Surveyor’s Chain

Unknown artist

In the colonial period and throughout the nineteenth century, most American surveyors measured distances with chains. The favored form was the Gunter, introduced by the English mathematician, Edmund Gunter, in 1620. The standard Gunter chain has 100 links and measures 66 feet (or 4 poles) overall. Thus 80 chains equal a mile, and 10 square chains equal an acre. This example is a half-Gunter, with 50 links measuring 33 feet overall. It is one of several instruments that James Griswold used to lay out the New York and Erie Canal.