Soundboard Crown measurement and evaluation

[Richard Eldon BARBER]

I heard last night the crown should match exactly the curvature of the
earth.


|Good Morning List,
|
|Time for another query from the list of what's been buggin' me.  I 
|would like 
|to know how to evaluate a soundboard's condition beyond cracks.  
|I'm aware of 
|one method of measuring the crown after searching the archives.  
|But 
|I don't 
|know what constitutes a GOOD or a BAD measurement, or WHY, exactly.