The next invention which we shall notice is that of Mr. James Stewart, of George-street, Euston-square, who had a patent for it in 1830. It will be observed that there are several motions connected with the operations of a piano which require great precision as to their time, duration, and intensity of action. The hammer must be made to strike the string at the same instant that the damper is withdrawn, and the hammer having done its duty must be instantly removed (even before the finger of the performer has left the key,) from the string, to allow the vibration to take place, and then the damper must return to stop the vibration of the string the moment that the finger is withdrawn from the key. Now as all the motions must be obtained by a very slight touch of the finger, and without any noise, the levers and connecting rods, by which they are trans mitted from the keys to the strings, become important considerations with piano-forte makers, and Mr. Stewart has simplified the action, and rendered it more certain, by the introduction of a short lever placed over, and parallel with the interior end of the finger lever. 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, &c. 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 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, &c. 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 laseitate, (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 manu facturers 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 merit. 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 lees 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 efikctually stop their vibra tion, and may eie raised by the simpler and cheaper modes herein specified." The introduction of cast iron into the framing of pianofortes, 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 indebted to M. Pleyel and Co., of Paris. At the present time the subeditution of metal for wood is general.
This part of the mechanism was considerably improved by Mr. J.G. 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.