horizon 
col horizon. Geographical horizon, a great circleof the 
terrestrial sphere, having any given station as its pole. 
The sensible horizon, or horizontal plane tangent to the 
surface of the earth at a given station, is sometimes distin- 
guished from the rational horizon, or plane parallel to the 
sensible horizon passing through the center of the earth. 
Horizon of an artificial globe, the broad horizon- 
tal ring in which the globe is fixed. On this are several 
concentric circles, which contain the months and days of 
the year, the corresponding signs and degrees of the eclip- 
tic, and the thirty-two points of the compass. On the 
same horizon, in geol. , said of fossils or strata which ap- 
pear to be of the same age. Physical horizon, the circle 
of tangency with the terrestrial sphere, or geoid, of a cone 
having its vertex at the eye of the observer. Rational 
or true horizon. .Same as astronomical horizon. Visi- 
ble horizon. See def. i. 
horizon-glass (ho-ri'zon-glas), n. Inastron., 
the small plane mirror which is firmly attached 
to the frame of a quadrant or sextant, and has 
one half silvered. In measuring an altitude of the 
sun the observer looks directly through its tranxparent 
half toward the horizon at the point directly under the 
sun. Formerly two horizon -glasses were often used, one 
the front glass as above described, the other, the back 
glass, so placed that the observer looked through it to 
the point of the horizon opposite to that under the sun ; 
this glass had simply a narrow unsilvered strip across its 
middle. 
horizontal (hor-i-zon'tal), a. and n. [= D. 
horizontaal = Q. horizontal =Dan. Sw. horizontal 
= F. Sp. Pg. horizontal = It. orizzontale, < ML. 
*horizontalis, < L. horizon, horizon: see horizon.'] 
1. a. 1. Of or pertaining to the horizon. 
As when the sun new-risen 
Looks through the horizontal misty air, 
Shorn of his beams. Milton, P. L., i. 595. 
2. Parallel to the horizon ; at right angles to 
the direction of gravity at any station ; being 
on a level; not vertical nor inclined: as, a hor- 
izontal line or surface; a horizontal position. 
Specifically (a) In mech., acting or working, or placed, 
wholly or with respect to its main parts, in a level plane : 
as, a horizontal drill ; a horizontal boring-machine ; a hori- 
zontal saw-mill and mortising-machine; a horizontal pump; 
a horizontal escapement ; a horizontal steam-engine. (>) 
In zool., being, as the parts, organs, surfaces, marks, etc., 
of a bilaterally symmetrical animal, parallel to a plane 
supposed to extend from end to end and from side to side 
of the body : as, horizontal wings (those which, in repose, 
lie flat over the body, so as to be parallel to the supposed 
plane). 
3. Measured or contained in a plane of the ho- 
rizon: as, horizontal distance Horizontal bar 
battery, cornice, distance, leaf, mill, parallax, etc. 
See the nouns. Horizontal line, (a) In JTJ>., the in- 
tersection of the horizontal and perspective planes ; an 
imaginary line crossing a picture parallel to its base or 
bottom line, and at the assumed level of the eye of the 
observer. (6) In figured ba*x, a dash under a note indi- 
cating that the tones of the last figured chord are to be 
continued without regard to the tone of the bass. Hori- 
zontal line of Camper, in craniom., the intersection of 
the horizontal plane of Camper with the median plane of 
the head. Horizontal plane, a plane parallel to the 
horizon, or not inclined to it; in pfrisp., a plane parallel to 
the horizon, passing through the eye and cutting the per- 
spective plane at light angles. Horizontal plane of 
Camper, in craniom., the plane passing through the cen- 
ter of the external auditory meatus on either side and the 
inferior nasal spine. Horizontal projection.? projec- 
tion made on a plane parallel to the horizon. Horizon- 
tal range of a projectile, the distance at which it falls 
on or strikes a horizontal plane, whatever be the angle of 
elevation. Horizontal root, steam-engine, etc. See 
the nouns. 
