Original poster: "BunnyKiller by way of Terry Fritz <teslalist@qwest.net>" <bunikllr@bellsouth.net> 1 atm at sea lvl = 14.7 lbs 32.4 ( sumodd) feet of fresh water at sea lvl = 1 atm thus 14.7/ (32.4*12) = .037 psi per inch Scot D