There were some backwoods hillbillies living across the river from each
other, who feuded constantly. John hated Clarence with a passion and
never passed up a chance to throw rocks across the river at Clarence. This
went on for years until one day the Corps of Engineers came to build a
bridge across that river. John was elated; he told his wife that finally he was
going to get the chance to cross over and whip Clarence.

He left the house and returned in a matter of minutes. His wife asked what
was wrong, didn't he intend to go over the bridge and whip Clarence? He
replied that he never had really seen Clarence up close and didn't realize
his size until he started over the bridge and saw the sign: "CLEARANCE 8
FT 3 IN"