equational 
lent \nililli ri-iiliiil as ;i|i|ilicd ID gearing and the 
like. Equational box, a system of ditien-ntial .< u 
ill'-', II < ,1 III iKlllhill ;tll<i 11) Iliachll!. s to obtain l-halC-d ill 
the relati\e. speed ,,f tin- bobbin and tlirr. - 
I ><tl >r,-nr (under 'li/> 'lit in 1 1, l>"l'lii,i, :uii I jhi I >"<" . 
equator (o-kwa'tor), . [< ME. <///// = F. 
I'l/iiii/i'iir = 1'g. i-i/iuiiliir = Sp. i-i-iiiiilnr = It. 
ei/iialori- = I), ii-qnntor = (!. liqitator = Dan. 
ii-l, i-ii Inr = S\v. I'l/nilnr, < Ml., ii-i/iiiilnr, the 
equator, < L. teijitare, make equal : Nee </""" I 
1. In null-nil., that imaginary great ein-le in 
Die he;i vens I ho piano of which is perpendicu- 
lar to the axis of tho earth. It li , > . i > w here 90 
distant from tin- e. lc -ii.il polo, which coincide with the 
extremities of the earth s axis, supposed I'l In- produced 
to inccl lii. heavens. .Mid its axis is this plodllced axis. 
It divides ill- ,'<'k.tiii sphere into tlit- northern and 
southern hemispheres. During his apparent yearly course 
the sun is twice in the equator, in the months of March 
anil September. Then the day and night are everywhere 
equal, whence tin; name equutur. 
This same cen le is deped also the weyere, equator, of 
tin- day, tor whan tin Mimic is in the hevedes of Aries V 
l.ilu-ii, than ben the dates & the nyhtes illike of lengthe In 
al thu world, t'f'inti-er. Astrolabe, 1. 17. 
As when his beams at noon 
fulminate from the equator. Milton, P. L., HI. 617. 
2. In gcog., that great circle of the earth every 
point of which is 90 from the earth's poles, 
which are also its poles, its axis being also the 
axis of the earth. It is In the plane of the celestial 
equator. Our earth is divitlctl by it into the northern and 
southern hemispheres. From this circle is reckoned the 
latitude of places both north and south. 
Hence 3. A similarly situated circle about 
any spherical body, or the region adjacent to it. 
Eccentric equator. Same a.t eyiiant. Magnetic 
equator, a line which nearly coincides with the geo- 
graphical equator, and at every point of which the verti- 
cal component of the earth's magnetic attraction is zero- 
that is to say, a dipping-needle carried along it remains 
Imri/ontal. It is hence called tho aclinic liu>'. 
equatorial (e-kwa-to'ri-al), a. and . [= F. 
equatorial, etc., ^ ML. "(equator, equator: see 
equator.] I. a. Of or pertaining to the equator: 
as, equatorial climates ; the equatorial diameter 
of the earth is longer than the polar diameter. 
Equatorial circle, see II. Equatorial dial. See 
dial. Equatorial migration. See miV"'"' - -Equa- 
torial telescope or instrument. Sec II. 
II. ii. An astronomical instrument contrived 
for the purpose of directing a telescope upon 
any celestial object of which the right ascen- 
sion and declination are known, and of keeping 
tho object in view for any length of time not- 
withstanding the diurnal motion. For these pur- 
poses a principal axis rusting on tlrm supports is placed 
parallel to the axis of the earth's rotation, and conse- 
quently pointing to the poles of tho heavens. On this polar 
axis there is placed, usually near one of its extremities, 
a graduated circle, the plane of which is perpendictitar 
to the polar axis, ami therefore parallel to the equator. 
This circle is called the equntortal circle, and measures 
by its ares the hour-angles, or differences of right ascen- 
sion. The polar axis carries a second circle, called the 
</, ./;,/.''/"/< cnv/c, the plane of which is at right angles to 
that of the equatorial circle. This last circle has a tele- 
10 >pc attached to it for making observations, which moves 
along with it in the sumo plane. The name equatorial, or 
''jutti'ii-i'it i mini, in-lit, is sometimes given to any astronom- 
ical instrument which has its principal axis of rotation 
parallel to the axis of the earth. 
equatorially (e-kwa-to'ri-al-i), adv. In an 
equatorial manner ; so as to Have the motion or 
position of au equatorial. 
With the rquitiiiriallii mounted refracting telescopes, 
only the usual observations were conducted. 
