THE DRAW-STOPS.

We have provided no means as yet for bringing the sliders under the control of the player. The mechanism by which this will be effected must depend upon our plans for the case and book-board.

Method 1.—As we have only five stops we may have resolved to arrange the knobs in a horizontal row above the key-board, and below the edge of the book. We shall soon see that this arrangement will result in much convenience and simplicity.

The ends of the sliders project at each end 2 or 3 inches beyond the margin of the sound-board. To the cheek of the wind-chest, below these projecting ends, will be screwed a stout balk of oak or mahogany (say 2½ inches square), constituting a bridge, and having stout levers, after the manner of backfalls, working in notches. These levers should be of oak, birch, or other hard wood, at least ½ or ? inch in thickness, and not less than 2 inches wide; and the pins on which they work should be very stout, say ¼ inch in diameter, and should be held down in their places by slips of hard wood firmly screwed down to the bridge. All this is sufficiently shown in Fig. 46, and it will be quite plain to the comprehension of every reader that these levers (like backfalls) may be askew to the straight line of the bridge, so that while their upper ends spread out to reach the sliders, their lower extremities may be brought into any position convenient of access.

The arms of these levers will of course be of unequal lengths. About 2 inches, or a trifle more, will be found a sufficient and agreeable play for the draw-stops. If the sliders have a play of 1 inch only, it is clear that the lower arm of the levers must be twice the length of the upper arm. At any rate the adjustment of the play of the draw-stops to that of the sliders should be made in fitting these levers, and not in any other part of the mechanism. The upper end of the lever, shaped into a tenon or tongue, will enter a square aperture in the end of the slider, and the edges of this aperture should be bevelled, in order that the lever may bear equally upon it in all positions. Rub the end of the lever with blacklead, and use this wherever there is friction of wood against wood.

The levers being fitted, three at one end and two at the other, or all the five at the same end, as may best suit the position of the wind-trunk, the form of the frame, and other considerations, it will be easy to connect them with the draw-stops by means of squares or bell-cranks.

Fig. 47 shows these squares or bell-cranks arranged upon a board which is screwed upon the key-frame. They may be cut out of sheet iron or may be made of oak, the arms halved together or joined by tenon and mortice. They should work upon a strong pin of iron or brass, and a small block underneath each square lifts it above the level of the board. A trace, or light rod of pine, 1 inch or ? square, notched at one end to receive the arm of the crank, and at the other to catch the end of the lever, is connected with each by a pin of iron or brass, and blacklead is used as before.

The draw-stops are generally turned and polished for a few inches at the end which appears in sight, and which carries the knob, and it is usual to line the holes through which this turned and polished part protrudes with scarlet or other cloth. The tails of these draw-bars, left square, should work in guides cut in a vertical piece at the back, or otherwise arranged to ensure parallel movement. A short slip of hard wood or of metal connects each draw-bar with its bell-crank. The action of this mechanism must not be considered satisfactory unless each stop operates with ease and exactness, and without any sense of elasticity or unequal resistance.

The knobs will be easily fashioned, from a good pattern, by any turner possessing a light lathe; nor is it difficult to engrave the names on the ivory faces. A convenient tool for this latter purpose may be made by grinding down the end of a small triangular file. But the engraver's "burin" may be bought at the tool-shops. The knobs will not be glued into the ends of the draw-bars until all is complete, that the engraved titles may be rightly adjusted at a true level.

Method 2.—If it is preferred to place the draw-stops to the right and left of the player, as in large organs, we shall have the bridges and levers as before. The draw-bars will run through guides at the back, fixed to some part of the frame, and their polished ends will be brought through lined holes in the cheeks of the case, fitted according to taste. The connection of these horizontal draw-bars with the vertical levers will be effected by squares or bell-cranks of a form known as "trundles." We give a representation of one of these in Fig. 48, where a is the slider, b the lever acting upon it, c the trace connecting it with d, an arm of the trundle e f. This trundle should be of oak, birch, or other hard wood; it has pins at each end, which are received into holes bored in bearers arranged accordingly, and not shown in the figure, or in the frame itself of the organ. (It is well to char these holes.) The trundles are of course placed parallel to each other in a row, and the second arm of each trundle will be inserted at the level answering to the position of the draw-bar. In the cut g h is this second arm and draw-bar.

The trundles are easily made of iron, and with manifest increase of strength and neatness. We have used gas-pipe for this purpose, ½ inch in external diameter. The arms made from iron slips, ½ inch wide and ¼ thick, were brought to a round pin at one end in the lathe. This round pin passes through a hole drilled through the trundle (whether tubular or solid), fitting it tightly, and the projecting end is spread out with a riveting hammer. All this may be done cold, but still more effectually with the aid of a forge. The ends of the trundle will be received in charred holes in bearers as before, using tallow as a lubricator; or if tube is adopted, brass or iron pins may be jammed into the ends of the tube, and trued up in the lathe. All such iron-work, introduced here or elsewhere in the organ, may be painted over with the composition known as "Brunswick black varnish," which will prevent rust. The holes in the arms, to receive the pins of the traces and draw-bars, will be drilled with ease in the ever-handy lathe, or with a bow and breast-plate, or by any blacksmith.

Method 3.—In small organs, with short sound-boards, the iron trundles may be made to act at once upon the sliders, without the intervention of the levers and bridge. When this is done the upper arm of the trundle will be quite at its top, and will be sloped or bent upwards as shown in Fig. 49. Near its end will be a short and strong pin, which will enter a little slot or oblong hole in the slider. The trundle will revolve in a wooden collar screwed to the cheek of the wind-chest, and at its base in a hole in a bearer or in the organ-frame as before. The draw-bar will act directly upon the lower arm of the trundle, and the lengths of the two arms must be proportioned to each other, so as to compensate for the difference between the play of the slider and that of the draw-stop.

Cases of peculiar construction may be easily imagined, in which two sets of trundles may become necessary, communicating with each other by long traces. In some other cases the trundles may be horizontally placed, like a roller-frame, and common squares may act upon the sliders; with upright traces connecting them with the arms of the horizontal trundles; while combinations of these various plans will suggest themselves to the inventive reader to meet possible exigencies of position or arrangement.

Method 4.—We may still further explain that trundles may be discarded by fixing common squares or bell-cranks upon steps or stages cut on the edge of a piece of thick plank, screwed to the organ-frame, the steps or stages corresponding to the levels of the draw-stops as arranged in the cheeks or jambs of the organ. The draw-bars will act directly on these squares, which will transmit the movement to the levers by traces; but in this case it is plain that the levers will be of varying lengths, and must be provided with separate bridges, in order that the proper relation may be maintained between the play of the several parts. This plan has much to recommend it.

We have entered at some length into the subject of the draw-stop action, because much of the comfort of the player depends upon its efficiency. The arrangement to be adopted should be well considered, and the plans for it matured at an early stage of the work. All the pins used should fit accurately, and it is well that means should be taken to prevent the dropping or working out of these pins. A very neat way of guarding against this common accident is to reduce a small portion of the end of the pin with a file or in the lathe, and to cut a screw-thread upon this reduced portion; a leather button will then render failure impossible. The other end of the pin is usually bent down at a right angle.

Composition pedals, for drawing and shutting off the stops in groups by the foot, are not wanted in so small an organ as ours, and we need not describe them.