709 



HORN. 



HORN MANUFACTURES. 



710 



tator to be at the centre of the earth, and not at the surface. If A B 

 represent a spectator standing upright, and c the centre of the earth, 

 then, if the circle VAX revolve round the axis B c, the physical boun- 

 dary is the circle described by T, or T u v, and the astronomical horizon 

 is the plane traced out by c x (indefinitely extended) drawn parallel to 

 B D, or perpendicular to c B ; and the angle D B T is called the dip of the 

 physical horizon. In consequence, however, of the refraction of light, 

 by which the rays are curved, as in the dotted line drawn from B, the 

 physical horizon is thrown farther than in the explanation just given ; 

 for instance, to the dotted circle K L M. The effect of this is to make 

 the distance A T greater by about its twelfth part. The rough rule for 

 finding the distance of the apparent horizon at sea is 1-^ of the square 

 root of the height of the spectator's eye, jn feet, gives the distance of 

 the physical horizon in miles. Thus, at a height of 100 feet, the horizon 

 is 13 miles off. 



The astronomical horizon divides the heavens into a visible and 

 invisible part. Properly speaking, it is the physical horizon which 

 does this ; but the distance of the fixed stars is so great, that the mag- 

 nitude of the whole earth is but as a point, and the planes traced out 

 by the revolutions of BD and ex may be confounded. It is cot pre- 

 cisely the same thing with the planets, and least of all with the moon ; 

 but this belongs to PARALLAX. Fur the general use of the astronomical 

 horizon, see SPHERE, DOCTRINE OF THE. 



The plane of the horizon at any place is perpendicular to the direction 

 of a plumb-line, or parallel to the surface of any fluid at rest. At sea, 

 when it is necessary to take the altitude of any heavenly body, the 

 physical horizon is, in tolerably fair weather, sufficiently well defined 

 for the purpose, and, with proper allowance for its dip, is used accord- 

 ingly. But in land observations with a sextant or other instrument 

 requiring an horizon, the surface of a fluid (generally mercury) is used, 

 which is called an artificial horizon, but might more properly be termed 

 an artificial portion of a horizontal plane. A very slight knowledge of 

 optics [REFLEXION] will show that the angle subtended at the eye by 

 a star and its image in a fluid is double of the star's altitude : this 

 angle, then, being measured and halved, the altitude of the star ia 

 found. 



HORN, a musical wind instrument, which in its primitive state 

 (that ia, formed of the horn of an animal, or simply a shell) has been 

 known from remote ages. Of the horns now in use. three are cor- 

 rectly denominated, the French horn, the buyle-horn, and the Russian 

 horn. These are made of brass. The basset horn (carno bassetto), and 

 the English horn (corno Ingleae), formed of wood, and partaking in 

 no regpect of what is generally considered the distinguishing character 

 of the horn, seem to be improperly named. 



The French h'arn, or now, par excellence, the horn, Ig a tube of about 

 ten feet, very narrow at top, widening considerably at the bottom, and 

 bent in rings for the convenience of the performer, as well as to render 

 it more portable. It ia not provided with holes, as the flute, &c., the 

 production of the various sounds depending upon the lips of the player, 

 the more or less pressure of his breath, and the insertion of the hand 

 in the bell, or wide end, of the instrument. As a simple tube, the 

 horn, governed by the lawn of acoustics [ACOUSTICS], yields only the 

 generating note, or tonic, and its aliquot parts, or harmonics, and, of 

 course, would be confined to one key, but for the contrivances jut 

 mentioned, by which the length of the instrument is adjusted to the 

 key required. This consists in m>oJb and thanks, or shifting pieces, 

 added as wanted to the upper end of the tube ; and thus the horn may 

 be employed in all keys. 



Music for the horn is always written in the key of c, an octave 

 higher than played, and in the treble clef ; and the key in which the 

 instrument is to be tuned is indicated by the composer. Thus, if the 

 piece be in E B, the words " corno in E S " are prefixed to the horn part. 

 Example, as written : 



Horns in E 9. 



The notes actually played are 



Tho natural scale of the Horn is that of the trumpet, but an octave 

 lower. It is written as follows : 



But the following are the sounds really produced : 



. 



