The Recent Revolution in Organ Building | Page 4

stop refers to the row of pipes, and not to the
stop-knobs by the keyboard which operate the mechanism bringing the
row of pipes into play. Much confusion of ideas prevails on this point,
and cheap builders used to take advantage of it by providing two
stop-knobs for each row of pipes, thereby making their instruments
appear to contain more pipes than were actually there. This practice
was at one time very prevalent in the United States.
The early organ-builders to obtain variety of tone divided the pipes into
groups placed in various positions, each playable from a separate
keyboard, and this practice prevails to this day. An average church
organ will contain three or four wind-chests, each with its quota of

pipes and designated as follows:
1. The Great organ, consisting of the front pipes and other
loud-speaking stops. Back of this and usually elevated above the level
of the Great organ pipes is
2. The Swell organ, all the pipes of which are contained in a wooden
box with Venetian shutters in front, the opening or closing of which
modifies the tone; below the Swell box is placed
3. The Choir organ, containing soft speaking pipes suitable for
accompanying the human voice; and back of all or on the sides is
4. The Pedal organ, containing the large pipes played by the pedals.
Larger instruments have still another wind-chest called the Solo organ,
the pipes of which are very loud and are usually placed high above the
Great organ.
In some large English organs, notably that in the Town Hall of Leeds, a
further division was effected, the pipes of the Great organ being placed
on two wind-chests, one behind the other. They were known as Front
Great and Back Great.
The original reason for dividing a church organ in this manner seems to
have been the impossibility of supplying a large number of stops with
wind from a single wind-chest.
It will thus be seen that our average church organ is really made up of
three or four smaller organs combined.
The wind-chest is an oblong box supplied with air under pressure from
the bellows and containing the valves (called pallets) controlling the
access of the wind to the pipes. Between the pallet and the foot of the
pipe comes another valve called the slider, which controls the access of
the wind to the whole row of pipes or stop. The pallet is operated from
the keyboard by the key action. Every key on the keyboard has a
corresponding pallet in the wind-chest, and every stop-knob operates a

slider under the pipes, so that both a slider must be drawn and a pallet
depressed before any sound can be got from the pipes. The drawings
will make this plain.
Fig. 1 is a front view and Fig. 2 a side view of the wind-chest. A is the
wind-chest into which compressed atmospheric air has been introduced,
either through the side or bottom, from the end of the wind-trunk B.
The pallets, C C C, are held against the openings, D D D, leading from
the wind-chest to the mouth of the pipes, by springs underneath them.
[Illustration: Fig. 1. The Wind-chest. Front View]
The spring S (Fig. 2) keeps the pallet C against the opening into D. The
wires called pull-downs (P, P, P), which pass through small holes in the
bottom of the wind-chest and are in connection with the keyboard, are
attached to a loop of wire called the pallet-eye, fastened to the movable
end of the pallet. A piece of wire is placed on each side of every pallet
to steady it and keep it in the perpendicular during its ascent and
descent, and every pallet is covered at top with soft leather, to make it
fit closely and work quietly. When P is pulled down (Fig. 1) the pallet
C descends, and air from the wind-chest A rushes through D into the
pipe over it. But the slider f is a narrow strip of wood, so placed
between the woodwork g and h that it may be moved backwards and
forwards from right to left, and is pierced with holes corresponding
throughout to those just under the pipes. If the apertures in the slider
are under the pipes, the opening of a pallet will make a pipe speak; if,
however, the slider has been moved so that the apertures do not
correspond, even if the pallet be opened and the chest full of air from
the trunks, no sound will be produced.
[Illustration: Fig. 2. The Wind-chest. Side View]
When the apertures in the slider are under those below the pipe, the
"stop," the handle of which controls the position of the slider, is said to
be out, or drawn. When the apertures do not