and the quarters. For the system of
vaulting in architecture known as "barrel-vaulting" see VAULT.

BARREL-ORGAN (Eng. "grinder-organ," "street-organ," "hand-organ," "Dutch
organ"; Fr. _orgue de Barbarie_, _orgue d'Allemagne_, _orgue mecanique_,
_cabinet d'orgue_, _serinette_; Ger. _Drehorgel_, _Leierkasten_; Ital.
_organetto a manovella_, _organo tedesco_), a small portable organ
mechanically played by turning a handle. The barrel-organ owes its name to
the cylinder on which the tunes are pricked out with pins and staples of
various lengths, set at definite intervals according to the scheme required
by the music. The function of these pins and staples is to raise balanced
keys connected by simple mechanism with the valves of the pipes, which are
thus mechanically opened, admitting the stream of air from the wind-chest.
The handle attached to the shaft sets the cylinder in slow rotation by
means of a worm working in a fine-toothed gear on the barrel-head; the same
motion works the bellows by means of cranks and connecting rods on the
shaft. The wind is thereby forced into a reservoir, whence it passes into
the wind-chest, on the sides of which are grouped the pipes. The barrel
revolves slowly from back to front, each revolution as a rule playing one
complete tune. A notch-pin in the barrelhead, furnished with as many
notches as there are tunes, enables the performer to shift the barrel and
change the tune. The ordinary street barrel-organ had a compass varying
from 24 to 34 notes, forming a diatonic scale with a few accidentals,
generally F#, G#, C#. There were usually two stops, one for the open pipes
of metal, the other for the closed wooden pipes. Barrel-organs [v.03
p.0433] have been made with as many as three or four cylinders set in a
circular revolving frame, but these more elaborate instruments were mainly
used in churches[1] and chapels, a purpose for which they were in great
demand for playing hymns, chants and voluntaries during the 18th and early
19th centuries. A barrel-organ was built for Fulham church by Wright, and a
large instrument with four barrels was constructed by Bishop for
Northallerton church in 1820.

[Illustration: FIG. 1.--Large stationary barrel-organ worked by hydraulic
power, from Solomon de Caus, _Les Raisons des forces mouvantes_
(Frankfort-on-Main, 1615).]

The origin of the barrel-organ is now clearly established, and many will
doubtless be surprised to find that it must be sought in