<!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 6.00.2900.2604" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#d8d0c8> <DIV><FONT size=2>Wood grains are rice-shaped, and swell like them with moisture, getting fatter rather than longer.  Thus = the soundboard and bridge push up against the strings, raising tension, and = then shrink down again.  Ron N. had a great presentation at Nashville = showing that the bridge alone pushes up the strings by, what, a 1/16"?  I = use the guitar analogy of bridge and top to piano bridge and soundboard, and = that seems to help.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>The inevitable loss of tension is just the Second = Law of Thermodynamics: everything trying to go to maximum entropy.  Even = without tuning pins turning, the pinblock wood crushes, grooves are made in the = capo bar, bridge pins are forced upright (or out!), etc., etc.  150 = pounds of tension per string * 250 strings is around 15 tons of tension, so it's a = big number to deal with.  That's why the 500 pounds of cast iron is there.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>--Cy Shuster--</FONT></DIV> <DIV><FONT size=2>Bluefield, WV</FONT></DIV></BODY></HTML>