Equilibrium

-Equal balancing of the mind between motives or reasons; equal diffusion or distribution of thought. (Fine Arts .) The just place or balance of a figure, or other object, so that it may appear to stand firmly. Also the due equipoise of objects, lights, shadows, ., against each other by some striking features. This quality is obvious in the works of nature, as well in the human form as in landscape. In the latter, for instance, the sun is generally the medium of producing it by strong contrasts of light and shadow. -In Architecture, the same means are employed to produce the most striking effects. ( Polit .) See BALANCE OF POWER. In equilibrio . [Lat.] In a state of equipoise or equilib rium. Equilibrium of Arches. ( Arch . ) This is a subject which is treated in that part of mathematical science called Statics. In this the conditions are considered in which any body, or number of bodies, will remain in a state of rest under the influence of forces that act in opposite directions, and mutually counteract each other. It is evident that the conditions of E. can be considered in theory only, as the slightest po ible addition to either of the counteracting forces would immediately give it a preponderating influence, and destroy the state of balance. In investigating the E. of A. , we must imagine the surfaces of the vou oirs to be perfectly smooth, and friction must be altogether disregarded, so that each stone may be considered to be sustained by the pre ure of those on either side of it, acting, under these conditions, in directions perpendicular to their surfaces. The theory on which the E. of A. depends is briefly this, that the weights of the vou oirs of which it is composed must be in the same proportion to each other as the sections of the chord of the arch, which are made by producing the lines which represent the junctures of the IMG:content-0065.png:[blocks in formation] 15 12 13 14 10 Fig . 954. PRINCIPAL FORMS OF ARCHES. sides of the vou oirs to the centre from which the line Equinunk', in Pennsylvania , a post-village of Wayne of intrados is described, supposing the arch to be a segmental arch. It is also nece ary that the perpendicular pa ing through the centre of gravity of any part of the arch should pa through a parallelogram formed by lines drawn perpendicular to the sides of the part in question from their extremities. In such an arch the vou oirs at the crown would be the least in depth, and each succe ive vou oir, from the crown toward the piers, would increase in thickne , so that the line of the extrados would not be described from the same centre as that from which the line of intrados has been described. The slightest alteration of the weight of any of the vou oirs of such an arch as this, in which the stones that compose it are supposed to be supported without friction, would cause it to be overturned; but when friction is taken into account, it is plain that an arch, which would remain in equilibrium under the conditions above stated, if they could exist in practice, would then be capable of sustaining a great amount of superincumbent pre ure; and, indeed, pre ure on the arch tends to make it stronger, by increasing the friction by which the pre ure on it is resisted. The theory of the E. of domes is somewhat similar to that of the E. of A. , if we consider the dome to consist of a series of exactly equal and opposite slices, that are formed by planes pa ing perpendicularly through the axis at a small angle to each other, and which support each other at the crown, being, in fact, a number of balanced arches, each of which would preserve its equilibrium, if it were left standing alone. But in the dome, E. will be maintained, and the structure will be stronger, if the weight of the upper part of each of such a series of contiguous balanced arches be greater than that which would be required to preserve E. in a balanced arch of similar form standing alone; because every stone in each circular and horizontal course, or each of the whole series of the opposite parts of the balanced arches, exerts a lateral pre ure on those on either side of it, and their tendency to fall inwards locks the whole structure tightly together. To insure the E. of an arch, friction being disregarded, it is therefore nece ary to bring the weight of the vou oirs composing the crown up to a certain limit, which must not be increased or diminished in any way; but in the dome, E. will be maintained, for the reasons above stated, when the weight of the upper portion of each of the series of arches of which it may be supposed to be composed exceeds this limit.