Pole - Unit of length and area. Also known as a perch or rod. As a unit of length, equal to 16.5 feet. As a unit of area, equal to a square with sides one pole long. An acre is 160 square poles. It was common to see an area referred to as "87 acres, 112 poles", meaning 87 and 112/160 acres. Taken from http://www.lest-we-forget.com/RootsLady/universal/survey1.htm