II, n. In craniom., the line drawn from the 
lower edge of the orbital cavity to the middle 
of the ear-cavity. 
horizontality (hor*i-zon-tal'j-ti), n. [< horizon- 
tal + -ity.~\ The state of being horizontal. 
No vase nor statue breaks the dead horizontality of the 
parapet. The American, XIII. 67. 
horizontalization (hor-i-zon'tal-i-za'shon), n. 
[< horizontal + -ize + -ation.] In craniom. , the 
act of placing the skull for craniometrical mea- 
surement so that the plane taken as the hori- 
zontal datum-plane shall be truly horizontal. 
Anthropologists are not entirely agreed on a horizontal 
datum-plane, but the alveolocondylean plane is usually 
preferred that is, a plane passing through the alveolar 
point tangent to the condyles. When this plane is made 
horizontal the skull looks to the horizon. When the skull 
Is fragmentary the horizontalization may become a diffi- 
cult problem, and the selection of an unusual datum-plane 
may be rendered necessary. 
horizontally (hor-i-zon'tal-i), adv. In a hori- 
zontal direction or position ; in the direction 
of the horizon; on a level: as, a line stretched 
horizontally. 
It is occasionally requisite that the object-end of the in- 
strument be moved up and down as well as horizontally 
or equatorially. Paley, Nat. Theol., vlii. 
horkey (h6r'ki), n. Same as hockey 2 . 
horkey-load (h6r'ki-16d), n. Same as hockey- 
load. 
Hormaphis (hor'ma-fis), . [NL., < Gr. bpfioc,, a 
cord, chain, necklace, + NL. aphis.'] A genus 
of plant-lice founded by Osten-Sacken in 1861, 
having the antennal joints deeply incised and 
2884 
well separated, and the first two oblique veins 
of the fore wings uniting in a fork. The spinous 
Female Spinous Gall-louse (Hormaphis tpinesus), the fore wings 
showing abnormal venation. {Much enlarged.) 
gall-louse, //. xjrinosus, forms on the stems of wych-hazel 
a gall, which is a deformation of the flower-bud. 
Horminum (hor-mi'num), n. [NL. (Linnaeus, 
1737), < Gr. opfttvov, a kind of sage.] A mono- 
typic genus of plants belonging to the natural 
order Labiatw and tribe Satureinea; the type of 
Endlicher'ssubtribe Hormintce, and of Lindley's 
tribe Horminida;. It is characterized by having the 
calyx 2-lipped ; the corolla with incurved, ascending tube ; 
the anthers linear, 1-celled, confluent ; leaves mostly radi- 
cal, dentate, the upper reduced to narrow bracts ; whorls 
0-flowered ; flowers violet-purple. The single species, //. 
Pyrenaiciim, is a native of the mountains of Europe. 
Bentham makes Horminum a section of the genus Salma ; 
Moench, a subgenus of Mentha; Tournefort, a synonym 
for the genus .SVilrta. 
hormogone, hormqgon (hdr'mo-gon, -gon), . 
Same as hormogonium. 
hormogonia, . Plural of hormogonium. 
hormogonimium (hor*mo-g6-nim'i-um), .; pi. 
liormoyonimia (-a). [NL., ^ Gr. op//of, a cord, 
chain, + y6vt/Mf, productive: see gonimium.] 
One of the common forms of gouidia of lichens, 
especially characteristic of the Collemacece. It 
is small, monilif orm, and contained in a syngo- 
nimium. 
hormogonium (hor-mo-go'ni-um), .; pi. hor- 
mogonia (-a). [NL., < Gr. dp/tof, a cord, chain, + 
j ovof, offspring.] In bot., a special reproductive 
body in the nostocs, having the form of a chain 
of roundish cells, from which new comobia are 
formed. Also hormogone, hormogon. 
The cells intermediate between two heterocysts escape 
in the form of a small chain, called a hormoyoniuni, and 
swim about with a spiral motion through the water. They 
at length become quiescent and begin to divide both trans- 
versely and longitudinally. Of the cells thus formed some 
become heterocysts, and in process of time a new Nostoc 
is formed. Farlow, Marine Algse, p. 12. 
hormogonous (hor-mog'o-nus), a. [As hormo- 
(jon-ium + -OMS.] Possessing or resembling a 
hormogonium. 
