How long is a furlong?
by Ron Kaiser
Originally, a furlong was the length of the furrow in one acre of a plowed field.
An acre is an area one furlong, which is 660 feet or 40 rods long. That equals about one-eighth of a mile. An acre’s width is one chain, which is 66 feet or 4 rods long. A rod is 16.5 feet. Are you with me so far? No? Well, let me start at the beginning.
In England in the late 13th and early 14th centuries, the rod was defined by law as 16.5 feet long. The “rod” may have been determined by the length of the pole used to control a team of four oxen. A rod is still is use by surveyors because whole numbers of it can be used for one acre of square measure.
The practice of surveyors using chains, and rods made into a detachable stiff chain, came about a century later when iron became a more plentiful and common material. A chain is a larger unit of length measuring 66 feet, or 100 links. Photo provided by Ron Kaiser
The “perfect” acre is a rectangular area of 43,560 square feet. It is bounded by sides of 660 feet and 66 feet (220 yards and 22 yards) or equivalently, 40 rods and 4 rods. An acre is therefore 160 square rods. Simple math right?
The practice of surveyors using chains, and rods made into a detachable stiff chain, came about a century later when iron became a more plentiful and common material. A chain is a larger unit of length measuring 66 feet, or 100 links.
The Waterloo Farm Museum has many surveyors’ chains, with brass markers to identify the lengths. The land couldn’t be sold until all the land in the territory was surveyed. First the base line and meridian line, then counties (83 in Michigan), sections (1 square mile, or 640 acres), townships (6 miles square), usually 36 to a county. No land sales could be processed until the parcel was accurately surveyed.
There, now you understand how our ancestors were able to buy land and start their farming lives when they first arrived in this land called Michigan. Thank God for surveyors.
Hope Salyer
Managing Editor, Newsprint Designer and Reporter for theStockbridge Community News. Board Member of the Stockbridge Area Educational Foundation. Public Relations Director of the Ann Arbor Electrical JATC and Union 4 Life charity.