The junction of these parts with the damper mechanism lies within the province of the action finisher and regulator and will therefore be treated in the chapter on action regulation.

It will be observed then, to return to the consideration of the action in its actual movements, that the depression of the key causes the wippen to rise at its forward end. This brings the escapement lever (4) to bear upon the roller (6), with which it is in continual contact, and raises the hammer-shank and hammer-head (5) and (7). At the same time the jack (3) is raised and its tail end is brought nearer to the button (8), which it finally touches. As soon as this happens the jack is tripped up and its head comes out of contact with the roller. The latter in the meantime, having been raised away from the escapement lever by the action of the jack, falls back into contact with the former and is then borne up on the lever so that the hammer is maintained in position near to the strings. The result of this is that so long as the finger is held on the front of the key, the whole action is continually in proper position to actuate the hammer. The jack is not permitted to fall away, for the roller is maintained in the right place by the escapement lever and it thus happens that a very small angular motion of the key obtained by slightly raising and depressing the finger, is sufficient to cause the whole action to be set in motion, and the operation of actuating the hammer to be gone through as often and as rapidly as required.

The pedal motions of the grand action are simple. The whole action and keys, as we know, are mounted upon the key-frame together, and thus form a homogeneous structure. The “piano” pedal is caused to shift this frame so that the hammers each strike only two of the members of each three-string group and only one of each two-string group. This is effected by the use of a heavy spring that is set in the side of the interior case and bears against the key-frame, and by a lever that operates from a hole cut in the bottom of the key-bed and engages with one of the bars of the key-frame. The pedal is connected with this iron lever so as to shift the key-frame, and the spring operates to push the key-frame back into place whenever the foot-pressure is removed from the pedal.

The “forte” pedal simply pushes up the whole line of damper levers (16) each of which is pivoted on flanges (21) for that purpose. The lifting is effected by means of a rod connecting with the pedal which is projected through the bottom of the key-bed and engages with a rail set under the line of damper levers and adapted to raise them when operated by the pedal-rod.

There are, however, two variations to the pedal mechanism of grand pianofortes that require some attention on account of their mechanical interest. These are clearly illustrated and described in the cut and specifications shown on adjoining page.

The working of the sostenuto pedal and of the new soft pedal device will be readily comprehended by reference to the cut.

It will be noted, in the first place, that the metallic action brackets which were omitted in the previous drawing for the sake of exhibiting the working parts more clearly, are now shown.