The “sostenuto pedal” is devised to permit the sustaining of a chord while the fingers of the performer, for the purpose of continuing the melody, are withdrawn from the keys. It will be observed that the action is provided with a rod (22) which is connected with a pedal and is adapted to be brought into contact with an additional damper-lever (23). This additional lever is provided with a tongue of felt, and when the rod is turned on its axis, this tongue engages with a similar metallic device on the rod, thus holding the damper up as long as the rod is kept in the position of contact. When the key is pressed down, the damper rises to clear the string, and brings the additional lever up with it, so that, if the rod is now caused to revolve, the tongues on each engage one with another and the damper is held up as long as the pedal is pressed down and irrespective of the position of the key. Provided that the keys are first depressed, the pedal will always hold up as many of the dampers as are thus raised. The result is to sustain the sound of the strings after the hand has been removed from the key. This gives a more permanent character to the harmonization of a melody, without the dissonance that comes from the releasing of all the dampers by the ordinary “forte” pedal. The “sostenuto pedal” is generally situated between the others in the lyre or pedal case at the level of the player’s feet.

The second device is also most interesting. It consists of a method for softening the sound of the string, by a method similar to that which is employed in the upright. It is claimed, and with some justice, that the use of the shifting key-frame is attended with various complications, and that the motion tends to hinder the adjustment of the action to the strings. Moreover the hammers become unevenly worn by being continually caused to strike two, instead of three, strings and this operates to cause loss of directness in the hammer-strokes.

In this new device, the hammer is provided with a swing-rail (25), having a cushion for the hammer-rebound similar to the ordinary cushion that is supported upon the wippen in most actions, and a rod (26) for pivoting it to the metallic action frame (24). The swing-rail also is fitted with a lifter (27), which is operated by the soft pedal through a lifter-rod (28). So far the process is simple. The effect of the motion of the swing-rail is to bring the hammer closer to the string and to soften the tone. But this is only accomplished at the cost of lost motion between the capstan-screw and the key. To avoid the loss of touch thus brought about, the lifter-rod is connected with two compensating levers (29) and (30), which are so adjusted that they form a continuous link between the parts where the lost motion would occur, and thus preserve the continuity of touch and the weight that is lost by the different actuating positions of the hammer. The ingenuity of this device commends it to the student of pianoforte mechanism, and the makers are entitled to great praise for the successful achievement of this important modification.

We may conclude our survey by giving a list of the materials of which grand actions are constructed.

Various Woods—
Pear treeDamper heads.
HollyJacks and other small parts.
SycamoreJacks and other small parts.
EbonyTops of black keys.
MapleHammer moldings and shanks.
MahoganyHammer moldings, buttons, etc.
White pineKey-frames.
Felts and Cloths—
BaizeOn key-frames, hammer-rails, etc.
BaizePunchings.
Flannel clothBushing centre pin holes, damper lifter holes, etc.
Tone feltUpper and under felt for hammer.
Hard feltBass damper wedges.
Soft feltTreble dampers, etc.
FlannelSundry action parts.
Leathers and Skins—
Doeskin Various parts of action, operating faces of hammer-butts, etc.
Buckskin
Elkskin
IvoryTops of white keys.
CelluloidFronts of white keys.
GraphiteLubrication of working parts.
IronAction frames, screws, etc.
BrassCentre pins, springs, pedal-feet, etc.

STANDARD AMERICAN UPRIGHT ACTION.