<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1491" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>Terry asked: "<FONT face="Times New = Roman" size=3> How can you =<BR>determine that? If the rib is curved, could it still = not be from panel =<BR>compression? You may well be correct, but I just don't = see how one could =<BR>be so sure.<BR><BR>Terry,</FONT></FONT></DIV> <DIV><FONT face=Arial size=2><FONT face="Times New Roman" = size=3>It's simple. Use a straight edge. If the rib "face" is curved and the "spine" is = straight, then the rib has a machined "crown". With an olde piano, the "spine" may = be curved the other way. Still a machined-in crown.<G> </FONT></FONT></DIV> <DIV><FONT face=Arial size=2>Joe Garrett, R.P.T.<BR>Captain, Tool Police<BR>Squares R I</FONT></DIV></BODY></HTML>