Alice Campbell wrote: > Well, that's not the main reason skyscrapers top out. The main reason is the ultimate strength of the rock beneath... It's possible to construct buildings which "float" in the surrounding geology, rather than rest upon it. Not thought practical on the scale we're discussing. regards, Jack -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads