Chapter 92

2. (Astron.) The great circle of the celestial sphere, coincident with the plane of the earth's equator; - - so called because when the sun is in it, the days and nights are of equal length; hence called also the equinoctial, and on maps, globes, etc., the equinoctial line.

Equator of the sun or of a planet (Astron.), the great circle whose plane passes through through the center of the body, and is perpendicular to its axis of revolution. -- Magnetic equator. See Aclinic.

E`qua*to"ri*al (?), a. [Cf. F. équatorial.] Of or pertaining to the equator; as, equatorial climates; also, pertaining to an equatorial instrument.

E`qua*to"ri*al, n. (Astron.) An instrument consisting of a telescope so mounted as to have two axes of motion at right angles to each other, one of them parallel to the axis of the earth, and each carrying a graduated circle, the one for measuring declination, and the other right ascension, or the hour angle, so that the telescope may be directed, even in the daytime, to any star or other object whose right ascension and declination are known. The motion in right ascension is sometimes communicated by clockwork, so as to keep the object constantly in the field of the telescope. Called also an equatorial telescope.

The term equatorial, or equatorial instrument, is sometimes applied to any astronomical instrument which has its principal axis of rotation parallel to the axis of the earth.

E`qua*to"ri*al*ly, adv. So as to have motion or direction parallel to the equator.

Eq"uer*ry (?; 277), n.; pl. Equerries (#). [F. écurie stable, for older escurie, escuirie (confused somewhat with F. écuyer, OF. escuyer, squire), LL. scuria, OHG. skiura, sc&?;ra, barn, shed, G. scheuer, from a root meaning to cover, protect, and akin to L. scutum shield. See Esquire, and cf. Ecurie, Querry.] 1. A large stable or lodge for horses. Johnson.

2. An officer of princes or nobles, charged with the care of their horses.

In England equerries are officers of the royal household in the department of the Master of the Horse.

Eq"ue*ry (?), n. Same as Equerry.

E*ques"tri*an (?), a. [L. equester, from eques horseman, fr. equus horse: cf. F. équestre. See Equine.] 1. Of or pertaining to horses or horsemen, or to horsemanship; as, equestrian feats, or games.

2. Being or riding on horseback; mounted; as, an equestrian statue.

An equestrian lady appeared upon the plains.

Spectator.

3. Belonging to, or composed of, the ancient Roman equities or knights; as, the equestrian order. Burke.

E*ques"tri*an, n. One who rides on horseback; a horseman; a rider.

E*ques"tri*an*ism (?), n. The art of riding on horseback; performance on horseback; horsemanship; as, feats equestrianism.

E*ques"tri*enne` (?), n. [Formed after analogy of the French language.] A woman skilled in equestrianism; a horsewoman.

E"qui- (?). [L. aequus equal. See Equal.] A prefix, meaning equally; as, equidistant; equiangular.

E"qui*an`gled (?), a. [Equi- + angle.] Equiangular. [Obs.] Boyle.

E`qui*an"gu*lar (?), a. [Equi- + angular. Cf. Equangular.] Having equal angles; as, an equiangular figure; a square is equiangular.

Equiangular spiral. (Math.) See under Spiral, n. -- Mutually equiangular, applied to two figures, when every angle of the one has its equal among the angles of the other.

E`qui*bal"ance (?), n. [Equi- + balance.] Equal weight; equiponderance.

E`qui*bal"ance, v. t. [imp. & p. p. Equibalanced (?); p. pr. & vb. n. Equibalancing (?).] To make of equal weight; to balance equally; to counterbalance; to equiponderate.

E`qui*cres"cent (?), a. [Equi- + crescent.] (Math.) Increasing by equal increments; as, an equicrescent variable.

E`qui*cru"ral (?), a. [L. aequicrurius; aequus equal + crus, cruris, leg.] Having equal legs or sides; isosceles. [R.] "Equicrural triangles." Sir T. Browne.

E"qui*crure (?), a. Equicrural. [Obs.]

E`qui*dif"fer*ent (?), a. [Equi- + different: cf. F. équidifférent.] Having equal differences; as, the terms of arithmetical progression are equidifferent.

E`qui*dis"tance (?), n. Equal distance.

E`qui*dis"tant (?), a. [L. aequidistans, -antis; aequus equal + distans distant: cf. F. équidistant.] Being at an equal distance from the same point or thing. -- E`qui*dis"tant*ly, adv. Sir T. Browne.

E`qui*di*ur"nal (?), a. [Equi- + diurnal.] Pertaining to the time of equal day and night; -- applied to the equinoctial line. Whewell.

E"qui*form (?), a. [L. aequiformis; aequus equal + forma form.] Having the same form; uniform. -- E`qui*for"mi*ty (#), n. Sir T. Browne.

E`qui*lat"er*al (?), a. [L. aequilateralis; aequus equal + latus, lateris, side: cf. F. équilatéral.] Having all the sides equal; as, an equilateral triangle; an equilateral polygon.

Equilateral hyperbola (Geom.), one whose axes are equal. -- Equilateral shell (Zoöl.), one in which a transverse line drawn through the apex of the umbo bisects the valve, or divides it into two equal and symmetrical parts. -- Mutually equilateral, applied to two figures, when every side of the one has its equal among the sides of the other.

E`qui*lat"er*al, n. A side exactly corresponding, or equal, to others; also, a figure of equal sides.

E`qui*li"brate (?), v. t. [imp. & p. p. Equilibrated (?); p. pr. & vb. n. Equilibrating (?).] [L. aequilibratus in equilibrium; aequus equal + libra balance. See Equilibrium.] To balance two scales, sides, or ends; to keep even with equal weight on each side; to keep in equipoise. H. Spenser.

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E`qui*li*bra"tion (?), n. 1. Act of keeping a balance, or state of being balanced; equipoise.

In . . . running, leaping, and dancing, nature's laws of equilibration are observed.

J. Denham.

2. (Biol.) The process by which animal and vegetable organisms preserve a physiological balance. H. Spenser.

E`qui*lib"ri*ous (?), a. Evenly poised; balanced. Dr. H. More. -- E`qui*lib"ri*ous*ly, adv.

E*quil"i*brist (?), n. One who balances himself in unnatural positions and hazardous movements; a balancer.

When the equilibrist balances a rod upon his finger.

Stewart.

E`qui*lib"ri*ty (?), n. [L. aequilibritas equal distribution. See Equilibrium.] The state of being balanced; equality of weight. [R.] J. Gregory.

E`qui*lib"ri*um (?), n.; pl. E. Equilibriums (#), L. Equilibria (#). [L. aequilibrium, fr. aequilibris in equilibrium, level; aequus equal + libra balance. See Equal, and Librate.] 1. Equality of weight or force; an equipoise or a state of rest produced by the mutual counteraction of two or more forces.

2. A level position; a just poise or balance in respect to an object, so that it remains firm; equipoise; as, to preserve the equilibrium of the body.

Health consists in the equilibrium between those two powers.

Arbuthnot.

3. A balancing of the mind between motives or reasons, with consequent indecision and doubt.

Equilibrium valve (Steam Engine), a balanced valve. See under Valve.

E`qui*mo*men"tal (?), a. [Equi- + momental.] (Mech.) Having equal moments of inertia.

Two bodies or systems of bodies are said to be equimomental when their moments of inertia about all straight lines are equal each to each.

Equimomental cone of a given rigid body, a conical surface that has any given vertex, and is described by a straight line which moves in such manner that the moment of inertia of the given rigid body about the line is in all its positions the same.

E`qui*mul"ti*ple (?), a. [Equi- + multiple: cf. F. équimultiple.] Multiplied by the same number or quantity.

E`qui*mul"ti*ple, n. (Math.) One of the products arising from the multiplication of two or more quantities by the same number or quantity. Thus, seven times 2, or 14, and seven times 4, or 28, are equimultiples of 2 and 4.

E*qui"nal (?), a. See Equine. "An equinal shape." Heywood.

E"quine (?), a. [L. equinus, fr. equus horse; akin to Gr. &?;, Skr. a&?;va, OS. ehu, AS. eh, eoh, Icel. j&?;r, OIr. ech, cf. Skr. a&?; to reach, overtake, perh. akin to E. acute, edge, eager, a. Cf. Hippopotamus.] Of, pertaining to, or resembling, a horse.

The shoulders, body, things, and mane are equine; the head completely bovine.

Sir J. Barrow.

||E*quin"i*a (?), n. [NL. See Equine.] (Med.) Glanders.

E`qui*noc"tial (?), a. [L. aequinoctials, fr. aequinoctium equinox: cf. F. équinoxial. See Equinox.] 1. Pertaining to an equinox, or the equinoxes, or to the time of equal day and night; as, the equinoctial line.

2. Pertaining to the regions or climate of the equinoctial line or equator; in or near that line; as, equinoctial heat; an equinoctial sun.

3. Pertaining to the time when the sun enters the equinoctial points; as, an equinoctial gale or storm, that is, one happening at or near the time of the equinox, in any part of the world.

Equinoctial colure (Astron.), the meridian passing through the equinoctial points. -- Equinoctial line (Astron.), the celestial equator; -- so called because when the sun is on it, the nights and days are of equal length in all parts of the world. See Equator.

Thrice the equinoctial line He circled.

Milton.

-- Equinoctial points (Astron.), the two points where the celestial and ecliptic intersect each other; the one being in the first point of Aries, the other in the first point of Libra. -- Equinoctial time (Astron.) reckoned in any year from the instant when the mean sun is at the mean vernal equinoctial point.

E`qui*noc"tial, n. The equinoctial line.

E`qui*noc"tial*ly, adv. Towards the equinox.

E"qui*nox (?), n. [OE. equinoxium, equenoxium, L. aequinoctium; aequus equal + nox, noctis, night: cf. F. équinoxe. See Equal, and Night.] 1. The time when the sun enters one of the equinoctial points, that is, about March 21 and September 22. See Autumnal equinox, Vernal equinox, under Autumnal and Vernal.

When descends on the Atlantic The gigantic Stormwind of the equinox.

Longfellow.

2. Equinoctial wind or storm. [R.] Dryden.

E`qui*nu"mer*ant (?), a. [Equi- + L. numerans, p. pr. of numerare to number.] Equal as to number. [Obs.] Arbuthnot.

E*quip" (?), v. t. [imp. & p. p. Equipped (?); p. pr. & vb. n. Equipping.] [F. équiper to supply, fit out, orig. said of a ship, OF. esquiper to embark; of German origin; cf. OHG. scif, G. schiff, Icel. skip, AS. scip. See Ship.] 1. To furnish for service, or against a need or exigency; to fit out; to supply with whatever is necessary to efficient action in any way; to provide with arms or an armament, stores, munitions, rigging, etc.; -- said esp. of ships and of troops. Dryden.

Gave orders for equipping a considerable fleet.

Ludlow.

2. To dress up; to array; accouter.

The country are led astray in following the town, and equipped in a ridiculous habit, when they fancy themselves in the height of the mode.

Addison.

Eq"ui*page (?; 48), n. [F. équipage, fr. équiper. See Equip.] 1. Furniture or outfit, whether useful or ornamental; especially, the furniture and supplies of a vessel, fitting her for a voyage or for warlike purposes, or the furniture and necessaries of an army, a body of troops, or a single soldier, including whatever is necessary for efficient service; equipments; accouterments; habiliments; attire.

Did their exercises on horseback with noble equipage.

Evelyn.

First strip off all her equipage of Pride.

Pope.

2. Retinue; train; suite. Swift.

3. A carriage of state or of pleasure with all that accompanies it, as horses, liveried servants, etc., a showy turn-out.

The rumbling equipages of fashion . . . were unknown in the settlement of New Amsterdam.

W. Irving.

Eq"ui*paged (?), a. Furnished with equipage.

Well dressed, well bred. Well equipaged, is ticket good enough.

Cowper.

E*quip"a*ra*ble (?) a. [L. aequiparabilis.] Comparable. [Obs. or R.]

