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27
The Music Trade Review
DECEMBER 31, 1927
The Technical and Supply Department — (Continued from page 25)
Second—It is not reasonable if the plate be vibrations by means of a vacuum tube ampli-
Piano Patents
free from internal strains set up by bad cooling. fier, also of radio type. With this outfit it is
Third—The answer is contained in the answer
to No. 1. Everything depends on the cir-
cumstances. If the piano were tuned even a
tone above A 440 the plate ought not to break,
subject to the condition noted in No. 2.
Oscillograph Experiments
Readers are aware that a Westinghouse "Os-
siso" has recently been set up in my laboratory.
Experiments have been under way for some
little time directed towards the discovery of
the best methods of making use of the powers
which the machine confers upon the acoustic
investigator. A short note on some of these
will- be interesting as indicating the limiting
conditions and the course which experimental
work must take.
Briefly described, the Ossiso is an instru-
ment which gives, visually, or photographically
as desired, a picture of the shape of a sound
wave. The method employed is much the same
as Dr. Miller uses in his Phonodeik, save that
his mechanism acts by direct contact with the
diaphragm on which the sounds at first im-
pinge, while the vibrator of the Ossiso is oper-
ated electrically. The machine consists essen-
tially of a vibrating element which is in effect
a pair of fine silver wires in a magnetic field
excited by a permanent magnet. When current
is passed in opposite directions along each wire,
they move torsionally in opposite directions, so
that a tiny mirror cemented across them par-
takes of a form of vibration which is a resultant
of the opposed motions of the wires. If now
a sound from any source is made to impinge
upon a microphone the vibrating electric cur-
rent set up passes in opposite directions along
the two wires, which vibrate as above said and
cause the mirror in turn to vibrate also. A
beam of light is thrown upon the mirror from
a small straight filament lamp, so that the vi-
brating mirror gives rise to a vibrating spot of
light. This spot of light is then reflected into
a revolving four-sided polygon of mirrors, and
on the principle of persistence of vision, fa-
miliar in the case of the intermittent moving
picture firm, appears to the eye as a continuous
band of light bent, bending this way and that
and giving from moment to moment a com-
plete picture of the shape of the sound wave
transmitted through the atmosphere from the
sounding body. The whole instrument is no
bigger than a commercial portrait or moving
picture camera, and can easily be carried in a
suitcase.
Preliminary Experiments
It is, of course, evident that almost every-
thing concerning the value of the results ob-
tained must depend upon the microphone. For
recording the wave-forms of speech, or of loud
continued sounds, the ordinary telephone trans-
mitter has been found satisfactory enough, but
quite a different condition appears when we
try to record the sounds given out by the piano.
These sounds in fact are extremely evanescent.
\ sound given out by a string-unison in the mid-
lie register of the piano loses about 75 per
cnt of its amplitude within .03 sec. It is cvi-
lent that the stiff diaphragm of the telephone
ransmitter, dealing with these delicate vibra-
ions, will smother some of their elements and
:listort others. Nor will the amplitude of the
vibration forms passed through the transmit-
ter be sufficiently great for satisfactory photo-
graphic results.
In the circumstances, it has been found ad-
visable to make use of a microphone of radio
transmitter type and to amplify the resulting
Tuners and Repairers
Our new illustrated catalogue *f Piane and
Player Hardware F«lta and Tools ii n«w
ready.
If you haren't receired your copy
please let us know.
OTTO R. TREFZ, JR.
1305-7-9 No. 27th St.
Phil*., Pa.
possible to obtain much better pictures con-
taining more of the components of the sounds
;md showing much wider amplitudes of curve.
Preliminary visual experiments are develop-
ing several very interesting facts. For instance,
adjacent unisons on a large grand piano of
high grade show marked differences, corre-
sponding to variations in the tone qualities,
which, however, the ear does not fully, if at all,
perceive. It is evident, as a result of these
experiments, that possibilities hitherto un-
known exist of developing more accurate tone
regulating.
Another point which comes out very clearly
in connection with the sounds given out by the
piano is that all the partial tones of which the
presence determines the tone quality drop out
(itif by one very rapidly, so that before the
sound has ceased it has become a pure funda-
mental sound, no matter in what region of the
instrument it originally arose. Moreover, in-
spection indicates that the theoretical dropping
out of partials from bass towards treble is cor-
rect, and that the tone quality becomes steadily,
simpler as the pitch increases, until in the upper
treble there is hardly any partial-tone element
left.
