The violin and the art of its construction: a treatise on the Stradivarius violin

by August Riechers

X. THE BASS-BAR.

After the F-holes have been cut out, the bass-bar can be fixed. It is made of pine and should be prepared in such a way that the year-rings lie perpendicularly to the belly. The height of the bass-bar under the bridge is 10 m/m. and at the two ends 4 m/m. The bass-bar must be 6 m/m. thick in the middle, decreasing in thickness by 1 m/m. towards the ends. The length should be 280 m/m. The bass-bar must be glued on so that it lies 35 m/m. from the bottom edge and 40 m/m. from the upper one. In order to determine exactly the position of the beam, the width of the bridge should be precisely marked as 40 m/m. on the inside of the belly and the bass-bar should then be placed to coincide exactly with the G-foot of the bridge, giving it at the same time such a slanting position as to bring its upper end within 4 or 6 m/m. of the middle line of the belly, while its lower end should, on the contrary, be purposely placed farther away from it. (See illustration).

In order that the bass-bar may obtain the right tension, the side of it lying next the belly must be slightly curved, sufficiently so for both ends, before they are glued, to stand away about 2 m/m. In the process of glueing, the ends must be firmly pressed down. The height of the bass-bar under the bridge should be 8 m/m., while at the ends the measurement should amount to 4 m/m. It is scarcely necessary to remark that the proportions of the bass-bar vary in different violins, according as they are smaller or larger, high or flat, strong or weak. A few examples are given here. In a violin of the ordinary type, no matter whether it be large or small, the proportions will be found to coincide with the above statement, while a highly arched violin has a less slanting and less tightened beam than the latter. In the case of wood of a thickness less than 1¹⁄₂ m/m., the beam should be 1 to 2 m/m. more towards the interior, and also be placed from 3 to 5 m/m. more slanting, and must in that case also be from 1 to 2 m/m. thicker. A bass-bar under strong tension gives a sharp and clear tone, while one of less tension gives a fuller and softer one. With bass-bars of the height of 12 and even 15 m/m. (so-called acoustic bass-bars), it is not possible to achieve any success. The fixing of the bass-bar completes the interior construction of the violin, and consequently the glueing-on of the belly can now be proceeded with.