interior mechanism. The instrument is included within a frame composed of four vertical posts AA, in both plates, connected by a horizontal frame B at top, and C at bottom. The latter has a board fitted into it, as is shown in the figures, which is the middle board of the bellows; of these there are three pair, each acting double; they are all three shown in plate 126 at D, E and F, and a section of one pair is seen in plate 125. The middle bellows D, which are much larger than the other two, are intended to be worked by the foot of the performer, by means of a treadle which comes out in the front of the instrument under the key board: the others EF are intended, one to be worked by the same handle which works the barrel, when it is to be used as a barrelorgan, and the third pair are to be moved by the hand of an assistant, in the usual manner of church organs. The bellows consist of a board ab, fig. 1. having valves in it, shutting downwards it is connected by leathers all round its edge with the middle board, which has also valves in it shutting downward. The chamber thus formed between the two boards is divided into two by a vertical partition (above d) extending from one board to the other: the board ab is jointed to this partition at the point d, and when worked vibrates on this joint as a center, enlarging one chamber and diminishing the other; which operation, by the arrangement of the valves, throws a constant stream of air into the regulator G of the bellows. Suppose the end a of the board ascending, and the other & descending; then the valves in b will be open to take in a supply of air to their chamber. The valves in a will be shut, and the air included in that chamber is forced up through the valves in the middle board, into the regulator, which consists of a large board G joined by leathers on all sides to the middle board, forming a great chamber to contain the air supplied by the bellows; and the weight of the board G always resting upon the included air, affords a constant supply to the organ during any intermission of the action of the bellows. The air passes off from the regulator by a wooden pipe H, fig. 4, called the wind trunk, and is by this conducted to a large shallow box at KK, called the wind chest, which is immediately beneath the assemblage of pipes LL. In the upper side of this chest are several valves f and g, fig. 1, which are kept shut by a small wire spring applied to each; when any of the valves are opened (by drawing down a wire h fastened to each, and coming through a small hole in the bottom of the wind chest), the air passes out of the wind chest into a horizontal groove which is seen just over the valves ƒ and g, fig. 1, and ascends through vertical passages into any of the pipes LL, causing them to sound. The wires h are hooked to the valves at their upper ends, and at the lower are jointed to levers r, which have their centers fixed in the beam R: at the opposite end of these, small rods s are jointed, which at the lower ends rest upon the extreme ends of the finger keys tu: by this ar

rangement, when the end v of any key is pressed down it raises the rod s; this draws down the wire h, and opens the valve, causing the pipe belonging to that key to emit a sound. The finger keys as shown in fig. 4 (at vv) are much nearer together than the wires h. To manage this the levers r are not placed parallel, but diverging from each other so that the ends s are close together; but the opposite ends are a considerable distance asunder. The keys to are fitted in a frame which slides in a groove Z of the framing; by this means the keys can be pushed back out of the way when the organ is not in use. Any of the passages which conduct the air from the valves to the pipes can be stopped or opened at pleasure by sliders called stops: these are shown at h, i and k, fig.4: they are narrow rulers of mahogany, sliding in passages which they exactly fill, and through which all the vertical passages to the pipes are conducted. The stops have holes through them answering to these passages, and when these holes are over the passages, they are open to allow the air to pass through; but by drawing the slider endways a small distance, the spaces between the holes in the stop apply themselves over the passages and shut them all up at once. Each stop opens passages to a complete set of pipes, consisting of one answering to each of the notes of the finger keys: these pipes are gradually diminished in size and length from the largest base note to the smallest treble, as is shown in fig. 4. at LL; but this row contains only about half the num ber of pipes corresponding with the finger keys, and the remaining numbers are placed in an other row for want of room; and the upper board mm on which the pipes are placed, "has horizontal passages cut in it to conduct the air from any valve to its respective pipe, when the same is not situated exactly over it. This organ is provided with five stops or sets of pipes, that is, five to each key, any one or all of which can be made to speak. The largest, MM, fig. 1, is a set of wooden pipes arranged in two rows; it is called the stop diapason. The next, N, is called the open diapason, from being metallic pipes open at the upper ends; O is the principal stop with metallic pipes, so called because it is that which is most generally used in the music adapted for organs; indeed it is almost always in use, the others being used as accompaniments to it. P is called the 12th stop, and Q the fifteenth; the latter being chiefly small pipes, can be contained in a single row. Each stop or system of pipes is provided with three sliders, one beneath the other, as shown at h, i, k, fig. 4: and by drawing either of these three, the same effect will be produced on the organ, viz. shutting off or opening the stop of pipes to which they belong. The sliders are drawn by levers at the end of them; the levers for the lower slides k are shown in fig. 2, plate 125; being fixed on the upper ends of spindles nnn, also seen in fig. 4. To the lower ends of these spindles, long levers, o, fig. 4, are fixed; and at the end of these small rods are jointed, which come through the case

