Pantologia. A new (cabinet) cyclopædia, by J.M. Good, O. Gregory, and N. Bosworth assisted by other gentlemen of eminence

DEC

DEBULLITION. 8. (debullitio, Lat.) A bubbling or seething over.

DECACHORDON, in antiquity, a mu sical instrument of ten strings, much resembling our harp.

DECACUMINATED. a. (decacumina tus, Latin.) Having the top or point cut off.

DECADE, a word used by some old writers for the number ten, and decades for an enumeration by tens. The word is formed from the Latin decas, which is derived from a Greek word of the same import. It has been more peculiarly appropriated to the number of books, q. d. decades, into which the Roman History of Titus Livius is divided. Hence also came decadal arithmetic, the Decameron of Boccacio, &c. The French adopted the computation of time by decades in their new calendar.

DE'CADENCY. s. (decadence, Fr.) Decay. DECAGON, a a plane geometrical figure of ten sides and ten angles. When all the sides and angles are equal, it is a regular decagon, and may be inscribed in a circle; otherwise,

not.

If the radius of a circle, or the side of the inscribed hexagon, be divided in extreme and mean proportion, the greater segment will be the side of a decagon inscribed in the same circle. And therefore, as the side of the decagon is to the radius, so is the radins to the sum of the two. Whence, if the radius of the circle be 7, the side of the inscribed decagon will be √5-1

x r.

If the side of a regular decagon be 1, its area will be 45+2√5= 7·6912088; therefore as 1 is to 7-6942088, so is the square of the side of any regular decagon to the area of the same: so that if s be the side of such a decagon, its area will be equal to 7-69120888. (See REGULAR FIGURE.)

DECAGYNIA. (¿ıza, ten, and yun, a woman or wife.) Ten-styled. The name of one of the orders in Linnéus's artificial system; comprehending those flowers which have ten styles. This occurs only in the class decandria.

DECALOGUE, the ten precepts or commandments delivered by God to Moses, after engraving them on two tables of stone. The Jews, by way of excellence, call these commandments the ten words, from whence they had afterwards the name of decalogue: but it is to be observed, that they joined the first and second into one, and divided the last into two. They understand that against stealing to relate to the stealing of men, or kidnapping; alleging, that the stealing one another's goods or property is forbidden in the last commandment. The church of Rome has struck the second commandment quite out of the decalogue; and to make their number complete, has split the tenth into two: the reason of which may be easily conceived.

DÉCAMERIS, a musical term, used by

DEC

Sauveur and others, to denote the of an octave. See MERIS.

To shift the camp: to move off.

To DECA'MP. v. n. (decamper, French.)

act of shifting the camp.
DECA/MPMENT. 8. (from decamp.) The

DECANDRIA. (ixa, ten, and awg, a man or husband.) Ten stamened. The name of comprehending all hermaphrodite flowers with the tenth class in Linnéus's artificial system; ten stamens. It is also the name of an order in the classes monadelphia, diadelphia, gynandria, and diœcia.

pour off gently by inclination (Boyle.)
To DECANT. v. a. (decanto, Latin.) To
The act of decanting or pouring off clear.
DECANTATION. 8. (decantation, Fr.)
DECANTER. s. (from decant.) A glass
vessel made for pouring off liquor clear.

cer who had ten other officers, or persons, un-
DECANUS, among the Romans, an offi-
der his charge; whence our English dean.
a ten-leaved calyx; as in hibiscus.
DECAPHYLLOUS CALYX. In botany,

To behead.
To DECAPITATE. v. a. (decapito, Lat.)

ancients, were officers who gathered the tri-
DECAPROTI, DECEMPRIMI, among the
butes, or taxes.

name of an action or process among the Athe-
DECASMUS, Axaou, in antiquity, the
nians, which was brought against any person
who offered a bribe.