EsEE 



By introducing the hand into the bell of the horn, a tolerably good 



semitonic scale can be produced ; and by the addition of two valves to 

 the instrument, the performer can command a still more perfect scale 

 of semitones. 



The bugle-horn is a tube of three feet ten inches in length, doubled 

 up in a small compass. The keyed buijle, or a bugle-horn with keys, is 

 that now in common use, the scale of which is as follows : 



The Russian horn is an unbent brass tube, conical in shape, of various 

 dimensions : the deepest toned is eight feet long aud nine inches in 

 diameter at the wide end, and the highest is two inches and a half in 

 length, by one at the wide end. The former gives A, an octave below 

 the first space in the bass ; the latter gives E, the third additional line 

 above the treble ; or 



Some of these horns, though not all, have keys, producing one or 

 two semitones ; but generally every note has its separate horn, and a 

 band of Russian horns counts almost as many individuals as diatonic 

 notes in a scale of between four and five octaves. 



Basset-horn, or corno bassetto. [BASSET-HoRN.] 



The English horn, or cnrno Inylese, is a deeper-toned oboe, but of 

 rather larger dimensions, somewhat bent, the lower end very open, and 

 is to the oboe what the basset-horn is to the clarionet, or what the 

 viola is to the violin. The tone of this instrument is extremely 

 pathetic, and by the Italians is thought so much to resemble the 

 human voice, that they sometimes call it the voce umana. The scale 

 of the corno Inylese (by which name it ia most commonly known by 

 musicians) is from A below the treble staff to B f above, or 



including all the semitones, except the lowest A (. 



Of late years M. Adolphe Sax, of Paris, has excited mueli attention 

 for his Sax-horns and Sa-x-trttmpets, which have had considerable 

 influence on military music. It is stated in the Jury Report (class x A), 

 his ,<i.i--hurnt (double bass in E flat, and B flat) have left ophi- 

 cleides very far in arrear ; and his small treble Sax-horn in B flat is the 

 only brass instrument known that can reach with certainty and just 

 intonation the notes of the upper octave of the flute. His cornets-a- 

 pistons are the best we are acquainted with. M. Sax has also created 

 the class of Saxophones, brass instruments with a simple reed, similar 

 to the clarionet. The effect of these new instruments possesses a 

 charm equal to the originality of their tone, and they carry to the 

 highest degree of perfection ' la roi.c expressive de rorchcstre.'" Favour- 

 able mention is also made of his bass and double bass clarionets, in 

 wood and metal. He has likewise filled up the gap in the tenor 

 trombone, between the lower E and the lowest B flat ; and his brass 

 bassoon is very perfect. He has also contrived a means of continuing 

 the sound in brass instruments from one note to another through all 

 the enharmonic intervals ; and he lias invented a means of changing, 

 by means of portable tubes, the monotonous character of the simple 

 bugle, and giving it the power of 'producing all the intervals of the 

 musical scale. 



HORN MANUFACTURES. It is customary in England to use 

 the same word to denote two quite different substances ; namely, the 

 branched bony horns of the stag genus; and the simple laminated 

 horns of tha oxgenus and other kindred genera. The purposes to which 

 the first of these kinds is applied are the same as those of bone aud 

 ivory, and the manufacture presents the same similarity. The other 

 kind of horn, to which the French appropriate the name cornc (while 

 they apply the name boi* to bony horns), is found in the ox, the 

 antelope, and the goat aud sheep. The structure of such horns may 

 be described as a number of conical sheaths inserted one into another, 

 the innermost lying upon the vascular membrane which covers 

 the bony core. The tip, or that portion of the point of the horn 

 which projects beyond the core, is very dense, and the several layers 

 of which it is composed are scarcely distinguishable ; while towards the 

 base the layers may be readily distinguished, owing to their successive 

 terminations forming prominent rings. Horn appears to consist of 

 coagulated albumen ; and there is a graduated connect ion between the 

 substance of horns, nails, claws, hoof's, scales, hair, feathers, and even 

 skin. 



The principal kinds of horn employed in manufacturing operations 

 are those of oxen, to which the hoofs of the same animals may be added. 

 The horns of bulls and cows are preferred, those of bullocks being thin 

 and of a coarse texture. The horns of goats and sheep are preferred, 



