ORGAN, CONSTRUCTION OF. 



ORGAN, CONSTRUCTION OF 1 . 



l-X) 



of a roller, with a pull-down and lerer, all in their relative com 

 B U the pull-down, ami U the lever, to which the key follows ; o is a 

 common form of a f/uare or caUrr, by which the trackers are united. 

 Trartrn are pieces of pine wood, | of an inch wide, and from I to 

 a | thick : they are of diflervnt lengths, and may be used to any extent. 

 The Birmingham organ is mid to have four miles and a half of trackers 

 in it. In the cathedral organ at Canterbury, they are employed to 

 remove the keys to a distance from the instrument, which is done to 

 the extent of ninety feet 11 is the form of a pedal-key ; I is the sharp, 

 and a is the maturaJ. The length is about two feet ; the distance from 

 centre to centre of each pedal is two inches and a half. 



Fiy. 8 represents an anemometer, or wind-gauge. It is a glass tube, 



Fif. . 



1 



bent as in the figure : the dark part is supposed to be water. A is the 

 place to which it is applied in the organ, which is generally the hole 

 for the pipe used as the pitch A or c. The pressure of the wind at B 

 drives the water up to c, and the measure of their difference is what is 

 called the tri nrf. Some organs have more, and some less ; two inches 

 and a half is the common measure. 



Pig. 9, represents a percussion valve. It may be said to be a small 

 bellows pressed by a spring. A is the wind-trunk, to which it is fixed ; 

 B is the valve itself, and c is the spring. The use of this part of an 

 organ is to steady the wind, which is sometimes disturbed by sudden 

 transitions or very rapid performance : the spring of the valve is regu- 

 lated so as to give way on such occasions and to moderate their 



Pig. 10 is a section of a common barrel-organ. A is the handle ; B 



the trorm and crank, which move the barrel and btUovi; is the barrel 

 on which the tune* are set The setting is effected by brass pins and 

 staples driven into the barrel at proper distances, accordingly as the 

 notes are longer or shorter. B is the key, the rising of which over the 

 pins causes it to press down the sticker (K) into the wind-chest (r), and 

 thus to open the pallet for the wind to enter the pipe above j o is the 

 bellows ; B, a stop-diapason pipe. This diagram shows only one barrel, 

 which is the common plan, but Messrs. Gray and Co. have introduced 

 three, by which great risk to the mechanixm is avoided and much 

 trouble is saved. 

 The tuning of organs is a subject on which there is much difference 



of opinion. Rome tune from c, on the unrqiinl temperament, and thr..\v 

 the imperfections on what is called the i<W/, or key of four Hat*. 

 Others tune from A, and adopt the rijixil temperament ; this latter cer- 

 tainly has the better reasoning in its form, as it approaches nearer to 

 the human voice, interferes less with the band, and is more agi 

 in general modulation. This subject has been minutely handle*! l>y 

 some scientific writers, who have given themselves the trouble of what, 

 may be called ti>littin<t octaves into mailer intrrrat*. But the advnnt- 

 ages of this minuteness have not yet extended beyond the schemers 

 themselves, for not one of their methods has yet left the cradle of iu 

 birth. The Temple organ is said to have 14 sounds in the octavo ; the 

 Foundling, 10 ; Hawke's patent, 17 ; Loeschman has 24, and Listen's 

 enharmonic organ as many as 59, of which 24 are on the keys, and the 

 rest on the pedals and other contrivances. If such schemes were to 

 become general, they would moke practical men tremble ; but flat .n'filn 

 ore still in use notwithstanding the enharmonic divisions, and they 

 have nothing to fear beyond an occasional dispute on the subject 



The numbers and kinds of stops are matters not subject to rule ; 

