We are now able to turn our attention to the action mechanism of the upright pianoforte. The historical chapter of this work contains a short description of the early history of the upright form. Of course, it will at once be seen that the only real mechanical difficulty in designing a vertical type of pianoforte was to be found in the department of touch-mechanism. The problem was indeed primarily of the action. As such it is interesting to note the efforts of Hawkins, Southwell and Loud, to produce an action that would approach in efficiency that of the grand. It was Robert Wornum, however, who found the solution, though not until nearly the end of the first quarter of the nineteenth century. The principle applied by Wornum possessed such value that it has never been superseded, and remains today the distinguishing feature of the upright action.

We refer, of course, to the tape. As applied to the action of uprights, this device has become universal, and all upright actions in consequence have for years been everywhere similar as to general design. Thus we do not find those radical differences of actuating principle that to this day distinguish American from certain European grand pianofortes. This is partly due to the fact that the great battles had already been fought out when the first successful upright actions were made. At present, the only remaining types of the ancient “sticker” leather-hinged action are to be found in old-fashioned and obsolete European pianofortes of the cheaper grade. None are made now, however, except in the case of a very few worthless commercial English instruments. In the United States the “sticker” action has hardly been heard of.

Thus it seems unnecessary to give detailed drawings of any but the accepted type of upright action. The reader’s attention is immediately called, therefore, to the drawing herewith given.

The method of operation may be seen very clearly. Depression of the key, to which is screwed the key-rocker (1), causes the Abstract (2) and the Wippen (6) to rise. This brings the Jack (7) to bear against the butt (18), which is raised, forcing the hammer (20) and (21) through the shank (19) against the string (32). As the hammer strikes, the rise of the jack has brought its tail against the regulating-button (16), which trips it up so that it falls towards the back-stop (14). The butt, being thus left free, drops back, assisted by the pull of the tape (13), until the back-stop is caught and held by the check (9), thus leaving time for the jack to get back under the hammer butt through the aid of the spring (8). Repetition of the hammer is thus assured, and while the rapidity of stroke cannot be so great as that of the grand, it is sufficiently so to satisfy ordinary users. Sometimes a spring is fastened to the front of the jack in connection with a silk loop and cord which stretches back and engages with the hammer spring (23). The latter is then fastened to the hammer butt instead of to a rail (24). This arrangement gives a far more rapid repetition to the action and causes it to approach the delicacy of the double escapement of the grand.

UPRIGHT ACTION SHOWING LOST-MOTION DEVICE, METALLIC REGULATING RAIL SUPPORT, CAPSTAN SCREW, JACK REGULATING RAIL AND METALLIC ACTION BRACKETS.