E*quip"a*rate (?) v. t. [L. aequiparatus, p. p. of aequiparare.] To compare. [R.]

E*quip"e*dal (?), a. [Equi- + L. pes, pedis, foot.] (Zoöl.) Equal- footed; having the pairs of feet equal.

E`qui*pend"en*cy (?), n. [Equi- + pendency.] The act or condition of hanging in equipoise; not inclined or determined either way. South.

E`qui*pen"sate (?), v. t. [Equi- + pensatus, p. p. of pensare to weigh. Cf. Equipoise.] To weigh equally; to esteem alike. [Obs.]

E*quip"ment (?), n. [Cf. F. équipement. See Equip.] 1. The act of equipping, or the state of being equipped, as for a voyage or expedition. Burke.

The equipment of the fleet was hastened by De Witt.

Hume.

2. Whatever is used in equipping; necessaries for an expedition or voyage; the collective designation for the articles comprising an outfit; equipage; as, a railroad equipment (locomotives, cars, etc. ; for carrying on business); horse equipments; infantry equipments; naval equipments; laboratory equipments.

Armed and dight, In the equipments of a knight.

Longfellow.

E"qui*poise (?), n. [Equi- + poise.] 1. Equality of weight or force; hence, equilibrium; a state in which the two ends or sides of a thing are balanced, and hence equal; state of being equally balanced; -- said of moral, political, or social interests or forces.

The means of preserving the equipoise and the tranquillity of the commonwealth.

Burke.

Our little lives are kept in equipoise By opposite attractions and desires.

Longfellow.

2. Counterpoise.

The equipoise to the clergy being removed.

Buckle.

{ E`qui*pol"lence (?), E`qui*pol"len*cy (?) }, n. [Cf. F. équipollence. See Equipollent.] 1. Equality of power, force, signification, or application. Boyle.

2. (Logic) Sameness of signification of two or more propositions which differ in language.

E`qui*pol"lent (?), a. [L. aequipollens; aequus equal + pollens, - entis, p. pr. of pollere to be strong, able: cf. F. équipollent.] 1. Having equal power or force; equivalent. Bacon.

2. (Logic) Having equivalent signification and reach; expressing the same thing, but differently.

E`qui*pol"lent*ly, adv. With equal power. Barrow.

{ E`qui*pon"der*ance (?), E`qui*pon"der*an*cy (?) }, n. [Equi- + ponderance: cf. F. équipondérance.] Equality of weight; equipoise.

E`qui*pon"der*ant (?), a. [Cf. F. équipondérant.] Being of the same weight.

A column of air . . . equiponderant to a column of quicksilver.

Locke.

E`qui*pon"der*ate (?), v. i. [Equi- + L. ponderare to weigh. See Ponderate.] To be equal in weight; to weigh as much as another thing. Bp. Wilkins.

E`qui*pon"der*ate, v. t. To make equal in weight; to counterbalance. "More than equiponderated the declension in that direction." De Quincey.

E`qui*pon"der*ous (?), a. [Equi- + L. pondus, ponderis, weight.] Having equal weight. Bailey.

E`qui*pon"di*ous (?), a. [L. aequipondium an equal weight; aequus equal + pondus weight.] Of equal weight on both sides; balanced. [Obs.] Glanvill.

E`qui*po*ten"tial (?), a. [Equi- + potential.] (Mech. & Physics) Having the same potential.

Equipotential surface, a surface for which the potential is for all points of the surface constant. Level surfaces on the earth are equipotential.

E`qui*rad"i*cal (?) a. [Equi- + radical.] Equally radical. [R.] Coleridge.

E`qui*ro"tal (?), a. [Equi- + L. rota wheel.] Having wheels of the same size or diameter; having equal rotation. [R.]

E`qui*se*ta"ceous (?), a. (Bot.) Belonging to the Equisetaceæ, or Horsetail family.

E`qui*set"i*form (?), a. [Equisetum- + -form.] (Bot.) Having the form of the equisetum.

||Eq`ui*se"tum (?), n.; pl. Equiseta (#). [L., the horsetail, fr. equus horse + seta a thick,, stiff hair, bristle.] (Bot.) A genus of vascular, cryptogamic, herbaceous plants; -- also called horsetails.

