Pedal keyboard. The keyboard is shown in [Plate IV] fig. 18 and [Plate V] fig, 19; it is located at the foot of the organ, where the organist’s feet are; with them he depresses the keys of this keyboard; thus, it is called “pedal.” This name also applies to the stops and pipes which this keyboard sounds. See Stops, the table of compasses of organ stops [Plate XI, fig. 67], and individual articles.

To make a pedal keyboard, first a frame, ABCD , fig. 18 , is made of Holland oak. Rail CD is around two inches wide and one and one-half inches thick; it has a dado or channel along the upper part of its inner surface, to receive the tails of the keys parallel [1] to the rail. Towards the front of the frame is a rail, I , around two inches square, with several holes for iron pins b b b , between which pedals fg may move vertically; this rail with pins is called the guide rail . There is yet another rail, c d , four or five inches wide and one inch thick, on which springs d e rest, returning the pedals to the top of the keyboard. All these parts must be joined to side rails AC , BD , with dovetails. The side rails are one and one-half inch thick and about six inches high at the guide, but only two at rail CD , so that the top board is slanted.

The keys are wooden bars [Plate IV, fig. 18], f g , one inch thick and two inches wide; their ends, g , fit into the dado we have described, on the inside of rail CD , where they are secured by pins ( see Pins); at the opposite end of each key a rod, h , is fitted, with a hole for the wire to the roller board. In organs without a Positive, the pedal keys have no rods, but the keys are made longer and pointed at end f , where a ring is fitted with the same function as the holes in the rods. Beneath each key a hole is made, into which one end of spring d e is inserted; the other end rests on rail c d , which is its base; this causes all the strength of the spring to bear against the pedal, raising it when it has been depressed, compressing the spring.

The top of the keyboard, which as we have said slopes upward towards the front, is a board, a b c d , [Plate V] fig. 19 , cut with as many slots as there are keys. These slots or mortises correspond to the natural intervals; they are four inches long and one inch wide, and stand on the center part of the key parallel with it; the accidentals or half-tones are only two inches long by one inch wide, and they stand towards the rod ends of the keys, as shown in fig. 19 . When the mortises have been cut, the top of the keyboard is placed on the frame and secured with screws; then the blocks are made of wood, one inch thick by as long as the mortises less one-third of an inch. The natural blocks must stand at least an inch above the top board, and the accidentals two inches; when they are fitted, they are glued to the keys so as to make a single piece. With this construction, it follows that placing a foot on a block and depressing it lowers the key, whose rod, h , pulls the wire or tracker from the roller board; when the foot is raised, spring d e , [Plate IV] fig. 18, which was compressed by the lowered key, is so no longer and raises it, returning things to their original condition.

1. In fact, “perpendicular” (Translator’s note).