The sun., 1910-11-27
PIANO HswMgRs.
Ho~ the Sariesrs slsrs in single set Are
Made TO Grade so Accurately.

Ho~ the arfetfz sisrs I'm q single vet trr
Made 10 Grsde so Accurately.
Piano hammers arc made oi a eorv
of wood with felt face. Looked at
as they stand in IN even row the ham
ners IN \ piano appear to be all alike.
but really both as To the size of the wooden
core and the thickness of the felt cover
ing they are graded IN size and weight
from the heavier harnm.rs that strike
the bass string at on. end OF the piano
down 10 the lighter hammers that strike
the lighter treble wires at the other
lt might seem that it would bs very
difficult to grade the hammers with the
perfect accuracy required, and u would
in fact be next 10 impossible To do 40
II they were made and assembled sepa-
rat-ly. but the hammers Of "A piano are
made all at once they are originally
all of a piece: aud the manner of their
manufacture - such that they could not
DO otherwise than grad" with accuracy
Formerly only mahogany was used
for the core Of piano hainrn.rs. noN
there are used also walnut and birch
probably more birch than any other
wood. Whatever the wood ~ must b"
fine and straight grained and hawiesS
and perfectly seasoned.
A. p Of such wood six or eight inch..~
longer han u required to make the total
number OF hammers IL run through
machine that moulds il into the shapes
required for the hammer cores in cross
section. this strip being thick at on.
end and tapering 20 the other end. This
piece Of moulding Ia finished and pol
ished and then 1t is ready to be "A wed
up into separate cores.
When the core moulding has been
sawed mp the side faces are smoothed and
polished and then IN. cores are closed
up together and held together rigidly and
exactly in line by clamps Then there is
put on these cores. in on. strip what is
called the under felt. this being OF uniform
thickness from end TO end Of the set II
cores. Then the hammer cores are ready
TO receiv. the outer feet the hammers
face
NJ one time rhe varying degree Of
thickness of felt covering was made 10y
putting on fewer or rnor. layers of felt.
now the grading IN the thich hess required
ON rhe hammers ~ accomplished with
absolute accuracy by the use of frlt
specially made for the purpose
Nih lof NilAS uNf II hdtlF lIt rntsAt~ It-
tween three and four feet square. such
sheets being Of about one inch in thick
ne-ss along one .dge and tapering to per
haps a quarter OF an inch in thickness
az the opposite edge
From one OF thes" sheets there - cat
for the outer felt of the hammers "A strip
about three inches in width cut oil down
the wedge. from the thick end To the thin.
the thick end To- go around the big cores
and So on along with the thin end aroun nd
the little cora-. this thick strip to be bent
around the hammer cores Just as tn.
thinner under felt was To make this
possible the long. thick strip Of felt il
bevelled on for its entire length from the
middle line down to either edge
This outer felt. with the beveIled edges
inside against the cores il glued on and
pressed on in a mould over the under felt.
and the set OF cores with their felt cover
ings is complete In this shape the set
OF cores look like taperinR moulded
strip OF wood with one edge covered with
a tapering rounded covering Of feI'
Then the felt on the hammer still
clamped tOge' her as they are. - finally
cleaned and finished and hen with a
sharp knife by hand. the hammers are
cut apart Glued under pressure "a thf,-
are the fets would be likely 20 stav on The
cores indefinitely. but 10 prevent he
possibility Of their coming OF IN any
climate each felt hammer covering is
wired on TO it's core by a ssitch Of sir.
taken through felt and core from, side TO
side Then in the heel OF each core ~
bored hole to receive the hammer
shank by which the hammer will M at
tached to the pianos action: and there -
your set OF piano hammers all complete
and ready % go into piano
There are piano fact ories in which pianos
are made complete in every part. includ-
ing the hammer and there ara fact oriss
in which some Of the parts used are bought
Of manufacturers who specialize in the
produce ION of one part or another Thus
'here arA factories in which are made
piano hammers exclusively
There are msdc in hIs coun, ~ annually
about 3OO,OO pianos : act of piano ham.
nars numbers ty-eiGh' 80 10 EQUIP
the pianos made here there ara annually
required somewhere about tv-ntv-sevarl
million piano hammers