Helmholtz and Steinway

[Ron Nossaman]

>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.

You're right John. I had been reading back and forth between Dan's articles
and supplied drawings, and the patent. The patent text does indeed give
good coverage to the rear duplex, while the drawings and text of the
articles does not. My mistake.


>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.

Yes it does, and I believe we were talking about the front duplex with the
string rocking on the capo then as well. Reported measurements from people
doing research along these lines indicate that longitudinal vibrations tend
to be of considerably higher frequency than transverse vibrations, so I
still don't understand nor accept that this could be. Nor do I understand
how any sort of detectable vibrational energy, longitudinal or transverse,
could pass across a bridge surface and two pin bearing points without
dragging the bridge with it. This should be relatively simple to test with
a monochord and a minimum of instrumentation, as I'm sure has been done.


>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.

In some aspects, yes, in others, no.


>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.  

I certainly would too, as well as longitudinal waves traveling across
bridges. It's been nearly 130 years since the patent was filed. One would
think someone should be able to demonstrate the effect by now if it exists.


Ron N