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TECHNICAI/roSUPPIY DEPARTMENT
William BraidWutefecAmcalEditor
The Broadwood Method of Sound Board
Work and a Tuner in Wildest Mexico
A. Brooker Tells of the System Used by This Famous English House—The Adven-
tures of a Worker for Music in the Mexican Home of Today
OME weeks ago we had a very interesting
letter from A. Brooker, of Cincinnati, who
years ago learned bellying in the world-
famous shop of Broadwood, in London. We
had been talking about the barless steel plate
which was a feature of the Broadwood grands
for many years, and Mr. Brooker supplied some
additional interesting details as to its construc-
tion.
I then asked him to tell us something about
the sound board work done years ago in this
famous shop and he now replies as follows:
"I am glad to accede to your request, as it
should be of interest to your readers to learn
how the bellying was done by the firm of
Broadwood.
Experiments were continually
being carried on by H. J. T. Broadwood and
the Rose brothers, men eminently fitted by
education and training to carry them to a
conclusion. And I think that in the final
analysis they had arrived at about where we
are to-day. As you often say in your articles,
we are still only where we were years ago.
"The principal difference, indeed, between the
Broadwoods of years ago and the manufac-
turers of to-day lies in the material and
workmanship. They exercised wonderful care
in the selection and drying of their lumber and
the demands they made on their bellymen were
very minute.
"The Broadwood sound boards were moulded
to a crown, not forced. The most important
point in their view was the^bearing, which
was determined by the amount of crown the
Doard had after it was glued in. For instance,
if the center showed 8/32 inch the bearing
would be 5/32 inch and graduated to the ex-
treme end. This, of course, is only an example.
"Another thing, their boards were not of
uniform thickness throughout. The treble end
was reduced from 12/32 inch to 8/32 inch, over
a square of eighteen inches at the extreme
treble, or about to the first break. This, in
my opinion, had a decided improving effect
on tone in this very difficult section of the
piano.
"Suspended Treble"
"What was called the 'suspended treble' was
a feature in the Broadwood uprights. Roughly
speaking, this meant that the lining of the
back was slotted at the extreme treble about
ten or twelve inches. A piece was then glued
on the under side of the board, thick enough
so that a space was left clear between it and
the back lining. The edge of the board was
then cut back about 4/32 inch, so that when
the sides were glued on it was left free. I have
found that this does improve the tone.
"In one of your articles you speak about
means of attaching the pin block in grand
pianos. This is an important consideration if
you want permanency in tuning. A pin block
cannot be held firmly enough merely by screws
driven in from the top through the plate. It
would be better to tap the plate on the under
S
Punching!
Washers
Bridle Straps
5814-37th Am.
side for machine screws with good-sized heads,
not interfering with the tuning pins. They
could be reinforced by screws from the top.
I believe in making the pin block an integral
part of the plate and entirely free from the
casework. There are some good reasons for
this."
Comment
The practice of thinning down the sound
board at the treble end is, of course, quite
common, and with good reason, but the
"suspended treble" sounds very interesting
Taking all things together, though, it is doubt-
ful whether any of these refinements have
made enough difference to be worth while.
Some inventors have compressed the board
by means of pushing screws from the rim,
others have stretched it, others again have left
one end free. Yet I am inclined to believe
that the simplest and the best plan of all is
simply to insist upon rigidity of the board in
its fastening around the sides. The more rigid-
ly the board is'fastened around its edges (and
that means all the way around) the more
efficiently will any vibratory energy excited
anywhere on the board be transmitted to the
edges and reflected back without loss. This
duty of reflecting the energy and returning it
promptly to its place of origin can be per-
formed satisfactorily only when the board is
fastened all around its edges with the greatest
rigidity. Nevertheless, one point of exception
may be made, and I believe that Mr. Brooker
will here agree with me. When the piano is
small and the bridges at bass and treble ends
must approach very close to the rim or the
sides, there may be too little response at the
treble end if the board there be thick and rigid.
In such circumstances it might be advisable
to free up the treble edge of the board; but I
am very doubtful as to the value of this in a
grand or even as to its practicability. Here
in fact is a point on which I should much
like to have some further information. Will
readers who know anything of the facts tell
me (1) what has been their experience with
cut-away, suspended or free sound boards in
uprights and (2) whether they have had oc-
casion to test grands manufactured in this way
for tone and for stability?
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29
The Land of Trouble
For a couple of years or more Joseph H.
Burroughs has been working for one of the
large music houses of Mexico City and has
had all sorts of adventures, traveling over the
lesser-known parts of the troublous Mexican
land. Some time ago I asked him to tell us
something about his life and work south of
the Rio Grande, and he has lately been kind
enough to write me a very interesting letter,
from which I extract the following paragraphs:
(You know, a little comic relief does this
page no harm once in a while. We do become
rather appallingly serious, don't we?)
"The City of Mexico," says Brother B,
"stands at an elevation of over 7,000 feet. It
possesses among other attractions some fine
parks, the finest being Chapultepec Park, where
the Presidential Palace is located. The Palace
stands at the highest point of the park and
from it you can get a wonderful view of the
surrounding country, the city, Chapultepec
Heights and the mountains. On a clear day
cne can see from the East old Mount Popo-
catepetl smoking profusely."
Mr. Burroughs goes on to comment amus-
ingly upon his struggles with the unknown
Spanish language and tells how he got lost in
Mexico City on the day of his arrival, being
(Continued on page 31)
William Braid White
Associate, American Society of Mechanical
Engineers; Chairman, Wood Industries
Division, A. S. M. E.; Member, American
Physical Society; Member, National Piano
Technicians' Association.
Consulting Engineer to
the Piano Industry
Tonally and Mechanically Correct Scales
Tonal and Technical Surreys of Product
Tonal Betterment Work in Factories
Reference! to manufacturers of unquestioned
position In Industry
For particulars, address
209
South State Street, CHICAGO
Piano Tuners and Technicians
George W. Braunsdorf, Inc.
Direct Manuiarturmr* of
now going on in my laboratory is expected to
bring for the first time some genuine in-
formation on all the questions which the con-
struction and behavior of the sound board
involves. The investigation which I have prom-
ised myself to make is very elaborate and very
complicated. It will consume a lot of time
and there will be no opportunity to tell much
of a story until the matter shall have progressed
a good deal further than it has yet. But the
work is being prepared, and in due time, if no
unforeseen obstacle intervenes, we shall have
something like a foundation on which to build
facts. And then, be assured, the piano industry
shall have the facts.
And let it be said at once, without the slight-
est reservation, that the piano industry is yet
to see its greatest development, this through
the application of science to tone production.
That new day is just beginning to dawn.
are In demand. The trad* needs tuners, regu-
lator* and repairmen. Practleal Shop ache*!.
Send for Catalog M
Y. M. C. A. Piano Technicians School
1421 Arch St.
Philadelphia, Pn.