THE ACTION.

This important subject will be prefaced by a few definitions, superfluous, perhaps, for some readers, necessary for others.

Backfall. A lever of any clean wood, ? inch or less in thickness, 1 inch or 2 inches in width, and seldom more than 1 or 2 feet in length, turning upon a wire as its axis or fulcrum.

Bridge. Backfalls occur in sets, corresponding to the number of keys in a manual or of pallets in a wind-chest. They are arranged side by side in notches formed by taking out the wood between saw-cuts in a balk of mahogany or oak 2, 3, or more inches square. This balk is called a bridge. Fig. 27 shows part of a set of backfalls and their bridge.

Square. Squares are now usually of metal, but may be easily made of wood, and consist of two arms, 2 or 3 inches long, united at a right angle to each other, or cut at once from a single piece, and turning on a wire as an axis passing through a hole at the intersection of the arms. Like the backfalls, they may be arranged side by side in a bridge, but the modern metal squares are screwed separately in their places (Fig. 28).

Sticker. A slender rod of light wood, not larger than a common cedar pencil, and from a few inches to a foot or two in length (Fig. 29).

Tracker. A flat riband of pine, sometimes several feet in length, about ? inch in width, and less than ? inch in thickness. Trackers, however, are now frequently slender round rods, like the stickers (see Fig. 30).

Tapped Wires. Formerly of brass, afterwards of tinned iron, and now generally of phosphor-bronze or some other alloy. These are pieces of wire about 3½ inches in length, from No. 16 to No. 18 in gauge, and cut with a screw-thread upon about half their length, with a ring or hook at the untapped end.

Buttons. Round nuts of old and thick leather, or latterly of a composition into which gutta-percha enters, pierced at their centre to receive the tapped part of the wire.

Cloths. Little discs of woollen cloth, mostly red, used as mufflers to prevent the rattling noise of wood against wood, or metal against metal.

Roller. An axis or shaft of light wood (but in certain cases of iron), turning easily on two wires as pivots, which enter holes in studs fixed firmly. The roller has two (or more) arms, 2 or 3 inches long, projecting from it, generally near its ends. It is plain that any motion given to the roller by acting on one of these arms will be transmitted to the other arm. Rollers are in sets, like backfalls and squares, and are arranged symmetrically on a board called a roller-board (Fig. 31).

The nine articles just described are all brought together in the action of an organ, even of a simple kind. We shall endeavour in this chapter to show how they are combined in ordinary circumstances, involving no peculiar complications.

A simple and rudimentary example of the principle underlying all systems of organ-action may be seen in Fig. 32. a b is the key-board, in which each key (as always in England) is balanced on a pin-rail near its centre, and has a pin, c, passing through a little mortice cut in it, while another pin, d, out of sight, near its fore end, keeps it in its place, parallel to its fellows. At the tail of the key, e is a sticker, having a wire thrust into each of its ends, and projecting about 1 inch; one of these wires is inserted in a small hole drilled in the key-tail, and conical beneath, or cut into a little mortice. A "cloth" is slipped upon the wire to prevent the end of the sticker from rattling upon the key-tail. The upper wire of the sticker slips into a similar hole (a cloth interposed as before) in the end of f, a backfall working in its bridge, g. The other end of f is connected at once to the pull-down of the pallet by a tapped wire and button. Clearly, if a finger is placed upon the key, its hinder end will rise and will push up the back end of the backfall, which will draw down the pallet; and by simply reversing the position of the backfalls as shown in the cut, we may pull down the pallets in the wind-chest when placed under the back of the sound-board.

If, then, we have fifty-four keys in the manual, a repetition of this simple apparatus fifty-four times will be requisite to bring every pallet, with the pipes controlled by it, under the command of the player.

But this is taking no account of the fact that the pipes are not planted in an unbroken chromatic series from bass to treble. In the arrangement shown in Fig. 5 (and in its reverse or opposite plan) it is plain that our simple backfalls would fail us; while in Fig. 6 some of the bass pipes are planted to the right of the player, equally out of reach.

