Furlong

furlongs per fortnight;
*one furlong per fortnight is 0.166 millimetres per second, which would be barely noticeable to the naked eye (the tip of an hour hand on a clock, measuring 3.75 feet in length, travels at about 1 furlong per fortnight).

The city of Chicago's street numbering system allots a measure of 800 address units to each mile. Logically, streets were subsequently laid out 8 to the mile. This means that every block in a 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. However, the blocks are irregular in shape as one moves further out from the center, but the numbering system remains the same (800 units to each mile) everywhere in Salt Lake County.