors. A few of Northumberland, with 700 horse to reduce months were spent with his parents, and then Comte the yet unsubdued provinces of the north. He returned to Paris, where for a time he made a scanty seized Durham, but had not held it for 48 hours living by teaching mathematics. It would seem when the people suddenly rose against him, and he that, some years before, he had completely freed perished in the flames of the bishop's palace, leaving himself from the influence of all existing social and two infant sons. The younger, William, became religious theories, and a reforming zeal was begin. | Chancellor of Scotland about 1133, and nine years ning to possess his mind, when in 1818 he came | later all but possessed himself of the see of Durham. into contact with St Simon, by whom his inclina. The chancellor's grandnephew, Richard, inherited tion towards the reconstruction of thought and life the English possessions of his family, and acquired was confirmed and strengthened. A definite rela- lands in Scotland. By his marriage with Hextilda, tion was established between them, by which Comte the granddaughter of Donald Bane, king of the remained for six years the disciple and collaborator Scots, he had a son William, who was Great Jus. of the older thinker; but there gradually became ticiary of Scotland, and about 1210 became Earl apparent a disagreement of aim and method, and of Buchan by marrying Marjory, daughter and the necessity felt by Comte of asserting the inde. heiress of Fergus, the last Celtic Earl of Buchan. pendence of his own conceptions led to a violent Their son, Alexander, Earl of Buchan, married rupture. In 1825 Comte married, but the union Isabella or Elizabeth, second daughter of Roger de proved unhappy, and after seventeen years of inter- Quenci, Earl of Winchester, and with her acquired mittent discord, ended in a separation. In the the high office of Constable of Scotland, with great following year Comte began a course of lectures in estates in Galloway, Fife, and the Lothians. By exposition of his system of philosophy, which was a previous marriage with a wife whose name has attended by several eminent men of science, but not been ascertained, William Comyn was father the course was soon interrupted by an attack of of Richard-whose son John (Red John Comyn) insanity, which disabled the lecturer for a few became Lord of Badenoch-and of Walter, who by months. His labours were afterwards resumed, and marriage became Earl of Menteith, and was one of the six volumes of his Philosophie Positive was pub. the guardians or regents of Scotland during the lished at intervals between 1830 and 1842, during minority of Alexander III. Through other mar. which period his livelihood was chiefly obtained riages the family obtained, for a time, the earlfrom the offices of examiner and tutor in the Ecole doms of Angus and Athole, so that, by the middle Polytechnique. After these positions were taken of the 13th century, there were in Scotland 4 earls, from him, owing to the prejudices of his colleagues, | 1 lord, and 32 belted knights of the name of Comyn. he resumed the private teaching of mathematics, | Within seventy years afterwards this great house but in his later years he was supported entirely by was so utterly overthrown that, in the words of a a 'subsidy' from his friends and admirers. In 1845 contemporary chronicle, there was no memorial Comte became acquainted with Clothilde de Vaux, left of it in the land, save the orisons of the monks and until her death within a year afterwards, a of Deer' (founded as a Cistercian monastery by close intimacy was maintained between them. On William Comyn, Earl of Buchan, in 1219). The Comte's side it was a passionate attachment, the Comyns perished in the memorable revolution purity of which was happily preserved, and its which placed Bruce on the throne of Scotland. influence is clearly shown in his later works, especi. Their chief, Black John Comyn, Lord of Badenoch, ally in the most important of these, the Politique great-grandson of William, Earl of Buchan, had, Positive. Comte died in his sixtieth year on 5th in 1291, been an unsuccessful competitor for the September 1857. He was buried in the cemetery of crown, as a descendant of the old Celtic dynasty Pere-la-Chaise. A full account of his system will through the granddaughter of King Donald Bane. be found in the article POSITIVISM. His works are His son, also called Red John Comyn, was one of Cours de Philosophie Positive ( 6 vols. Paris, 1830–42; the wardens of Scotland, and distinguished himself freely translated into English, and condensed by by his gallant resistance to the English. Suspected Harriet Martineau, 2 vols. 1853), Traité Elémentaire by Bruce of betraying him to Edward, Comyn fell de Géométrie Analytique (1843), Traité d'Astronomie | under Bruce's dagger, before the altar of the Fran. Populaire (1845), Discours sur l'Ensemble du Posi. ciscan friars at Dumfries in 1306; and his kindred tivisme (1848), Système de Politique Positive (4 vols. went down, one after another, in the struggle to 1851-54; Eng. trans. 1875 et seq., Longmans), and avenge him. John Comyn, Earl of Buchan, the Catéchisme Positiviste, ou Sommaire Exposition de son of Alexander and Isabella de Quenci, was de. la Religion Universelle (1 vol. Paris, 1852). Comte's feated by Bruce in a pitched battle, near Inverury, Testament was published with a good many of his | in 1308, when his earldom was wasted with such letters in 1884.
relentless severity, that-we are told by the poet 398
who sang the victories of Bruce—for sixty years tion cultivate coca and cacao, and collect medicinal afterwards men mourned the desolation of Buchan. barks from the surrounding forests. -(5) Cox. Such of the Comyns as escaped the sword found CEPCION, a town of Mexico, 50 miles W. of Chirefuge, with their wives and children, in England, huahua, in the upper Yaqui valley, famous for its where, although they were so poor as to be depend. apples.-(6) CONCEPCION DE LA VEGA, a town of ants on the bounty of the English court, they | San Domingo, 5 miles SE. of Santiago, with 9000 married into the best families, so that, in the words inhabitants. of Mr Riddell, their blood at this day circulates Conception, in Psychology. Sce IDEA. through all that is noble in the sister kingdom.' See M. E. Cumming-Bruce, Family Records of the
Conception, IMMACULATE. See IMMACULATE Bruces and the Comyns (Edin. 1870).