Here we resort, then, to rollers. Fig. 33 shows a single roller, in which i k is the roller, turning on pivots in studs, and having arms, l, m, of wood or of iron, projecting from it. The sticker from the key-tail pushes up the arm l when the key is depressed; the roller turns on its pivots, and the arm m pushes up the tail of the backfall by another sticker, the pallet being thus opened as before; and it is plain that by arranging a set of rollers on a board, as in Fig. 31, we may act with ease upon pallets to the right and left which could not be reached in any other way.

The roller-board as here described is placed above the key-board, with action by stickers; but it might be as easily placed immediately under the wind-chest, with action by trackers. In this latter case, the key-tail will push up the end of the backfall, the other end of which will draw down a roller arm by means of a tracker; the other arm of the roller will be hooked to the pull-down of the pallet by means of another tracker. If so placed, room must of course be left for the roller-boards by fixing the wind-chest at a sufficient height above the backfalls. Figs. 34 and 35 show, sufficiently for our purpose, but without any pretension to exactness of detail, the two positions of the roller-board, and it is easy to see that by reversing the backfalls, and in Fig. 35 the roller-board also, we can act upon a back wind-chest.

Probably the reader has already surmised that the notches in the bridge are by no means necessarily parallel to each other, or, in other words, that the backfalls themselves are not parallel. The left-hand pipes, as shown in Fig. 6, are reached by cutting the notches in the bridge askew, so that while one end of the backfall is over the key-tail, the other may be under the pull-down; and as this applies to the whole set of backfalls, except those connected with the rollers, the whole of the notches will be cut at varying angles to the central line or axis, and the complete set of backfalls, when put in their places, will present a fan-shaped plan. Hence it is sometimes called a "fan-frame."

But parallel backfalls occur constantly as transmitters of motion from the keys to the rollers, and in other positions which will be noticed. The plantation of pipes shown in Fig. 5, for instance, and the reverse of it, which has the larger pipes in the centre, can only be adopted by having a roller for every pallet; and in this case the backfalls will be parallel, whether the action be by stickers or by trackers.

Already, we hope, we have given explanations so far intelligible that ingenious reader's might have no difficulty in devising for themselves some one of the numerous distinct combinations which may be made of the nine pieces or members which we began by defining.

Let us take, however, the very common arrangement of Fig. 6 as that of our organ, and apply to it the rules already laid down.

1. The keys will be procured, of course, from a maker, unless the cost—fifty to sixty shillings—can be saved by adapting an old set. We ourselves are admirers of the old-fashioned claviers with black naturals and white sharps, or sharps of bone or ivory with an ebony line down the middle of each. We possess two specimens of double manuals of this kind; one of them, taken from an organ by the elder England, is extremely handsome, with a mahogany frame almost black from age, purfled like a highly finished violin. It was presented to the writer many years ago by the late excellent builder, Mr. Walker. The other double set, in a plainer frame, was bought at a sale for the sum of one shilling and sixpence! The chief objection to the use of old claviers is that the keys, from long usage or from original faulty construction, rattle audibly against their guide-pins. This, however, may be quite obviated by bushing the little mortices which receive the guide-pins with fine cloth, as modern piano keys are bushed, or with thin leather—for instance, the kid of old gloves. If the keys are handsome, a little patience bestowed in this way may well reward the operator, who will find the movement of his old manual when this is done as silent as he can wish it to be.

2. We shall assume that the front board of the wind-chest is above the keys, and that the organ is to stand against the wall. Hence the backfalls will be turned towards the player, as in Figs. 32 and 34. But all that we shall say will be applicable to backfalls acting on a back wind-chest.

