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 typical Chicago neighborhood (in either North/South or East/West direction but rarely both) is approximately one furlong in length. Salt Lake City's blocks are also each a square furlong in the downtown area. The blocks become less regular in shape further from the center, but the numbering system (800 units to each mile) remains the same everywhere in Salt Lake County. Blocks in central Logan, Utah, and in large sections of Phoenix, Arizona, are similarly a square furlong in extent (eight to a mile, which explains the series of freeway exits: 19th Ave, 27th, 35th, 43rd, 51st, 59th ...). City blocks