Rods and LinksDate: 03/28/2002 at 01:09:25 From: Marybeth Johnson Subject: Rods and links I need to know how many rods and links there are in a foot. Date: 03/28/2002 at 07:57:36 From: Doctor Sarah Subject: Re: Rods and links Hi Marybeth - thanks for writing to Dr. Math. From Russ Rowlett's _How Many? A Dictionary of Units of Measurement_: http://www.unc.edu/~rowlett/units/ rod (rd) a traditional unit of distance equal to 5.5 yards (16 feet 6 inches or exactly 5.0292 meters). The rod and the furlong were the basic distance units used by the Anglo-Saxon residents of England before the Norman conquest of 1066. The Saxons generally called this unit the gyrd, a word which comes down to us as the name of a different unit, the yard. "Rod" is another Saxon word which meant just what it means today: a straight stick. The Normans preferred to call the gyrd a pole or a perch (a word of French origin, meaning a pole; see perche). The length of the rod was well established at about 5 meters at least as early as the eighth century. Scholars are not sure how it was related to shorter units. It may have been considered equal to 20 "natural" feet (actual foot lengths; see foot), or it may have been measured "by hand" as 30 shaftments. In any case, when the modern foot became established in the twelfth century, the royal government did not want to change the length of the rod, since that length was the basis of land measurement, land records, and taxes. Therefore the rod was redefined to equal 16.5 of the new feet. This length was called the "king's perch" at least as early as the time of King Richard the Lionheart (1198). Although rods and perches of other lengths were used locally in Britain, the king's perch eventually prevailed. The relationship between the rod and the other English distance units was confirmed again by the Parliamentary statute of 1592, which defined the statute mile to be either 320 rods or 1760 yards, thus forcing the rod to equal exactly 5.5 yards or 16.5 feet. link a traditional unit of distance used by surveyors, equal to 0.01 chain. In Britain, one link is exactly 0.66 feet, or 7.92 inches, or approximately 20.12 centimeters. In the U.S., both 66-foot and 100-foot chains have been used; for a 100-foot chain the link is the same as the foot. - Doctor Sarah, The Math Forum http://mathforum.org/dr.math/ |
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