Helmholtz and Steinway

[John Delacour]

At 9:27 AM -0800 11/17/01, Delwin D Fandrich wrote:

>Dan, you've made several references to Helmholz's direct involvement in the
>invention and development of the tuned duplex stringing system. What
>evidence do you know of the he actually had a direct hand in this work?
>Other than his general work in acoustics being used by Steinway as a
>reference, that is.

There is only one reference to the name Steinway in Helmholtz' book 
and it is brought up in connexion with measurements he took while 
investigating the effect of the strike point on the strength of the 
partials.  In his conclusions on this topic he was mistaken -- A.J 
Hipkins of Broadwood's and Kützing both find his conclusions 
surprising and not verified in practice.  Another famous theory of 
Helmholtz regarding the ear (he has primarily a physiologist) has 
also been proved false.

I would not be without Helmholtz' book and would recommend it to 
anyone as basic reading and reference material (Dover, 
ISBN:0-486-60753-4) but I can't say it's ever been of any direct use 
to me in piano-making and the translator's notes are a good deal more 
enlightening than Helmholtz' own tentative insights into the 
pianoforte.

So far as I can see, there is no mention in the whole work of the 
discordant longitudinal vibrations in stretched steel wire to which 
Theo Steinway refers in his patent.

However, there is no doubt that Theodore Steinway was an intimate 
friend of Helmholtz, if we are to believe Dolge, a mutual friend 
("...who has often discussed problems of piano building with him ... 
until the early morning hours"), who writes: ".... [T. Steinway] 
returned to Germany to be near Helmholtz and benefit from that great 
savant's epoch-making discoveries.  It was but natural that in time 
he became an intimate friend of Helmholtz....etc".  [Pianos and Their 
Makers p. 304]

Ron N. sees in the patent an emphasis on the 'agraffe section' and 
the addition of the back length as an afterthought.  Now matter how I 
read the patent, I can't see that;  they both seem to be given equal 
importance.

At 10:53 PM -0600 11/9/01, Ron Nossaman wrote:
>it's not a longitudinal movement effect and the wire doesn't have to slide on
>the capo. It's a  transverse deflection and leverage effect.
>
>So tell me. How does a transverse plucking movement and subsequent vibration
>transmute into a longitudinal compression wave of indeterminate frequency
>traveling along the plucked segment, past the apparently impassibly high
>friction of the capo, and into the speaking length where it again transmutes
>back into transverse vibrations at the speaking frequency of the segment? I'd
>love to hear how this works.

Well Steinway, whose patent I had not read until today, seems to be 
saying something very similar to what I said and to discount your 
contention that transverse vibration is conveyed to the back length 
by the movement of the bridge etc.

Though I am not swallowing Steinway's claims hook, line and sinker, 
I'd say they make a lot more sense than most I've read here on the 
subject.

Exactly how the waves travelling along the wire excite transverse 
harmonic oscillations, I'm not qualified to say, but Steinway appears 
to be saying that they do and I'd certainly like to see this 
demonstrated.  What is certain is that Theodore Steinway was an 
outstanding practical and scientific pianomaker.

JD