 they vary in almost every organ, and seem more under the command 

 of circumstances, such as space and price, than any other parts of the 

 instrument 



In treating the mechanism of the organ in so general a manner, we 

 shall hardly be expected to point out all the improvements whieh have 

 been made of late years in its various ports : a few however may be 

 mentioned. Considerable strength both of hand and foot, as well as 

 consummate musical skill, are required in an organist; the expenditure 

 of wind also may vary from a few hundred to many thousand euliie 

 feet per second. With a small expenditure of wind there is a greater 

 elasticity of the air, and consequently a greater pressure against the 

 valves so as to make them more difficult to open. The remedy for 

 this was Mr. Barker's Pneumatic Lever, in which the elasticity of the air 

 itself is made to overcome the resistances which had previously been 

 thrown upon the organist Mr. Willis has a contrivance for admitting 

 wind to the pipes of the pedal-organ ; it is formed by covering the 

 aperture with a piece of leather, fixed at one end, and attached at the 

 other to a wooden roller, so that when the latter is moved by the 

 pedal key, it wraps the leather round it and so uncovers the opening, 

 when the key is released a spring brings the roller back, and by un- 

 rolling the leather, again covers the aperture. Mr. Bishop's 

 Pedalt, for opening and shutting the stops by the foot instead of the 

 hand, are of great value, as is also his A nti-coticiu*!<i "/'/""'"'* for 

 preventing the pulsation or concussion of air in the wind-chest, when 

 a large number of pipes are made to cease speaking suddenly and a 

 few only are held on. Mr. Willis has also introduced mechanical 

 improvements for producing creicendo and i/iiiiinuriitln effects, enabling 

 the player to draw or shut off any required number of the stops, one 

 after the other in succession by one continuous movement, in < 

 distinction to the intermittent or repetition movements. Mr. Holt 

 has introduced the pneumatic lever, or valve, to^ced-pipes, so that 

 when the wind is admitted it expands and causes a spring or j i. k 

 tipped with india-rubber to strike the tongue and set it in motion, 

 similar to the contrivance explained under HARMONIUM. The wind 

 then keeps up the vibrations. By this contrivance the reeds may be 

 made of thicker metal, and a fuller, rounder tone be pro< 

 Lorenzi, of Paris, has introduced various novelties. The highly ex- 

 pressive tones of the organ depend principally on a repetition of sounds 

 which succeed each other as the keys are touched. The keys act upon 

 two stops, the first upon one pipe, and the second upon 

 unison with it. The sound-board is divided into two parts with douMo 

 valves, so that those of the first part admit wind to the pipes which 

 are acted on only by the first stop, and those of the other port admit 

 wind to the pipes which are acted on by the other stop. By pressing 

 the key lightly to the first stop, and playing one note only, a soft 

 sound is produced ; and by depressing the key entirely, the second stop is 

 brought into action, and greater expression and power are thus attained. 

 In this arrangement there may be a single sound-board in two parts, or 

 two separate sound-boards may be used. The notes of the' first ]>art, 

 particularly of the flute, bugle, and trombone stops, are of grca 

 cacy and sweetness; and those of the other port, produced by the 

 second series of stops, are of the greatest power and are occasionally 

 double. The transition from piano to forte is not perceptible when 

 the second note is commenced, but it is necessary to separate the first 

 from the second part of the sound-board, as also of the pipes by en- 

 closing them in a swell-box. By opening the swell the full power of 

 the notes is obtained, without any violent transposition from piano to 

 forte. The mechanism for effecting this is attached to a pedal, so that 

 it may be disengaged from the keys when required. Another mode of 

 giving expression and increasing the force by vibration or trembling, 

 and increasing and decreasing the sound, when applied to the fono- 

 chromic organ with two valves, allows the performer gradually to 

 augment the sound to double its usual force, and to diminish it again 

 in the same manner, thus producing effects of a novel and delightful 

 character. In order to obtain this result, an expansive bellows is em- 

 ployed ; this forms a reservoir, and at the same time (on op 

 valve) increases the force of the air nearly twofold. It is ill 

 longitudinally into two parts, the part answering to ordinary bellows 

 occupying three-fifths, the other part two-fifths, so as to make two 

 bellows united. This smaller part communicates with the larger by 



