The pedal-board should be laid upon the floor so that the distance between the upper surface of the pedal natural keys and the upper surface of the manual natural keys may be 28 inches.
The manual should overhang the pedal-board so that the front of its sharps may be just over the front of the pedal-sharps.
The seat of the player, to correspond with these arrangements, should be 22 inches above the pedals. The dip, or fall, of the pedals, under the foot of the player, need not exceed ⅝ inch, or at most ¾ inch, where they pass through the rack.
The connection between the pedals and keys will be by backfalls, working in a strong bridge secured to the frame below the key-board. These may be parallel, in which case a roller-board will be requisite, or disposed as a fan-frame. The hinder end of each backfall has a tapped wire passing through a hole in it, and carrying a button on its top, muffled with a disc of cloth or baize. The lower end of the wire underneath the backfall is bent into a ring, so as to be easily turned round by the finger and thumb. These adjustable buttons push up the tails of the keys when the fore ends of the backfalls are drawn down by trackers connecting them with the pedals. The eyes or rings on the pedals, to which these trackers are hooked, should be bushed, and great care should be taken to secure noiseless action in every part.
The pedal-board is usually secured to the floor by a couple of screws passing through the side cheeks. But it is sometimes convenient, especially in small rooms, to make it removable at pleasure. This can be easily done by fitting a set of false or dwarf pedals, about 6 inches in length, in a bridge spaced to correspond with the keys of the pedal-board, and screwed to the floor under the organ. These false pedals are practically short backfalls, turning on a wire near their hinder end, and having the trackers hooked to them an inch or two from their fore end; and some simple form of spring should be placed under each. Then we have only to adjust matters so that the protruding ends of the organ-pedals may rest upon the fore ends of these false pedals, either or both of them being leathered or otherwise muffled at the point of contact, and it is plain that the pressure of the foot on any pedal will pull down the manual key as before. Two iron pins should be fitted to the pedal frame, going into holes in brass or iron plates screwed to the floor. These guide-pins will insure instantaneous fitting of the pedal-board at any time.
CHAPTER XII.
TWO-MANUAL ORGANS.
This treatise must not close without some reference to organ work of a more advanced kind than that which we have taken as the groundwork or medium of our hints on this subject.