n of the
construction of the organ at the beginning of the last century and
explain the technical terms we shall use later.

As everybody knows, the tone comes from the pipes, some of which are to
be seen in the front of the instrument. The pipes are of various
shapes and sizes and are arranged in ranks or rows upon the
_wind-chest_. Each of these ranks is called a _stop_ or _register_.
It should be borne in mind that this word _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 ob