XIII. THE FINGER-BOARD AND NUT.
Both these portions of the instrument must be made of ebony (Fig. 12). Before the finger-board is glued, the surfaces to be joined must be made particularly smooth. The length is 268 m/m. in an instrument of normal size, and in those which are longer and shorter, the necessary proportion is easily determined. The width of the upper end, near the nut, is 24 m/m., while at the lower end it measures 45 m/m.
The curve at the nut should be the same as the curve of the bridge, the thickness being from 4 to 5 m/m. Whilst the centre of the finger-board should form a straight line lengthways, it must be hollowed out under the E-string equally to the depth of 1 m/m., and under the G-string to 1¹⁄₂ m/m., in order to prevent the jarring and rattling of the strings. The thickness of the nut must be 5 m/m. on the under side and 4 m/m. on the upper. The distance between the two outer string-grooves must be from 16 to 18 m/m. The strings lie at the nut (a) in the case of E, A, and D-strings at a distance of ¹⁄₂ m/m. from the finger-board, the G-string 1 m/m. The thickness of the neck, including the finger-board, is 18 m/m. at the upper curve (Fig. 8b I.) for a hand of ordinary size, and 24 m/m. at the lower curve (Fig. 8b II); but this thickness can be altered according to the wish of the performer.