Page:The American Cyclopædia (1879) Volume XIII.djvu/506

 490 PIANOFORTE represented by the ends of the strings toward the right-hand side of the performer, and lying nearer to him. The ends of the strings corre- sponding to the straight side of the harp thus lie, in grands, in front, terminating in this case, however, in a less marked curve ; and the like extremities in the squares, which until recently always terminated in a straight line, lie to the left hand and back of the instrument. It is near to this part of the strings at the remote side in squares, and in front in grands that the hammers are always made to strike, the proper distance of the point of striking being about one eighth to one ninth the entire length of each string. The parts of the framing and connections of the strings can now be under- stood. Always at the ends which are arranged in what we have called the harp curve, the strings are permanently fastened to pins or studs, now made to enter and project directly from the iron plate. About each one of these, called the hitch pins, a string is in some cases bent, so as to return to the other side, corre- sponding to two single wires,; in other cases, each single wire is secured to a pin by termina- ting in a loop. In either case, the strings termi- nate in ends at the opposite (answering to the straight) side, and each is here wound about a larger movable pin, by turning which the tuner increases or relaxes the tension. .The plate in which stand the hitch pins is termed the string plate; that receiving and giving support to the tuning pins (wrest pins), the wrest plank ; and this, owing to the greater sonorousness of wood than of iron, is almost invariably a wooden strip or plank, though in various ways let into and supported by the iron castings which furnish the required strength to the part. The string plate and wrest plank are secured by bolts and otherwise to firm timbers beneath them ; the whole being received with- in the parts of the case. But the chief part of the strain of the strings is borne, in grands, by means of several strong iron or steel bars rising above the strings, and running parallel with them, and in squares by one or two such bars, these being formerly, and in Europe still in most instances, cast separately, and then firmly screwed down to the iron plates at both ends. In grand pianos the framing and sound board are severed across in front, to allow of the rise of the hammers, this part being strengthened by arches of metal and otherwise. The system of metallic bracing, first generally introduced by the invention of Thorn and Allen in 1820, was brought nearly to its present form, including the tension bars above referred to, by Pierre Erard of Paris in 1825. The sound- ing board is a sheet of thin, carefully prepared board, usually made of American spruce, free from knots and flaws, strengthened on the un- der side with small transverse ribs, and now made to extend across nearly the entire instru- ment, beneath the strings. Its edges merely are grasped between parts of the frame and case, and sometimes at particular points only, so that the middle portion is left free to vi- brate. On its perfection the quality of the tones must depend in a high degree. 2. Strings. At first steel wires were used for the treble notes of the pianoforte, and brass for the bass ; and as all the wires were short, those for the lower notes were wound or overlapped by wires of less thickness, for the purpose of in- creasing their weight, to a greater extent than is now required. Mr. Collard introduced in 1827 the plan of bending each wire about the hitch pin, as now commonly practised, thus obviating the tendency of the string to yield, twist, or break, in consequence of the noose formed at the end. Steel wire was also intro- duced throughout. A few of the lower strings are still wound, the upper of these with soft iron, the lower with copper ; and this lapping is now with finer wire, and very close. The length of the vibrating part of each string is determined by the places of two bridges, over or through holes in which the strings are stretched. The bridge nearest the hitch pins is upon and attached to the sound board, to which it aids in communicating the vibration of the strings ; the other runs along the edge of the wrest plank or plate, near to the tuning pins. Beyond the bridges at either end the string is known as dead wire, and any inter- fering vibration of this part is prevented by interlacing these ends with stout tape, or in other ways. When both supports determin- ing the vibrating length of the strings were bridges merely, the blow of the hammer from below tended slightly to elongate the string and to lift it from the nearer bridge, and so altered the tone. To prevent this result, Sebastien Erard invented in 1808 the plan of passing the strings at the end struck by the hammers through holes piercing the bridge or rim pro- jecting from the wrest plank, and so shaping the latter that from these holes the strings slope directly upward to the pins. The effect of this important improvement, termed the upward bearing, is that the string is no longer lifted or appreciably lengthened by the blow of the hammer, since to this the strain of the string is now directly opposed ; and its length remaining constant, its pitch is equable and its tone stronger. An improvement called the agraffe (d graffe) was also introduced by Se- bastien firard in 1819, in which the bridge just spoken of is conveniently replaced by a stud or pin for each string, pierced with two or three holes for the wires, and made fast below in the wrest plank, 3. Action. By the action of the piano is to be understood the mechanism, consisting of several small interposed parts, by which the pressure of the finger upon each key is to be transmitted in the most effective man- ner through the hammer to the corresponding string. The oldest of the actions which have been (in modified forms) retained are those of the square piano. In the original of these the key had upon it near its inner end a lifter of stout wire capped with a soft leather but-