g become generally recognized as a
phenomenal appearance in art. Meanwhile, great improvements were
continually carried on for the purpose of rendering the instrument
impervious to the forcible attacks made upon its stability by these
new virtuosi. In the early appearances of Liszt it was necessary to
have several pianos in reserve upon the stage, so that when a hammer
or string broke, which very often happened, another instrument could
be moved forward for the next piece.

The most important improvement in the solidity of the piano came from
the iron frame, which was introduced tentatively, somewhere about
1821, in the form of what is now called a "hitch-pin plate," or half
iron frame. About 1825 an American, Alpheus Babcock, of Philadelphia,
patented a full iron frame, but it was imperfect, and nothing came of
it. Conrad Meyer, of Philadelphia, in 1833, patented an iron frame and
manufactured pianos with it, which are still in existence. In 1837,
Jonas Chickering, of Boston, perfected the iron frame by including in
the single casting the pin bridge and damper socket rail. This
improvement still remains at the foundation of the piano making of the
world. Previous to this invention some of the American piano makers
had constructed their cases upon a solid wooden bottom plank _five
inches thick_. In 1855 the firm of Steinway & Sons exhibited their
first overstrung scale, in which the bass strings were spread out and
carried over a part of the treble strings, thus affording them more
latitude for vibration, without interfering, and bringing the bridges
nearer to the center of the sounding board. The idea of overstringing
was not new at this time, Lichtenberg, of St. Petersburg, having
exhibited a grand piano with overstringing at the London exposition
in 1851, and Theodore Boehm, the celebrated improver of the flute,
having invented an overstrung system for square pianos as early as
1835. In 1853, also, Jonas Chickering combined an iron frame with an
overstrung system in square pianos, the instrument having been
completed and exhibited after his death. The Steinway system of
overstringing, however, was more extended, and solved the acoustical
difficulties of cross-vibrations more successfully by spreading the
long strings, and this, therefore, is the system now generally
followed. The superiority of this principle was immediately
acknowledged, and it has since been applied to grands and uprights,
and few makers in the wo