Hormospermeae (hor-mo-sper'me-e), n. pi. 
[NL., < Gr. iipfiof , a cord, chain, + sntp/ia, a seed, 
+ -ece.] One of the principal divisions of the 
Florideai, or red and purple seaweeds, as pro- 
posed by Agardh (1851). It Includes the orders 
Squamariacece and Sphcerococcoidetr, and the suborder 
Cramiefp (also called DeUswriece, from the genus Deles- 
g>'ria), characterized by having the spore-bearing fila- 
ments articulated in amoniliform manner, and superficial 
or radiating in the pericarp. 
horn (horn), n. [< ME. horn, < AS. horn = OS. 
horn (in comp. ) = OFries. horn = OD. horn, 
horen, D. horen = MLG. horen, LG. horn = OHG. 
MHG. G. horn = Icel. Sw. Dan. horn = Goth. 
haurn = L. cornu (> ult. E. corn 2 , cornet, etc.) = 
W. Gael, and Ir. corn (the Old Celtic form is rep- 
resented by the entry nApvov, trumpet, in Hesy- 
chius), a horn; with formative -n, akin to Gr. 
Ktpaf (Ktpar-), a horn (see cerato- and carat), with 
formative -t; of the same root as AS. heorot, 
heart, E. hart, and L. cenus, deer: see hart 1 and 
Cervus. See hornet.'} 1. An excrescent growth 
upon the head in certain animals, serving as a 
weapon of offense or defense. See def. 3. The 
horns of cattle, sheep, and goats are familiar examples. 
Such horns, technically called rornua cava or hollow horns, 
are permanent or non-deciduous ; they always grow upon 
the head, and are hollow, being formed upon a solid core 
of true bone. They are usually in one pair, right and 
left ; sometimes in two pairs, and in some fossil animals 
even in three. There may also be but one, as in some 
rhinoceroses, or there may be two placed one behind the 
other, as in others. True horns are distinguished from 
antlers by being hollow, permanent, and unbranched (ex- 
cept in the pronghorn antelope). They occur usually in 
both sexes. See Cavicomia, cornu. 
And I stood upon the sand of the sea, and saw a beast 
rise up out of the sea, having seven heads and ten horns, 
and upon his horns ten crowns. Rev. xiii. 1. 
It is said, "God sends a curst cow short hornt." 
SAa*.,Much Ado, ii. 1. 
2. An antler of a deer. Antlers are not true horns, 
but are bony, solid, and deciduous, and are for the most 
part confined to the male sex. They are technically called 
c'lrniia solida or corntia decidua (that is, solid or decidu- 
ous horns). See antler. 
3. Hardened and thickened epidermis or cuti- 
cle, as that of which nails, claws, and hoofs con- 
horn 
sist, differing from hair or other cuticular struc- 
tures chiefly in density and mnssiveness. The 
character of horn as a cuticular outgrowth or appendage 
is well illustrated in the pronghorn antelope, in which the 
transition from a mass of agglutinated hairs covering a 
bony core of the frontal bone to hard horny substance at 
the tip is very gradual and readily observed. The thick- 
ened skin of the human heel is horn, and similar special 
thickenings are called corns. Tortoise-shell is another 
kind of horn, as are also the hard covering of the beak and 
feet of birds, the scales of reptiles, etc. Horn in this sense 
is related to bone or cartilage only in that it belongs to the 
same general group of connective tissues. 
Neatly secur'd from being soil'd or torn, 
Beneath a pane of thin translucent horn, 
A book. Cowper, Tirocinium,!. 12". 
4. Something made of horn, or like or likened 
to a horn in position, shape, use, or purpose. 
The conquering Brute on Corineus brave 
This horn of land bestow'd, and mark'd it with his name. 
