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THE MUSIC TRADE REVIEW
respond better for the hard usage; others
"smart" and "crack up" when so treated,
being at their best when used with moderate
force. Others, again, will not bear a piano
passage, requiring a distinctly firm blow
RELATING TO THE PIANO AND
before they emit their best note.
The
OTHER INSTRUMENTS
USEFUL
AND INTERESTING ALIKE TO THE fault, in all these cases, is most always a
want of adjustment between the string and
MANUFACTURER, DEALER AND
the sounding-board — the balance of forces
WORKMAN
not being rightly struck.
THE SOUNDING-BOARD and its Importance.
Experience and theory both suggest that
The relation of the string to the sounding- the size of the sounding-board should ex-
board is a matter of special interest to the ceed the actual demands of the string.
maker of pianofortes; good tone is depend- The margin thus left provides for the out-
ent upon a right adjustment of these parts. flow of all energy possibly generated by
That the string influences the sounding- forceful playing. If rightly made and per-
board is well known, but that the sounding- fectly fitted this extra surface will not at all
board governs the movements of the string interfere with the effect of piano playing.
is not so much considered; yet, in a very
important sense, this is literally true. The THE PIANO PLATE and the Shrinkage of Iron.
The action of fluid cast iron in the mould
attachment of the string to the bridge per-
mits the energy of the moving string to be is somewhat curious. When poured into a
transmitted to the sounding-board. But it mould in a state of fluidity, cast iron, and
also enables the latter to influence the especially what is known technically as
vibrations of the string, assisting it to "very gray," expands at the moment of
maintain its sonorous trembling, and also solidification, thus giving a sharp impres-
modifying its character. Thus the tone sion in the mould. The expansion, slight
emitted when the string is attached to the but very noticeable, extends until in the
sounding-board is not only louder and process of cooling the iron attains the stage
longer, but also deeper than that heard of red heat. Contraction then takes place,
when the string alone is sounding. The with the result that the cooled iron is notice-
In making
reason for this latter is that the fundamental ably smaller than the mould.
movement of the board is much slower patterns for iron castings, therefore, pattern
than the corresponding movement of the makers commonly allow about one-eighth
string; thus the sounding-board reacts up- of an inch per foot for shrinkage. The
on the string, maintaining the time and shrinkage in castings, however, is by no
amplitude of its swing for a longer period means a constant quality, but varies ma-
than would be possible to the string apart terially with the proportion existent in the
pattern and the character of the metal used
from such aid.
—
as much as one tenth of an inch per foot
The string is the receiver and transformer
being
allowed when casting beams and only
of energy. The force represented in the
one
thirty-second
of an inch with large
blow delivered by the hammer is taken by
cylinders.
the wire and passed on to the sounding-
PRACTICAL
POINTERS..
board in the form of sonorous vibration.
It is important, then, that this latter
agent co-operate with the string, being
fitted to lend itself to the requirements of
the moving wire. Three things present
themselves for consideration in connection
with this co-operation—i. e., the size, shape
and flexibility of the board as compared
with the weight, length and elasticity of
the string. If the string generates more
energy than the board is capable of dealing
with, the surplus force is then, as it were,
turned back upon the string, disturbing its
vibration. This may happen when the
sounding-board is not large enough, or not
sufficiently free. In the latter case, owing
either to faults in making or fixing; in the
former, owing to the genera] superficial
area being too small or the shape such that
the surface at the point of excitation is too
small.
But a sounding-board should not only
conspire with the string in a general way,
but also in particular effects. Thus, during
both light and heavy playing, there should
be a ready response on the part of the
sounding-board to the movements of the
string. This is a very severe requirement,
and one that few instruments fulfill per-
fectly. Most instruments possess a weak
point. Some you may "thrash," and they
When any metal in a fluid state is poured
into a cold mould, solidification commences
at the outside. As the cooling is continued,
the castings, therefore, would consist of a
rigid outside envelope containing a soft in-
terior. If, therefore, the condition of a
small piece of such metal in the center of a
square be considered during cooling, it will
be seen that the contracting force existing
on each side of the square will be the same.
A cube or sphere of cast iron contracts in
cooling in a uniform manner throughout its
mass, If two squares be placed side by
side, forming a rectangle on each half of
the sides, the contracting forces are as be-
fore, but on the ends, there being no rigid
division between the two squares, both
parts exert a unit of contracting force. The
result is that the contracting force of the
ends is equal to that of the sides, or, on a
unit of length, the contracting forces are
double as great on the ends as on the sides.
In casting, therefore, thin strips, the
shrinkage of the length is very great, while
in the thickness it is scarcely appreciable.
A square plate shrinks little in thickness,
but equally in width and breadth; a flat
disk shrinks little in thickness, but equal-
ly in all diameters. A thin ring shrinks
more in diameter than a thick one, and so
on. When it is known that iron with differ-
ent shrinkage from that generally employed
is to be used in a foundry, the patterns are
altered to meet the changed conditions.
Silicon, unless in excessive quantities,
gives a gray, soft iron which has the mini-
mum shrinkage. In many cases a judi-
cious mixture of iron will give the desired
result without extra expense in pattern
making. Charcoal iron has usually a high-
er melting point than that of less pure
iron made with coke. It sets more quickly
in the mould and contracts more, so that
an extra allowance for shrinkage must be
made in all patterns employed. It will be
seen from the above that pattern makers
require special technical skill as well as
knowledge of the iron to be used in casting
for their patterns. There are few employ-
ments which require greater specialized
knowledge of rather a wide range than that
of pattern making.
PIANO KEYS—How to Re-cover Them.
In very old pianos sometimes the yellow-
ness of the ivory keys penetrates to the
under side of the ivory. In such a case, of
course, scraping is out of the question.
Try diluted spirit of salt to bleach, then
rub with fine glass-paper, and polish with
methylated spirit and whiting.
If this
treatment is not successful, re-cover them
with a sheet of celluloid. Proceed as follows
to cover: Remove old ivory from keys by
means of a warm flat-iron and a thin knife.
Now take one octave of keys at a time, and
a piece of flat board wide enough to lay
them on. Glue a couple of strips of news-
paper, one inch wide, across the board, one
at the back and the other in the front.
Where this paper crosses put a dab of glue
on the bottom of keys, and stick them on
the paper level, leaving a space between
each key head, so that a fine saw would
pass between. Have the glue hot, about
the consistency of syrup. Soak one side of
the celluloid with methylated spirit: this
softens it, and makes it take the glue better.
After waiting a few minutes, glue the
same side, and put a piece of wood (pre-
viously made hot) on the top and press
down with hand-screws. When this is dry,
the keys can easily be torn all together from
the paper. Then turn top side down on
the bench, and cut between each key with
a dovetail saw; and when the sharp comes,
cut across with saw, and draw a sharp pen-
knife along the side of key; finish with a
file. Before cutting apart from the board
it will be as well to polish them. Rub well
with fine glass-paper, and polish with
methylated spirit, spirit of camphor, and
putty-powder or whiting, all to be mixed
together to a paste, and applied with a felt
rubber. After separating keys and bevel-
ing edges with a fine file, polish edges with
rubber.
The Trade Directory, which is a feature
of Tlic Reviciu each month, is complete. In
it appears the navies and addresses of all
firms engaged in the manufacture of musical
instruments and the allied trades. The Re-
view is sent to the United States Con-
sulates throughout the world, and is on file
in the reading rooms of the principal hotels
in America.