Practical Organ Building

by W. E. Dickson

An easy way of making such a bridge rise and fall is shown in Fig. 56. The bridge a, which cannot be too solid and heavy, is held between guides, c d, which are blackleaded and accurately adjusted. At each end of the bridge is fitted a little roller or wheel of box-wood, turning freely on a pin. To the frame below is fitted another such roller, or two, as in the figure. Between these two or three rollers, at each end of the bridge, an inclined plane of wood, e, is made to traverse by means of a horizontal trundle and arms. It will be seen at a glance that when the inclined plane is pushed between the rollers by drawing or thrusting in a stop-handle, it lifts the bridge between the guides and dislocates the action; when it is withdrawn, the bridge resumes its place by its own weight, and the action is again in order.

It is now easy to understand the construction of the remaining couplers. The choir-coupler (Fig. 52, p. 152), has two bridges, x, y, with two sets of short backfalls and communicating stickers. If the bridges are fixed, then on depressing any key on the upper manual its tail raises the backfall, which presses down the lower backfall, which in its turn pushes up the tail of the lower key and causes the note to be heard. If the upper bridge be made to rise or the lower to fall ½ inch, then the keys are at once disconnected.

(c) The coupling of manuals to pedals is generally effected by rising and falling bridges, carrying backfalls which push up the tails of the keys. These bridges are arranged one above the other beneath the keyboards in large organs with three or four manuals, each bridge bringing its own manual into connection with the pedals by the movement already described. One roller-board (the rollers are often of iron for the sake of compactness) suffices for all the sets of backfalls, and the stickers (in this case generally flat strips of wood) pass through mortices cut in the tails of the lower keys to act upon the tails of the keys to which they belong.

The reader will easily perceive from these hints how the pedals may be made to act through their whole extent upon one of our manuals, and through only a part of their extent upon the other manual, as we have hinted at page 148. There will be two bridges, one over the other, and a very little ingenuity will be required to plan the roller-board so that the central C of the pedals shall pull down the lowest C of the second manual (be it upper or lower), and thus give the octave below (or 16-feet pitch) without additional pipes from that note upwards. But this, perhaps, belongs to the subject of the pedal organ, which we reserve for the conclusion of this book.

It is right to add here that in old-fashioned organs, both in England and on the Continent (where many such instruments remain unaltered), the manuals were made to couple by being drawn out or pushed in about ½ inch. A spur or protuberance of wood was glued to the upper part of the tail of each key, and a similar spur to the under part of the tail of the key in the manual above. These spurs had rounded ends covered with leather. On shifting one of the key-boards backwards or forwards the spurs met each other, and the coupling was effected. Or the spurs were glued under the front of each key, immediately behind the beading of the key-frame, and upon the upper surface of each key in the manual beneath it, and a similar shifting brought about a like result. We see no objection to this very simple old-fashioned arrangement strong enough to induce us to discard it from consideration.

The common type of small church organ with Great and Swell (throughout) would be vastly improved by the introduction of a manual between the other two, having no stops of its own, but coupled to both by such spurs. Instead of two qualities of sound, namely Swell alone and Great and Swell combined (the incessant use of the coupler being the inveterate habit of most players), we should have three: Great alone, Swell alone, and combination of Great and Swell. This obvious improvement could be introduced into new organs or added to existing instruments at a very small cost. There should be a coupler to connect this Combination Manual with the pedals.

It is undeniable that the addition of a pedal organ with a Sub-bass or Bourdon of 16-feet tone is a very important and valuable improvement to any organ, large or small. It gives a dignified cathedral-like solemnity and grandeur which every ear can appreciate. We shall bring our treatise to a close by a few remarks upon it.

1. The pipes will be made precisely like those of the Stopped Diapason, of which they may be regarded as a continuation, and they should be of stout material, the last four or five of inch stuff, then three-quarters to the twelfth or thirteenth note above.

On the question of scale the most diverse opinions have found favour of late years. A writer whose dicta are entitled to respect[5] urges that the lowest pipe (CCC, 16-feet tone) should have the enormous if not preposterous scale of 11½ by 13 inches inside measurement, and that the next six pipes above it should be in proportion. After that, he says, a smaller scale may suffice. It is clear that if this ruling be correct we may dismiss the idea of introducing a Sub-bass into our chamber organ. Mr. Hopkins, on the other hand, prints two scales for 16-feet toned Bourdons, the larger of which gives 6⅛ inches by 4⅝ as the inside measurement of the CCC pipe; while the smaller gives 5 inches by 3⅜ for the same pipe. We may safely adopt this larger scale of Mr. Hopkins; and we will only say further that with our light 2-inch wind the mouths should be cut up one-third of the width, or rather less, and the foot-holes should be of ample size.

[5] Rev. F. G. Hayne, Mus. Doc., "Hints on the Purchase of an Organ." Novello, 1867.