The Equiseta have hollow jointed stems and no true leaves. The cuticle often contains siliceous granules, so that one species (E. hyemale) is used for scouring and polishing, under the name of Dutch rush or scouring rush.

E*quis"o*nance (?), n. [Equi- + L. sonans, p. pr. of sonare to sound: cf. F. équisonnance. See Sonant.] (Mus.) An equal sounding; the consonance of the unison and its octaves.

E*quis"o*nant (?) a. Of the same or like sound.

Eq"ui*ta*ble (?), a. [F. équitable, from équité. See Equity.] 1. Possessing or exhibiting equity; according to natural right or natural justice; marked by a due consideration for what is fair, unbiased, or impartial; just; as an equitable decision; an equitable distribution of an estate; equitable men.

No two . . . had exactly the same notion of what was equitable.

Macaulay.

2. (Law) That can be sustained or made available or effective in a court of equity, or upon principles of equity jurisprudence; as, an equitable estate; equitable assets, assignment, mortgage, etc. Abbott.

Syn. -- Just; fair; reasonable; right; honest; impartial; candid; upright.

Eq"ui*ta*ble*ness, n. The quality of being equitable, just, or impartial; as, the equitableness of a judge, a decision, or distribution of property.

Eq"ui*ta*bly, adv. In an equitable manner; justly; as, the laws should be equitably administered.

Eq"ui*tan*cy (?), n. [Cf. LL. equitantia. See Equitant.] Horsemanship.

Eq"ui*tant (?), a. [L. equitans, -antis, p. pr. of equitare to ride, fr. eques horseman, fr. equus horse.] 1. Mounted on, or sitting upon, a horse; riding on horseback.

2. (Bot.) Overlapping each other; -- said of leaves whose bases are folded so as to overlap and bestride the leaves within or above them, as in the iris.

Eq`ui*ta"tion (?), n. [L. equitatio, fr. equitare: cf. F. équitation.] A riding, or the act of riding, on horseback; horsemanship.

The pretender to equitation mounted.

W. Irving.

E`qui*tem`po*ra"ne*ous (?), a. [L. aequus equal + tempus, temporis, time.] Contemporaneous. [Obs.] Boyle.

||Eq"ui*tes (?) n. pl [L., pl. of eques a horseman.] (Rom. Antiq.) An order of knights holding a middle place between the senate and the commonalty; members of the Roman equestrian order.

Eq"ui*ty (?), n.; pl. Equities (#). [F. équité, L. aequitas, fr. aequus even, equal. See Equal.] 1. Equality of rights; natural justice or right; the giving, or desiring to give, to each man his due, according to reason, and the law of God to man; fairness in determination of conflicting claims; impartiality.

Christianity secures both the private interests of men and the public peace, enforcing all justice and equity.

Tillotson.

2. (Law) An equitable claim; an equity of redemption; as, an equity to a settlement, or wife's equity, etc.

I consider the wife's equity to be too well settled to be shaken.

Kent.

3. (Law) A system of jurisprudence, supplemental to law, properly so called, and complemental of it.

Equity had been gradually shaping itself into a refined science which no human faculties could master without long and intense application.

Macaulay.

Equitable jurisprudence in England and in the United States grew up from the inadequacy of common-law forms to secure justice in all cases; and this led to distinct courts by which equity was applied in the way of injunctions, bills of discovery, bills for specified performance, and other processes by which the merits of a case could be reached more summarily or more effectively than by common-law suits. By the recent English Judicature Act (1873), however, the English judges are bound to give effect, in common-law suits, to all equitable rights and remedies; and when the rules of equity and of common law, in any particular case, conflict, the rules of equity are to prevail. In many jurisdictions in the United States, equity and common law are thus blended; in others distinct equity tribunals are still maintained. See Chancery.

Equity of redemption (Law), the advantage, allowed to a mortgageor, of a certain or reasonable time to redeem lands mortgaged, after they have been forfeited at law by the nonpayment of the sum of money due on the mortgage at the appointed time. Blackstone.