Science, IV. 62. 
equery, equerry (ek'we-ri or e-quer'i), H. ; pi. 
equi'i-iis, n/iii ri-ies (-riz). [Altered, in simula- 
tion of L. eqnuSj a horse, from OF. excuurif, is- 
ruii-ie.mtitl. !'. rcurie, a stable, < ML. scitrin. n 
stable, < OIIG. xt-inni, MHO. scltiurc, G. scheitcr, 
a shed. Heneo, by apheresis, qun-ry, qiiirry: 
see qtterry. In the second sense appar. mixed 
with OF. exi-nyi-r, a squire, in the phrase ixi'iii/t r 
f(Yxrif///-rV, an equery, lit. squire of the stable ; 
esquyer,*>Y.. esquire, si/uirc: sre<. -,/)>< l, squire. ] 
It. A stable for horses. 
I made the proof ofttinn 9 upon sir R. 1'.. that in. ... 
Sir Robert 1'yt- of the rqiin-rii. I!<iiilf, Works, VI. :;. ,t. 
2. In the household of a prince or nobleman, 
an officer who lias the superintendence and man- 
agement of horses. In Knt-'land the equciics are offi- 
cers of the IIOIIM 'hnlil of the >o\ , ] -, 'Un. in the department 
of tin-Master of the llo,s,.,,t whom tin- lir.-t is styled chief 
ciptcn and clerk -marshal. Their duties fall in rotation, 
and when tin- sovereign rides abroad in state an ecplcry 
goes in the leading coach. iMlieels w ith the same dellonii- 
llation form part of tin- c>t ililishnienls of the mcmbt l - oi 
the royal family. 
The Kinir iu royal robes and equipage. Afterwartls fol- 
low M 'tenicll -jriit. pell- ioM'T-.. 
Kr*lint. lii.-iry. \pril -J:i. 1861. 
eques (e'kwez). .: pi. eqniies (ek'wi-tez). [L., 
u horseman, a knight, < ii/im.--, a horse: see 
Equus.] 1. In Rom, ttntiq., oue of the knights, 
1983 
an order of Roman citi/ens. See 
2. [<"y'-] A genus of lislit-s of the pcrcoid 
series and family Kriii-iiiilit; reju-esented by 
species found in the Caribbean Hea and along 
the Atlantic coasts of tropical America, typi- 
cal of the subfamily Ki/iiitiiiii: ihci.clt..] IMM-. 
III. 'ill. /,'/"''. /";ic, "lilt li v, i , a e< HI -pic lion si v -t l [pel I specie^ 
h:i\in<_- ail ohlonu: !>o.ly. with tin- back iinnipeil and the 
doisal line \i i y comex, a short, hiyh, and acute tirst <lor- 
sal tin, a luni;, low s, ,i .l.irsal tin, and belted broadly 
\\ ith hlackisji iio\vn on a gray inn-yellow grou ml. each IM it 
beinx edyed with a whitish color. Two otln i -p- 
knonn from tin- Atlantic coast ami one from the Paclflc. 
equestrian (e-kwes'tri-an), a. and n. [= F. 
i : </ iii-Ntre = Sp. ecuestre = Pg. It. equcntre, < L. 
ri/in-xiri- (i-qaestr-), belongingto a horse (or to a 
horseman), < cqutt-H, a horse (> eques (r</uit-), a 
horseman): see A'gMK.*.] I. a. 1. Pertamingor 
relating to horses or horsemanship; concerned 
with horses or riding; consisting in or accom- 
panied with performances on horseback: as, a 
person of equestrian tastes; an cqiirxtrinn pic- 
ture ; equestrian feats, exercise, or sports. 
I should bo glad if a certain e>iite*tri<iti order of ladies, 
some of whom one meets in the evening at every outlet 
of the town, would take this subject into their serious 
consideration. Spectator, No. 104. 
2. Riding or represented as riding on a horse ; 
exercising or mounted ou horseback : as, eques- 
trian performers; an equestrian statue of Wash- 
ington. Equestrian statues are usually cast In bronze 
and mounted on a stone pedestal. Few early monuments 
of this kind are extant, the valuable metal they contained 
tempting ravagers to destroy them. 
An equestrian lady appeared upon the plain. Sjtectator. 
3. Of or pertaining to the Roman equites or 
knights: as, the equestrian order. See cquitcs. 
