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.

[Illustration: 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.

[Illustration: Fig. 74.

IMPROVED ACTION OF THE ERARD CONCERT GRAND. (1821.)

_C_ is the key; _d_ is a pilot, centered at _dd_ to give the blow,