DECASTYLE, a building with ten co-
lumns in front.

excellence; to decline from the state of per-
To DECAY. v. n. (decheoir, Fr.) To lose
fection; to be gradually impaired (Pope).

decay (Clarendon).
To DECAY. v. a. To impair; to bring to

from the state of perfection; state of deprava-
DECAY. 8. (from the verb.) 1. Decline
diminution; the marks of decay (Locke). 3.
tion or diminution (Pope). 2. The effects of
Declension from prosperity (Shakspeare). 4.
The canse of decline (Bacon).

canses decay (Shakspeare).
DECA/YER, 8. (from decay.) That which

Asia, which, according to the signification of
DECCAN, an extensive tract of country in
its name (the South), has been supposed to
include the whole region south of Hindustan
Proper. But, in its more accurate sense, it
contains only the countries situate between
Hindustan Proper, the Carnatic, the Western
Sea, and Orissa; namely, the provinces of
Candeish, Doulatabad, Visiapour, Golconda,
and the W. part of Berar.

departure from life (Hooker.)
DECE'ASE. 8. (decessus, Latin.) Death;

die; to depart from life (Chapman).
To DECE'ASE. v. n. (decédo, Latin.) To

a cheat; a fallacy (Job). 2. Stratagem; arti-
DECEIT. 8. (deceptio, Latin.) 1. Fraud;
fice (Shakspeare).

dulent; full of deceit (Shakspeare).
DECEITFUL. a. (deceit and full.) Fran

DECEITFULLY. ad. Fraudulently (Wot

ton).

DECEITFULNESS. 8. (from deceitful.) Tendency to deceive (Matthew).

DECEIVABLE. a. (from deceive.) 1. Subject to fraud; exposed to imposture. 2. Subject to produce error; deceitful (Bacon). DECEIVABLENESS. 8. (from deceiva ble.) Liableness to be deceived (Gov. of the Tongue).

To DÉCEIVE. v. a. (decipio, Latin.) To cause to mistake; to bring into errour; to impose upon (Locke). 2. To delude by stratagem. 3. To cut off from expectation (Locke). 4. To mock to fail (Dryden). 5. To deprive by fraud or stealth (Bacon). DECEIVER. s. (from deceive.) One that leads another into error; a cheat (South). DECEMBER, the last month in the year, wherein the sun enters the tropic of Capricorn, and makes the winter solstice. In Romulus's year, December was the tenth month, whence the name, viz. from decem, ten. This month contains 31 days.

DECEMFIDOUS CALYX. In botany. A ten-cleft calyx, or rather perianth. As in potentilla and fragaria. See CLEFT.

DECEMLO'CULAR PERICARP. botany. A ten-celled pericarp or seed-vessel; as in linum.

DECEMPEDA, Anacos, ten-feet rod; an instrument used by the ancients in measuring.

DECEMPEDAL. a. (from decempeda, Latin.) Ten feet in length.

DECE/MVIRATE. s. (decemviratus, Lat.) The dignity and office of the ten governors of Rome; any body of ten men.

DECE/MVIRI, an order of annual magis. trates among the Romans, created with a sovereign power to draw up and make laws for the people; thus called, because their number was ten. To the decemviri was given all the legis lative authority ever enjoyed by the kings, and after them by the consuls. One among them had all the ensigns and honours of the func. tion; and the rest had the like in their turn, during the year of their decemvirate. They were originally two in number, called duumviri, till the year of Rome 358, when their number was increased to ten; five chosen from the plebeians and five from the patricians. Sylla increased their number to fifteen, called quindecemvirs.

DE/CENCE. DECENCY. S. (decence, Fr.) 1. Proper formality; becoming ceremony (Spenser). 2. Suitableness to character; propriety (South). 3. Modesty; not ribaldry; not obscenity (Roscommon).

DECENNALIA, ancient Roman festivals, celebrated by the emperors every tenth year of their reign, with sacrifices, games, and largesses for the people. The emperor Augustus first instituted these solemnities.

DECENNIAL. a. (from decennium, Latin.) What continues for the space of ten

years.

coming; fit; suitable (Dryden). 2. Grave; not gaudy (Milton). 3. Not wanton; not immodest.

DECENTLY, ad. 1. In a proper manner; with suitable behaviour; without ostentation (Broome). 2. Without immodesty (Dryden).

DECEPTIBILITY s. (from deceit.) Liableness to be deceived (Glanville).

DECE/PTIBLE. a. (from deceit.) Liable to be deceived; subject to fraud (Brown.)

