S&S D Duplex

[Duplexdan@aol.com]

Robin,

You may be interested in the distinction between " langeschwingungen" and 
"lengthsschwingungen" which have appeared in the original patent of CFT 
steinway of 1872. The original patent in German is available in the La 
Guardia Archives. It may help to resolve your concerns regarding transverse 
and longitundinal vibrations. My own research indicates that when the duplex 
scale is in tune with the speaking length, the "langeschwingungen" and the 
"lengthsschwingungen" both contribute to the tone and duration of piano tone 
as described by CFT Steinway's patent 1246848.

Dan Franklin