At the lower end of the plate, and just below the bridges,[B] the hitchpins are driven firmly into holes drilled to receive them. Their purpose is to support the lower ends of the strings. The bass strings are separate, and each has a loop with which to fasten it to the hitchpin. In the treble, one piece of wire forms two strings; the two ends are secured to the tuning pins above, and the string is simply brought around the hitchpin. The bridges communicating with the sound-board are at the lower end of the sound-board. Notice, there is a portion of the length of each string between the bridge and the hitchpin.
At the upper end of the strings, a "bearing-bar," situated between the tuning pins and upper bridge, is attached to the pin-block by screws which draw it inward; its function is to hold the strings firmly in position. You will notice that the lengths of the strings, above the bearing-bar, vary considerably, even in the three strings comprising the unison. (We will speak of the effect of this in tuning, farther on.)
After that portion of the case is completed which forms the key-bed or action frame, we are ready to set in the
Action
By this is meant the keys and all those intricate parts which convey the motion of the key to the hammers which strike the strings, and the dampers which mute them.
The requisites of the action are as follows:
The keys must descend quickly and easily at the touch of the performer, giving quick response.
The weight of the hammer must be properly proportioned to the strings it causes to vibrate.