DECEPTION. s. (deceptio, Latin.) 1. The act or means of deceiving; cheat; fraud fallacy (South.) 2. The state of being deceived (Milton).

ful.

DECE/PTIOUS. a. (from deceit.) Deceit

DECEPTIVE. a. (from deceit.) Having the power of deceiving.

DECE/PTORY. a. (from deceit.) Containing means of deceit.

DE/CERPT. a. (decerptus, Latin.) Cropped; taken off.

DECE/RPTIBLE. a. (decerpo, Lat.) That may be taken off.

DECE/RPTION. s. (from decerpt.) The act of cropping or taking off.

DECERTATION. 8. (decertatio, Lat.) A contention; a striving; a dispute.

DECE/SSION. s. (decessio, Latin.) A departure; a going away.

DECHALES (Claudius Francis Milliet), an excellent mathematician, mechanist, and astronomer, descended from a noble family, was born at Chamberry in 1611. His princi pal performances are an edition of Euclid's Elements, in which the unserviceable propositions are rejected, and the use of those retained is shown; a Discourse on Fortification; and another on Navigation. These with others have been collected, first in three vols. folio, afterwards in four, under the title of Mundus Mathematicus: being, indeed, a tolerably complete course of mathematics. He died in 1678, professor of mathematics, at Turin.

To DECHARM. v. a. (decharmer, Fr.) To counteract a charm; to disenchant (Harvey).

To DECIDE. v. a. (decido, Latin.) 1. To fix the event of; to determine (Dryden). 2. To determine a question or dispute (Glanville).

DE/CIDENCE. s. (decidentia, Latin.) 1. The quality of being shed, or of falling off. 2. The act of falling away (Brown).

DECIDER. s. (from decide.) 1. One who determines causes (Watts). 2. One who determines quarrels.

DECIDUA. (decidua membrana, from decido, to fall down.) Membrana decidua. In anatomy, a very thin and delicate membrane or tunic, which adheres to the gravid uterus, and is said to be a reflection of the chorion, and, on

that account, is called decidua reflexa. The tunica decidua comes away after delivery in small pieces mixed with the lochia.

DECIDUOUS LEAF. (deciduus.) In botany, falling off in the autumn. Calyx or perianth: falling after the corol opens; as in berberis, and the class tetradynamia. Corol or petals falling off with the rest of the flower. Applied also to stipules; as in padus, cerasus, populus, tilia, ulinus, quercus, and many other trees; bractes, and legumes. See CADUCOUS.

DECIDUOUSNESS. 8. (from deciduous.) Aptness to fall.

DECIL, in astronomy, the aspect of two planets which are 36° distant from each other. DE/CIMAL. a. (decimus, Lat.) Numbered by ten; multiplied by ten.

DECIMALS, any thing proceeding by tens; as decimal arithmetic, decimal fractions, decimal scales, &c.

DECIMAL ARITHMETIC, in a general sense, may be considered as the common arithmetical computation in use, in which the decimal scale of numbers is used, or in which the places of the figures change their value in a tenfold proportion. In this sense, the word includes both the arithmetic of integers and decimal fractions. In a more restrained sense, however, it means only

DECIMAL FRACTIONS, which are fractions whose denominator is always a 1 with some number of ciphers annexed, more or fewer according to the value of the fraction, the numerator of which may be any number whatever; as To See the treatise on ARITHMETIC in our first volume.

To DECIMATE. v. a. (decimus, Lat.) To tithe; to take the tenth.

DECIMATION. 8. (from decimate.) 1. A tithing; a selection of every tenth. 2. A selection by lot of every tenth soldier for punish ment (Dryden).

To DECIPHER. v. a. (dechiffrer, Fr.) 1. To explain that which is written in ciphers (Sidney). 2. To unfold; to unravel; to explain. 3. To write out; to mark down in characters (South). 4. To stamp; to characterize; to mark (Shakspeare).

DECIPHEKER. s. (from decipher.) One who explains writings in cipher.

DECISION. 8. (from decide.) I. Determination of a difference (Woodward). 2. Determination of an event (Shakspeare).

