Measuring chain

A chain is a unit of length; it measures 66 feet or 22 yards (20.1168m). There are 10 chains in a furlong, and 80 chains in one statute mile. An acre is the area of 10 square chains (that is, an area of one chain by one furlong). The chain has been used for several centuries in England and in some other countries influenced by British practice. The chain was commonly used with the mile to indicate land distances and in particular in surveying land for legal and commercial purposes.