erval of a major third. It sounds two octaves below the lower note.
The writer is not aware that this has ever been used as an organ stop,
but it is found written in the organ compositions of Guilmant and other
first-rate composers. It will be seen that a skilful organist, with a
knowledge of these tones, can produce effects from small organs not
available to the ordinary player.

Reverting once more to our Flute, whose tube is shortened by lifting
the fingers from the holes, it is not generally known that this can be
done with an organ pipe; the writer has met with instances of it in
England. The two lowest pipes of the Pedal Open Diapason were each
made to give two notes by affixing a pneumatic valve near the top of
the pipe. When the valve was closed the pipe gave CCC. When the
organist played CCC sharp, wind was admitted to the valve, which
opened, and this shortened the pipe. The device worked perfectly, only
that it was not possible to hold down both CCC and CCC sharp and make
"thunder"! The organist of Chester Cathedral had been playing his
instrument twice daily for ten years before he found this out, and then
he only discovered it when the pipes were taken down to be cleaned. It
is an admirable makeshift where a builder is cramped for room.

Organ pipes are divided into three families--Flues, Reeds and
Diaphones. The flues are subdivided into Diapasons, Flutes, and
Strings, and we now proceed to consider each of these groups separately.

DIAPASONS.

The pipes usually seen in the front of an organ belong to the Great
organ Open Diapason, long regarded as the foundation tone of the
instrument. The Open Diapason may vary in size (or scale) from 9
inches diameter at CC to 3 inches. The average size is about 6 inches.

The Diapasons of the celebrated old organ-builders, Father Schmidt,
Renatus Harris, Green, Snetzler and others, though small in power, were
most musical in tone quality. Though sounding soft near the organ, the
tone from these musical stops seems to suffer little loss when
traveling to the end of quite a large building. About the year 1862
Schulze, in his celebrated organ at Doncaster, England, brought into
prominence a new and much more brilliant and powerful Diapason. The
mouths of the pipes were made very wide and they were more freely
blown. Schulze's work was imitated by T. C. Lewis, of England, and by
Willis. It has also exercised very great influence on the work done by
a