Page:The American Cyclopædia (1879) Volume XIII.djvu/507

 PIANOFOKTE 491 ton, this striking and elevating the hammer ; while still beyond this rose a sticker which at the same time lifted from the wire a damper above it a lever having a bit of soft cloth at the end ; on releasing the key, this damper re- turned upon the string, checking its vibration. This arrangement formed the single action. Its faults were that the tone was thin and wiry ; that in playing very piano the pressure on the key did not always cause the hammer to reach the string; while, if the hammer rest was brought too near the string, the hammer did not quit the latter soon enough, and the effect of this was termed blocking. To remedy these defects, Longman and co. introduced the hop- per or grasshopper, invented in 1786 by John Gieb. This hopper took the place of the lifter ; it was a jointed upright piece which, when the key was pressed down, engaged in a notch un- der the hammer, and just before the instant of striking slipped past the end of the hammer, allowing this after the blow suddenly to fall. With this was employed also a second or under hammer, multiplying the velocity of the first, on the principle of the compound lever. This mechanism was the double action, still substan- tially in use with many makers in uprights and squares. To this was afterward added the Irish damper, the invention of Southwell (1794-'8), which was simply an upright rod, with a piece of soft cloth above, which the key, so long as it remained depressed, lifted off the string. Still the hammers would sometimes rebound from the string with such force as to return upon it, checking its sound. To remedy this, a small, inclined, rough surface of felt was so fixed on a wire support as to be rubbed by the head of the hammer in its descent, and thus gradually to destroy its velocity ; this was called the check. The English grand action, so called, already al- luded to as that of Backers, adopted by Broad- wood, Stodart, and others, consisted of a key, a jack (lever, in place of the hopper), a button so placed as to regulate the sweep of the jack, a spring pressing to restore the jack to its place after the movement, a hammer on the but of which the jack acted, the check, and a damper arrangement, of which various forms could be employed, with rails and sockets connecting or fixing the needful points. But in this arrange- ment it was still a defect that, after a stroke of the hammer, the jack could not reengage it un- til, by release of the key, the parts had returned to their first position. This required time, and any note could not be rapidly repeated. The defect was first remedied by an invention of Sebastien Erard in 1821, improved in 1827, termed the repetition action. This was an im- provement upon a previous action of his, which as now modified, under the name of the French action, is still in use with many makers in America and Europe, and the origin of which is believed to be due to Petzold. In the repe- tition action, consisting of an arrangement of levers and springs too complex to be described here, the hammer is caused to be, through its whole sweep, at the command of the player, so that the note can be reproduced at half stroke, or at any fraction of an entire stroke. To se- cure this result, when the hammer recoils from the string, it is, by means of a roller, lever, and spring, upheld so long as the key is not entirely released, and in such a way that it can neither return to the string nor fall ; and while thus suspended near the string, its blow upon the string may be, by aid of an escapement button, repeated at the pleasure of the player. The French repetition action is thus complex and delicate. Broadwood retained the English grand action, applying to it directly a repetition adapted from the French by Southwell, prob- ably in 1827. This was accomplished by pass- ing through the hammer but a block or bar, a spring pressing upon this so that when the jack passes the notch it is caught by this bar, and the hammer is sustained ready to repeat the blow, until, as before, the key is entirely released. The escapement button also appears in this arrangement, and a second spring deter- mining the height at which the hammer shall rest. The varieties of grand action are very great, those used in the United States being all based on either the English, here described, or the French of Petzold and firard. Stops were early introduced into the piano, but, save in parts of continental Europe, they have been abandoned ; several pedals are there also used, but in England and this country only two, one for for te effects, the other for piano. The for te pedal is quite effectual, and besides not injurious to the instrument. The earlier piano pedal, passing the action to one string, is straining to the centres of the hammers, and apt to disturb the tuning of the unisons the strings intended to yield the same note. The jeu celeste, a later pedal arrangement, obviates these defects. In this, tongues or strips of soft leather or wool are so held, that by pressure on the pedal they can be raised between the strings and the hammers, thus softening the sound. This, of late somewhat contested, we have seen in a piano of Petzold's, marked 1823; and in the same also is found the long or full sound board, supposed by many to have been more recently introduced. It should be added that the ham- mers are of wood, the heads covered, accord- ing to size, with one or more layers of thick and firm felt. This material, soft woollen. &c., are introduced in many parts also to prevent the click or rattling which would otherwise attend the movements. Various contrivances have been resorted to for the purpose of se- curing sustained sounds in the pianoforte; a very good example of these was Mott's sosti- aente pianoforte (1817), in which the continued tone was attained by communicating the vibra- tion of the strings to silk threads and skeins arranged in a peculiar manner. The aeolian attachment of Isoard consists in causing a current of air, supplied by a bellows, to act on the string, thus prolonging its tone on the principle of the ssolian harp. A similar effect