Fig. 72.
CRISTOFORI'S ACTION.
[According to his original diagram.]
A is the string; b the bottom; c the first lever, or key; there is a pad, d, upon the key to raise a second lever, e, which is pivoted upon f; g is the hopper—Cristofori's linguetta mobile—which, controlled by the springs i and l, effects the escape, or immediate drop, of the hammer from the strings after the blow has been struck, although the key is still kept down by the finger. The hopper is centered at h. M is a rack or comb on the beam, s, where, h, the butt, n, of the hammer, o, is centered. In a state of rest the hammer is supported by a cross or fork of silk thread, p. On the depression of the key, c, the tail, q, of the second lever, e, draws away the damper, r, from the strings, leaving them free to vibrate. (Hipkins.)
The pianoforte proper was not invented until 1711, when a Florentine mechanic, named Cristofori, invented what he called a Fortepiano, from its capacity of being played loud or soft. The essential feature of the pianoforte mechanism is in the use of the hammer to produce the tone, and the necessary provision for doing this successfully is to secure an instantaneous escapement of the hammer from contact with the wire, as soon as the blow has been delivered, while at the same time the key remains pressed in order to hold the damper away from the strings and allow the tone to go on. These features were all contained in Cristofori's invention. The above diagram, [Fig. 72], illustrates the mechanism employed. It is from Cristofori's published account of his invention, dated 1711; but there is in Florence a pianoforte of his manufacture still existing, dated 1726, in which the action is more perfect, as shown in [Fig. 73].
Fig. 73.
ACTION OF CRISTOFORI'S FORTEPIANO. DATE 1726.
[Besides several minor improvements over his first idea, the later instrument has a hammer check, p, and the hammer is more developed.]
The invention of Cristofori was taken up in Germany almost immediately, and a Dresden piano maker, Silbermann, became very celebrated. It was the pianofortes of his manufacture in the palace at Potsdam, which Frederick the Great made Bach try, one after another. The form of these instruments was the same as that of Mozart's piano, shown in [Fig. 71]. The square-formed piano began to be made about 1750, but the instrument involved no application of new principles, being merely a clavier with pianoforte mechanism. The new form, so much more compact and inexpensive, began to be popular, and was soon the standard form for private families, as that of the clavier had been before, and as the square piano, remained until as late as about 1870, when the inherent mechanical difficulties of the upright were for the first time satisfactorily overcome. Pepys, in his diary, tells of having purchased a virginal which pleased him very much. It cost five guineas—about $26.