humidity and unisons

[Newton Hunt]

> So the bridge "rolls" (speaking length
> side rises more than back side).

I am beginning to disbelieve in bridge rolling and more in
bad soundboard installation.  I think Del pointed me in this
direction.  Mechanically it make far more sense.

> So frankly, I haven't the foggiest idea how it happens. Just know it
> does, from long years of observing. 

I HATE that feeling!!

That is the source of my confusion, a bridge that rolls
right to left?  I don't think so so much.  Yet crazy things
happen in pianos.

		Newton