This lever being short, and joined near its movable end by a small connecting brass rod to the finger lever, furnishes in itself the required variety of motions, by placing the rods which act upon the hammer, damper, etc. at different distances from the fulcrum on which it turns. In addition to this, Mr. Stewart has introduced an improved inclined plane for receiving the tail of the hammer, and stopping it silently, after it has struck the string.
To obviate the objections which have been raised to the elevated casing of the upright or cabinet piano-fortes, especially those whose fronts are covered with silk, which have a tendency to deaden the voice in case of accompaniment, Mr. Simon Thompson, of Yarmouth, has contrived to obviate the necessity of any portion of the instrument rising above the locking board, so that the top of the instrument is flat like a table. This object he effects by lowering the string frame, till its upper surface coincides with the top of the locking board, and making the keys bent levers, turning twice at right angles between the fulcrum on which they move, and the extremities which act upon the hammers. On the inner ends of each key, rests an upright guide wire, or slight rod, and to this are attached various projecting pieces which actuate the hammers, the dampers, etc. much in the usual manner; so that this improvement, which is a very important one, is obtained without in the smallest degree altering the other parts of the instrument.
The spirit of improvement in this interesting branch of art seems recently to have equally pervaded our transatlantic brethren. In the Journal of the Franklin Institute, (which contains accounts of all the American patents,) we observe one by Mr. Jesse Thompson, of New York, dated October, 1830, for an improvement in the action of the upright piano-forte, some points in which our own manufacturers may deem worthy of adoption in a modified form. The following claim attached to the specification of this patent, will give to those acquainted with the subject a general idea of the variations introduced in this action. "What I claim as new, and as my own invention, is, first, the application of the finger lever directly to the foot of the connecting rod, dispensing with the jack, springs, and all intermediate gearing. By this more immediate operation of the finger on the hammer, no time is lost between the touch and the blow; the action is more controllable by the finger; the blow is quicker, and more powerful; the hammer can never block; it relieves less from the string, and requires much less depth of touch. The simplicity of its construction renders the work much cheaper, and less liable to get out of order, than any known action.
From this perfection of the action, I have been able to render the span of the natural action to six and a half inches, and the others in proportion, without in any degree interfering with a clear and rapid execution: or the common span of the octave may be retained. Second, the placing the dampers below the hammer rail, by which position the dampers fall on the brass strings near the middle of them, and thus more instantaneously and effectually stop their vibration, and may be raited by the simpler and cheaper modes herein specified."
The introduction of cast iron into the framing of piano-fortes, in lieu of the cumbrous masses of wood previously used, to resist the powerful tension of so many wires, was a great modern improvement, to which we believe we stand vol.. II.
p p indebted to M. Pleyel and Co., of Paris. At the present time the substitution of metal for wood is general.
This part of the mechanism was considerably improved by Mr. J. C. Schwieso, of Regent-street, for which he obtained a patent in 1831. The string board of the piano-forte is secured between a stout cast iron frame, and to the latter is cast a projecting plate, through which the tuning pins pass. These tuning pins are made of steel, their lower ends are turned cylindrical, for coiling the ends of the wire, and the upper ends are made square for the reception of the key. To give these tightening pins the requisite friction to retain any required degree of tension on the strings, and enable them to be turned with facility, they are tapped below the square head to receive a nut, which screws against the upper side of the projecting plate, and they have underneath a collar and washer, which are drawn against the plate by the action of the nut above, leather washers being also interposed to give a degree of elasticity to the bearing parts. To produce the requisite friction, the nuts are screwed up; and in order that the pins may be turned at pleasure, without altering the friction by which they are held, each nut is perforated with two holes, and the square key which fits over the square heads has at its extremity two projecting pins, which enter the holes in the nuts and therefore turn the pins and nuts together without altering the friction Mr. Schwieso applies tightening pins of this kind to the harp and violin.