CONCEPTION. Conacre is the custom of letting land in Ireland
Conception of Our Lady, an order of nuns, in small portions for a single crop, the rent being
founded in Portugal in 1484 by Beatrix de Sylva, paid either in money or in labour.
| in honour of the immaculate conception. It was
confirmed in 1489 by Pope Innocent VIII. In Conant, THOMAS JEFFERSON, D.D., American
1489 Cardinal Ximenes put the nuns under the biblical scholar, born in Brandon, Vermont, in 1802, direction of the Franciscans, and imposed on them graduated at Middlebury in 1823, and afterwards
the rule of St Clara. The order subsequently spread filled chairs of Languages in various colleges and into Italy and France. seminaries. In 1856 he published a translation of the book of Job, and in 1857 he was appointed by
Conceptualism. See NOMINALISM. the American Bible Union to revise the Scriptures.
Concert. See Music. On this work he was engaged until 1875, and he Concertina, a musical instrument invented in was also a member of the American committee of 1829 by Sir Charles Wheatstone, the sounds of the Old Testament Company who prepared the which are produced by free vibrating reeds of metal, revised version. His works include translations of as in the accordion. The scale of the concertina is Gesenius' Hebrew grammar and critical English very complete and extensive, beginning with the versions of both old and New Testament books. | lowest note of the violin, G, and ascending chroDied April 30, 1891.
matically for four octaves. Violin, flute, and oboe Concarneau, a village of Brittany, on the
music can be performed on the concertina with good east coast of Finistère, 15 miles by rail SE. of Quim
effect, and it has an extensive repertoire of music per. Its inhabitants are largely engaged in the
specially written for itself. Every sound in the sardine fisheries and in pisciculture. Pop. (1886)
scale is double, and can be produced either by 5496.
pulling the bellows open, or by pressing them
together. Concertinas are now made in France and Concealment is a technical expression in the
Germany, but not so perfectly as in England. The criminal law of both England and Scotland ; as in keys in the German concertina are constructed on
ment of pregnancy and birth, concealing the same principle as those in the accordion, which treasure-trove, concealing ore from a mine, conceal- | play one note when the bellows are expanded, and ment by a seller from a purchaser of any instru
another when contracted. ment material to the title with intent to defraud,
Concerto, a musical composition for a solo &c. The concealment of another's crime may
instrument, with orchestral accompaniments, calcu. expose to a charge of misprision, or it may amount
lated to give the performer an opportunity to display to a charge of accession after the fact-e.g. where
the highest mechanical skill, as well as intellectual the body of a murdered person is concealed. In
cultivation in the art. The concerto consists of bankruptcy, concealment of debtor's property is a
three movements, each of which, like the whole, serious offence. In civil transactions, but especially in particular contracts, such as insurance and
has a certain character, and like the symphony or
the sonata, to which it approximates in form, resuretyship, where a high measure of good faith is
quires a clear development and treatment of the expected, the concealment of a material fact may
| motives, and & strict adherence to the rules of often invalidate an obligation.
form. A peculiar feature, usually introduced in Concealment of Birth. See BIRTH.
the first movement, but frequently also in the last, Concepcion, (1) a province of Chili, stretching
is the Cadenza (q.v.). When the form is in any from the Andes to the coast north of Arauco. It is
way abridged, it is then called a concertino. From an important agricultural and cattle-raising district,
the beginning of the last century to the present and has valuable coal-mines. Area, 3535 sq. m.;
time, the pianoforte and the violin are the solo pop. (1885) 182,459.–CONCEPCION, the capital,
instruments mostly used for the concerto. The near the mouth of the Biobio, is one of the most
oldest violin concertos are those by Torelli, the regular and handsome towns of the republic,
first being published in 1686. The form was dealthough it has suffered severely from earthquakes.
veloped by Corelli, Tartini, Bach, and Handel, and Its cathedral and several of the other public reached its modern shape under Mozart, though buildings are noteworthy, and its port, Talcahuano, some important modifications were introduced by on Concepcion Bay, is the safest and best harbour
Beethoven, whose violin concerto and pianoforte in all Chili, and ranks next to Valparaiso as a mart
concertos are regarded as the highest achievements of foreign trade. Pop. 19,000.-(2) CONCEPCION
| in this form. Concertos for wind-instruments have DEL URUGUAY, the former capital of the Argen- been less regarded, and are generally written by tine province of Entre Rios, on the Uruguay, 180 the performers themselves, and seldom deserve to miles SE of Paraná by the Entre Rios Rail. be called classical works.Weber's clarinet con: way, with large slaughter-houses and active river. | certo may be mentioned as one of the few exceptions. trade. Pop. 10,000.-(3) ConcePCION, a town of There are also concertos for various combinations of Paraguay, on the Paraguay River, about 260 solo instruments, such as Bach's for two or more miles above Asuncion, with trade in maté. The pianofortes, or Beethoven's for piano, violin, and official pop. (1879) 10,697, includes the surround.
violoncello. ing districts ; the town has less than 2000 in Conch (Gr. konché, 'a shell'), a marine shell, habitants. -(4) The name of several places in especially of the Strombus gigas (see STROMBID.E); Bolivia, the largest being CONCEPCION DE APOLO. | and, in art, a spiral shell used by the Tritons as a BAMBA, capital of the province of Canpolican, trumpet, and still used by some African peoples in formerly a Franciscan mission. Its Indian popula. / war. The native whites of the Bahamas are called