The keys, whether new or old, will probably be 18 or 19 inches in length from their front edges to the rear. Their position in the frame should be such as to allow the front edge to project 10 inches at least beyond the front line of the wind-chest, in order to allow room for a book-board; hence our backfalls will be short. But their shortness will not be an evil, since the extent of their play or oscillation is extremely trifling. One-third of an inch will be a sufficient descent of the pull-down; the other end of the backfall will traverse a similar space, and it will easily be seen how small an arc will be described by any point near the centre. Backfalls from 4 to 6 inches in length will, therefore, present no practical inconvenience. At the same time it must be admitted that with such short backfalls the obliquity of those to the extreme left will be somewhat embarrassing, and we shall recommend the use of rollers for the six pallets to the left as well as those to the right, especially since, as we shall show, the width of the roller-board will not be materially increased thereby.

The backfalls should be of oak or mahogany, and the bridge of the same, or other hard wood. If the bridge is not sufficiently strong and rigid, a disagreeable and perceptible yielding of the whole manual will take place when the player presses down a chord. The backfalls, if parallel, or if only at a moderate degree of obliquity, will oscillate upon a single wire extending throughout the whole range. This wire should be sunk in a score or channel made with a V-tool before the notches of the bridge are cut; and it should be held firmly down by small cross slips of oak screwed with very fine screws into the wood of the bridge between every six or so of the backfalls. This is much better than the common way of driving in little staples of wire, which are apt to split the wood, and are not easily extracted in case of repairs becoming necessary. The small holes for such screws may be bored conveniently with a drill, revolving by means of the Archimedean drill-stock, now sold in all tool-shops for the use of fret-cutters.

Stickers may be quickly, easily, and neatly made by a bead plane. Take a piece of three-eighth pine board of the requisite length and dress it over. Then, with a three-eighth bead plane, strike a bead along one edge, reversing the board when cut half through, and using the plane as before. A slender wooden rod will be the result, which will only require a little smoothing with glass-paper. To fit the wires into the ends of the stickers, mark the centre of the rod with a punch or other suitable pointed tool, and pierce a hole with a fine drill revolving in the lathe. The wire may then be driven down without fear of splitting the sticker or of entering it obliquely and penetrating the side of it.

For trackers we prefer round rods, made precisely as above, but with a ¼-inch bead. If tapped wires are to be inserted in the ends of the trackers, it is well to flatten the inserted end of the wire by hammering it, that it may not turn round in the wood when the button is afterwards applied. A fine saw-cut is made in the end of the tracker, the flattened part of the tapped wire inserted, and strong red thread, well waxed, neatly tied round. The ends thus whipped are sometimes varnished with a red composition. But this is superfluous.

If flat trackers are unavoidable, they may be cut from a three-eighth pine board with a gauge, armed with a cutting-point instead of the usual scoring-pin. A smoothing plane should be specially prepared by fixing two slips of wood to its face. These slips will prevent the plane from cutting anything thinner than themselves. Then, the plane being held firmly down upon the bench, an assistant, walking backwards, draws the tracker beneath the blade until it is reduced to the same thickness as the slips, say ? inch. The tapped wires will be inserted and the ends whipped as before.

The squares shown in Fig. 28 are cut from thin boards of oak or mahogany. Perhaps it will be found less troublesome and laborious to make each square of two distinct arms, halved together and glued at the angle, or more effectually joined by tenon and mortice. Metal squares can be bought ready made, or they may be cut with shears from brass plate. But we should use wood ourselves.

The rollers will be of pine or deal. They are cut out and dressed up as square or rectangular rods of the requisite length, but two of their sides are afterwards rounded or curved. It follows from this that when arranged side by side on their board the curved sides may be nearly in contact. As our rollers are short, three-quarters stuff will suffice for them, but rods inch or more square should be used when rollers have a length exceeding 2 feet or 30 inches.

