erring
regularity. The pulsations of sound are regulated by this admirable
contrivance. If mellowness of quality be sought, a slight alteration
of its position or form will produce a favourable change of singular
extent; if intensity of tone be requisite, the sound-post is again the
regulator. It must, of course, be understood that its power of
changing the quality of the tone is limited in proportion to the
constitutional powers of the instrument in each case. It is not
pretended that a badly constructed instrument can be made a good one
by means of this subtle regulator, any more than a naturally weak
person can be made robust by diet and hygiene.

The position of the sound-post is usually one-eighth to three-eighths
of an inch behind the right foot of the bridge, the distance being
variable according to the model of the instrument. If the Violin be
high-built, the post requires to be nearer the bridge, that its action
may be stronger; whilst flat-modelled instruments require that the
post be set further away from the bridge. It is not possible to have
any uniform arrangement of the sound-post in all instruments; as we
have remarked before in reference to the bass-bar, the variations in
the thickness, outline, model, &c., of the Violin are so frequent as
to defy identity of treatment; uniformity has been sought for, but
without success.

The post can only be adjusted by a skilful workman, who either plays
himself or has the advantage of having the various adjustments tested
by a performer. The necessity of leaving this exceedingly delicate
matter in practised hands cannot be too strongly impressed upon the
amateur, for the damage done in consequence of want of skill is often
irreparable.

There are two methods of setting the sound-post in the instrument: the
first fixes it in such a position as to place the grain of the post
parallel with the grain of the belly; the second sets it crosswise.

The next important feature to be mentioned is the bridge, which forms
no small part of the vibrating mechanism of the instrument, and needs
the utmost skill in its arrangement. Its usual position is exactly
between the two small niches marked in each sound-hole, but this
arrangement is sometimes altered in the case of the stop being longer
or shorter. Many forms of bridges have been in use at different
periods, but that now adopted is, without doubt, the best. In
selecting a bridge great care is requisite that the wood be su