-See ARCH. co.. on the Delaware River, abt. 24 m. N.N.E. of Hones dale. Equip, (e- kwip ',) v.a. [Fr. équiper , from L. Lat. eschi pare , from Goth. skip , a ship.] To fit, as a ship for sea; to accoutre; to furnish; to supply with men, ordnance, and munitions of war, as a ship; to furnish with arms, or a complete suit of arms. (Used chiefly in a naval and military sense.) -To dre up; to adorn; to decorate, as the person; as, "equipped in a ridiculous habit." - Add is on. Equipage, (ek'wi- pāj ,) n. [Fr.] ( Mar. ) The crew of a ship, together with all a ship's furniture, masts, sails, arms, munitions, . ( Mil .) The furniture of an army or body of troops. In this sense it includes arms, artillery, utensils, provisions, . Camp E. includes tents and things nece ary for accommodation in camp; while field E. consists of arms, artillery, wagons, tumbrels, . - Ornamental furniture; accoutrements; apparel; as, " equipage of Pride." - Pope. Equilibrium-valve, n . ( Mach .) The valve in the steam-pa age of a Cornish engine for opening the communication between the top and bottom of the cylinder, to render the pre ure equal on both sides of the piston. Equimul'tiple, a . [Fr.; Lat. æquus , and multiplico , to multiply.] Multiplied by the same number or quality. -n. (Geom. and Arith .) Any number or quantity multiplied by the same number or quantity as another: thus, mA and m B are equimultiples of A and B, whatever magnitudes the latter may represent; or, 4 times 2, or 8, and four times 4, or 16, are equimultiples of 2 and 4. Equine, Equinal, ( ē - kwin ' , ) a. [Lat. equinus , from equus , a horse.] Pertaining to a horse; denoting the horse kind. Equinec'e ary, a . Requisite in an equal degree. Equin'ia, n. [Lat. equinus .] ( Med .) See GLANDERS. Equinoctial, (ē- kwi -nok's he-al,) a. [Fr. equinoxial ; Lat. æquus , and nox , noctis , night. See EQUINOX.] Pertaining to the equinoxes; having the nights equal to the days; as, the equinoctial line. - Relating or pertaining to the time of the equinoxes; as, an equinoctial gale. - Pertaining or having reference to the regions or climate of the equinoctial line or equator. "Pining with equinoctial heat."- Philips . E. colure. (Astron.) The meridian pa ing through the equinoctial points. - E. flowers , those which open at a stated hour. - E. points . (Astron.) The two opposite points of the celestial sphere in which the ecliptic and equator intersect each other; the one being the first point of Aries, and the other the first point of Libra. See PRECESSION. - E. time . Astronomers sometimes give the date of an occurrence in equinoctial time to get rid of differences. This is reckoned from the moment when the point of Aries pa es the vernal equinox. -n. The equator. See EQUATOR. Equinoctially, adv. Towards the equator; in the direction of the equinox. Equinox, ( ¿ ' kwe - noks ,) n. [Lat. æquus , and nox, noctis , night. See NOCTURNAL.) ( Astron .) The time at which the sun pa es through the equator in one of the equinoctial points. When the sun is in the equator, the days and nights are of equal length all over the world, whence the derivation of the term. This happens twice every year; namely, about the 21st of March, and the 22d of September: the former is called the vernal , and the latter the autumnal equinox. The equinoxes do not divide the year into portions of equal length; for in consequence of the earth being at its greatest distance from the sun during the summer months, and its angular motion in its orbit being consequently slower, the interval from the vernal to the autumnal equinox is greater than that from the autumnal to the vernal. In other words, the sun continues longer on the northern than on the southern side of the equator. At the beginning of the present cent., the difference amounted to 7 days 16 hours and 51 minutes. The summer in the northern hemisphere is consequently longer than in the southern by this quantity; and to this circumstance some meteorologists ascribe, in part at least, the higher temperature that is found to prevail in the northern hemisphere under the same parallel. - See PRECESSION. Equinoctial wind : used chiefly in poetry. - Retinue; attendance, as the carriage, horses, and liveries which indicate the fortune or rank of a person when appearing abroad; as, the equipage of a nobleman. Equipaged, ( ek'we - pajd ,) a. Furnished with an equipage; attended with a handsome or splendid retinue. "A goodly train of squires and ladies equipag'd well."-Spenser. Equip'arate, v . a . To make comparison. (R.) Equip'edal, a. [Lat. æquus , and ped is , foot.] Having equal feet.