Iron roller-arms have some great advantages, and they may be bought at a moderate price per gross, neatly bushed at the holes to prevent a rattling of metal against metal. But we ourselves deliberately prefer arms of wood, involving, as they do, much greater labour. If these are used, they should be made of oak or other hard wood, and let neatly into a little mortice in the flat side of the roller. After they are glued in, the holes may be pierced in each end of the roller to receive the wires or pivots on which it revolves, and which should be stout and rounded smoothly at the external extremity. One of the reasons why we prefer wooden arms is this, viz. that the pivot can be driven into or through the arm, which may thus be at the extreme end of the roller; while if iron arms are used a margin or surplus must be left at each end of the roller to allow room for the insertion of the pivot without interfering with the arm, the screw of which passes through the axis of the roller. But it is undeniable that iron arms abridge labour and save time.

The studs in which the pivots are supported are also among the fittings which can be obtained from the shops; but we have always made our own of oak, turning the peg or shank in the lathe. These studs must be bushed with cloth. Drill the hole truly through the stud, using a borer much larger than the pivot-wire. Cut a strip of red cloth about ? inch in width. Point one end of it, and draw it through the hole in the stud. It will adapt itself to the circular hole, and will take the form of a cloth pipe lining the hole, and effectually preventing a rattling noise which would certainly be heard in its absence.

The planning of a roller-board, so as to economise space as much as possible, is one of those operations which call for forethought and ingenuity. The forms which it may assume are numerous; we shall indicate by one or two simple diagrams some of the combinations of the fan-frame with rollers which occur in ordinary practice.

Fig. 36 shows the usual way of carrying the touch to the pallets on the right and left in the common form of sound-board shown in Fig. 6. A set of backfalls is assumed as in situ under the wind-chest, parallel to each other as regards the six pallets at each extremity, but fan-framewise as regards the pallets from Tenor C to the top. As the actual key-board (disregarding its frame) is about 2 feet 6 inches in width, while the row of pull-downs on which it is to operate extends to a length of 4 feet or more, we see that there will be an overhanging margin or surplus of the wind-chest on each side of some 9 or more inches, and it is probable that all the pallets affected by rollers will be included in these overhanging portions of the chest.

Take a piece of three-quarters or five-eighths board, the full length of the wind-chest, and wide enough for your twelve rollers when placed as we shall now direct. Dress it up, and give it two coats of priming. At its lower edge mark the exact centres of the key-tails from end to end of the key-board. At its upper edge mark the precise centres of the tails of the twelve backfalls on which the rollers are to act, fixing the board temporarily so that precision may be secured. Along the two side margins of the board (which has been squared up true) mark rows of dots at equal distances, say 1 inch or considerably less, according to the scantling of your rollers, which may be placed as close to each other as possible without actual contact when made to revolve through a small arc on their pivots. You have now all the data which you require, and may draw pencil lines showing the exact place of every stud on the board, the exact length of every roller, and the exact spots on each roller at which the arms must be inserted.

Fig. 36, in which x y is the key-board, the rollers and stickers being represented by lines only, shows that the longest roller, that of CC sharp, is placed by itself at the top. This is done in order to enable us to use a single stud, common to two rollers, throughout the board until we come to the last, which will stand alone. If the rollers of CC and of its sharp were thus placed in a line, running into a single stud, there would be hardly room enough for the latter, as the arms would be in immediate contiguity. By giving the CC sharp roller a place by itself, we get the following pairs: CC and DD sharp; DD and FF; EE and G; FF sharp and A; G-sharp and B natural; A sharp will have its own two studs. Thus we obtain a distance of fully 1¾ inch between the centres of the contiguous arms of these pairs of rollers; and if iron arms are used, there is room to drive in the pivot without meeting with the interruption of the screw in the heart of the wood.

When these measurements have been made, and lines drawn in pencil or chalk, the holes for the shanks of the studs may be bored, and the board cleaned over and perhaps repainted. When the work is complete, the cleanly planed rollers with their neat studs on the dark background of the board should present a pleasing appearance.

