The principal object of the bar is to resist the pressure of the strings
upon the top. All old violins require to be rebarred, owing to the
height of the present musical pitch over that of one hundred years ago.
The old short bars are no longer adapted to the greater strain, and more
powerful ones are needed. From long continued strain, the pulling of the
two extremes toward the centre, and the downward pressure of the bridge
at that point, the tops of many old violins have bulged up at the ends
and sunk down in the centre. The adjustment of a new bar will have a
tendency to remedy this. As the bar was originally placed by Gaspar da
Salo, so it should be placed now; that is, not in the direction of the
fibres of the top, but obliquely, the end under the finger–board being
nearest the centre. In this position it appears to give ample support
to the bridge and to allow a fuller and richer tone.[30]
[30] See Mr. Colton’s note p. 376.