II. n. A rider on horseback ; specifically, one 
who earns his living by performing feats of 
agility and skill on horseback in a circus. 
equestrianism (e-kwes'tri-an-izm), n. [< eques- 
trian + -</.] The performance of an eques- 
trian ; horsemanship. 
equestrienne (e-kwes-tri-en'), . [A spurious 
F. form (in circus-bill French), < equestrian + 
F. fern, suffix -ennc.~\ A female rider or per- 
former on horseback. 
equi-. [L. ceqtii-, before a vowel a;qu-, combin- 
ing form of teqiius, equal : see equal.] An ele- 
ment of words of Latin origin, meaning ' equal ' 
('having equal . . . '), as in equidistant, equiva- 
lent, etc. 
equiangled (e ' kw i -ang ' gld), a. [< L. aquus, 
equal, + E. angle 3 + -fd 2 . Cf. equiangular.] 
Having equal angles ; equiangular. 
For, whereas that consists of twelve {equilateral and 
<Kquianyled pentagons, almost all the planes that made up 
our granite were quadrilateral. Bvyle, Works, III. 534. 
equiangular (e-kwi-ang'gu-liir), a. [Formerly, 
in accordance with strict L. analogy, equnngu- 
lar; < L. a'</), equal, + aiigulus, au angle, + 
-ar'*.] In yeoni., having all the angles equal. 
Equiangular spiral, the logarithmic spiral, a curve 
making everywhere the same angle with its radius vector. 
equianharmonic(e-kwi-an-har-mon'ik), a. [< 
L. tuquu.t, equal, + E. (inharmonic.] Equally 
auharmonic : applied in mathematics to the 
situation of four points or other elements (one 
of which at least must be imaginary) whose an- 
harmonic ratio is a cube root of unity. 
equianharmonically (e-kwi-an-har-mon'i-kal- 
i), iitlr. In an equianharmonic situation. 
equibalance (e-kwi-bal'ans), r. /. ; pret. and pp. 
equibalaneed, ppr. equilialanciiig. [< L. a'attua, 
equal, + E. balance. Cf. equilibrate.] To be of 
equal weight with something ; counterbalance. 
[Rare.] 
In Mahomet . . . the passions of amorousness ami am- 
bition were almost ei/n Unlum; ./. 
( 7/r/-//Vr;i i;,-ti' : ii'iin'ii Aiqieal, p. 48 (Ord MS.). 
equibiradiate (6*kwi-bi-ra'di-at), a. [< L. 
n I/in/.-,-, equal, + bi-, two-, + radius, ray.] Hav- 
ingtvvoequal rays, as a sponge-spicule. Soil a a. 
equiconvex (e-kwi-kon'veks ), a. [< L. (equiis, 
equal, + enntefus, convex.] Having two con- 
vex surfaces of equal curvature. 
equicrescent (e-kwi-kres'ent), a. [< L. trqiiux, 
equal, + cr<'nn-ii(t-)>t, increasing.] Increasing 
at the same rate ; having equal increments. 
equicrural (e-kwi-kro'ral), a. [< L. aqtius, 
equal. + CI-H.V ((//-), leg, + -al.] Having legs 
of equal length; isosceles. 
We .-iicee.ssjvely draw lines from angle to angle, until 
seven eiiiiicntrtit triangles be de 
r Broirne, Vulg. KIT. 
equicruret (e'kwi-kriir), a. Same as eqiiirnirnl. 
An i-'/iu'i -i > trianglt- . . . go U|HHI a ei-rtain propor- 
tion of h-nath and breadth. Sir A', lli'ihii. Bodies, ix. 
Equiculus (e-kwik'u-lus), . Same as Eqttu- 
li ('.--, 1. 
equiformity 
equid (ok'wid), n. A hoofed mammal of the 
family Kqniiln: 
Equidse (ok'wi-df-), . />!. [NL., < Equu* + 
-ill" .] A family of solidungulate perissodap- 
tyl hoofed quadrupeds: tho horse family. The 
middle di^it and liuof of each foot are enlarged, and alone 
-uppoi t the l<od> ; and the lateral digits are more or less 
reduced in sue. and are fum-tiotileu or wanting. In living 
genera the first and fifth digits and corresp.,n,iiii- 
piMlials are wanting : the se.-on.l and fourth 
wanting, but their metapodlnls are prestnt, tl 
duced to mere splint IK nn-s ; the femur has a fosxa a!">\ . 