I am not suggesting that there is anything
particularly novel about these results. Much
of what is said here has been observed in other
ways. What, however, is interesting is that this
new method of analysis enables us clearly to
obtain experimental verification of theoretical
results, after a fashion remarkable and unusual-
ly convenient and simple.
In due course I shall have more definite and
specific results to se.t forth.
Correspondence
is solicited and should be addressed to William
Braid White, 5149 Agatite avenue, Chicago.
A. H. Nilson Dies
BRIDGEPORT, CONN., December 19.—Axel Hilmer
Nilson, president and treasurer of the A. H.
Nilson Machine Co., of this city, passed away
on Monday, December 12. Mr. Nilson was not
only the chief executive, but the founder of
this company which bears his name, and under
his skilful leadership it grew from humble be-
ginnings to a large manufacturing organization
serving almost every field of commercial en-
deavor and selling its machines in practically
every country on the globe. In the piano in-
dustry the A. H. Nilson Co. is well and favor-
ably known as manufacturers of piano action
machinery and special machines for special pur-
poses.
Felt Customs Decision:
The United States Customs Court handed
down a decision recently applying to various
items, including piano felts, fixing the correct
valuations for tariff purposes on merchandise
shipped to American importers from all parts
of the world. Listed among a large group of
American firms covered by the decision was
Charles Pfriemer, Inc., New York, importing
piano felts from Wilton, England. These rul-
ings, which are technical and much in detail
regarding prices, packing, and freight rates,
etc., are an index of many classes of goods that
are entering into the commerce of the country.
Shailer in New England
W. M. Shailer, vice-president and secretary of
Philip W. Getting & Son, Inc., New York, im-
porters of Weickert piano felts, who returned
recently from a short business trip to Buffalo, is
visiting the piano manufacturing trade in Bos-
ton and New England.
Adjustable Damper-Wire Connection for
Grand Piano Actions. Patent No. 1,653,590. A
damper construction for grand piano actions,
including a damper wire, a damper head, and
means of connection therebetween including a
laterally disposed terminal at the upper end of
the damper wire, a clamping clement engaging
said terminal, the damper head carried by the
clamping element for vertical adjustments
thereon and the clamping element constituting
means for allowing lateral adjustments of the
damper head with respect to the damper head
from said damper wire.
Music roll for Automatic Pianos and the
Like. Franklin G. Dunham, Brooklyn, N. Y.,
assignor to the Aeolian Co., Meridan, Conn.
Patent No. 1,652,003. In combination with a
music-roll for an automatic musical instrument,
a baton-movement indicating diagram appro-
priate to the tempo of the composition; and in-
signia on the roll indicating the beats of the
measures relatively to the music perforations,
said diagram comprising insignia similar to the
foregoing applied to the respective baton move-
ments in said diagram to correlate them with
the respective measure beats to which they
belong
Drying Pad for Pianos. Frederick C. Bill-
ings, Miami, Fla. Patent No. 1,650,004. A dry-
ing pad for pianos comprising an absorbent
member having a spaced apart top and bottom,
reinforcing members interposed between the
top and bottom for stiffening said pad, and a
flap secured to said pad along one of its longi-
tudinal edges.
Piano Action. John T. Rydbcrg, Harrison,
N. ]., assignor by direct and Mesne assignments
to Supreme Player Action Corp., of New Jersey.
Patent No. 1,650,095. A piano player action
formed of cellulose ester plastic, the several
members thereof being joined to form an in-
tegral structure.
A piano hammer action having pyroxylin
hammer heads and their shank members formed
of a pyroxylin plastic in tubular formation.
Australian Wool Conditions
WASHINGTON, D. C, December 24.—Half the
current wool clip in Australia has been disposed
of with the closing of the first half of the wool
selling season at Sydney on December 15, ac-
cording to advices received by the Department
of Agriculture from M. R. Lawton, Consul Gen-
eral at Sydney. Competition was particularly
keen from Japan and the Continent.
Consult the Universal Want Directory of
The Review. In it advertisements are inserted
free of charge for men who desire positions.
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 la Factories
References
to manufacturers of unquestioned
position ! • Industry
For particulars,
mddrett
209 South State Street, CHICAGO