DECISIVE. a. (from decide.) 1. Having the power of determining any difference; conclusive (Rogers). 2. Having the power of settling any event (Philips).

DECISIVELY. ad. (from decisive.) In a conclusive manner.

DECISIVENESS. 8. (from decisive.) The power of argument or evidence to terminate any difference, or settle an event.

DECISORY. a. (from decide.) Able to determine or decide.

DECIUS, a Roman emperor, born A.D. 201, in Pannonia. The emperor Philip sent him to quell a sedition in Mosia; but instead

of obeying his directions, he turned his arms against him, and on his death assumed the imperial diadem. He distinguished himself by his expedition against the Persians, and by his persecution of the Christians. In his march against the Goths, he entered into a bog, where he and his army perished by the attack of the enemy, A.D. 251.

To DECK. v. a. (decken, Dutch.) 1. To cover; to overspread (Milton). 2. To dress; to array (Shakspeare). 3. To adorn; to embellish (Prior).

Deck of a ship, is a planked floor from stem to stern, upon which the guns lie, and where the men walk to and fro. Great ships have three decks, first, second, and third, beginning to count from the lowermost. Halfdeck reaches from the main-mast to the stem

of the ship. Quarter-deck is that aloft the steerage, reaching to the round house. Flushdeck is that which lies even in a right line fore and aft, from stem to stern. A rope-deck is made of cordages, interwoven and stretched over a vessel, through which it is easy to annoy an enemy who comes to board her. They are little used but by small vessels, to defend them from privateers. See SHIPBUILDING.

DECKENDORF, a town of Lower Bavaria, seated near the Danube. Lat. 48. 42 N. Lon. 12. 55 E.

DECKER. 8. (from deck.) A dresser; one that apparels or adorns; a coverer.

To DECLAIM. v. n. (declamo, Lat.) To harangue; to speak to the passions; to rheto ricate; to speak set orations (Ben Jonson).

DECLAIMER. 8. (from declaim.) One who makes speeches with intent to move the passions (Addison).

DECLAMATIÓN. 8. (declamatio, Lat.) A discourse addressed to the passions; an harangue; a set speech (Taylor).

Among the Greeks, declamation was the art of speaking indifferently on all subjects, and on all sides of a question; of making a thing appear just that was unjust; and of triumphing over the best and soundest reasons. Such sort of declamations, M. de St. Evremond observes, were fit only to corrupt the mind, by accustoming men to cultivate their imagination, rather than to form their judgment, and to seek for versimilitudes to impose upon, rather than solid reasons to convince, the understanding. It is said that a certain orator, named Plotius Gallus, first introduced the use of declamations at Rome. In this way Cicero formed himself for eloquence. The term frequently occurs both in Horace and Juvenal. Among us, declamation is restrained to certain exercises, which scholars perform, to teach them to speak in public. We say, a declamation against Hannibal, against Pyrrhus, the declamation of Quintilian, &c.

In the colleges of the Jesuits, declamations are little theatrical or dramatic performances, consisting of a few scenes not divided into acts, rehearsed by the students by way of exercise, and to form them for speaking in public.

DECLAMATOR. s. (Lat.) A declaimer; an orator (Tatler).

DECLAMATORY.

a. (declamatorius, at.). Relating to the practice of declaiming; pertaining to declamation (Wotton). 2. Appealing to the passions (Dryden), DECLA'RABLE. a (from declare.) Capable of proof or illustration (Brown). DECLARATION. 8. (from declare.) 1. A proclamation or affirmation; open expression; publication (Tillotson). 2. (In law.) The showing forth of an action personal in any suit, though it is used sometimes for real actions (Cowell).

DECLARATIVE. a. (from declare). Making declaration; explanatory (Grew). 2. Making proclamation (Swift).

DECLARATORILY. ad. (from declaratory.) In the form of a declaration; not in a decretory form (Brown).

DECLARATORY. a. (from declare.) Affirmative; expressive; not decretory; not promissory (Tillotson).

To DECLARE. v. a. (declaro, Latin.) 1. To clear; to free from obscurity (Boyle). 2. To make known; to tell evidently and openly (Dryden). 3. To publish; to proclaim (Chronicles). 4. To show in open view (Addison).

