Furlong the fundamental unit of land measurement. A furlong was forty rods, an acre four by 40 rods, or four rods by one furlong, and thus 160 square rods. At the time, the Saxons used the North German foot, which was 10 percent longer than the foot of today. When England changed to the shorter foot in the late 13th century, rods and furlongs remained unchanged, since property boundaries were already defined in rods and furlongs. The only thing that changed was the number of feet and yards in a rod or a furlong, and the number of square feet and
Furlong because turning a team of oxen pulling a heavy plough was difficult. This offset the drainage advantages of short furrows and meant furrows were made as long as possible. An acre is an area that is one furlong long and one chain (66 feet or 22 yards) wide. For this reason, the furlong was once also called an acre's length, though in modern usage an area of one acre can be of any shape. The term furlong, or shot, was also used to describe a grouping of adjacent strips within an open field. Among the early Anglo-Saxons, the rod was