Syn. -- Right; justice; impartiality; rectitude; fairness; honesty; uprightness. See Justice.

E*quiv"a*lence (?), n. [Cf. F. équivalence, LL. aequivalentia.] 1. The condition of being equivalent or equal; equality of worth, value, signification, or force; as, an equivalence of definitions.

2. Equal power or force; equivalent amount.

3. (Chem.) (a) The quantity of the combining power of an atom, expressed in hydrogen units; the number of hydrogen atoms can combine with, or be exchanged for; valency. See Valence. (b) The degree of combining power as determined by relative weight. See Equivalent, n., 2. [R.]

E*quiv"a*lence, v. t. To be equivalent or equal to; to counterbalance. [R.] Sir T. Browne.

E*quiv"a*len*cy (?), n. Same as Equivalence.

E*quiv"a*lent (?), a. [L. aequivalens, -entis, p. pr. of aequivalere to have equal power; aequus equal + valere to be strong, be worth: cf. F. équivalent. See Equal, and Valiant.] 1. Equal in worth or value, force, power, effect, import, and the like; alike in significance and value; of the same import or meaning.

For now to serve and to minister, servile and ministerial, are terms equivalent.

South.

2. (Geom.) Equal in measure but not admitting of superposition; -- applied to magnitudes; as, a square may be equivalent to a triangle.

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3. (Geol.) Contemporaneous in origin; as, the equivalent strata of different countries.

E*quiv"a*lent (?), n. 1. Something equivalent; that which is equal in value, worth, weight, or force; as, to offer an equivalent for damage done.

He owned that, if the Test Act were repealed, the Protestants were entitled to some equivalent. . . . During some weeks the word equivalent, then lately imported from France, was in the mouths of all the coffeehouse orators.

Macaulay.

2. (Chem.) That comparative quantity by weight of an element which possesses the same chemical value as other elements, as determined by actual experiment and reference to the same standard. Specifically: (a) The comparative proportions by which one element replaces another in any particular compound; thus, as zinc replaces hydrogen in hydrochloric acid, their equivalents are 32.5 and 1. (b) The combining proportion by weight of a substance, or the number expressing this proportion, in any particular compound; as, the equivalents of hydrogen and oxygen in water are respectively 1 and 8, and in hydric dioxide 1 and 16.

This term was adopted by Wollaston to avoid using the conjectural expression atomic weight, with which, however, for a time it was practically synonymous. The attempt to limit the term to the meaning of a universally comparative combining weight failed, because of the possibility of several compounds of the substances by reason of the variation in combining power which most elements exhibit. The equivalent was really identical with, or a multiple of submultiple of, the atomic weight.

3. (Chem.) A combining unit, whether an atom, a radical, or a molecule; as, in acid salt two or more equivalents of acid unite with one or more equivalents of base.

Mechanical equivalent of heat (Physics), the number of units of work which the unit of heat can perform; the mechanical energy which must be expended to raise the temperature of a unit weight of water from 0° C. to 1° C., or from 32° F. to 33° F. The term was introduced by Dr. Mayer of Heilbronn. Its value was found by Joule to be 1390 foot pounds upon the Centigrade, or 772 foot pounds upon the Fahrenheit, thermometric scale, whence it is often called Joule's equivalent, and represented by the symbol J. This is equal to 424 kilogram meters (Centigrade scale). A more recent determination by Professor Rowland gives the value 426.9 kilogram meters, for the latitude of Baltimore.

E*quiv"a*lent, v. t. To make the equivalent to; to equal; equivalence. [R.]

E*quiv"a*lent*ly, adv. In an equal manner.

E`qui*val"ue (?), v. t. To put an equal value upon; to put (something) on a par with another thing. W. Taylor.

{ E"qui*valve (?), E"qui*valved (?), } a. [Equi- + valve.] (Zoöl.) Having the valves equal in size and from, as in most bivalve shells.

E`qui*val"vu*lar (?), a. (Zoöl.) Same as Equivalve or Equivalved.

E*quiv"o*ca*cy (?), n. Equivocalness.