Skeleton of Hone (f-qttut 
. 
fr, frontal hone : t'. cervical vertebra : D. dorsal vertebrap ; /-, lum- 
bar vertebra; ; cd, caudal vertebra ; if, scapula : ft. pelvis ; ma, 
mandible; AM, hurncnis ; ra, radius; tf, cnrpus: ittf, metacarpus i 
_/!, femur ; tit*, tibia ; i'-i , calcaneum : far, tarsus ; tnt. rnetauinu-i : 
/, phalanges. 
the ectocondvle ; the shaft of the ulna is atrophied, and 
its extremity is consolidated with the radius ; the nbula 
is rudimentary and ankylosed with the tibia : the skull is 
much elongated ; the lower jaw is very deep behind ; aud 
the bony orbit of the eye Is complete. The dentition is : 
milk-teeth, di. ', dc. ! . dm. ,' ; permanent teeth, i. ). c. | , 
pm. and in. jj X 2 = 40. The two genera Enuun and An- 
nwt (seatx^ely distinct from each otiier) are the only living 
representatives of the family ; but there are many fossil 
genera, ranging through the Tertiary, as llipixirioti, Mery- 
chippuf, I'rotoriippitJi, J/iWii'j;/x, Kpitiipirwt, and Eohip. 
inttt. See these words ; see also httrite, apgl, zebra, quaqfta, 
and cuts under fiock, ttoo/, periutodaftiil, and tttjiiiliintfuiate. 
equidifferent (e-kwi-dif 'er-ent), a. [< L. a-quus, 
equal, + differen(t-)x, different.] 1. Having 
equal differences ; arithmetically proportional. 
2. In cryntal., having a common difference: 
having a different number of faces presented by 
the prism and by each summit, the three num- 
bers forming a series in arithmetical progres- 
sion, as 6, 4, 2 Equidifferent series, an arithmet- 
ical series having the difference between the first and sec- 
ond, the second and third, the third and fourth terms, etc., 
the same ; an arithmetical progression. 
equidistally (e-kwi-dis'tal-i), nrfr. Peripheral- 
ly; equally as regards distal arrangement. 
The genus Actinophrys has been cited, where the ani- 
mal Is composed of cells arranged equidigtally around a 
common center. K. D. Cope, Origin of the Fittest, p. 19i 
equidlstance (e-kwi-dis'tans), n. [= It. equi- 
ainlama, < NL. 'equidixtantia, "tequidistantia, < 
LL. (equidistan(t-)x, equidistant: see equidis- 
tant.] Equal distance. 
The collateral equulintanee of cousln-srcrman from the 
stock whence both descend. 
Up. Hall, Cases of Conscience, iv. 5. 
equidistant (e-kwi-dis'tant), a. [= F. Equidis- 
tant = Pr. equidistant = It. equidittlante, < LL. 
tFqttidistan(t-)s, < L. tequun, equal, + distan(t-)s, 
distant.] Equally distant. 
The compleat Circle ; from whose every-place 
The Cent re stands an eirui-distant space. 
Si/leester, tr. of Du Bartass Weeks, H., The Columnes. 
Any constant periodical appearance or alternation of 
ideas in seemingly e<ruidi*tant spaces of duration, if con- 
stantly and universally observable, would have as well 
distinguished the intervals of time as those that have been 
made use of. Locke, Human I'mlerstanding, II. xiv . 19. 
equidistantly (e-kwi-dis'tant-li), adv. At the 
same or an equal distanced 
The porch Is simple, consisting only of sixteen pillar*, 
disposed equidistantl'l. 
J. t'erffiitton. Hist. Indian Arch., p. 380. 
equidiurnal (e'kwi-di-er'nal), n. [< L. a-quux, 
equal, + diurnits, daily: see diurn, diurnal.] 
Having or pertaining to days of equal length: 
equivalent to equinoctial. 
The circle which the sun describes in his diurnal mo- 
t i< in w hen the days and nights are equal the Greeks called 
the i-.jiiid , urnal, the Latin astronomers the equinoctial. 
aud the corresponding circle on the earth was the equator. 
Whewll. 
equiform (e'twi-fdrm), a. [< L. cequiformig, 
uniform, < (equus, equal, + forma, shape.] Hav- 
ing the same shape or form. 
equiformal (e'kwi-f6r-mal), a. [< equifnrm + 
-al.] Same as equiform." 
The tetth bcini: fjui/iirntal. Bnctjc. Ilrit.. XVI. 660. 
equiformityt (e-k\vi-fdr'mi-ti), n. [< equiform 
+ -ity.] The character of being equiform; 
uniformity. 