of the instrument close to the finger keys, and have handles fixed upon them. These are marked with the names of the stop of pipes they belong to, and any one being thrust in moves the slider and opens the stop of pipes, which will then be sounded by pressing the finger keys. The middle sliders are drawn by levers, as shown in fig. 3, at p, and also in fig. 4 from the arm of this lever a wire g proceeds to connect it with a pedal, by which the slider is moved. These pedals are used in quick music to change the pipes upon which the keys operate by drawing another slider. The upper sliders are drawn by levers adapted to the purpose which are moved by pins in the barrel, when the organ is used in that manner. The barrel is shown at T in fig. 125: it is a wooden cylinder with a number of pins projecting from its surface: these, as it revolves, catch the ends of short levers w, the other ends of which have wire going to a set of valves g exactly similar to the others, and opening into the same passages. The barrel has a wheel upon one end of it, with teeth which are engaged by the worm of an endless screw, upon the end of which is a handle to turn it round, and also a crank, which gives motion to the bellows. The barrel is furnished with a number of short pins, disposed in such intervals upon its surface as to lift the different valves in the succession required for the tune it is intended to perform. The barrel is longer than the set of levers w which it applies to, by the space between two levers; and the barrel can be moved endways that quantity. Now by moving it a portion of this distance, an entire new set of pins is brought into action upon the levers w, and this set of pins serves for another tune.

After the minute description we have given of the parts, it is needless to say much of their mode of action. The bellows are constantly worked either by the hand or foot, and continually blow into the regulator G. If more air is pumped in here than passes out at the wind trunk, the top G rises; but when it gets to the height which is intended, a string fastened to the top raises up a valve in the middle board, and suffers the air to escape by returning into the bellows: by this means the regulator can never be in danger of bursting. A string a is fastened to the top of the regulator, and passes over a small pulley y fixed on the end of a small spindle which comes through the front of the instrument, and has a hand or index pointing to marks upon a small dial plate, indicating the height to which the top has risen, and consequently the quantity of air; in this state of the instrument, by pressing any finger key, a valve is opened, and air admitted into any pipe according to the stops which are out.

The organ pipes are of two kinds; those shown at M, which are square wooden trunks with a small pipe at bottoin, bringing the air to them, this air passes out at a very narrow crevice, marked 1 in M, and the current of air is split as it issues by the edge of one side of

the trunk, which is cut to a sharp edge for that purpose. The vibration of the air contained in the trunk causes the sound; at the top of the trunk a plug is fitted, and by sliding this up or down, the pipe is adjusted to the note it is intended to sound.

The other kind of pipes are on the same principle, but formed of metal instead of wood, and are tuned by pinching up or battering out the top of the pipe, so as to enlarge or dimi nish the aperture of the upper end; if much alteration is required, a small piece is cut off of the upper end.

ORGAN denotes also any natural instrument, as the tongue is the organ of speech.

O'RGANARII, ancient organists who per formed on the hydraulic organ. Said to have been so called from the word organum, applied to a certain part of that instrument. ORGAN-BELLOWS. A well-known pneumatic machine attached to an organ, and the office of which is to supply the pipes with wind. The general fault in the bellows of organs is their want of capacity, which renders it laborious to the blower to keep the chest full, and renders the instrument liable to continual exhaustion when performed on in full chords.

ORGAN-BUILDER. An artist whose profession it is to construct, and to tune and repair organs. An organ-builder, besides possessing a nice, accurate, and cultivated ear, and a sound judgment in the vibratory qualities of wood and metal, ought to be acquainted with pneumatics, generally versed in practical mechanics, and so far informed in plain coun terpoint and the simple elements of musical composition, as, in some degree, to be capable of trying the different stops and combinations of his own instruments, and of deciding for himself on their effects in performance.

ORGA'NICAL. ORGANIC. a. (organique, French; organicus, Latin.) 1. Consisting of various parts co-operating with each other (Milton). 2. Instrumental; acting as instrements of nature or art, to a certain end (Mill.). 3. Respecting organs (Holder).

ORGANICALLY. ad. (from organical.) By means of organs or instruments (Locke). ORGA'NICALNESS. s. (from organical.) State of being organical

ORGANISM. s. (frem organ.) Organical structure (Grew).

ORGANIST, a term which may, in strictness of speech, be applied to any masterly per former on the organ; but in its common ac ceptation signifies a professor of music who holds the office of organist to some cathedral, parochial church, or chapel, or is the deputy of a person so appointed.

ORGANISTS. The old name applied to those Romish priests who organized, or sung in parts.