Drayton, Polyolbion, i. 50ft. 
We skirt the western horn of Sabioncello, and another 
turn leads us through the channel. 
E. A. Freeman, Venice, p. 192. 
The wood which grides and clangs 
Its leafless ribs and iron hornn. 
Tennyson, In Memoriam, cvii. 
Specifically (n) Afeeler; a tentacle; an antenna; an ovi- 
positor ; also, the tuft of feathers upon the head of sundry 
birds, resembling a horn ; a plumicorn, as that of various 
owls. 
As the snail, whose tender hornn being hit, 
Shrinks backward in his shelly cave with pain. 
Shak., Venus and Adonis, 1. 1033. 
((/) A wind-instrument more or less resembling a horn in 
shape and size, and originally made of horn : as, a hunt- 
ing-Aorn; a tin horn. In the simpler forms the horn is 
used chiefly to give signals, producing single or slight- 
ly variable loud tones. The nuntlng-horn, however, was 
early elaborated and made capable of producing a variety 
of calls, fanfares, and simple tunes. Wood, ivory, and v;i- 
i inns metals have been used for making horns. 
He's blawn his horn sae sharp and shrill ; 
Up start the deer on every hill. 
Eothwell (Child's Ballads, I. 159). 
With horns and trumpets now to madness swell, 
Now sink in sorrows with a tolling bell. 
Pope, Dunciad, Ii. 228. 
Waked at dead of night, I heard a sound 
As of a silver horn from o'er the hills 
Blown. Tennyson, Holy flrail. 
(c) By extension, a musical wind-instrument of the trum- 
pet class, developed from the hunting-horn (previously 
modified for use in orchestras under the name corno di 
caccia), and distinctively called the French horn, having 
a slender tube of brass or silver, several feet long, grace- 
fully curved upon itself, terminating in a flaring bell, and 
blown throuuh a mouthpiece of conoidal bore. Its tones 
are harmonics of the 
natural tone of the tube, 
produced by slightly 
varying the method and 
fressure of the blowing, 
ts compass is about four 
octaves, the series of 
tones in the two upper 
octaves being diatonic 
and partially chromatic. 
In addition to these 
primary or open tones, 
modified or closed tones 
are produced by insert- 
ing the hand into the 
bell, so as to alter the 
pitch of an open tone 
chromatically. The 
pitch of the fundamen- 
tal tone, and thus of the 
whole series of open 
tones, is altered by de- 
tachable crooks, which 
increase the actual 
length of the tube. 
From eight to twelve 
such crooks are made, 
pitching the instrument 
in nearly all the chro- 
matic keys between the 
second C below middle 
C and the second P. - be- 
che'straThonf- i'fliigeihoral'or keyed which the Instrument is 
bugle ; 4, post-horn ; 5, hunting-horn. to be Set is indicated at 
the beginning of each 
piece ; but the music is written in the key of C. The 
pitch of the tube is still further affected by the tuning- 
Klide, which is one of the curves of the tube so arranged 
that it can be pushed in or out at will. Ventils or valves 
are sometimes added to the tube to facilitate rapid pas- 
sages. Horns are the most valuable orchestral instru- 
ments of their class. Their tone is mellow, pervasive, and 
blending, with a peculiar romantic quality. Tne French 
horn is sometimes used singly or as a solo instrument, but 
in orchestras it is nearly always combined in pairs or in 
quartets, and used both for melodic effects, especially in 
fanfares and similar figures, and for sustained chords as a 
harmonic basis for free instrumentation, (a) A drinking- 
vessel of the shape of a horn or made of a horn. See drink- 
ing-horn. 
They attended the banquet and served the heroes with 
horns of mead and ale. Mason, Notes on Gray's Poems. 
They sit with knife in meat and wine in horn. 
Tennyxon, Merlin and Vivien. 
(e) A long projection, frequently of silver or gold, worn 
on the forehead by natives of some Asiatic countries. (/) 
One of the extremities (cusps) of the moon when waxing 
and waning, and hence of any crescent-shaped object. 