To DECLA'RE. v. n. To make a declaration ; to proclaim some resolution (South). DECLAREMENT. 8. (from declare.) Discovery; declaration; testimony (Brown). DECLARER. s. (from declare.) A proclaimer; one that makes any thing known. DECLENSION. 8. (declensio, Latin.) 1. Tendency from a greater to a less degree of excellence (South). 2. Declination; descent (Burnet).

DECLENSION, in grammar, an inflection of nonns according to their cases, as nominative, genitive, dative, &c. It is a different thing in the modern languages, which have not properly any cases, from what it is in the ancient Greek and Latin. With respect to languages where the nouns admit of changes either in the beginning, the middle, or ending, declension is properly the expression of all those changes in a certain order, and by certain degrees called cases. With regard to languages where the nouns do not admit of changes in the same number, declension is the expression of the different states a noun is in, and the different relations it has; which difference of relations is marked by particles, as of, to, from, by, &c.

DECLINABLE. a. (from decline.) Having variety of terminations.

DECLINATE STEM. In botany, a declined or declining stem. Descending archwise. The least degree of curvature towards the earth. Opposed to ascending.-Applied also to the peduncle, stamen, and style, as likewise to the leaf.

DECLINATION. s. (declinatio, Latin.) 1. Descent; change from a better to a worse state; decay (aller). 2. The act of bends ing down. 3. Variation from rectitude; ob

lique motion; obliquity (Bentley). 4. Variation from a fixed point (oodward).

DECLINATION, in astronomy, the distance of the sun, a star, planet, or other point of the sphere of the world, from the equator, either northward or southward. It is the same with latitude in geography. Declination is either real or apparent, according as the real or apparent place of the object is considered.

The declination of any heavenly body, as of a star, may be easily found by the following rule: -Take the meridian altitude of the star, at any place where the latitude is known; the complement of this is the zenith distance, and is called north or south, as the star is north or south at the time of observation. Then, 1. When the latitude of the place and zenith distance of the star are of different kinds, namely, one north and the other south, their difference will be the declination; and it is of the same kind with the latitude, when that is the greatest of the two, otherwise it is of the contrary kind. 2. If the latitude and the zenith distance are of the same kind, i. e. both north, or both south, their sum is the declination; and it is of the same kind with the latitude. (0. Gregory's Astron. pa. 31.)

Accurate tables of the sun's declination are published regularly in the nautical almanacs. DECLINATION (Parallels of), are small circles of the sphere parallel to the equator.

DECLINATION (Parallax, or Refraction of), is such an arch of a meridian as is equal to the change produced in the declination by parallax or refraction, respectively.

DECLINATION OF THE MAGNETIC NEEDLE, is the distance of the magnetic from the true meridian in degrees measured upon the horizon. Inclination is the angle which the dipping needle makes with the horizon, as measured on a vertical or azimuth circle. The changes in the declination and inclination presented by the words variation and alteration respectively.

may

be re

After the discovery of that most useful property of the magnet, or loadstone, namely, the giving hardened iron and steel a polarity, the compass was for many years used without knowing that its direction in any-wise deviated from the poles of the world; and about the middle of the 16th century, so certain were some of its inflexibly pointing to the north, that they treated with contempt the notion of the variation, which about that time began to be suspected. However, careful observations soon discovered, that in England and its neighbourhood, the needle pointed to the eastward of the true north; but the quantity of this deviation being known, mariners became as well satisfied as if the compass had none; because they imagined that the true course could be obtained by making allowance for the true declination.

From successive observations made afterwards, it was found that the deviation of the needle from the north was not a constant quantity, but that it gradually diminished ; and at last, about the year 1658 or 1660, it was

found at London that the needle pointed due north, and has ever since been getting to the westward; and now the declination is more than 24° to the westward of the north: so that in any one place it may be suspected the declination has a kind of libratory motion, traversing through the north to unknown limits eastward and westward. But the settling of this point must be left to time.

During the time of the said observations it was also discovered that the declination of the needle was different in different parts of the world, it being west in some places when it was east in others; and in places where the de