ORGANISTS OF THE HALLELUJAH. An appellation given about the year 1200 to certain priests or clerks, who assisted in the perforrance of the mass. There were generally four of them. They sung in parts, i. e, they

rganized the melody; particularly that applied to the word Hallelujah, by adding to it other parts, and thence were called Organists of the Hallelujah.

ORGANIZATION. s. (from organize.) Construction in which the parts are so disposed as to be subservient to each other (Locke).

To O'RGANIZE. v. a. (organiser, Fr.) To construct so as that one part co-operates with another; to form organically (Hooker).

An

ORGANIZED PIANO-FORTE. instrument of modern invention, consisting of an organ and piano-forte, so conjoined that the same set of keys serve for both; or for either singly, at the pleasure of the performer.

ORGAN-KEYS, those moveable, project ing levers, in the front of an organ, placed and fitted to receive the fingers of the performer; and which, by a counected movement with the valves, or pallets, admit or exclude the wind from the pipes. When a single key of an organ is pressed down, all those pipes are heard which are permitted by that key, and the stops, then out, to receive the wind.

ORGAN-MUSIC. Concertos, voluntaries, preludes, services, anthenis, chants, psalms, hymns, and whatever is either expressly composed for the organ, or the performance of which requires the accompaniment of that instrument.

ORGAN-PIPES. The square and cylindri cal tubes in an organ, from which proceed the various sounds of that noble and complicated instrument. The square pipes are always made of wood, the round ones of metal, consisting of a compound of lead, and grain tin.

ORGAN-STOP. An expression applied to any collection of pipes coming under one general name: as when we say, the dulciana stop is sweet, the trumpet stop is powerful, &c.

O'RGANLOFT. s. (organ and loft.) The loft where the organ stands (Tatler).

ORGANO. Ital.) Organ. The word organo is found at the beginning of that stave in the score of oratorio chorusses, instrumental authens, &. designed for the organ, and the execution of the thorough-bass.

ORGANO PICCIOLO. (Ital.) A small, or chamber-organ. See ORGAN.

ORGANORUM INTABULATURE. The general name formerly given to voluntaries, preludes, and all compositions for the

organ.

ORGANUM. The art of descant,'or double singing. An old mode of singing in two arts, generally in thirds, and first suggested by the organ, from the facility that instrument affords of sounding two or more notes at once. This word was also applied by the ancients to a brazen vessel which formed a principal part in the hydraulic organ, out of which the air, pressed by the incumbent water, was forced into the tibiæ, or pipes.

ORGANZINE, in commerce, a description of silk usually imported from Italy into this country. It is of the utmost importance to the manufacturer, as none of the principal

articles could be fabricated without it; and the Italians, aware of this, long kept the art of throwing it a most profound secret. It was introduced into this country by the enterprise and skill of Messrs. Thomas and John Lombe, the latter having at the risk of his life, and with wonderful ingenuity, taken a plan of one of these complicated machines, in the king of Sardinia's dominions, from which, on his return, they established a similar set of mills in the town of Derby; and in consideration of the great hazard and expense attending the undertaking, a patent was granted to sir Thomas Lombe, in 1718, for securing to him the exclusive privilege of working organzine for the term of 14 years; but the construction of buildings and engines, and the instruction of the workmen, took up so much time, that the 14 years were nearly expired before he could derive any advantage from it, in conse quence of which he petitioned parliament, in 1731, to grant him a further term; but parlia ment considering it an object of national importance, granted him the sum of 14,000l. on condition that he should allow a perfect model of the machinery to be taken, and deposited in the Tower of London for public inspection. Similar mills were, in consequence, set up in different parts of the country; but owing to the difficulties that were experienced in procuring raw silk of the proper size for organ zine, the exportation of which from Italy was prohibited, and to the mills having subsequently found employment for other purposes, the quantities worked into organzine, for many years, bore scarcely any proportion to the imports from Italy; it has, however, been since revived and improved, in consequence of which it is now carried to a very considerable

extent.

The process which the silk undergoes to bring it into this state, consists of six different operations: 1. The silk is wound from the skein upon bobbins. 2. It is then sorted. 3. It is spun, or twisted, on a mill in the single thread. 4. Two threads thus spun are doubled or drawn together through the fingers of a wo man, who at the same time cleans thera by taking out the slubs which may have been left in the silk by the negligence of the foreign reeler. 5. It is then thrown by a mill, that is, the two threads are twisted together either slack or hard, as the manufacture may require; and it is wound at the same time in skeins upon a reel. 6. The skeins are sorted according to their different degrees of fineness, and then the process is complete.

Organzine was for many years made only from Italian silk, but when considerable improvements were made in the culture of silk in India, it suggested the possibily of throwing some of the finer silks of Bengal into organzine. The experiments of individuals were not very satisfactory, but in the beginning of 1794, the East India Company took up the subject with the view of increasing the annual consumption of Bengal silk in this country; and having it in