The wires of the piano are made to sound by means of small wooden levers, called hammers, each of which has a lim ing projection at its end, covered with many folds of leather, so as to produce a clear tone. These hammers are impelled upwards by means of the keys, which be ing depressed by the fingers, and ba lancing on small flat battens, on which they are arranged, and kept steady by strong pins passing through near the points of equilibrium ; also having little knobs of pump-leather standing on stems of wire, at their inner ends, cause the le vers to rise on the least touch of the fin ger, with a smart stroke, so as just to touch the three wires of their respective notes. The levers being fixed to a frame, parallel with the keys, by means of vel lum binges, return instantly to thek places, and lay on a small parallel apron covered with baize, so that no rat tling nor jingling results from their retrocession. These hammers may be distinctly seen when working, as they pass through a braid slit made in the soending-board, the whole breadth of the instrument. At the inner extremities of the.keys are small pieces of buff-leather, which take off the sound that would else proceed from their contact with the shafts of the dampers ; which are contri vances for stopping the tones of such wires as are struck by the hammers, so soon as the finger is taken off from the key. The devices for damping, as it is technically called, have been numerous ; and their several inventors have never failed to up hold their own modes, as the ne ultra of ingenuity. It would, perhaps, be im possible to detail their several merits with any show of utility to the reader, or with impartiafity to the inventors: if, however, simplicity of construction, certainty of ac tion, and facility of repair, may give a shit* to pre-eminence, the common ba lance-damper may assuredly urge its pre tensions to the palm. This is nothing more than a round stem, like s anal ce dar-pencil, which is crossed at right an gles by a flat bar, one of whose ends is alit, as that it may be guided by a slender perpendicular pin, as it rises, in conse quence of the key's pressure upwards at the other end is a small piece of broad cloth, single or double, accordinic to the powers of the wire (the longest vibrating most forcibly). This little piece of cloth, by fatting on the wire when the key it released, instantly stops the sound. The reader will, from this de.seription, collect, that when slow p•sseges are played, the continuance of each note is in exact ra tio with the time of the key's being kept down ; and that, in rapid passages, where the touches are light imettransient, even defying the quickest to follow movements of the the opera tion of the dampers must be as rapid as that of the hammers, else a confusion of tones will be heard.
Most grand piano-fortes have two Foe dais, one for each foot, communicating with the interior. One serves to raise all the dampers completely, which in tim ing is a consideritble convenience ; the serves to throw the whole of the key-frame to the right, more or less ; by this means the hammers are slid at the same moment, in a body, about a quarter of an inch to the right ; so as to quit either one or two, at pleasure, of the left hand wires of each note ; and to strike epee only one, or two, as judged proper for the greater or less diminution of round. Other pedals are sometimes af fixed, for the purpose of opening a kind of flat cover, like Venetian blinds, laying over the wives, thereby to allow more or less sound to pass. The sounding-board, or .belly, is made of very fine narrate deals, chiefly imported from the conti nent, so closely joined that, in many, no line, or indication of junction, can be dis tinguished. This belly returns the sound,
causing it to reverberate very forcibly. The long keys are exteriorly covered with ivory plates ; and the semitones, or sharp and fiat keys, are made of ebo ny : they stand higher, but are nearly two inches shorter than the keys of the natu ral notes.
The Narprichord is of the plectreted species, whereas the piano-forte is of the pulsatile. The former resembles the grand piano-forte in every instance, ex cepting that, in lieu of hammers, it has jacks ; which, rising perpendicularly, pass the wires, and by means of short pieces of stiff quill, projecting frogs their iides, displace the wires from their right lines, and consequently cause them to sound so soon as the quills have passed. The dampers of the harpsichords are on the jacks. This instrument is partly derived frem the polyplectrum of Guido.
The Square Piano-Forte is very differ ent in form from the grand. It, however, near) has an action, or movements, nearl simi lar. its belly is short, and the b ' , or the sounding boatel, is rather curve . In some the tuning-pegs, which are four or five in a line, form a kind of column on the right ; in others they are immediately beyond that bridge which is nearly paral lel with the keys. Each note has two wires ; Brae in alt, and indeed, down to G on the ctif.line, are usually steel, from No 8 to l2 the middle notes have brass wire ; about half an octave of the brass part is furnished with copper ; and the eight or ten lowest notes are of brass wire, on which a thinner wire of the same metal is wound in an open spiral manner ; whereby a deep tone is produc ed. A patent has lately been takes out, by a manufacturer in Golden-square, for bass notes, formed entirely of spiral wires. This is founded on the principle of increased length giving an increase of tone : these bass notes are, no doubt, louder than those on the common con struction, but it remains to be ascertain ed how far they can bear comparison with them in other essential qualities. The square piano-fortes are made with pedals, but not for sliding the keys and removing the hammers laterally. That could not be done to any purpose in this instrument; as the wires, instead of re ceding from the player in a perpendicu lar line with the keys, lie across at nearly right angles. One pedal is all that is ne cessary, namely, to raise the dampers while tuning. Many young ladies raise the dampers while playing, for the pur pose of increasing the sound ; they cer tainly succeed : and, at the same time, produce an abominable jargon, highly of fensive to a good ear ; and, in general, a sure proof of the want of a delicate fin ger, and of judicious expression.
We have one species of the piano forte of which the notes are formed by collision ; this is the Cele-tuna, whose re markably soft and fascinating tones re sult from the passage of silken lines over its wires. The action of this instrument cannot easily be described in writing ; we will, therefore, pass on to the considera tion of the Spinet. This is a plectrated instru ment ; its shape is not much unlike a harp laid horizontally. it is cased the same as a pianoforte: the notes have double wires, almost wholly of steel, there being but few of brass ; they are touched by jacks, as in the harpsichord ; and, like it, the tones are very wiry and rough. Its compass is rarely more than four octavel, or at most five. This instrument is com pletely out of vogue : such as we now' see are, in general, from 25 to ,50 years old. It evidently was the parent of the harpsichord, as that was of the several kinds of piano-fortes.