Since the introduction of cast-iron frames for piano-fortes, considerable expense has been incurred in drilling the holes for, and fitting in the pins, so as to give them the properties mentioned in Mr. Schwieso's patent. To remedy these inconveniences, Mr. W. Allen, of Catherine-street, Strand, casts two dovetailed grooves along that end of the frame where the tightening pins are to be inserted, into which he drives pieces of wood of a corresponding shape, to fill up the dovetailed grooves, and to receive the tuning pins. It is evident, that by this ingenious and simple contrivance, the expense of manufacture will be diminished, and the instruments will be improved.
Self-acting Pianofortes have of late years been introduced: they combine the most rapid and brilliant execution with distinctness and neatness. Their harmony is necessarily more full than can be produced by eight fingers, the elements of chords having no other limit than the extent of its scale; the time cannot be otherwise than perfectly equable throughout, yet where pathos is to be expressed, the time can be accelerated or retarded in any degree.
The mechanism of a self-acting piano-forte usually or principally consists of a cylinder turning horizontally on its axis, acted upon by a coiled spring, and regulated by a fly-wheel. On the surface of the cylinder, a determined arrangement of brass pins is formed, each of which, in passing under a rank of levers, elevates one end of the required lever, and depresses the other. The depressed end pulls down with it a slender rod, which is connected by a slide with the tail of a bent lever, on the further end of which is the hammer which strikes the string. The slide can be shifted further from, or nearer to the axis, on which the hammer lever turns, and thus the stroke of the hammer is made feeble or strong to any required degree. When wound up, the instrument will continue to play for a considerable time; and it is provided with a bench of keys like the ordinary piano-forte, so that a person may accompany the instrument, or play a duet with it.
A very beautiful instrument of this kind we have seen, that was manufactured by Clementi and Co.; it had two barrels, each of which played nine tunes. The velocity was regulated by two revolving balls, similar to the governor of a steam-engine.
Messrs. Rolfe and Sons, of Cheapside, have distinguished themselves in this branch of art by several improvements, which were the subject of a recent patent. These improvements they divide into three sections; and their self-acting pianofortes are constructed either with the first section only, or with the first and second section combined, or with the three sections united. The first section consists of a new apparatus for effecting the transitions of forte and piano, by which means the difficulty of producing those desirable changes is removed, by transferring the mechanical action from the weakest and most uncertain part of the arrangement, viz. the cylinder, to the more powerful and certain action of the engine, by which transfer the liability to derangement in instruments intended for exportation is avoided. To this branch of their patent, Messrs. Rolfe and Sons have annexed a hand movement, or register, by which the existing arrangement, or distribution of forte and piano, may at any time be changed, or altered to suit particular Views, or may at any moment be removed from the government of the self-acting apparatus which produces the effect, and be operated upon by the hand, and again be restored to the control of the machine, at pleasure.
The second section consists of a new barrel movement for changing the tunes, which is effected by the introduction of an inclined plane, which forms an abutment for the axis of the cylinder. This plane is divided into eight portions, and is moved by a radial lever upon a pinion, which by its rotation one revolution moves upon a second dial an index to the extent of one eighth of its circumference, moving the inclined plane to a proportionate extent. By this simple arrangement the motions are rendered very steady and accurate, and eight distinct airs may thus be performed.
The third section consists in the application of a set of dampers to the self-performing action, which are altogether independent of the dampers; so that each note of the self-acting or mechanical part of the instrument, in common with each particular note of the finger action, possesses its appropriate damper, connected with and identified by its kindred note, hammers, or keys, and acting simultaneously therewith. In conjunction with the application of the mechanical dampers, suitable staples are introduced into the cylinders, which, acting upon each particular damper as occasion may require, suspends its operation, and enables them to retain the vibration of any given note, or the root and relative intervals of harmonious combinations, in the same manner as the finger of a performer sustains the vibration of chords, whose existence is to be prolonged by continued pressure of the keys, according to the duration expressed by the determined value given to them by the author in the composition performed.
In addition to this, the whole set of mechanical dampers are occasionally raised by the cylinder, according to circumstances, in order to produce the effect, or full swell, of the open pedal when moved by the foot of the performer.