Sometimes the roller-board lies horizontally. It is then usually called a roller-frame. Fig. 37 is a slight sketch showing how a roller-frame may be united with squares in certain cases. a b is a key-board, acting by stickers on a set of squares, c, arranged in a bridge. d is another set of squares in a longer bridge under the pull-downs of a chest, e, let us say that of the second manual in an instrument of considerable size, placed at the back of the case, and possibly some feet from the player. f is a roller-frame, transmitting the touch by trackers to the extreme pallets right and left.

If economy of height is no object, however, the roller-board will be placed between the squares d and the chest e in the usual vertical position, or it may be above the keys.

Sometimes space is saved by inserting the roller-arms on opposite sides of the rollers, cutting apertures in the board through which one arm of each pair may protrude. This plan may be regarded as a compromise between the fan-frame and roller-board, the latter doing duty as a set of backfalls.

This arrangement is sketched in Fig. 38. The roller-board, g, is above the key-tails, which act by stickers on arms brought through openings in the board. The opposite arms, h h, in front as usual, act on the pull-downs by trackers. We have adopted this plan in a very small organ, and under the necessity of economising space as much as possible, with complete success, although every pallet had its roller, the fan-frame being entirely absent.

Rollers are often made of iron, especially in the case of pedal movements, where space is not abundant. It will easily be understood that iron tubes of small calibre, plugged with wood at the ends to receive the pivots, and having iron arms screwed into drilled holes, would present no serious difficulties to the workman, and might be arranged upon a board little more than half the size of that required by a set of rollers in wood.

We must not close this chapter without explaining that the plantations of pipes sketched or indicated in Figs. 8 and 9 may be contrived without grooving by an arrangement involving no serious difficulty or complication.

In Fig. 39, a b c is a sound-board shown in section, divided internally into two unequal parts by a longitudinal bar at b. The front part, b c, nearest to the player, has 42 channels, and carries all the pipes from Tenor C upwards. The hinder part has 12 channels only, and supplies the bass octave. These two separate internal divisions will have their pallets and springs as usual, and a single wind-chest may include both sets of pallets, or two wind-chests may be united by a short trunk, or separate trunks may be fitted to each, at the discretion and convenience of the builder. We have now only to adapt a set of backfalls in a fan-frame to the front pallets, and a roller-board acting on twelve parallel backfalls to the pallets of the bass octave, and we have a very compact and sightly arrangement of pipes without a single groove, every pipe standing on its wind. If the back pipes were these—Stopped Diapason, Bass, 4-feet tone, and open Flute, wood, 4 feet; while the front pipes comprised a Dulciana, Stopped Diapason, and Principal, or some equivalent—this little instrument might be entirely satisfactory in all respects.

We may add that this arrangement of a double sound-board and wind-chest has been successfully applied by the writer to an organ with two manuals. The sound-board was about 5 feet 3 inches in length. The front division had 84 channels, viz. 42 for each of the two manuals from Tenor C to top F; the hinder division had 24 channels, viz. 12 for each manual bass octave. There were practically eight stops, two of them grooved to each other in the bass. Of this grooving, when there are two manuals, we shall have something to say in a subsequent page. It is not quite so simple an affair as the grooving already described.

When the key-board is in its place, the stickers adjusted, and the keys levelled by attention to the buttons on the tapped pull-downs, a heavy damper or "thumping-board" should be laid across the key-board. In modern organs this is generally a solid bar of lead, about ½ inch thick, and about 1½ inch in width; it is covered with baize on its under side, and a guide-pin, moving loosely in a little vertical groove cut in the key-frame at each end, keeps it in position. Our damper may be of oak or mahogany, very straight and true, and loaded with lead, run when fluid into cavities made with a large centre-bit. The damper, lying upon the keys, and supported by them, helps to keep them level, and by receiving the blow or shock of each key, as the finger leaves it, it prevents a tapping noise which might be heard if the rising keys were stopped only by the board of the key-frame.

The descent or fall of the keys when pressed by the fingers should not exceed ? inch.

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